Search

Most neuropsychological assessments of episodic memory bear little similarity to the events that patients actually experience as memories in daily life. The first aim of this study was to use a virtual environment to characterize episodic memory profiles in an ecological fashion, which includes memory for central and perceptual details, spatiotemporal contextual elements, and binding. This study included subjects from three different populations: healthy older adults, patients with amnestic mild cognitive impairment (aMCI) and patients with early to moderate Alzheimer's disease (AD). Second, we sought to determine whether environmental factors that can affect encoding (active vs. passive exploration) influence memory performance in pathological aging. Third, we benchmarked the results of our virtual reality episodic memory test against a classical memory test and a subjective daily memory complaint scale. Here, the participants were successively immersed in two virtual environments; the first, as the driver of a virtual car (active exploration) and the second, as the passenger of that car (passive exploration). Subjects were instructed to encode all elements of the environment as well as the associated spatiotemporal contexts. Following each immersion, we assessed the patient's recall and recognition of central information (i.e., the elements of the environment), contextual information (i.e., temporal, egocentric and allocentric spatial information) and lastly, the quality of binding. We found that the AD patients' performances were inferior to that of the aMCI and even more to that of the healthy aged groups, in line with the progression of hippocampal atrophy reported in the literature. Spatial allocentric memory assessments were found to be particularly useful for distinguishing aMCI patients from healthy older adults. Active exploration yielded enhanced recall of central and allocentric spatial information, as well as binding in all groups. This led aMCI patients to achieve better performance scores on immediate temporal memory tasks. Finally, the patients' daily memory complaints were more highly correlated with the performances on the virtual test than with their performances on the classical memory test. Taken together, these results highlight specific cognitive differences found between these three populations that may provide additional insight into the early diagnosis and rehabilitation of pathological aging. In particular, neuropsychological studies would benefit to use virtual tests and a multi-component approach to assess episodic memory, and encourage active encoding of information in patients suffering from mild or severe age-related memory impairment. The beneficial effect of active encoding on episodic memory in aMCI and early to moderate AD is discussed in the context of relatively preserved frontal and motor brain functions implicated in self-referential effects and procedural abilities. (Contains 5 figures and 3 tables.)

Despite the growing interest in the study of attentional refreshing, the functioning of this working memory maintenance mechanism, including its cerebral underpinnings, is still debated. In particular, it remains unclear whether refreshing promotes long-term memory and whether it, in return, depends on long-term memory content to operate. Here, we used direct maintenance instructions and measured brain activity to investigate working memory maintenance with two objectives: (1) test if different behavioral and oscillatory patterns could be observed when participants were instructed to use attentional refreshing versus verbal rehearsal, and (2) observe whether and how refreshing is modulated when maintaining novel (pseudowords) versus familiar (words) memoranda. We conducted an EEG experiment using a modified Brown-Peterson task, in which we manipulated the type of maintenance engaged through explicit instructions (verbal rehearsal vs. refreshing), the type of memoranda (words vs. pseudowords), and the memory load (2 vs. 6). Using scalp EEG, we measured both neural oscillations during working memory maintenance and ERPs during the concurrent parity judgment task. For words, we showed that verbal rehearsal benefited more short-term recall whereas refreshing benefited more delayed recall. In keeping with these behavioral differences between maintenance instructions, frontal-midline theta power increased with memory load only when using verbal rehearsal, whereas occipito-parietal alpha desynchronization was larger with refreshing than verbal rehearsal. When maintaining pseudowords, verbal rehearsal also benefitted short-term recall more than refreshing. However, no long-term memory benefit of refreshing was observed for pseudowords, and oscillatory activity was not different under the two maintenance instructions. Our results provide new evidence supporting the independence between attentional refreshing and verbal rehearsal, and bring new insight into refreshing functioning. We discuss the possible interpretations of these results and the implications for the attentional refreshing literature., (© 2024 Massachusetts Institute of Technology.)

Emotions are known to influence cognitive performance, particularly working memory (WM) in both its aspects, processing, and maintenance. One explanatory mechanism might be that negative stimuli capture attentional resources, leaving fewer resources for attentional maintenance and processing of information in WM. However, this attentional capture was only investigated using WM tasks in which participants were explicitly asked to process negative items. The aim of this paper was to determine whether explicit processing of emotional stimuli is necessary to impair WM performance, or if their mere presence is enough to capture attention. For this purpose, participants performed a complex span task in which they alternated between memorizing a series of neutral words and processing either emotional images or neutral ones. In Experiment 1, participants were instructed to explicitly process emotional images, whereas in Experiment 2, emotional images were presented without any processing being required. In both experiments, we observed a decrease in memory performance when the images were negative compared to neutral. Whether or not voluntary processing is involved, emotional images seem to capture attentional resources, which in turn leads to a decline in memory performance. These results were discussed in relation to attentional theories and the influence of emotion on the specific mechanisms of WM., (© 2024. The Psychonomic Society, Inc.)

