106 results on '"TODD RM"'
Search Results
2. Illness.
- Author
-
Todd RM
- Published
- 2009
- Full Text
- View/download PDF
3. Book review. Law and ethics.
- Author
-
Todd RM
- Published
- 2007
- Full Text
- View/download PDF
4. Capturing spontaneous interactivity: a multi-measure approach to analyzing the dynamics of interpersonal coordination in dance improvisation.
- Author
-
Whitehead PM, De Jaegher H, Santana I, Todd RM, and Blain-Moraes S
- Abstract
Introduction: Interpersonal coordination is widely acknowledged as critical to relating with, connecting to, and understanding others, but the underlying mechanisms of this phenomenon are poorly understood. Dance-particularly improvised dance-offers a valuable paradigm for investigating the dynamics of interpersonal coordination due to its inherent ability to connect us. However, conventional approaches to studying coordination often fail to capture the co-creative spontaneity that is intrinsic to such interactions., Methods: This study combined multiple measures of interpersonal coordination to detect moments of high coordination between two freely improvising dancers. We applied maximum correlation vectors, normalized Symbolic Transfer Entropy (NSTE), and surveys to analyze the time-varying dynamics of similarity in movement speeds, directed influence, and subjective perception of dancers engaged in an improvisation task., Results: This multi-measure approach offers a means of capturing the interplay between different dimensions of interpersonal coordination., Discussion: This approach may be used to understand the underlying mechanisms of co-creative social interactions in improvised dance and other forms of spontaneous interactivity., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Whitehead, De Jaegher, Santana, Todd and Blain-Moraes.)
- Published
- 2024
- Full Text
- View/download PDF
5. Short-Term Memory Capacity Predicts Willingness to Expend Cognitive Effort for Reward.
- Author
-
Forys BJ, Winstanley CA, Kingstone A, and Todd RM
- Subjects
- Humans, Male, Female, Young Adult, Adult, Adolescent, Cognition physiology, Individuality, Anticipation, Psychological physiology, Motivation physiology, Reward, Memory, Short-Term physiology
- Abstract
We must often decide whether the effort required for a task is worth the reward. Past rodent work suggests that willingness to deploy cognitive effort can be driven by individual differences in perceived reward value, depression, or chronic stress. However, many factors driving cognitive effort deployment-such as short-term memory ability-cannot easily be captured in rodents. Furthermore, we do not fully understand how individual differences in short-term memory ability, depression, chronic stress, and reward anticipation impact cognitive effort deployment for reward. Here, we examined whether these factors predict cognitive effort deployment for higher reward in an online visual short-term memory task. Undergraduate participants were grouped into high and low effort groups ( n
HighEffort = 348, nLowEffort = 81; nFemale = 332, nMale = 92, MAge = 20.37, RangeAge = 16-42) based on decisions in this task. After completing a monetary incentive task to measure reward anticipation, participants completed short-term memory task trials where they could choose to encode either fewer (low effort/reward) or more (high effort/reward) squares before reporting whether or not the color of a target square matched the square previously in that location. We found that only greater short-term memory ability predicted whether participants chose a much higher proportion of high versus low effort trials. Drift diffusion modeling showed that high effort group participants were more biased than low effort group participants toward selecting high effort trials. Our findings highlight the role of individual differences in cognitive effort ability in explaining cognitive effort deployment choices., Competing Interests: The authors declare no competing financial interests., (Copyright © 2024 Forys et al.)- Published
- 2024
- Full Text
- View/download PDF
6. Factors perpetuating functional cognitive symptoms after mild traumatic brain injury.
- Author
-
Picon EL, Wardell V, Palombo DJ, Todd RM, Aziz B, Bedi S, and Silverberg ND
- Subjects
- Humans, Male, Female, Adult, Cross-Sectional Studies, Middle Aged, Young Adult, Memory Disorders etiology, Memory Disorders physiopathology, Metacognition physiology, Depression physiopathology, Depression etiology, Brain Concussion physiopathology, Brain Concussion complications, Neuropsychological Tests, Cognitive Dysfunction etiology, Cognitive Dysfunction physiopathology
- Abstract
Introduction: Self-reported memory difficulties (forgetting familiar names, misplacing objects) often persist long after a mild traumatic brain injury (mTBI), despite normal neuropsychological test performance. This clinical presentation may be a manifestation of a functional cognitive disorder (FCD). Several mechanisms underlying FCD have been proposed, including metacognitive impairment, memory perfectionism, and misdirected attention, as well as depression or anxiety-related explanations. This study aims to explore these candidate perpetuating factors in mTBI, to advance our understanding of why memory symptoms frequently persist following mTBI., Methods: A cross-sectional study of 67 adults (n = 39 with mTBI mean = 25 months ago and n = 28 healthy controls). Participants completed standardized questionnaires (including the Functional Memory Disorder Inventory), a metacognitive task (to quantify discrepancies between their trial-by-trial accuracy and confidence), and a brief neuropsychological test battery. We assessed candidate mechanisms in two ways: (1) between-groups, comparing participants with mTBI to healthy controls, and (2) within-group, examining their associations with functional memory symptom severity (FMDI) in the mTBI group., Results: Participants with mTBI performed similarly to controls on objective measures of memory ability but reported experiencing much more frequent memory lapses in daily life. Contrary to expectations, metacognitive efficiency did not differentiate the mTBI and control groups and was not associated with functional memory symptoms. Memory perfectionism was strongly associated with greater functional memory symptoms among participants with mTBI but did not differ between groups when accounting for age. Depression and checking behaviors produced consistent results across between-groups and within-group analyses: these factors were greater in the mTBI group compared to the control group and were associated with greater functional memory symptoms within the mTBI group., Conclusions: This study highlights promising (e.g., depression, checking behaviors) and unlikely (e.g., metacognitive impairment) mechanisms underlying functional memory symptoms after mTBI, to guide future research and treatment.
- Published
- 2023
- Full Text
- View/download PDF
7. Characterizing affiliative touch in humans and its role in advancing haptic design.
- Author
-
Kryklywy JH, Vyas P, Maclean KE, and Todd RM
- Subjects
- Humans, Touch physiology, Haptic Technology, Skin, Emotions physiology, Physical Stimulation, Touch Perception physiology, Stroke
- Abstract
An emerging view in cognitive neuroscience holds that the extraction of emotional relevance from sensory experience extends beyond the centralized appraisal of sensation in associative brain regions, including frontal and medial-temporal cortices. This view holds that sensory information can be emotionally valenced from the point of contact with the world. This view is supported by recent research characterizing the human affiliative touch system, which carries signals of soft, stroking touch to the central nervous system and is mediated by dedicated C-tactile afferent receptors. This basic scientific research on the human affiliative touch system is informed by, and informs, technology design for communicating and regulating emotion through touch. Here, we review recent research on the basic biology and cognitive neuroscience of affiliative touch, its regulatory effects across the lifespan, and the factors that modulate it. We further review recent work on the design of haptic technologies, devices that stimulate the affiliative touch system, such as wearable technologies that apply the sensation of soft stroking or other skin-to-skin contact, to promote physiological regulation. We then point to future directions in interdisciplinary research aimed at both furthering scientific understanding and application of haptic technology for health and wellbeing., (© 2023 The Authors. Annals of the New York Academy of Sciences published by Wiley Periodicals LLC on behalf of New York Academy of Sciences.)
- Published
- 2023
- Full Text
- View/download PDF
8. Gender Impacts the Relationship between Mood Disorder Symptoms and Effortful Avoidance Performance.
- Author
-
Forys BJ, Tomm RJ, Stamboliyska D, Terpstra AR, Clark L, Chakrabarty T, Floresco SB, and Todd RM
- Subjects
- Male, Humans, Female, Mood Disorders, Motivation, Students, Reward, Depression, Anxiety, Anxiety Disorders
- Abstract
We must often decide how much effort to exert or withhold to avoid undesirable outcomes or obtain rewards. In depression and anxiety, levels of avoidance can be excessive and reward-seeking may be reduced. Yet outstanding questions remain about the links between motivated action/inhibition and anxiety and depression levels, and whether they differ between men and women. Here, we examined the relationship between anxiety and depression scores, and performance on effortful active and inhibitory avoidance (Study 1) and reward seeking (Study 2) in humans. Undergraduates and paid online workers ([Formula: see text] = 545, [Formula: see text] = 310; [Formula: see text] = 368, [Formula: see text] = 450, [Formula: see text] = 22.58, [Formula: see text] = 17-62) were assessed on the Beck Depression Inventory II (BDI) and the Beck Anxiety Inventory (BAI) and performed an instructed online avoidance or reward-seeking task. Participants had to make multiple presses on active trials and withhold presses on inhibitory trials to avoid an unpleasant sound (Study 1) or obtain points toward a monetary reward (Study 2). Overall, men deployed more effort than women in both avoidance and reward-seeking, and anxiety scores were negatively associated with active reward-seeking performance based on sensitivity scores. Gender interacted with anxiety scores and inhibitory avoidance performance, such that women with higher anxiety showed worse avoidance performance. Our results illuminate effects of gender in the relationship between anxiety and depression levels and the motivation to actively and effortfully respond to obtain positive and avoid negative outcomes., Competing Interests: The authors declare no competing financial interests., (Copyright © 2023 Forys et al.)