The causes of forgetting in working memory (WM) remain a source of debate in cognitive psychology, partly because it has always been challenging to probe the complex neural mechanisms that govern rapid cognitive processes in humans. In this review, we argue that neural, and more precisely animal models, provide valuable tools for exploring the precise mechanisms of WM forgetting. First, we discuss theoretical perspectives concerning WM forgetting in humans. Then, we present neuronal correlates of WM in animals, starting from the initial evidence of delay activity observed in the prefrontal cortex to the later synaptic theory of WM. In the third part, specific theories of WM are discussed, including the notion that silent versus non-silent activity is more consistent with the processes of refreshing and decay proposed in human cognitive models. The review concludes with an exploration of the relationship between long-term memory and WM, revealing connections between these two forms of memory through the long-term synaptic hypothesis, which suggests that long-term storage of interference can potentially disrupt WM., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The ability of the brain to extract patterns from the environment and predict future events, known as statistical learning, has been proposed to interact in a competitive manner with prefrontal lobe-related networks and their characteristic cognitive or executive functions. However, it remains unclear whether these cognitive functions also possess a competitive relationship with implicit statistical learning across individuals and at the level of latent executive function components. In order to address this currently unknown aspect, we investigated, in two independent experiments (N Study1  = 186, N Study2  = 157), the relationship between implicit statistical learning, measured by the Alternating Serial Reaction Time task, and executive functions, measured by multiple neuropsychological tests. In both studies, a modest, but consistent negative correlation between implicit statistical learning and most executive function measures was observed. Factor analysis further revealed that a factor representing verbal fluency and complex working memory seemed to drive these negative correlations. Thus, the antagonistic relationship between implicit statistical learning and executive functions might specifically be mediated by the updating component of executive functions or/and long-term memory access., (© 2024. The Author(s).)

Previous studies found that working memory maintenance contributes to long-term memory formation, and some evidence suggests that this effect could be larger when individuals are informed of the final long-term memory test. However, no study so far has explored whether and how working memory maintenance adapts when long-term retention is intentional. In this study, we conducted two experiments using verbal complex span tasks followed by delayed-recall tests. In both experiments, we evaluated working memory maintenance by varying the cognitive load of the concurrent task and with memory strategies reports. We manipulated intentions to remember at long term by warning participants of the final delayed recall or not (Experiment 1) or by monetarily rewarding immediate or delayed-recall performance (Experiment 2). We found no evidence that intentions changed the working memory maintenance mechanisms and strategies used, yet the cognitive load (Experiment 1) and rewards (Experiment 2) effects on delayed recalls were increased with a higher intention to remember at long term. We discuss possible interpretations for these results and suggest that the effect of intentions may not be due to a change in the kind of maintenance mechanisms used. As our results cannot be explained solely by encoding or maintenance processes, we instead propose that intentions produce a combined change in encoding and maintenance. However, the exact nature of this modulation will need further investigation. We conclude that understanding how intentions modulate the effect of working memory on long-term memory could shed new light on their relationship., (© 2023. The Psychonomic Society, Inc.)

Among other bodily signals, the perception of sensations arising spontaneously on the skin with no external triggers contributes to body awareness. The topic of spontaneous sensations (SPS) being quite recent in the literature, there is still a debate whether this phenomenon is elicited by peripheral cutaneous units' activity underlying tactile perception or originates directly from central mechanisms. In a first experiment, we figured that, if SPS depended on peripheral afferents, their perception on the glabrous hand should relate to the hand tactile sensitivity. On the contrary, we found no relationship at all, which led us to envisage the scenario of SPS in the absence of cutaneous units. In a second experiment, we present the case of Julie, a right-hand amputee that could perceive and report SPS arising on her phantom limb syndrome. We found that SPS distribution on the phantom limb followed the same gradient as that observed in control participants, unlike SPS perceived on the intact left hand. Those findings are crucial to the understanding of neural factors determining body awareness through SPS perception and provide insights into the existence of a precise neural gradient underlying somesthesis., 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 © 2024 Elsevier Inc. All rights reserved.)

Previous research has shown that working memory processes are affected by emotions. However, it is not clear if both components - maintenance and processing of information - are modulated by emotion. Since emotion is intimately related to attention, we focused on attentional maintenance in working memory. In a previous study, using a complex span task, we showed that processing emotionally negative information reduced maintenance of neutral information in working memory. The objective of the present study was first to replicate the results of our previous study and second to investigate whether maintaining emotional information would affect processing of neutral information. In Experiment 1, young adults were asked to remember a series of five letters each followed by images, either negative or neutral, to be categorized. In Experiment 2, participants were required to memorize a series of five images, either negative or neutral, each followed by digits to be categorized. In order to focus on attentional maintenance, in both experiments the tasks were performed under continuous articulatory suppression. In Experiment 1, longer processing times were observed for emotional stimuli than neutral ones, and lower recall of series of letters when negative stimuli were processed. In Experiment 2, higher memory performance was observed for negative images than neutral ones and longer processing times of digits when a series of negative stimuli was maintained. Overall, our results show that emotion impacts both processing and attentional maintenance in working memory. This is consistent with models of working memory suggesting an attentional trade-off between maintenance and processing., (© 2023. The Psychonomic Society, Inc.)

Stroke is the main cause of acquired disability in adults, and specific deficits in working memory (WM) are among the most common cognitive consequences. In neuropsychological routine, WM is most of the time investigated in the framework of the multicomponent model (Baddeley & Hitch, 1974, The psychology of learning and motivation, 47). Using a more recent theoretical WM model, the time-based resource-sharing (TBRS) model (Barrouillet et al., 2011, Psychol. Rev., 118, 175), the aim of the present study was to investigate in young post-stroke patients to which extent attentional maintenance is impaired in WM. To address this question, we discarded other factors known to directly influence WM performance, that is processing speed and short-term memory span. We proposed to 53 post-stroke patients and to 63 healthy controls a complex span paradigm in which participants were asked to alternate between the memorization of a series of images and a concurrent parity judgement task of a series of digits. To investigate the attentional maintenance processes, we manipulated the cognitive load (CL) of the concurrent task. CL effect is typically interpreted as the involvement of attentional maintenance processes. The task was adapted to each participant according to their processing speed and memory span. As expected, the results showed higher recall performance in healthy controls compared with post-stroke patients. Consistent with the literature, we also observed higher performance when the CL was low compared with high. However, the improvement in recall at low CL was smaller for post-stroke patients compared with controls, suggesting that post-stroke WM deficit could be in part due to a deficit of the attentional maintenance processes., (© 2022 The British Psychological Society.)

Contradictory results in the literature suggest that attentional refreshing can seemingly not operate efficiently in the absence of semantic representations, while at the same time it does not rely directly on retrieval from semantic memory. The objective of the present study was a better understanding of the bidirectional links between working memory (WM) and long-term memory (LTM), by assessing on the one hand the role of WM mechanisms in long-term recall and on the other hand how their functioning is modulated by the prior LTM content. Through two experiments, we investigated a new hypothesis: attentional refreshing requires stable WM representations independently of the presence or the absence of associated LTM traces. We manipulated this stability through short-term consolidation (Experiment 1) and multiple presentations of memoranda (Experiment 2) to evaluate how it would affect maintenance of words and pseudowords. While we found that lexicality, short-term consolidation and multiple presentations affected short-term and long-term recall, both experiments converged on the conclusion that none of these factors modulated the effect of the cognitive load of the concurrent processing task, suggesting that refreshing does not depend on LTM content nor WM representations' stability. Additionally, we found that delayed recall performance was not affected by the cognitive load, in contradiction with previous literature. These results provide new insight into the functioning of refreshing and the links between WM and LTM., Competing Interests: The authors have no competing interests to declare., (Copyright: © 2023 The Author(s).)

Body awareness may arise in the total absence of sensory input, as suggested by the spontaneous occurrence of normal and pathological (i.e., hallucinatory) bodily sensations. These phenomena may arise due to back-projections from higher-order cortical areas to the primary (SI) and secondary (SII) somatosensory cortices, and would appear to be reflected in cortical oscillatory activity in both SI and SII. Here, we set to investigate the relationship of SI and SII in SPS. Healthy participants underwent an EEG recording session at rest, and then completed an experiment on the perception of spontaneous sensations occurring on the hands. Cortical oscillatory activity was extracted from specified ROIs in the somatosensory cortices. The findings showed that (i) SPS perceived in the fingers correlated positively with alpha-band oscillations recorded in SI, and that (ii) SPS perceived in the palm correlated positively with gamma-band oscillations and negatively with beta-band oscillations recorded in SII. Apart from supporting the idea that the somatosensory cortices are involved in bodily awareness even in the absence of sensory input, these findings also suggest that default oscillatory activity in the somatosensory cortices reflects individual differences in bodily awareness. The results are interpreted in terms of neural and cognitive processes that may give rise to bodily awareness and modulate it, and their importance in understanding body perception distortions and bodily delusions and hallucinations is discussed., (Copyright © 2022 Elsevier B.V. All rights reserved.)

A regular rhythmic stimulation increases people's ability to anticipate future events in time and to move their body in space. Temporal concepts are usually prescribed to spatial locations through a past-behind and future-ahead mapping. In this study, we tested the hypothesis that a regular rhythmic stimulation could promote the forward-body (i.e., toward the future) projections in the peri-personal space. In a Visual Approach/Avoidance by the Self Task (VAAST), participants ( N = 24) observed a visual scene on the screen (i.e., a music studio with a metronome in the middle). They were exposed to 3 s of auditory isochronous or non-isochronous rhythms, after which they were asked to make as quickly as possible a perceptual judgment on the visual scene (i.e., whether the metronome pendulum was pointing to the right or left). The responses could trigger a forward or backward visual flow, i.e., approaching or moving them away from the scene. Results showed a significant interaction between the rhythmic stimulation and the movement projections ( p < 0.001): participants were faster for responses triggering forward-body projections (but not backward-body projections) after the exposure to isochronous (but not non-isochronous) rhythm. By highlighting the strong link between isochronous rhythms and forward-body projections, these findings support the idea that temporal predictions driven by a regular auditory stimulation are grounded in a perception-action system integrating temporal and spatial information., 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 © 2022 Ferreri, Versace, Victor and Plancher.)

Aim: Body awareness arises when attending to and maintaining awareness of visuospatial body representations. By the same token, focussing on representations transfers them to working memory. Body awareness and working memory seemingly rely on similar processes and recruit common parietal areas involved in perception. Therefore, we asked whether visuospatial working memory abilities would define individual differences in the perception of spontaneous sensations (SPS), i.e., bodily sensations perceived in the absence of triggers (e.g., tactile stimulation or movement), when attending to the body. Method: Participants completed two visuospatial working memory tasks to assess various mechanisms: (i) the decay of representations was assessed through a Brown-Peterson task in which the delay between the memorandum presentation and its recall was manipulated, and (ii) the impact of distractors' interference and cognitive load (i.e., complexity) on recall performances were assessed through a complex span task that required the processing of distractors while maintaining a memorandum. A standard SPS task involving localization and characterization of SPS perceived on the hands was completed afterwards. Results: Low performance due to decay, distractors' interference and cognitive load in visuospatial working memory was associated with a decrease in the frequency of SPS. Additionally, low performance due to distractors' cognitive load predicted a decrease in the perception of surface-type sensations, and high performance despite distractors' interference led to a better perception of SPS on less sensitive areas of the hand. Conclusion: We discuss how visuospatial working memory processes might contribute to body awareness and perceptual distortions of the body.