- Published
- 2023
- Full Text
- View/download PDF
9. Cognitive-affective processes and suicidality in response to repetitive transcranial magnetic stimulation for treatment resistant depression.
- Author
-
Terpstra AR, Vila-Rodriguez F, LeMoult J, Chakrabarty T, Nair M, Humaira A, Gregory EC, and Todd RM
- Subjects
- Humans, Transcranial Magnetic Stimulation, Suicidal Ideation, Cognition, Depressive Disorder, Treatment-Resistant therapy, Suicide
- Abstract
Background: Repetitive transcranial magnetic stimulation (rTMS) can elicit 45-55 % response rates and may alleviate suicidality symptoms in treatment resistant depression (TRD). Blunted anticipatory reward sensitivity and negatively biased self-referential processing may predict trajectories of depressive and suicidality symptoms in rTMS for TRD and be modulated during treatment., Methods: Fifty-five individuals with TRD received four weeks of low-frequency rTMS applied to the right dorsolateral prefrontal cortex (LFR-rTMS) and were followed until 17 weeks post-baseline. Participants completed behavioral measures of anticipatory reward sensitivity and self-referential processing at baseline and five weeks post-baseline (approximately one-week post-treatment). We examined whether baseline anticipatory reward sensitivity and self-referential processing predicted trajectories of depressive and suicidality symptoms from baseline to follow-up and whether these cognitive-affective variables showed change from baseline to week five., Results: Anticipatory reward sensitivity and negative self-referential encoding at baseline were associated with higher overall depressive symptoms and suicidality from baseline to 17 weeks post-baseline. At week five, participants self-attributed a higher number of positive traits and a lower number of negative traits and had a lesser tendency to remember negative relative to positive traits they had self-attributed, compared to baseline., Limitations: The specificity of these results to LFR-rTMS is unknown in the absence of a comparison group, and our relatively small sample size precluded the interpretation of null results., Conclusions: Baseline blunted anticipatory reward sensitivity and negative biases in self-referential processing may be risk factors for higher depressive symptoms and suicidality during and after LFR-rTMS, and LFR-rTMS may modulate self-referential processing., Competing Interests: Conflict of Interest FVR receives in-kind equipment supports for this investigator-initiated trial from MagVenture and has received honoraria for participation in advisory board for Janssen. The rest of the authors declare no competing interests., (Copyright © 2022. Published by Elsevier B.V.)
- Published
- 2023
- Full Text
- View/download PDF
10. Decomposing Neural Representational Patterns of Discriminatory and Hedonic Information during Somatosensory Stimulation.
- Author
-
Kryklywy JH, Ehlers MR, Beukers AO, Moore SR, Todd RM, and Anderson AK
- Subjects
- Humans, Touch, Magnetic Resonance Imaging methods, Neuroimaging, Brain Mapping methods, Brain diagnostic imaging, Brain physiology
- Abstract
The ability to interrogate specific representations in the brain, determining how, and where, difference sources of information are instantiated can provide invaluable insight into neural functioning. Pattern component modeling (PCM) is a recent analytic technique for human neuroimaging that allows the decomposition of representational patterns in brain into contributing subcomponents. In the current study, we present a novel PCM variant that tracks the contribution of prespecified representational patterns to brain representation across areas, thus allowing hypothesis-guided employment of the technique. We apply this technique to investigate the contributions of hedonic and nonhedonic information to the neural representation of tactile experience. We applied aversive pressure (AP) and appetitive brush (AB) to stimulate distinct peripheral nerve pathways for tactile information (C-/CT-fibers, respectively) while patients underwent functional magnetic resonance imaging (fMRI) scanning. We performed representational similarity analyses (RSAs) with pattern component modeling to dissociate how discriminatory versus hedonic tactile information contributes to population code representations in the human brain. Results demonstrated that information about appetitive and aversive tactile sensation is represented separately from nonhedonic tactile information across cortical structures. This also demonstrates the potential of new hypothesis-guided PCM variants to help delineate how information is instantiated in the brain., Competing Interests: The authors declare no competing financial interests., (Copyright © 2023 Kryklywy et al.)
- Published
- 2023
- Full Text
- View/download PDF
11. Rate of perceived stability as a measure of balance exercise intensity in people post-stroke.
- Author
-
Shenoy A, Peng TH, Todd RM, Eng JJ, Silverberg ND, Tembo T, and Pollock CL
- Subjects
- Humans, Female, Male, Reproducibility of Results, Walk Test, Exercise Therapy, Postural Balance, Walking, Stroke
- Abstract
Purpose: This study investigates the reproducibility and concurrent validity of the Rate of Perceived Stability (RPS) Scale in people with stroke., Methods: On two separate days (2-10 days apart), participants provided their RPS ratings during clinical measures: 1)16 tasks from Community Balance and Mobility Scale (CB&M), 2)6-minute walk test (6MWT), and 3)self-paced gait speed. Intraclass correlations (ICCs) assessed between day test-retest reliability of RPS ratings. Standard error of measurement (SEM) and smallest detectable change (SDC) addressed level of between day agreement. Spearman rank correlations ( r
s ) quantified relationships between RPS, and general rating of perceived challenge, task-performance scores., Results: Thirty participants with stroke (50% female) participated. ICC ranged from 0.46 to 0.93 across tasks with 12/19 tasks showing ICCs above 0.75 (good test-retest reliability). SEM was 1-point for each task and SDC ranged from 2 to 4 across tasks. Concurrent validity between RPS and ratings of perceived challenge was good-to-excellent ( rs ranged 0.78-0.94, p < 0.01). Higher RPS (indicative of feeling less stable) was associated with lower balance performance scores on CB&M tasks, negative relationships ranged in strength from fair to good-to-excellent in 10/16 tasks ( rs ranged -0.46 to -0.81, p ≤ 0.01)., Conclusions: RPS shows promise as a measure of balance intensity in people with stroke.IMPLICATIONS FOR REHABILITATIONThe RPS is a reliable and valid measure of balance intensity in ambulatory people with stroke.The RPS scale may be a useful clinical tool to address the gap in practice of measuring balance intensity during rehabilitation of walking balance post-stroke.- Published
- 2022
- Full Text
- View/download PDF
12. Lateralization of autonomic output in response to limb-specific threat.
- Author
-
Kryklywy JH, Lu A, Roberts KH, Rowan M, and Todd RM
- Abstract
In times of stress or danger, the autonomic nervous system (ANS) signals the fight or flight response. A canonical function of ANS activity is to globally mobilize metabolic resources, preparing the organism to respond to threat. Yet a body of research has demonstrated that, rather than displaying a homogenous pattern across the body, autonomic responses to arousing events - as measured through changes in electrodermal activity (EDA) - can differ between right and left body locations. Surprisingly, an attempt to identify a function of ANS asymmetry consistent with its metabolic role has not been investigated. In the current study, we investigated whether asymmetric autonomic responses could be induced through limb-specific aversive stimulation. Participants were given mild electric stimulation to either the left or right arm while EDA was monitored bilaterally. In a group-level analyses, an ipsilateral EDA response bias was observed, with increased EDA response in the hand adjacent to the stimulation. This effect was observable in ∼50% of individual particpants. These results demonstrate that autonomic output is more complex than canonical interpretations suggest. We suggest that, in stressful situations, autonomic outputs can prepare either the whole-body fight or flight response, or a simply a limb-localized flick, which can effectively neutralize the threat while minimizing global resource consumption. These findings are consistent with recent theories proposing evolutionary leveraging of neural structures organized to mediate sensory responses for processing of cognitive emotional cues. Significance statement The present study constitutes novel evidence for an autonomic nervous response specific to the side of the body exposed to direct threat. We identify a robust pattern of electrodermal response at the body location that directly receives aversive tactile stimulation. Thus, we demonstrate for the first time in contemporary research that the ANS is capable of location-specific outputs within single effector organs in response to small scale threat. This extends the canonical view of the role of ANS responses in stressful or dangerous stresses - that of provoking a 'fight or flight ' response - suggesting a further role of this system: preparation of targeted limb-specific action, i.e., a flick., Competing Interests: The authors declare no competing financial interests., (Copyright © 2022 Kryklywy et al.)