The temporoparietal junction (TPJ), along with the anterior insula (AI) and the extrastriate body area (EBA), play a major part in embodiment and self-awareness. However, these connections also appear to be frequently engaged in arousal and attentional processing of external events. Considering that these networks may focus attention both toward and away from the self, we set to investigate how they contribute to the perception of spontaneous sensations (SPS), a common phenomenon related to self-awareness and mediated by both interoceptive and attentional processes. In Experiment 1, resting-state EEG was recorded, as well as arousal reported via a questionnaire, followed by a SPS task. Functional TPJ-AI and TPJ-EBA connectivity were computed using eLORETA. Spatial correlational analyses showed that less frequent SPS coincided with greater TPJ-AI and TPJ-EBA functional connectivity, especially in the theta and alpha frequency bands. High self-reported arousal predicted low intensity and low confidence in the location of SPS. Resting-state skin conductance level (SCL) was recorded in Experiment 2, followed by the SPS task. Less frequent SPS coincided with greater SCL. Findings are interpreted in terms of attention and self-related processes, and a discussion of the TPJ participation in self-awareness through SPS is presented., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Background/study Context: Recent research has shown a benefit of temporally regular structure presented during the maintenance period in short-term memory for young adults. Because maintenance is impaired in aging, we investigated whether older adults can also benefit from the temporal regularities for maintenance and how their cognitive capacities might affect this potential benefit., Methods: Healthy older adults (range: 63-90 years old) had to memorize visually presented letters and maintain them in short-term memory for 6 s until recall. The six-second retention interval was either filled with an isochronous rhythmic sound sequence that provided a temporally regular structure or silent., Results: The effect of the isochronous rhythm on recall performance was modulated by inhibition capacities of older adults: as compared to silence, improved recall performance thanks to the rhythm emerged with increased inhibitory capacity of the participants., Conclusion: Even though maintenance of older adults benefits less from the presence of temporal regularities than does the maintenance of younger ones, our findings provide evidence for improved maintenance in short-term memory for older adults in the presence of a temporally regular structure, probably due to enhanced attentional refreshing. It further provides perspectives for training and rehabilitation of age-related working memory deficits.

Abstract . A large literature suggests that the way we process information is influenced by the categories that we have learned. We examined whether, when we try to uniquely encode items in working memory, the information encoded depends on the other stimuli being simultaneously learned. Participants were required to memorize unknown aliens, presented one at the time, for immediate recognition of their features. Some aliens, called twins, were organized into pairs that shared every feature (nondiscriminative feature) except one (discriminative feature), while some other aliens, called hermits, did not share feature. We reasoned that if people develop unsupervised categories by creating a category for a pair of aliens, we should observe better feature identification performance for nondiscriminative features compared to hermit features, but not compared to discriminative features. On the contrary, if distinguishing features draw attention, we should observe better performance when a discriminative rather than nondiscriminative feature was probed. Overall, our results suggest that when items share features, people code items in working memory by focusing on similarities between items, establishing clusters of items in an unsupervised fashion not requiring feedback on cluster membership.

The model developed by Atkinson and Shiffrin describes memory as a flow of information that enters and leaves a short-term storage and that in some cases consolidates into a long-term store. Their model has stimulated 50 years of memory research and, like every model, has also received several criticisms. It has been argued that a single short-term store in charge of both maintaining memory items and processing other cognitive tasks is not plausible. Some authors have evaluated the proposal of a rehearsal process as the unique way to transfer information into long-term memory as not being likely. Finally, the idea that information decays from the short-term store in the absence of rehearsal maintaining the memory traces has been and is still debated in the working memory literature. In this article, we reconsider these criticisms and show why they are not totally legitimate. We describe a recent working memory model, the time-based resource-sharing (TBRS) model (Barrouillet, P., & Camos, V. (2015). Working memory: Loss and reconstruction. Hove, UK: Psychology Press), that shares several theoretical assumptions with the model initially proposed by Atkinson and Shiffrin, assumptions supported by empirical findings. Consequently, the model proposed by Atkinson and Shiffrin in 1968 may be far from outdated and still provide an inspiring framework for memory study.

Antiepileptic drugs impair episodic memory in patients with epilepsy, but this effect has so far only been examined with tests that do not provide first-person experience-an aspect that is crucial for episodic memory. Virtual reality techniques facilitate the development of ecologically valid tests. In the present study, we measure the effect of antiepileptic drug changes in a within-subject design using a virtual reality test in order to provide direct evidence for effects of antiepileptic drugs on episodic memory. Among 106 recruited patients, 97 participated in a virtual reality test up to six times during a 4-day hospitalization, and 78 patients underwent changes in drug load during this period. There were six parallel versions of a virtual town test, with immediate recall and delayed recall after about 12 h. The test requires recall of elements, details, sequence of experience, and egocentric and allocentric spatial memory. We determined drug load by defined daily dose, and compared test performance at lowest antiepileptic drug load to highest antiepileptic drug load. Across the six towns, performance was lower in delayed compared to immediate recall. There was an overall effect of medication when comparing patients taking vs. not taking antiepileptic drugs and/or psychoactive drugs ( p = 0.005). Furthermore, there was a within-subject effect of antiepileptic drug load ( p = 0.01), indicating lower test performance at higher drug load. There was no effect of gender, daytime, circadian type, depression, seizures, lesions, and epilepsy. For patients with temporal lobe epilepsy, there was no effect of lateralization. The present study provides direct evidence for episodic memory impairment due to antiepileptic drugs, suggesting that a small change in drug load can matter. This study can serve as a proof of principle for the methodology, but a larger sample is needed to examine the differential effects of individual antiepileptic drugs., (Copyright © 2020 Höller, Höhn, Schwimmbeck, Plancher and Trinka.)

In the epilepsy monitoring unit of the Department of Neurology at the University Clinic of Salzburg 20 adult patients were recruited to participate in a validation of 6 parallel versions of the virtual reality test for episodic memory. Patients were tested up to 7 times, i.e. twice a day, in the morning and evening, beginning on Monday evening. Each session consisted of learning a new town and immediate recall for this town. All sessions but the first one included also delayed recall of the previously learned town and a recognition test. Recall included the sub-scales what, details, when, egocentric where and allocentric where. Recognition memory was tested by presenting the patients 30 sentences of which 15 were true and 15 were false. While not all patients completed the full testing schedule, at immediate recall for 9 patients a full data set (7 sessions) is available. All patients were free of antiepileptic medication (N = 19) or medication was kept constant across the week (N = 1). This data can be used to demonstrate the feasibility to use the virtual reality test in the epilepsy monitoring unit e.g. to monitor effects of seizures or medication on episodic memory., (© 2020 The Author(s).)

Previous research has shown that emotional stimuli may interfere with working memory (WM) processes, but little is known about the process affected. Using a complex span task, the present study investigated the influence of processing negative emotional content on attentional maintenance in WM. In two experiments conducted under articulatory suppression, participants were asked to remember a series of five letters, each of which was followed by an image to be categorised. In half of the trials, the images were negative and in the other half, they were neutral. In both experiments, our results showed longer processing times for emotional stimuli than neutral stimuli, and lower memory performance when participants processed negative stimuli. We propose that emotional stimuli direct more attentional resources towards the processing component of the WM task, thereby reducing the storage capacity available for the items that are to be remembered.

In the present study, we used a complex span task to explore how memory traces resulting from Self-Performed Task (SPT) and Verbal Task (VT) are maintained in working memory. Participants memorised series of five sentences describing an action either through SPT or VT. Between pairs of sentences, participants performed a concurrent task that varied according to its nature and its cognitive load. The concurrent task was either a verbal task, a low cognitive load motor task or a high cognitive load motor task. A control condition served as a baseline. First, we observed that performance in SPT and VT did not decrease with verbal or motor suppression, but was lower with an increase of the cognitive load. This suggests that memory traces are maintained through attentional refreshing whatever the encoding (SPT or VT). Second, while the enactment effect was replicated in the control condition, it tended to vanish with a verbal concurrent task; moreover, it was reversed with motor concurrent tasks. Surprisingly, the latter effect resulted from an increase of VT memory performance when participants repeated the same gesture between sentences. Finally, our results provide additional evidence that the enactment effect does not rely on attention.

Bloodless pediatric cardiac surgery is the intent of most surgical centers especially in the Jehovah's Witness population where it is a desire not to administer blood products because of religious belief. It is a tremendous feat, considering that most pediatric cardiovascular prime volumes are more than 20% of the patient's estimated blood volume (EBV). We report on our bloodless strategy for a 2-year old Jehovah's Witness with trisomy 21 and complete atrioventricular canal repair, who underwent atrial septal defect and ventricular septal defect patch closure, pulmonary artery debanding, and pulmonary arterioplasty. We modified our circuit to reduce our prime volume to approximately 10% of the EBV and removed 200 mL of the patient's blood before surgery as acute normovolemic hemodilution. We did not alter our institutional standards for transfusion of blood and blood products. The post cardiopulmonary bypass (CPB) hematocrit was 30%. We conclude that bloodless CPB surgery can be performed safely in Jehovah's Witness patients with a carefully planned interdisciplinary approach.

To prevent forgetting in working memory, the attentional refreshing is supposed to increase the level of activation of memory traces by focusing attention. However, the involvement of memory traces reactivation in refreshing relies in the majority on indirect evidence. The aim of this study was to show that refreshing relies on the reactivation of memory traces by investigating how the reactivation of an irrelevant trace prevents the attentional refreshing to take place, and (2) the memory traces reactivated are sensorial in nature. We used a reactivated visual mask presented during the encoding (Experiment 1) and the refreshing (Experiment 2) of pictures in a complex span task. Results showed impaired serial recall performance in both experiments when the mask was reactivated compared to a control stimulus. Experiment 3 confirmed the refreshing account of these results. We proposed that refreshing relies on the reactivation of sensory memory traces.

The present study investigated the time course of refreshing in young and old adults by analyzing the influence of memory load on response times for the processing of concurrent information. One to five squares sequentially displayed in random locations had to be memorized. Before the serial recall of the squares' locations, participants performed self-paced parity judgments on sequentially presented numbers. Trials without squares-not requiring memorization, but only parity judgments-constituted the control condition. Response times of parity judgments were separated for responses to the first digit and for responses to subsequent digits. In young adults, the results provided evidence for consolidation and refreshing, namely, the linear increase of first and subsequent response times with memory load. For old adults, a different pattern emerged: (1) the mean response time for the first digit processing was longer with memorization than without, probably reflecting task-switching rather than consolidation; and (2) in contrast to young adults, memory load did not affect subsequent response times, suggesting a deficit in the initiation of refreshing. Overall, findings support the hypothesis of impaired refreshing in aging., (© 2018 New York Academy of Sciences.)

Understanding the factors that make working memory (WM) traces stable over time is important because WM is the keystone of general cognitive achievement. Two views of attentional WM maintenance have been suggested to account for the long-term retention of WM information. First, the distractors in a WM task are thought to foster the creation of episodic memory cues through covert retrieval. Second, the cognitive load (CL) of the distractors is thought to vary long-term memory instantiation. In this study, we propose an additional parsimonious perspective: the total time during which each trace is under the control of attention in WM is the key to long-term retention. Participants performed a complex span task in which the CL and number of distractors were orthogonally manipulated, and thereafter the participants performed a delayed recall test. Similar to previous findings, the results showed effects of the number of distractors and of CL on delayed recall. Our results went further, however, by showing a non-linear relationship between delayed recall performance and the free time accumulated between encoding and immediate recall. The role of time in episodic memory performance and the underlying WM maintenance mechanism are discussed., (© 2018 New York Academy of Sciences.)