- Published
- 2022
- Full Text
- View/download PDF
13. In the hands of the beholder: Wearing a COVID-19 mask is associated with its attractiveness.
- Author
-
Dudarev V, Manaligod MG, Enns JT, and Todd RM
- Subjects
- Habits, Humans, Masks, Reproducibility of Results, SARS-CoV-2, COVID-19 prevention & control
- Abstract
Protective facial masks reduce the spread of COVID-19 infection and save lives. Yet a substantial number of people have been resistant to wearing them. Considerable effort has been invested in convincing people to put on a mask, if not for their own sake than for those more vulnerable. Social and cognitive psychologists know that use and liking go both ways: people use what they like, and they like what they use. Here we asked whether positive attitudes towards facial masks were higher in those who had been wearing them longer. We asked participants in a diverse sample ( N = 498 from five countries and more than 30 US states) to rate how attractive and emotionally arousing masks and other objects associated with COVID-19 were in comparison to neutral objects, as well as reporting on their mask-wearing habits. To confirm reliability of findings, the experiment was repeated in a subset of participants 8-10 weeks later. The findings show that regular use of protective masks was linked to their positive appraisal, with a higher frequency and a longer history of wearing a mask predicting increased mask attractiveness. These results extended to other COVID-related objects relative to controls. They also provide critical ecological validity for the idea that emotional appraisal of everyday objects is associated with our experience of using them. Practically, they imply that societal measures to encourage mask wearing may have contributed to positive emotional appraisals in those who put them on, whether due to personal choice or societal pressure.
- Published
- 2022
- Full Text
- View/download PDF
14. Forces and translation distance during an inferior glide of the shoulder in asymptomatic individuals measured with the novel pliance glove and ultrasound imaging.
- Author
-
Sillevis R, Todd RM, Speare JP, Shamus E, and van Duijn A
- Subjects
- Biomechanical Phenomena, Humans, Humeral Head diagnostic imaging, Range of Motion, Articular, Ultrasonography, Shoulder diagnostic imaging, Shoulder Joint diagnostic imaging
- Abstract
Background: There has been limited research on how the variance of force affects manual therapy outcomes and what the best practices should be. No specific force threshold necessary to achieve a predetermined translational distance within the joint has been quantified within the literature., Purpose: To quantify the amount of force necessary to perform an inferior glide to the glenohumeral joint and reach to end range. A secondary aim was to determine the impact of co-variables, such as gender, height, weight, and age, on the amount of force required to translate the humeral head within the glenohumeral joint., Methods: A convenience sample of 64 healthy subjects were recruited. Musculoskeletal ultrasound imaging using the GE LogiQe was used to measure the translation of the humeral head. The manipulation force was measured using the novel pliance glove device and software. The ANOVA was used to determine if there was a difference in translation distance and force between trials. The Pearson's correlation was used to correlate translation and force and between covariables., Results: There was no significant difference in translation distance between trials (p = .14). There was no significant difference in the mean force for this translation (p = .45). There was a poor correlation between age and force (r = 0.28) and weight and force (r = 0.12)., Conclusion: An average force of 14.27 N (n = 61) was needed to displace the humeral head to reach end range. This was the first study using the combination of a flexible force sensor technology and real-time ultrasound imaging to measure humeral head translation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Ltd. All rights reserved.)
- Published
- 2022
- Full Text
- View/download PDF
15. Sense and timing: Localizing objects during emotional distraction.
- Author
-
Kryklywy JH, Dudarev V, and Todd RM
- Subjects
- Cues, Facial Expression, Humans, Space Perception, Attention, Emotions
- Abstract
There is substantial evidence demonstrating that emotional information influences perception. Yet across studies, findings of how it does so have been highly inconsistent. In particular, emotional context (task-unrelated emotional information in the environment) has a variable influence on spatial perceptual accuracy, sometimes improving and sometimes impairing the ability to localize objects. Here, we tested the hypothesis that the heterogenous nature of emotional influences on target localization is influenced by the specific combination of sensory modalities used in the task. In the present series of experiments, we used a cross-modal localization task to identify how emotional context influences the accuracy of spatial perception. By presenting nonemotional target stimuli alongside emotional nonspatial distractor items (facial expressions or vocalizations), we were able to systematically investigate how emotional stimuli presented to individual sensory modalities acted to modulate spatial perception at distinct stages of perception and action. In three separate experiments, distractor items were presented prior to or during target presentation or after presentation during the localization response. Intramodal emotional distractors influenced localization accuracy when they overlapped in timing with targets, and the direction of this effect was both modality and valence specific (Experiment I). Additionally, targeted contrasts revealed that auditory but not visual emotional distractors influenced localization of visual targets when presented during the behavioral response, with negative cues improving localization accuracy compared to neutral or positive cues (Experiment II). We suggest such effects reflect distinct patterns of unimodal versus multimodal processing in brain regions involved in early versus late stages of perceptual processing. (PsycInfo Database Record (c) 2021 APA, all rights reserved).
- Published
- 2021
- Full Text
- View/download PDF
16. Warped rhythms: Epileptic activity during critical periods disrupts the development of neural networks for human communication.
- Author
-
Reh R, Williams LJ, Todd RM, and Ward LM
- Subjects
- Adolescent, Adult, Animals, Child, Child, Preschool, Humans, Infant, Infant, Newborn, Young Adult, Brain Waves physiology, Cerebral Cortex growth & development, Cerebral Cortex metabolism, Cerebral Cortex physiopathology, Communication, Epilepsy, Temporal Lobe metabolism, Epilepsy, Temporal Lobe physiopathology, Human Development physiology, Nerve Net growth & development, Nerve Net metabolism, Nerve Net physiopathology, Neuronal Plasticity physiology, Social Perception
- Abstract
It is well established that temporal lobe epilepsy-the most common and well-studied form of epilepsy-can impair communication by disrupting social-emotional and language functions. In pediatric epilepsy, where seizures co-occur with the development of critical brain networks, age of onset matters: The earlier in life seizures begin, the worse the disruption in network establishment, resulting in academic hardship and social isolation. Yet, little is known about the processes by which epileptic activity disrupts developing human brain networks. Here we take a synthetic perspective-reviewing a range of research spanning studies on molecular and oscillatory processes to those on the development of large-scale functional networks-in support of a novel model of how such networks can be disrupted by epilepsy. We seek to bridge the gap between research on molecular processes, on the development of human brain circuitry, and on clinical outcomes to propose a model of how epileptic activity disrupts brain development., (Copyright © 2020 Elsevier B.V. All rights reserved.)
- Published
- 2021
- Full Text
- View/download PDF
17. Assessing the efficacy of tablet-based simulations for learning pseudo-surgical instrumentation.
- Author
-
Kryklywy JH, Roach VA, and Todd RM
- Subjects
- Adolescent, Adult, Female, Humans, Learning, Male, Young Adult, Clinical Competence, General Surgery education, General Surgery instrumentation, Health Personnel education, Virtual Reality
- Abstract
Nurses and surgeons must identify and handle specialized instruments with high temporal and spatial precision. It is crucial that they are trained effectively. Traditional training methods include supervised practices and text-based study, which may expose patients to undue risk during practice procedures and lack motor/haptic training respectively. Tablet-based simulations have been proposed to mediate some of these limitations. We implemented a learning task that simulates surgical instrumentation nomenclature encountered by novice perioperative nurses. Learning was assessed following training in three distinct conditions: tablet-based simulations, text-based study, and real-world practice. Immediately following a 30-minute training period, instrument identification was performed with comparable accuracy and response times following tablet-based versus text-based training, with both being inferior to real-world practice. Following a week without practice, response times were equivalent between real-world and tablet-based practice. While tablet-based training does not achieve equivalent results in instrument identification accuracy as real-world practice, more practice repetitions in simulated environments may help reduce performance decline. This project has established a technological framework to assess how we can implement simulated educational environments in a maximally beneficial manner., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2021
- Full Text
- View/download PDF
18. From Architecture to Evolution: Multisensory Evidence of Decentralized Emotion.
- Author
-
Kryklywy JH, Ehlers MR, Anderson AK, and Todd RM
- Subjects
- Animals, Brain physiology, Humans, Emotions, Sensation
- Abstract
Emotional appraisal in humans is often considered a centrally mediated process by which sensory signals, void of emotional meaning, are assessed by integrative brain structures steps removed from raw sensation. We review emerging evidence that the emotional value of the environment is coded by nonvisual sensory systems as early as the sensory receptors and that these signals inform the emotional state of an organism independent of sensory cortical processes. We further present evidence for cross-species conservation of sensory projections to central emotion-processing brain regions. Based on this, we argue not only that emotional appraisal is a decentralized process, but that all human emotional experience may reflect the sensory experience of our ancestors., (Copyright © 2020 Elsevier Ltd. All rights reserved.)
- Published
- 2020
- Full Text
- View/download PDF
19. Affect-biased attention and predictive processing.
- Author
-
Ransom M, Fazelpour S, Markovic J, Kryklywy J, Thompson ET, and Todd RM
- Subjects
- Bayes Theorem, Cognition, Entropy, Humans, Attentional Bias
- Abstract
In this paper we argue that predictive processing (PP) theory cannot account for the phenomenon of affect-biased attention - prioritized attention to stimuli that are affectively salient because of their associations with reward or punishment. Specifically, the PP hypothesis that selective attention can be analyzed in terms of the optimization of precision expectations cannot accommodate affect-biased attention; affectively salient stimuli can capture our attention even when precision expectations are low. We review the prospects of three recent attempts to accommodate affect with tools internal to PP theory: Miller and Clark's (2018) embodied inference; Seth's (2013) interoceptive inference; and Joffily and Coricelli's (2013) rate of change of free energy. In each case we argue that the account does not resolve the challenge from affect-biased attention. For this reason, we conclude that prediction error minimization is not sufficient to explain all mental phenomena, contrary to the claim that the PP framework provides a unified theory of all mental phenomena or the brain's cognitive functioning. Nevertheless, we suggest that empirical investigation of the interaction between affective salience and precision expectations should prove helpful in understanding the limits of PP theory, and may provide new directions for the application of a Bayesian perspective to perception., Competing Interests: Declaration of competing interest None., (Copyright © 2020 Elsevier B.V. All rights reserved.)