Recent evidence suggests that working memory (WM) performance can be enhanced in the presence of an isochronous rhythm during the retention interval because it improves refreshing. Considering the cognitive load (CL) effect as an indicator of refreshing, the present study investigated whether an isochronous rhythm might benefit memory performance under varying cognitive load. For that goal, the presence of a regular rhythm and the cognitive load of the concurrent task (i.e., reading of digits that were either same or different within a trial) were systematically varied. Recall performance was decreased by high cognitive load compared with low cognitive load but was improved in the regular rhythm condition compared with the silent condition. No interaction between cognitive load and rhythm was observed. The present results suggest that temporal regularities might speed up the reading of the digits rather than improve the efficiency of refreshing, resulting in more time available for refreshing and, consequently, improved memory performance. These findings are interpreted in the framework of the dynamic attending theory and in the scope of recent models of working memory, which are also considering the temporal components of working memory and the importance of the temporal structure of working memory tasks., (© 2018 New York Academy of Sciences.)

Music cognition research has provided evidence for the benefit of temporally regular structures guiding attention over time. The present study investigated whether maintenance in working memory can benefit from an isochronous rhythm. Participants were asked to remember series of 6 letters for serial recall. In the rhythm condition of Experiment 1A, a wood block sound was presented 6 times with a regular stimulus-onset-asynchrony during the delay between encoding and recall. In the silent condition, no sound was presented. The presence of the regular rhythm resulted in improved memory performance (Experiment 1A.), an effect also observed under articulatory suppression (Experiment 2), suggesting that temporal regularities can enhance maintenance in working memory including attentional refreshing. Experiment 1B confirmed this interpretation by showing that the presentation of a nonisochronous rhythm did not result in improved memory performance in comparison to a silent condition. The findings are discussed in relation to current working memory models and the theoretical framework of dynamic attending. (PsycINFO Database Record, ((c) 2018 APA, all rights reserved).)

One way of maintaining information in working memory is through attentional refreshing, a process that was recently shown to be independent from verbal rehearsal. In the classical working memory complex span task, the usual assumption is that memoranda are refreshed in a cumulative fashion, starting from the first item, going in a forward order until the latest one, and cycling until there is no time to continue the process. However, there is no evidence that refreshing operates in that way. The present study proposes a computational modelling study, which constitutes a powerful method to investigate alternative hypotheses. Different refreshing schedules are investigated within computational implementation of the time-based resource sharing model. Their ability to fit three sets of behavioral data and to reproduce the major time-based resource sharing predictions were evaluated using standard model selection criteria. Besides an already published schedule in which the attentional focus is expanded, it appeared that one schedule, the least-activated-first, outperforms the classical cumulative one. The memory trace refreshed at a given time is the one that is the least activated in working memory at that time. These findings characterized the time course of attentional refreshing in working memory and specified the contribution of refreshing to primacy and recency effects. Moreover, in the light of various fields of cognitive psychology, we propose that such refreshing schedules can operate without a homunculus within a general framework including cognitive control and strategic considerations.

Memory is one of the most important cognitive functions in a person's life as it is essential for recalling personal memories and performing many everyday tasks. Although a huge number of studies have been conducted in the field, only a few of them investigated memory in realistic situations, due to methodological issues. The various tools that have been developed using virtual environments (VEs) have gained popularity in cognitive psychology and neuropsychology because they enable to create naturalistic and controlled situations, and are thus particularly adapted to the study of episodic memory (EM), for which an ecological evaluation is of prime importance. EM is the conscious recollection of personal events combined with their phenomenological and spatiotemporal encoding contexts. Using an original paradigm in a VE, the objective of the present study was to characterize the construction of episodic memories. While the concept of working memory has become central in the understanding of a wide range of cognitive functions, its role in the integration of episodic memories has seldom been assessed in an ecological context. This experiment aimed at filling this gap by studying how EM is affected by concurrent tasks requiring working memory resources in a realistic situation. Participants navigated in a virtual town and had to memorize as many elements in their spatiotemporal context as they could. During learning, participants had either to perform a concurrent task meant to prevent maintenance through the phonological loop, or a task aimed at preventing maintenance through the visuospatial sketchpad, or no concurrent task. EM was assessed in a recall test performed after learning through various scores measuring the what, where and when of the memories. Results showed that, compared to the control condition with no concurrent task, the prevention of maintenance through the phonological loop had a deleterious impact only on the encoding of central elements. By contrast, the prevention of visuo-spatial maintenance interfered both with the encoding of the temporal context and with the binding. These results suggest that the integration of realistic episodic memories relies on different working memory processes that depend on the nature of the traces.

Background/Study Context: Age-related deficits in working memory (WM) are commonly described in the literature. However, age-related deficits in WM maintenance mechanisms have received less attention. Based on recent models of WM, the present study aims at determining the conditions under which older adults are able to maintain information. More precisely, we wondered whether the cognitive load effect, taken as evidence for active maintenance in WM, is observed in normal aging and whether it interacts with the level of interference of a concurrent task., Methods: Young (mean age = 21.62; SD = 2.51) and healthy older (mean age = 71.92; SD = 5.18) participants performed a complex WM task. They had to remember five images while reading three words presented after each image. We compared trials in which every word was new (inducing high interference) with trials where words were repeated (inducing low interference). The pace at which the reading task was performed was either fast or slow, resulting in a high or a low cognitive load., Results: As suggested in the literature, young participants presented better performance at slow pace compared with fast pace but were not influenced by interference. Older participants also performed better at slow pace but only when interference was low. Interestingly, the older population showed negative correlations between slow-pace trials and switching abilities. Finally, although computational simulations with time-based resource sharing* (TBRS*) provide a good fit for young adult performance, several parameters had to be adjusted to fit the older participants' performance, including duration of trace refreshing., Conclusion: Our findings suggest that a decrease in WM performance with aging can be explained by a difficulty in taking advantage of WM maintenance opportunities, especially in conditions of high interference. The computational investigations are consistent with this interpretation given that the parameters to be adjusted involve maintenance in WM. Finally, the computational approach seems a relevant way to address causes of forgetting in aging.

Background: The aim of this study was to evaluate outcome measures after the use of del Nido (dN) cardioplegia compared with conventional multidose high-potassium (non-dN) cardioplegia in neonates and infants., Methods: We retrospectively analyzed data in patients, aged younger than 1 year, undergoing cardiopulmonary bypass (CPB) from January 2012 to August 2015. We changed our cardioplegia protocol from non-dN to dN administered in a single or infrequently dosed strategy in September 2013. The outcomes of the dN group (n = 107) are compared with the non-dN group (n = 118). We analyzed variables for demographic, intraoperative, early postoperative, and discharge variables., Results: The two groups were similar in age, weight, height, CPB, and cross-clamp time; preoperative and postoperative echocardiographic systolic functions; first 24-hour postoperative urine output and inotropic score; length of stay; and mortality rate. The Society of Thoracic Surgeons/European Association for Cardio-Thoracic Surgery Congenital Heart Surgery (STAT) mortality category was significantly higher in the dN group (p = 0.03). The cardioplegia dosing interval was lower for the non-dN group (p < 0.001). The volume and doses of cardioplegia per patient were significantly higher in the non-dN group (p < 0.001). In a subanalysis, when the Norwood patients were excluded from both groups, the overall STAT mortality category difference was no longer significant. The demographic, early postoperative, and discharge variables still showed no significant difference when the two groups were compared., Conclusions: Similar outcomes can be achieved with less frequent interruption of the operation and lower volume of cardioplegia when using dN cardioplegia solution compared with conventional cardioplegia. The dN cardioplegia with extended ischemic interval can be used as an alternative strategy in the neonatal and infant population during cardiac operations., (Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Centrifugal pumps are considered to be less destructive to blood elements (1) when compared to roller pumps. However, their large prime volumes render them unsuitable as arterial pumps in heart lung machine (HLM) circuitry for children. In November of 2014, the circuit at Arnold Palmer Hospital, a Biomedicus BP-50 with kinetic assist venous drainage (KAVD) and 1/4″ tubing was converted to a roller pump in the arterial position with gravity drainage. Vacuum-assisted venous drainage (VAVD) was mounted on the HLM as a backup, but not used. Tubing was changed to 3/16″ in the arterial line in patients <13 kg. A retrospective study with a total of 140 patients compared patients placed on cardiopulmonary bypass (CPB) with Biomedicus centrifugal pumps and KAVD (Centrifugal Group, n = 40) to those placed on CPB with roller pumps and gravity drainage (Roller Group, n = 100). Patients requiring extra-corporeal membrane oxygenation (ECMO)/cardio-pulmonary support (CPS) or undergoing a hybrid procedure were excluded. Re-operation or circulatory arrest patients were not excluded. Prime volumes decreased by 57% from 456 ± 34 mL in the Centrifugal Group to 197 ± 34 mL in the Roller Group ( p < .001). There was a corresponding increase in hematocrit (HCT) of blood primes and also on CPB. Intraoperative homologous blood transfusions also decreased 55% from 422 mL in the Centrifugal Group to 231 mL in the Roller Group ( p < .001). The Society of Thoracic Surgeons--European Association for Cardio-Thoracic Surgery (STAT) categorized intubation times and hospital length of stay (LOS) for all infants showed a trend toward reduction, but was not statistically significant. Overall mortality was 5% utilizing the centrifugal configuration and 0% in the roller pump cohort. We demonstrated that the transition to roller pumps in the arterial position of the HLM considerably reduced our priming volume and formed a basis for a comprehensive blood conservation program. By maintaining higher HCTs on CPB, we were able to reduce intraoperative homologous blood transfusions.

It is well known that working memory performance changes with age. Two recent computational models of working memory, TBRS* and SOB-CS, developed from young adults WM performances are opposed regarding the postulated causes of forgetting, namely time-based decay and interference for TBRS* and SOB-CS, respectively. In the present study, these models are applied on a set of complex span data produced by young and older adults. As expected, these models are unable to account for the older adult data. An investigation on the effect of the main parameters of these models showed that the poorer performance of older adults does not come from a weaker encoding of item but rather from difficulties during the free time that immediately follows each distractor, as well as from a higher level of confusion between items. These results are discussed with respect to the current theories of working memory and aging., (Copyright © 2016 Cognitive Science Society, Inc.)

Memory tasks combining storage and distracting tasks performed at either encoding or retrieval have provided divergent results pointing towards accounts of forgetting in terms of either temporal decay or event-based interference respectively. The aim of this study was to shed light on the possible sources of such a divergence that could rely on methodological aspects or deeper differences in the memory traces elicited by the different paradigms used. Methodological issues were explored in a first series of experiments by introducing at retrieval computer-paced distracting tasks that involved articulatory suppression, attentional demand, or both. A second series of experiments that used a similar design was intended to induce differences in the nature of memory traces by increasing the time allowed for encoding the to-be-remembered items. Although the introduction of computer-paced distracting tasks allowed for a strict control of temporal parameters, the first series of experiments replicated the effects usually attributed to event-based interference. However, deeper encoding abolished these effects while time-related effects remained unchanged. These findings suggest that the interplay between temporal factors and event-based interference in forgetting at short term is more complex than expected and could depend on the nature of memory traces., (Copyright © 2012 Elsevier B.V. All rights reserved.)