- Published
- 2020
- Full Text
- View/download PDF
20. Emotional Objectivity: Neural Representations of Emotions and Their Interaction with Cognition.
- Author
-
Todd RM, Miskovic V, Chikazoe J, and Anderson AK
- Subjects
- Humans, Cognition physiology, Cognitive Neuroscience, Emotions physiology, Learning physiology, Perception physiology
- Abstract
Recent advances in our understanding of information states in the human brain have opened a new window into the brain's representation of emotion. While emotion was once thought to constitute a separate domain from cognition, current evidence suggests that all events are filtered through the lens of whether they are good or bad for us. Focusing on new methods of decoding information states from brain activation, we review growing evidence that emotion is represented at multiple levels of our sensory systems and infuses perception, attention, learning, and memory. We provide evidence that the primary function of emotional representations is to produce unified emotion, perception, and thought (e.g., "That is a good thing") rather than discrete and isolated psychological events (e.g., "That is a thing. I feel good"). The emergent view suggests ways in which emotion operates as a fundamental feature of cognition, by design ensuring that emotional outcomes are the central object of perception, thought, and action.
- Published
- 2020
- Full Text
- View/download PDF
21. The influence of the noradrenergic/stress system on perceptual biases for reward.
- Author
-
Ehlers MR, Ross CJD, and Todd RM
- Subjects
- Adult, Anger physiology, Female, Happiness, Humans, Male, Receptors, Adrenergic, alpha-2 genetics, Young Adult, Adaptation, Psychological physiology, Facial Expression, Facial Recognition physiology, Norepinephrine physiology, Personality physiology, Reward, Stress, Psychological physiopathology
- Abstract
Previous research has established a role for the norepinephrine (NE)/stress system in individual differences in biases to attend to reward or punishment. Outstanding questions concern its role in the flexibility with which such biases can be changed. The goal of this preregistered study was to examine the role of the NE/stress system in the degree to which biases can be trained along the axis of valence in the direction of reward. Participants genotyped for a common deletion variant of ADRA2b (linked to altered NE availability) experienced either an acute stress induction or a control procedure. Following stress induction, a "bias probe" task was presented before and after training. In the bias probe task, participants made forced choice judgments (happy or angry) on emotional faces with varying degrees of ambiguity. For bias training, participants viewed unambiguously angry faces in a task exploiting visual adaptation effects. The results revealed an overall shift from a slightly positive bias in categorizing faces pretraining to a more positive bias after training. Carriers of the deletion variant overall showed a more positive bias than did the noncarriers. Follow-up analyses showed that pretraining bias was a significant predictor of bias change, with those who showed a more negative bias preadaptation changing more in a positive direction. Critically, this effect was observed under control but not under stress conditions. These results suggest that the NE/stress system plays an important role in influencing trait-like biases as well as short-term changes in the tendency to perceive ambiguous stimuli as being more rewarding than threatening.
- Published
- 2019
- Full Text
- View/download PDF
22. Cardiovascular Magnetic Resonance in the Oncology Patient.
- Author
-
Jordan JH, Todd RM, Vasu S, and Hundley WG
- Subjects
- Cancer Survivors, Cardiotoxicity, Heart drug effects, Heart physiopathology, Heart radiation effects, Heart Diseases etiology, Heart Diseases physiopathology, Humans, Predictive Value of Tests, Radiation Injuries etiology, Radiation Injuries physiopathology, Radiotherapy adverse effects, Risk Factors, Antineoplastic Agents adverse effects, Heart diagnostic imaging, Heart Diseases diagnostic imaging, Magnetic Resonance Imaging, Neoplasms therapy, Radiation Injuries diagnostic imaging
- Abstract
Patients with or receiving potentially cardiotoxic treatment for cancer are susceptible to developing decrements in left ventricular mass, diastolic function, or systolic function. They may also experience valvular heart disease, pericardial disease, or intracardiac masses. Cardiovascular magnetic resonance may be used to assess cardiac anatomy, structure, and function and to characterize myocardial tissue. This combination of features facilitates the diagnosis and management of disease processes in patients with or those who have survived cancer. This report outlines and describes prior research involving cardiovascular magnetic resonance for assessing cardiovascular disease in patients with or previously having received treatment for cancer., (Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2018
- Full Text
- View/download PDF
23. Experiential History as a Tuning Parameter for Attention.
- Author
-
Kryklywy JH and Todd RM
- Abstract
[Peer commentary on "Visual selection: usually fast and automatic; seldom slow and volitional," by J. Theeuwes]. Journal of Cognition . In his current opinion piece, Theeuwes emphasizes the role of selection history as a third source of attentional selection, beyond top-down and bottom-up mechanisms, thus challenging traditional dual-process models of attention. While we agree that selection history impacts the allocation of attention, our own work suggests that this terminology may be too restrictive, and propose the simple term history as a better reflection of the impact of learning on our selection biases. Furthermore, we propose that the role of selection/experiential history on attention may not be as a unique third source of attentional selection, but rather as a tuning parameter, allowing certain categories of item to be endowed with greater task-based or feature-driven salience in a context and history dependent manner. This conceptualization presents an alternative to abandoning dual-process models of attention altogether. Rather, we can reimagine how task-based and feature-driven processes may be controlled by past experience in a dynamic and adaptable system., Competing Interests: The authors have no competing interests to declare.
- Published
- 2018
- Full Text
- View/download PDF
24. Implicit guidance of attention: The priority state space framework.
- Author
-
Todd RM and Manaligod MGM
- Subjects
- Brain physiology, Humans, Semantics, Attention physiology, Learning, Motivation physiology, Visual Perception physiology
- Abstract
Visual selective attention is the process by which we tune ourselves to the world so that, of the millions of bits per second transmitted by the retina, the information that is most important to us reaches awareness and directs action. Recently, new areas of attention research have opened up as classic models dividing attention into top-down and bottom-up systems have been challenged. In this paper, we propose a theoretical framework, the priority state space (PSS) framework, integrating sources of salience that guide visual attention according to a nested hierarchy of goals. Using the PSS framework as a scaffold, we review evidence of selected sources of implicit attentional guidance, including recent research on statistical learning, semantic associations, and motivational and affective salience. We next summarize current understanding of the underlying neural circuitry facilitating guidance of attention by specific sources of salience, including key neuromodulator systems, with an emphasis on affective salience and the noradrenergic system. Finally, we discuss evidence for common mechanisms of prioritization, including integration of sources of salience via priority maps, and introduce the concept of the PSS as a model for mapping a complex dynamic attentional landscape., (Copyright © 2017 Elsevier Ltd. All rights reserved.)
- Published
- 2018
- Full Text
- View/download PDF
25. Episodic autobiographical memory is associated with variation in the size of hippocampal subregions.
- Author
-
Palombo DJ, Bacopulos A, Amaral RSC, Olsen RK, Todd RM, Anderson AK, and Levine B
- Subjects
- Adolescent, Female, Follow-Up Studies, Functional Laterality physiology, Hippocampus anatomy & histology, Hippocampus diagnostic imaging, Humans, Image Processing, Computer-Assisted, Individuality, Magnetic Resonance Imaging, Male, Neuropsychological Tests, Young Adult, Hippocampus physiology, Memory, Episodic
- Abstract
Striking individual differences exist in the human capacity to recollect past events, yet, little is known about the neural correlates of such individual differences. Studies investigating hippocampal volume in relation to individual differences in laboratory measures of episodic memory in young adults suggest that whole hippocampal volume is unrelated (or even negatively associated) with episodic memory. However, anatomical and functional specialization across hippocampal subregions suggests that individual differences in episodic memory may be linked to particular hippocampal subregions, as opposed to whole hippocampal volume. Given that the DG/CA
2/3 circuitry is thought to be especially critical for supporting episodic memory in humans, we predicted that the volume of this region would be associated with individual variability in episodic memory. This prediction was supported using high-resolution MRI of the hippocampal subfields and measures of real-world (autobiographical) episodic memory. In addition to the association with DG/CA2/3 , we further observed a relationship between episodic autobiographical memory and subiculum volume, whereas no association was observed with CA1 or with whole hippocampal volume. These findings provide insight into the possible neural substrates that mediate individual differences in real-world episodic remembering in humans., (© 2017 Wiley Periodicals, Inc.)- Published
- 2018
- Full Text
- View/download PDF
26. The Blur of Pleasure: Appetitively Appealing Stimuli Decrease Subjective Temporal Perceptual Acuity.
- Author
-
Roberts KH, Truong G, Kingstone A, and Todd RM
- Subjects
- Adult, Female, Humans, Male, Young Adult, Emotions physiology, Motivation physiology, Time Perception physiology, Visual Perception physiology
- Abstract
Anecdotal reports that time "flies by" or "slows down" during emotional events are supported by evidence that the motivational relevance of stimuli influences subsequent duration judgments. Yet it is unknown whether the subjective quality of events as they unfold is altered by motivational relevance. In a novel paradigm, we measured the subjective experience of moment-to-moment visual perception. Participants judged the temporal smoothness of high-approach positive images (desserts), negative images (e.g., of bodily mutilation), and neutral images (commonplace scenes) as they faded to black. Results revealed approach-motivated blurring, such that positive stimuli were judged as smoother and negative stimuli as choppier relative to neutral stimuli. Participants' ratings of approach motivation predicted perceived fade smoothness after we controlled for low-level stimulus features. Electrophysiological data indicated that approach-motivated blurring modulated relatively rapid perceptual activation. These results indicate that stimulus value influences subjective temporal perceptual acuity; approach-motivating stimuli elicit perception of a "blurred" frame rate characteristic of speeded motion.