The sources of forgetting in working memory remain the matter of intense debate. According to the SOB model (serial order in a box; Farrell & Lewandowsky, 2002), forgetting in complex span tasks does not result from temporal decay but from interference produced by the encoding of distractors that are superimposed over memory items onto a composite memory. The main tenet of the model is that the encoding strength of a distractor is a function of its novelty, with novel distractors being encoded with a large encoding weight that interferes with other memories, whereas repeated distractors would result in negligible encoding weight and no further forgetting. In the present study, we tested the 2 main predictions issuing from this model. First, recall performance should be better in complex span tasks in which distractors are repeated than in tasks in which every distractor is novel. Second, increasing the number of novel distractors should lead to more interference and poorer recall. In 5 experiments in which we controlled for attentional demand and temporal factors, none of these predictions were verified, whereas a strong effect of the pace at which distracting tasks were performed testified that they involved forgetting. We conclude that, contrary to the SOB model, the novelty of distractors plays no role per se in forgetting. (PsycINFO Database Record (c) 2013 APA, all rights reserved)., ((c) 2013 APA, all rights reserved.)

A range of empirical findings suggest that active learning is important for memory. However, few studies have focused on the mechanisms underlying this enactment effect in episodic memory using complex environments. Research using virtual reality has yielded inconsistent results. We postulated that the effect of action depends on the degree of interaction with the environment and freedom in the planning of an itinerary. To test these hypotheses, we disentangled the interaction and planning components of action to investigate whether each enhances factual and spatial memory. Seventy-two participants (36 male and 36 female) explored a virtual town in one of three experimental conditions: (a) a passive condition where participants were immersed as passenger of the car (no interaction, no planning); (b) a planning-only condition (the subject chose the itinerary but did not drive the car); (c) an interaction-only condition (the subject drove the car but the itinerary was fixed). We found that itinerary choice and motor control both enhanced spatial memory, while factual memory was impaired by online motor control. The role of action in memory is discussed.

Objective: The aims were (1) to explore the effects of normal aging on the main aspects of episodic memory--what, where, and when,--and on feature binding in a virtual environment; (2) to explore the influence of the mode of learning, intentional versus incidental; and (3) to benchmark virtual environment findings collected with older adults against data recorded in classical neuropsychological tests., Method: We tested a population of 82 young adults and 78 older adults without dementia (they participated in a short battery of neuropsychological tests). All the participants drove a car in an urban virtual environment composing of 9 turns and specific areas. Half of the participants were told to drive through the virtual town; the other half were asked to drive and to memorize the environment (itinerary, elements, etc.). All aspects of episodic memory were then assessed (what, where, when, and binding)., Results: The older participants had less recollection of the spatiotemporal context of events than the younger with intentional encoding (p < .001), but similar recollection with incidental encoding (except for verbal spatial aspect). The younger participants showed better binding than older ones regardless of the type of encoding (p < .001). For the older participants the virtual test was sensitive to mnesic complaints as well as general cognitive changes (p < .05 to p < .01)., Conclusion: We view these results as an indication that virtual environments could provide helpful standard tools for assessing age effects on the main aspects of episodic memory.

It is well known that the occurrence of false memories increases with aging, but the results remain inconsistent concerning Alzheimer's disease (AD). Moreover, the mechanisms underlying the production of false memories are still unclear. Using an experimental episodic memory test with material based on the names of famous people in a procedure derived from the DRM paradigm [Roediger, H. L., III, & McDermott, K. B. (1995). Creating false memories: Remembering words not presented in lists. Journal of Experimental Psychology: Learning, Memory & Cognition, 21, 803-814], we examined correct and false recall and recognition in 30 young adults, 40 healthy older adults, and 30 patients with AD. Moreover, we evaluated the relationships between false memory performance, correct episodic memory performance, and a set of neuropsychological assessments evaluating the semantic memory and executive functions. The results clearly indicated that correct recall and recognition performance decreased with the subjects' age, but it decreased even more with AD. In addition, semantically related false recalls and false recognitions increased with age but not with dementia. On the contrary, non-semantically related false recalls and false recognitions increased with AD. Finally, the regression analyses showed that executive functions mediated related false memories and episodic memory mediated related and unrelated false memories in aging. Moreover, executive functions predicted related and unrelated false memories in AD, and episodic and semantic memory predicted semantically related and unrelated false memories in AD. In conclusion, the results obtained are consistent with the current constructive models of memory suggesting that false memory creation depends on different cognitive functions and, consequently, that the impairments of these functions influence the production of false memories.

We assessed the effect of suggestion on the Deese-Roediger-McDermott paradigm and associated it with the Remember-Know-Guess paradigm. Undergraduate students were given either lists of semantically related words or texts containing these words. After the recall task, if participants did not produce the critical lure, the experimenter suggested that the word had been present, using either a question (moderate suggestion) or an assertion (strong suggestion); these conditions were compared to a condition without suggestion. Afterwards, participants took a recognition test. The results showed that strong suggestions lead to more false recognitions than other conditions and the state of consciousness associated with false recognitions tends to be a feeling of knowing rather than remembering, regardless of the verbal version (list or text). Therefore moderate suggestions did not lead to more false recognitions compare to no suggestion. We discuss the impact of suggestion on consciousness associated with false memories.

The principal interest of virtual reality is its potential to create experiments close to daily life with a perfect experimental control. In a first time, we review the studies illustrating the contribution of virtual reality for neuropsychology, mainly for memory study. In a second time, we present the results of an experiment in which the subjects were driving in a virtual town, that tested all the episodic memory components, i.e. the memories of what, where and when events happened. Young and elderly adults performed the virtual test, either with intentional or incidental encoding, and either in active (they drove a virtual car) or passive exploration of the town (they were passengers). The results showed that older subjects recalled the spatiotemporal context and the details of the events in a lower proportion than younger, as well in active as in passive condition. Subject's memory complaints were correlated with the virtual scores, but not with usual verbal episodic memory tests. Therefore, virtual tests seem to allow a better assessment of episodic memory than the usual ones, especially because of their spatiotemporal memory assessment, and appear to be a hopeful tool for a neuropsychology closer to patient's daily life than the usual tests.