- Published
- 2017
- Full Text
- View/download PDF
27. Acute psychophysiological stress impairs human associative learning.
- Author
-
Ehlers MR and Todd RM
- Subjects
- Adult, Blood Pressure, Conditioning, Classical, Conditioning, Operant, Female, Heart Rate, Humans, Hydrocortisone analysis, Male, Young Adult, Association Learning, Habits, Stress, Psychological
- Abstract
Addiction is increasingly discussed asa disorder of associative learning processes, with both operant and classical conditioning contributing to the development of maladaptive habits. Stress has long been known to promote drug taking and relapse and has further been shown to shift behavior from goal-directed actions towards more habitual ones. However, it remains to be investigated how acute stress may influence simple associative learning processes that occur before a habit can be established. In the present study, healthy young adults were exposed to either acute stress or a control condition half an hour before performing simple classical and operant conditioning tasks. Psychophysiological measures confirmed successful stress induction. Results of the operant conditioning task revealed reduced instrumental responding under delayed acute stress that resembled behavioral responses to lower levels of reward. The classical conditioning experiment revealed successful conditioning in both experimental groups; however, explicit knowledge of conditioning as indicated by stimulus ratings differentiated the stress and control groups. These findings suggest that operant and classical conditioning are differentially influenced by the delayed effects of acute stress with important implications for the understanding of how new habitual behaviors are initially established., (Copyright © 2017 Elsevier Inc. All rights reserved.)
- Published
- 2017
- Full Text
- View/download PDF
28. Alternation between different types of evidence attenuates judgments of severity.
- Author
-
Whitman JC, Zhao J, and Todd RM
- Subjects
- Adolescent, Adult, Female, Humans, Male, Young Adult, Judgment
- Abstract
Most real-world judgments and decisions require the consideration of multiple types of evidence. For example, judging the severity of environmental damage, medical illness, or negative economic trends often involves tracking and integrating evidence from multiple sources (i.e. different natural disasters, physical symptoms, or financial indicators). We hypothesized that the requirement to track and integrate across distinct types of evidence would affect severity judgments of multifaceted problems, compared to simpler problems. To test this, we used scenarios depicting crop damage. Each scenario involved either two event types (i.e. mold damage and insect damage), or one event type. Participants judged the quality of the crop following each scenario. In Experiments 1 and 2, subjective judgments were attenuated if the scenario depicted multiple event types, relative to scenarios depicting single event types. This was evident as a shallower slope of subjective severity ratings, as a function of objectively quantifiable severity, for scenarios with multiple event types. In Experiment 3, we asked whether alternation between event types might contribute to this attenuation. Each scenario contained two event types, and the sequence of events either alternated frequently between types or was organized into two sequential groups. Subjective judgments were attenuated for scenarios with frequently alternating sequences. The results demonstrate that alternation between distinct event types attenuates subjective judgments of severity. This suggests that a requirement to integrate evidence across multiple sources places extra demands on the cognitive system, which reduces the perceived evidence strength.
- Published
- 2017
- Full Text
- View/download PDF
29. SOAP Opera: Self as Object and Agent in Prioritizing Attention.
- Author
-
Truong G and Todd RM
- Subjects
- Brain diagnostic imaging, Humans, Attention physiology, Brain physiology, Ego, Models, Theoretical
- Abstract
A growing body of evidence has demonstrated that multiple sources of salience tune attentional sets toward aspects of the environment, including affectively and motivationally significant categories of stimuli such as angry faces and reward-associated target locations. Recent evidence further indicates that objects that have gained personal significance through ownership can elicit similar attentional prioritization. Here we discuss current research on sources of attentional prioritization that shape our awareness of the visual world from moment to moment and the underlying neural systems and contextualize what is known about attentional prioritization of our possessions within that research. We review behavioral and neuroimaging research on the influence of self-relevance and ownership on cognition and discuss challenges to this literature stemming from different modes of conceptualizing and operationalizing the self. We argue that ownership taps into both "self-as-object," which characterizes the self as an object with a constellation of traits and attributes, and "self-as-subject," which characterizes the self as an agentic perceiver and knower. Despite an abundance of research probing neural and behavioral indices of self-as-object and its effects on attention, there exists a paucity of research on the influence of self-relevance of attention when self is operationalized from the perspective of a first-person subject. To begin to address this gap, we propose the Self as Ownership in Attentional Prioritization (SOAP) framework to explain how ownership increases salience through attention to external representations of self-identity (i.e., self as object) and attention to contextually mediated permission to act (i.e., self as subject).
- Published
- 2017
- Full Text
- View/download PDF
30. Genesis and Maintenance of Attentional Biases: The Role of the Locus Coeruleus-Noradrenaline System.
- Author
-
Ehlers MR and Todd RM
- Subjects
- Animals, Association Learning physiology, Brain physiology, Brain physiopathology, Cues, Humans, Locus Coeruleus physiopathology, Mental Disorders physiopathology, Attentional Bias physiology, Locus Coeruleus physiology, Norepinephrine physiology
- Abstract
Emotionally arousing events are typically better remembered than mundane ones, in part because emotionally relevant aspects of our environment are prioritized in attention. Such biased attentional tuning is itself the result of associative processes through which we learn affective and motivational relevance of cues. We propose that the locus coeruleus-noradrenaline (LC-NA) system plays an important role in the genesis of attentional biases through associative learning processes as well as their maintenance. We further propose that individual differences in and disruptions of the LC-NA system underlie the development of maladaptive biases linked to psychopathology. We provide support for the proposed role of the LC-NA system by first reviewing work on attentional biases in development and its link to psychopathology in relation to alterations and individual differences in NA availability. We focus on pharmacological manipulations to demonstrate the effect of a disrupted system as well as the ADRA2b polymorphism as a tool to investigate naturally occurring differences in NA availability. We next review associative learning processes that-modulated by the LC-NA system-result in such implicit attentional biases. Further, we demonstrate how NA may influence aversive and appetitive conditioning linked to anxiety disorders as well as addiction and depression.
- Published
- 2017
- Full Text
- View/download PDF
31. I saw mine first: A prior-entry effect for newly acquired ownership.
- Author
-
Truong G, Roberts KH, and Todd RM
- Subjects
- Adult, Female, Humans, Male, Ownership, Time Factors, Young Adult, Attention physiology, Attentional Bias physiology, Pattern Recognition, Visual physiology, Set, Psychology
- Abstract
Previous research has shown that attentional sets can be tuned to implicitly prioritize awareness of universally aversive or rewarding stimuli. But can mere ownership modulate implicit attentional prioritization as well? In Experiments 1 and 2, participants learned whether everyday objects belonged to them (self-owned) or the experimenter (other-owned) and completed a temporal order judgment task in which pairs of stimuli appeared onscreen with staggered timing. Results revealed a prior-entry effect, in which participants were more likely to report seeing a self-owned object first when 2 objects appeared simultaneously. In Experiment 3, no ownership status was assigned and no such effect was observed. Individual differences in the prior-entry effect were unrelated to independent self-construal, positive associations for self-owned objects, or loss aversion. These results suggest that attentional prioritization is not limited to universally salient stimuli. Rather, self-relevance, even when recently acquired, can engage an implicit attentional set that biases our perception of the environment. (PsycINFO Database Record, ((c) 2016 APA, all rights reserved).)
- Published
- 2017
- Full Text
- View/download PDF
32. Dynamics of neural recruitment surrounding the spontaneous arising of thoughts in experienced mindfulness practitioners.
- Author
-
Ellamil M, Fox KC, Dixon ML, Pritchard S, Todd RM, Thompson E, and Christoff K
- Subjects
- Brain Mapping, Female, Humans, Magnetic Resonance Imaging, Male, Middle Aged, Mindfulness methods, Nerve Net physiology, Parietal Lobe physiology, Recruitment, Neurophysiological physiology, Temporal Lobe physiology, Thinking
- Abstract
Thoughts arise spontaneously in our minds with remarkable frequency, but tracking the brain systems associated with the early inception of a thought has proved challenging. Here we addressed this issue by taking advantage of the heightened introspective ability of experienced mindfulness practitioners to observe the onset of their spontaneously arising thoughts. We found subtle differences in timing among the many regions typically recruited by spontaneous thought. In some of these regions, fMRI signal peaked prior to the spontaneous arising of a thought - most notably in the medial temporal lobe and inferior parietal lobule. In contrast, activation in the medial prefrontal, temporopolar, mid-insular, lateral prefrontal, and dorsal anterior cingulate cortices peaked together with or immediately following the arising of spontaneous thought. We propose that brain regions that show antecedent recruitment may be preferentially involved in the initial inception of spontaneous thoughts, while those that show later recruitment may be preferentially involved in the subsequent elaboration and metacognitive processing of spontaneous thoughts. Our findings highlight the temporal dynamics of neural recruitment surrounding the emergence of spontaneous thoughts and may help account for some of spontaneous thought's peculiar qualities, including its wild diversity of content and its links to memory and attention., (Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2016
- Full Text
- View/download PDF
33. The neural correlates of memory for a life-threatening event: An fMRI study of passengers from flight AT236.
- Author
-
Palombo DJ, McKinnon MC, McIntosh AR, Anderson AK, Todd RM, and Levine B
- Abstract
We investigated the neural correlates of remote traumatic reexperiencing in survivors of a life-threatening incident: the near crash of Air Transat (AT) Flight 236. Survivors' brain activity was monitored during video-cued recollection of the AT disaster, September 11
th , 2001 (9/11), and a comparatively non-emotional (neutral) event. Passengers showed a robust memory enhancement effect for the AT incident relative to the 9/11 and neutral events. This traumatic memory enhancement was associated with activation in the amygdala, medial temporal lobe, anterior and posterior midline, and visual cortex in passengers. This brain-behavior relationship also held in relation to 9/11, which had elevated significance for passengers given its temporal proximity to the AT disaster. This pattern was not observed in a comparison group of non-traumatized individuals who were also scanned. These findings suggest that remote, traumatic memory is mediated by amygdalar activity, which likely enhances vividness via influences on hippocampal and ventral visual systems.- Published
- 2016
- Full Text
- View/download PDF
34. Tuning to the Positive: Age-Related Differences in Subjective Perception of Facial Emotion.
- Author
-
Picardo R, Baron AS, Anderson AK, and Todd RM
- Subjects
- Adolescent, Adult, Anger, Arousal, Child, Child, Preschool, Female, Happiness, Humans, Male, Photic Stimulation, Young Adult, Facial Expression, Perception physiology
- Abstract
Facial expressions aid social transactions and serve as socialization tools, with smiles signaling approval and reward, and angry faces signaling disapproval and punishment. The present study examined whether the subjective experience of positive vs. negative facial expressions differs between children and adults. Specifically, we examined age-related differences in biases toward happy and angry facial expressions. Young children (5-7 years) and young adults (18-29 years) rated the intensity of happy and angry expressions as well as levels of experienced arousal. Results showed that young children-but not young adults-rated happy facial expressions as both more intense and arousing than angry faces. This finding, which we replicated in two independent samples, was not due to differences in the ability to identify facial expressions, and suggests that children are more tuned to information in positive expressions. Together these studies provide evidence that children see unambiguous adult emotional expressions through rose-colored glasses, and suggest that what is emotionally relevant can shift with development.
- Published
- 2016
- Full Text
- View/download PDF
35. What BANE can offer GANE: Individual differences in function of hotspot mechanisms.
- Author
-
Todd RM, Ehlers MR, and Anderson AK
- Subjects
- Humans, Norepinephrine, Arousal, Emotions, Individuality
- Abstract
In this commentary we focus on individual differences in proposed mechanisms underlying arousal-based enhancement of prioritized stimuli. We discuss the potential of genotyping studies for examining effects of noradrenergic processes on stimulus prioritization in humans and stress the importance of potential individual differences in the activity of specific receptor subtypes in hotspot processes proposed by the GANE model.
- Published
- 2016
- Full Text
- View/download PDF
36. Iconic faces are not real faces: enhanced emotion detection and altered neural processing as faces become more iconic.
- Author
-
Kendall LN, Raffaelli Q, Kingstone A, and Todd RM
- Abstract
Iconic representations are ubiquitous; they fill children's cartoons, add humor to newspapers, and bring emotional tone to online communication. Yet, the communicative function they serve remains unaddressed by cognitive psychology. Here, we examined the hypothesis that iconic representations communicate emotional information more efficiently than their realistic counterparts. In Experiment 1, we manipulated low-level features of emotional faces to create five sets of stimuli that ranged from photorealistic to fully iconic. Participants identified emotions on briefly presented faces. Results showed that, at short presentation times, accuracy for identifying emotion on more "cartoonized" images was enhanced. In addition, increasing contrast and decreasing featural complexity benefited accuracy. In Experiment 2, we examined an event-related potential component, the P1, which is sensitive to low-level visual stimulus features. Lower levels of contrast and complexity within schematic stimuli were also associated with lower P1 amplitudes. These findings support the hypothesis that iconic representations differ from realistic images in their ability to communicate specific information, including emotion, quickly and efficiently, and that this effect is driven by changes in low-level visual features in the stimuli.
- Published
- 2016
- Full Text
- View/download PDF
37. Soldiers With Posttraumatic Stress Disorder See a World Full of Threat: Magnetoencephalography Reveals Enhanced Tuning to Combat-Related Cues.
- Author
-
Todd RM, MacDonald MJ, Sedge P, Robertson A, Jetly R, Taylor MJ, and Pang EW
- Subjects
- Adult, Cues, Emotions physiology, Humans, Magnetoencephalography, Male, Middle Aged, Neuropsychological Tests, Attention physiology, Brain physiopathology, Military Personnel psychology, Stress Disorders, Post-Traumatic physiopathology, Stress Disorders, Post-Traumatic psychology, War Exposure adverse effects
- Abstract
Background: Posttraumatic stress disorder (PTSD) is linked to elevated arousal and alterations in cognitive processes. Yet, whether a traumatic experience is linked to neural and behavioral differences in selective attentional tuning to traumatic stimuli is not known. The present study examined selective awareness of threat stimuli and underlying temporal-spatial patterns of brain activation associated with PTSD., Methods: Participants were 44 soldiers from the Canadian Armed Forces, 22 with PTSD and 22 without. All completed neuropsychological tests and clinical assessments. Magnetoencephalography data were collected while participants identified two targets in a rapidly presented stream of words. The first target was a number and the second target was either a combat-related or neutral word. The difference in accuracy for combat-related versus neutral words was used as a measure of attentional bias., Results: All soldiers showed a bias for combat-related words. This bias was enhanced in the PTSD group, and behavioral differences were associated with distinct patterns of brain activity. At early latencies, non-PTSD soldiers showed activation of midline frontal regions associated with fear regulation (90-340 ms after the second target presentation), whereas those with PTSD showed greater visual cortex activation linked to enhanced visual processing of trauma stimuli (200-300 ms)., Conclusions: These findings suggest that attentional biases in PTSD are linked to deficits in very rapid regulatory activation observed in healthy control subjects. Thus, sufferers with PTSD may literally see a world more populated by traumatic cues, contributing to a positive feedback loop that perpetuates the effects of trauma., (Copyright © 2015 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.)
- Published
- 2015
- Full Text
- View/download PDF
38. Neurogenetic variations in norepinephrine availability enhance perceptual vividness.
- Author
-
Todd RM, Ehlers MR, Müller DJ, Robertson A, Palombo DJ, Freeman N, Levine B, and Anderson AK
- Subjects
- Adolescent, Adult, Female, Functional Neuroimaging, Gene Deletion, Heterozygote, Humans, Magnetic Resonance Imaging, Male, Norepinephrine genetics, Photic Stimulation, Prefrontal Cortex physiology, Young Adult, Emotions physiology, Norepinephrine physiology, Perception physiology, Receptors, Adrenergic, alpha-2 genetics
- Abstract
Emotionally salient aspects of the world are experienced with greater perceptual vividness than mundane ones; however, such emotionally enhanced vividness (EEV) may be experienced to different degrees for different people. We examined whether BOLD activity associated with a deletion variant of the ADRA2b gene coding for the α2b adrenoceptor modulates EEV in humans. Relative to noncarriers, ADRA2b deletion carriers showed higher levels of perceptual vividness, with the ventromedial prefrontal cortex (VMPFC) showing greater modulation by EEV. Deletion carriers were also more sensitive to the featural salience of the images, suggesting a more pervasive role of norepinephrine in perceptual encoding. Path analysis revealed that, whereas a simple model by which the amygdala modulated the lateral occipital complex best characterized EEV-related activity in noncarriers, contributions of an additional VMPFC pathway best characterized deletion carriers. Thus, common norepinephrine-related neurogenetic differences enhance the subjective vividness of perceptual experience and its emotional enhancement., (Copyright © 2015 the authors 0270-6474/15/356506-11$15.00/0.)
- Published
- 2015
- Full Text
- View/download PDF
39. Deletion variant in the ADRA2B gene increases coupling between emotional responses at encoding and later retrieval of emotional memories.
- Author
-
Todd RM, Müller DJ, Palombo DJ, Robertson A, Eaton T, Freeman N, Levine B, and Anderson AK
- Subjects
- Adolescent, Adult, Female, Gene Deletion, Genetic Variation, Humans, Male, Recognition, Psychology physiology, Young Adult, Emotions physiology, Memory, Episodic, Mental Recall physiology, Receptors, Adrenergic, alpha-2 genetics
- Abstract
A deletion variant of the ADRA2B gene that codes for the α2b adrenoceptor has been linked to greater susceptibility to traumatic memory as well as attentional biases in perceptual encoding of negatively valenced stimuli. The goal of the present study was to examine whether emotional enhancements of memory associated with the ADRA2B deletion variant were predicted by encoding, as indexed by the subjectively perceived emotional salience (i.e., arousal) of events at the time of encoding. Genotyping was performed on 186 healthy young adults who rated positive, negative, and neutral scenes for level of emotional arousal and subsequently performed a surprise recognition memory task 1 week later. Experience of childhood trauma was also measured, as well as additional genetic variations associated with emotional biases and episodic memory. Results showed that subjective arousal was linked to memory accuracy and confidence for ADRA2B deletion carriers but not for non-carriers. Our results suggest that carrying the ADRA2B deletion variant enhances the relationship between arousal at encoding and subsequent memory for moderately arousing events., (Copyright © 2013 Elsevier Inc. All rights reserved.)
- Published
- 2014
- Full Text
- View/download PDF
40. Temporal-spatial neural activation patterns linked to perceptual encoding of emotional salience.
- Author
-
Todd RM, Taylor MJ, Robertson A, Cassel DB, Doesburg SM, Lee DH, Shek PN, and Pang EW
- Subjects
- Adult, Attention, Attentional Blink physiology, Female, Humans, Magnetoencephalography, Male, Young Adult, Emotions physiology
- Abstract
It is well known that we continuously filter incoming sensory information, selectively allocating attention to what is important while suppressing distracting or irrelevant information. Yet questions remain about spatiotemporal patterns of neural processes underlying attentional biases toward emotionally significant aspects of the world. One index of affectively biased attention is an emotional variant of an attentional blink (AB) paradigm, which reveals enhanced perceptual encoding for emotionally salient over neutral stimuli under conditions of limited executive attention. The present study took advantage of the high spatial and temporal resolution of magnetoencephalography (MEG) to investigate neural activation related to emotional and neutral targets in an AB task. MEG data were collected while participants performed a rapid stimulus visual presentation task in which two target stimuli were embedded in a stream of distractor words. The first target (T1) was a number and the second (T2) either an emotionally salient or neutral word. Behavioural results replicated previous findings of greater accuracy for emotionally salient than neutral T2 words. MEG source analyses showed that activation in orbitofrontal cortex, characterized by greater power in the theta and alpha bands, and dorsolateral prefrontal activation were associated with successful perceptual encoding of emotionally salient relative to neutral words. These effects were observed between 250 and 550 ms, latencies associated with discrimination of perceived from unperceived stimuli. These data suggest that important nodes of both emotional salience and frontoparietal executive systems are associated with the emotional modulation of the attentional blink.
- Published
- 2014
- Full Text
- View/download PDF
41. Tuning to the significant: neural and genetic processes underlying affective enhancement of visual perception and memory.
- Author
-
Markovic J, Anderson AK, and Todd RM
- Subjects
- Animals, Attention physiology, Brain physiology, Humans, Models, Biological, Norepinephrine metabolism, Receptors, Adrenergic, alpha-2 metabolism, Emotions physiology, Memory physiology, Receptors, Adrenergic, alpha-2 genetics, Visual Perception genetics
- Abstract
Emotionally arousing events reach awareness more easily and evoke greater visual cortex activation than more mundane events. Recent studies have shown that they are also perceived more vividly and that emotionally enhanced perceptual vividness predicts memory vividness. We propose that affect-biased attention (ABA) - selective attention to emotionally salient events - is an endogenous attentional system tuned by an individual's history of reward and punishment. We present the Biased Attention via Norepinephrine (BANE) model, which unifies genetic, neuromodulatory, neural and behavioural evidence to account for ABA. We review evidence supporting BANE's proposal that a key mechanism of ABA is locus coeruleus-norepinephrine (LC-NE) activity, which interacts with activity in hubs of affective salience networks to modulate visual cortex activation and heighten the subjective vividness of emotionally salient stimuli. We further review literature on biased competition and look at initial evidence for its potential as a neural mechanism behind ABA. We also review evidence supporting the role of the LC-NE system as a driving force of ABA. Finally, we review individual differences in ABA and memory including differences in sensitivity to stimulus category and valence. We focus on differences arising from a variant of the ADRA2b gene, which codes for the alpha2b adrenoreceptor as a way of investigating influences of NE availability on ABA in humans., (Copyright © 2013 Elsevier B.V. All rights reserved.)
- Published
- 2014
- Full Text
- View/download PDF
42. Genes for emotion-enhanced remembering are linked to enhanced perceiving.
- Author
-
Todd RM, Müller DJ, Lee DH, Robertson A, Eaton T, Freeman N, Palombo DJ, Levine B, and Anderson AK
- Subjects
- Adolescent, Adult, Female, Gene Deletion, Heterozygote, Humans, Male, Young Adult, Attentional Blink genetics, Emotions physiology, Individuality, Receptors, Adrenergic, alpha-2 genetics
- Abstract
Emotionally enhanced memory and susceptibility to intrusive memories after trauma have been linked to a deletion variant (i.e., a form of a gene in which certain amino acids are missing) of ADRA2B, the gene encoding subtype B of the α2-adrenergic receptor, which influences norepinephrine activity. We examined in 207 participants whether variations in this gene are responsible for individual differences in affective influences on initial encoding that alter perceptual awareness. We examined the attentional blink, an attentional impairment during rapid serial visual presentation, for negatively arousing, positively arousing, and neutral target words. Overall, the attentional blink was reduced for emotional targets for ADRA2B-deletion carriers and noncarriers alike, which reveals emotional sparing (i.e., reduction of the attentional impairment for words that are emotionally significant). However, deletion carriers demonstrated a further, more pronounced emotional sparing for negative targets. This finding demonstrates a contribution of genetics to individual differences in the emotional subjectivity of perception, which in turn may be linked to biases in later memory.
- Published
- 2013
- Full Text
- View/download PDF
43. KIBRA polymorphism is associated with individual differences in hippocampal subregions: evidence from anatomical segmentation using high-resolution MRI.
- Author
-
Palombo DJ, Amaral RS, Olsen RK, Müller DJ, Todd RM, Anderson AK, and Levine B
- Subjects
- Adolescent, Adult, Case-Control Studies, Female, Gene Frequency, Genetic Association Studies, Genotype, Humans, Image Processing, Computer-Assisted, Magnetic Resonance Imaging, Male, Reproducibility of Results, Young Adult, Hippocampus anatomy & histology, Individuality, Intracellular Signaling Peptides and Proteins genetics, Phosphoproteins genetics, Polymorphism, Genetic genetics
- Abstract
The KIBRA gene has been associated with episodic memory in several recent reports; carriers of the T-allele show enhanced episodic memory performance relative to noncarriers. Gene expression studies in human and rodent species show high levels of KIBRA in the hippocampus, particularly in the subfields. The goal of the present study was to determine whether the KIBRA C→T polymorphism is also associated with volume differences in the human hippocampus and whether specific subfields are differentially affected by KIBRA genotype. High-resolution magnetic resonance imaging (T2-weighted, voxel size=0.4×0.4 mm, in-plane) was used to manually segment hippocampal cornu ammonis (CA) subfields, dentate gyrus (DG), and the subiculum as well as adjacent medial temporal lobe cortices in healthy carriers and noncarriers of the KIBRA T-allele (rs17070145). Overall, we found that T-carriers had a larger hippocampal volume relative to noncarriers. The structural differences observed were specific to the CA fields and DG regions of the hippocampus, suggesting a potential neural mechanism for the effects of KIBRA on episodic memory performance reported previously.
- Published
- 2013
- Full Text
- View/download PDF
44. Shared neural substrates of emotionally enhanced perceptual and mnemonic vividness.
- Author
-
Todd RM, Schmitz TW, Susskind J, and Anderson AK
- Abstract
It is well-known that emotionally salient events are remembered more vividly than mundane ones. Our recent research has demonstrated that such memory vividness (Mviv) is due in part to the subjective experience of emotional events as more perceptually vivid, an effect we call emotionally enhanced vividness (EEV). The present study built on previously reported research in which fMRI data were collected while participants rated relative levels of visual noise overlaid on emotionally salient and neutral images. Ratings of greater EEV were associated with greater activation in the amygdala and visual cortex. In the present study, we measured BOLD activation that predicted recognition Mviv for these same images 1 week later. Results showed that, after controlling for differences between scenes in low-level objective features, hippocampus activation uniquely predicted subsequent Mviv. In contrast, amygdala and visual cortex regions that were sensitive to EEV were also modulated by subsequent ratings of Mviv. These findings suggest shared neural substrates for the influence of emotional salience on perceptual and mnemonic vividness, with amygdala and visual cortex activation at encoding contributing to the experience of both perception and subsequent memory.
- Published
- 2013
- Full Text
- View/download PDF
45. Affective salience can reverse the effects of stimulus-driven salience on eye movements in complex scenes.
- Author
-
Niu Y, Todd RM, and Anderson AK
- Abstract
In natural vision both stimulus features and cognitive/affective factors influence an observer's attention. However, the relationship between stimulus-driven ("bottom-up") and cognitive/affective ("top-down") factors remains controversial: Can affective salience counteract strong visual stimulus signals and shift attention allocation irrespective of bottom-up features? Is there any difference between negative and positive scenes in terms of their influence on attention deployment? Here we examined the impact of affective factors on eye movement behavior, to understand the competition between visual stimulus-driven salience and affective salience and how they affect gaze allocation in complex scene viewing. Building on our previous research, we compared predictions generated by a visual salience model with measures indexing participant-identified emotionally meaningful regions of each image. To examine how eye movement behavior differs for negative, positive, and neutral scenes, we examined the influence of affective salience in capturing attention according to emotional valence. Taken together, our results show that affective salience can override stimulus-driven salience and overall emotional valence can determine attention allocation in complex scenes. These findings are consistent with the hypothesis that cognitive/affective factors play a dominant role in active gaze control.
- Published
- 2012
- Full Text
- View/download PDF
46. Psychophysical and neural evidence for emotion-enhanced perceptual vividness.
- Author
-
Todd RM, Talmi D, Schmitz TW, Susskind J, and Anderson AK
- Subjects
- Adolescent, Adult, Analysis of Variance, Brain blood supply, Cues, Electroencephalography, Evoked Potentials, Visual physiology, Eye Movements physiology, Female, Humans, Image Processing, Computer-Assisted, Magnetic Resonance Imaging, Male, Mental Recall, Noise, Oxygen blood, Photic Stimulation, Psychophysics, Time Factors, Young Adult, Attention physiology, Brain physiology, Brain Mapping, Emotions physiology, Recognition, Psychology physiology, Visual Perception physiology
- Abstract
Highly emotional events are associated with vivid "flashbulb" memories. Here we examine whether the flashbulb metaphor characterizes a previously unknown emotion-enhanced vividness (EEV) during initial perceptual experience. Using a magnitude estimation procedure, human observers estimated the relative magnitude of visual noise overlaid on scenes. After controlling for computational metrics of objective visual salience, emotional salience was associated with decreased noise, or heightened perceptual vividness, demonstrating EEV, which predicted later memory vividness. Event-related potentials revealed a posterior P2 component at ∼200 ms that was associated with both increased emotional salience and decreased objective noise levels, consistent with EEV. Blood oxygenation level-dependent response in the lateral occipital complex (LOC), insula, and amygdala predicted online EEV. The LOC and insula represented complimentary influences on EEV, with the amygdala statistically mediating both. These findings indicate that the metaphorical vivid light surrounding emotional memories is embodied directly in perceptual cortices during initial experience, supported by cortico-limbic interactions.
- Published
- 2012
- Full Text
- View/download PDF
47. Affect-biased attention as emotion regulation.
- Author
-
Todd RM, Cunningham WA, Anderson AK, and Thompson E
- Subjects
- Brain Mapping, Humans, Individuality, Models, Neurological, Affect physiology, Amygdala physiology, Attention physiology, Emotions physiology
- Abstract
The affective biasing of attention is not typically considered to be a form of emotion regulation. In this article, we argue that 'affect-biased attention' - the predisposition to attend to certain categories of affectively salient stimuli over others - provides an important component of emotion regulation. Affect-biased attention regulates subsequent emotional responses by tuning one's filters for initial attention and subsequent processing. By reviewing parallel research in the fields of emotion regulation and affect-biased attention, as well as clinical and developmental research on individual differences in attentional biases, we provide convergent evidence that habitual affective filtering processes, tuned and re-tuned over development and situation, modulate emotional responses to the world. Moreover, they do so in a manner that is proactive rather than reactive., (Copyright © 2012 Elsevier Ltd. All rights reserved.)
- Published
- 2012
- Full Text
- View/download PDF
48. Withholding response in the face of a smile: age-related differences in prefrontal sensitivity to Nogo cues following happy and angry faces.
- Author
-
Todd RM, Lee W, Evans JW, Lewis MD, and Taylor MJ
- Subjects
- Adolescent, Adult, Age Factors, Analysis of Variance, Anger, Child, Child, Preschool, Cues, Discrimination, Psychological physiology, Face, Female, Happiness, Humans, Magnetic Resonance Imaging, Male, Photic Stimulation, Prefrontal Cortex growth & development, Psychomotor Performance physiology, Reaction Time, Smiling psychology, Young Adult, Aging physiology, Emotions physiology, Facial Expression, Human Development physiology, Prefrontal Cortex physiology
- Abstract
The modulation of control processes by stimulus salience, as well as associated neural activation, changes over development. We investigated age-related differences in the influence of facial emotion on brain activation when an action had to be withheld, focusing on a developmental period characterized by rapid social-emotional and cognitive change. Groups of kindergarten and young school-aged children and a group of young adults performed a modified Go/Nogo task. Response cues were preceded by happy or angry faces. After controlling for task performance, left orbitofrontal regions discriminated trials with happy vs. angry faces in children but not in adults when a response was withheld, and this effect decreased parametrically with age group. Age-related changes in prefrontal responsiveness to facial expression were not observed when an action was required, nor did this region show age-related activation changes with the demand to withhold a response in general. Such results reveal age-related differences in prefrontal activation that are specific to stimulus valence and depend on the action required., (Copyright © 2012 Elsevier Ltd. All rights reserved.)
- Published
- 2012
- Full Text
- View/download PDF
49. Genetic differences in emotionally enhanced memory.
- Author
-
Todd RM, Palombo DJ, Levine B, and Anderson AK
- Subjects
- Humans, Models, Neurological, Nerve Tissue Proteins physiology, Polymorphism, Genetic, Amygdala physiology, Emotions physiology, Memory physiology, Mental Processes physiology, Nerve Tissue Proteins genetics
- Abstract
Understanding genetic contributions to individual differences in the capacity for emotional memory has tremendous implications for understanding normal human memory as well as pathological reactions to traumatic stress. Research in the last decade has identified genetic polymorphisms thought to influence cognitive/affective processes that may contribute to emotional memory capacity. In this paper, we review key polymorphisms linked to emotional and mnemonic processing and their influence on neuromodulator activity in the amygdala and other emotion-related structures. We discuss their potential roles in specific cognitive processes involved in memory formation, and review links between these genetic variants, brain activation, and specific patterns of attention, perception, and memory consolidation that may be linked to individual differences in memory vividness. Finally we propose a model predicting an influence of noradrenergic, serotonergic, and dopaminergic processes on emotional perception, as well as on memory consolidation and self-regulation. Outside of the laboratory, it is likely that real-life effects of arousal operate along a continuum that incorporates other "non-emotional" aspects of memory. For this reason we further discuss additional literature on genetic variations that influence general episodic memory processes, rather than being specific to emotional enhancement of memory. We conclude that specific neuromodulators contribute to an amygdala-driven memory system that is relatively involuntary, embodied, and sensorily vivid., (Copyright © 2010 Elsevier Ltd. All rights reserved.)
- Published
- 2011
- Full Text
- View/download PDF
50. The changing face of emotion: age-related patterns of amygdala activation to salient faces.
- Author
-
Todd RM, Evans JW, Morris D, Lewis MD, and Taylor MJ
- Subjects
- Adolescent, Adult, Amygdala blood supply, Analysis of Variance, Brain Mapping, Child, Child, Preschool, Facial Expression, Female, Humans, Image Processing, Computer-Assisted, Magnetic Resonance Imaging, Male, Motion, Oxygen blood, Photic Stimulation, Recognition, Psychology, Young Adult, Aging, Amygdala physiology, Emotions physiology, Face, Pattern Recognition, Visual physiology
- Abstract
The present study investigated age-related differences in the amygdala and other nodes of face-processing networks in response to facial expression and familiarity. fMRI data were analyzed from 31 children (3.5-8.5 years) and 14 young adults (18-33 years) who viewed pictures of familiar (mothers) and unfamiliar emotional faces. Results showed that amygdala activation for faces over a scrambled image baseline increased with age. Children, but not adults, showed greater amygdala activation to happy than angry faces; in addition, amygdala activation for angry faces increased with age. In keeping with growing evidence of a positivity bias in young children, our data suggest that children find happy faces to be more salient or meaningful than angry faces. Both children and adults showed preferential activation to mothers' over strangers' faces in a region of rostral anterior cingulate cortex associated with self-evaluation, suggesting that some nodes in frontal evaluative networks are active early in development. This study presents novel data on neural correlates of face processing in childhood and indicates that preferential amygdala activation for emotional expressions changes with age.
- Published
- 2011
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.