Search

A neighborhood's social cohesion, referring to the emotional and social connection of people within it, tends to have an influential impact on its crime level. Traditional approaches to measuring social cohesion and collective efficacy are mostly interviews and surveys, which are usually costly in time, money, and other resources. Big social media data provides us with a new and cost-effective source of such information. We believe the combination of spatial and contextual information of geotagged Twitter posts (tweets) can gauge the residents' collective emotions in a neighborhood. The positivity and negativity of these collective emotions may be used to approximate the collective efficacy of the community. Inspired by the broken window theory, we propose a broken emotion conjecture to explain the relationship between collective emotion and crime. To test this conjecture, we collected data on four types of crime (assaults, burglaries, robberies, and thefts) and all public geotagged tweets (N = 778,901) in Cincinnati, Ohio, USA in 2013. We extracted innovative variables from tweets' spatial and contextual information to explain community crime and enlighten new criminology theory. Results of negative binomial models show: (1) with necessary socio-economic and land-use factors controlled, the more negative the collective emotion of a neighborhood, the more the crime (except for theft); (2) however, the positivity of the collective emotion of a neighborhood does not have any statistically significant influence on crime. These correspond well with signal detection theory in psychology. The proposed broken emotion conjecture is supported with data from Cincinnati and its general applicability should be tested in other regions. [ABSTRACT FROM AUTHOR]

Multiple theories have used perceptual sensitivity and response criterion indices to explain the decrements in performance across time on task (i.e., vigilance decrement). In a recent study, McCarley and Yamani (2021) offered conceptual and methodological advances to this debate by using a vigilance task that parametrically manipulates noise and signal and analyzes the outcomes with psychometric curves. In the present Commentary, we reanalyze data (N = 553) from a different, already existing vigilance task, the Attentional Networks Test for Interactions and Vigilance—executive and arousal components (ANTI-Vea). Psychometric curves with the ANTI-Vea showed robust changes in response criterion and lapse rate, although not in sensitivity. Our interpretation is that the need to keep the standard in memory in McCarley and Yamani's task could produce a decrease in sensitivity and be related to reduced fidelity of the memory representation rather than to a decrement in perceptual abilities across time on task. [ABSTRACT FROM AUTHOR]

Historically, inaccurate credibility assessments have resulted in tremendous costs to businesses and to society. Recent research offers unobtrusive credibility assessment aids as a solution; however, the accuracy of these decision aids is inadequate, and users often resist accepting the aids' recommendations. We follow the principles of signal detection theory to improve the accuracy of recommendations in computer-aided credibility assessment by combining automated and participatory decision support. We also leverage participation in decision-making theory to explain and predict an increased acceptance of assessment aid recommendations when perceptual cues are elicited from users. Based on these two theories, we design and test a hybrid decision aid to perform automated linguistic analysis and to elicit and analyze perceptual cues from an observer. Results from a laboratory experiment indicate that decision aids that use linguistic and perceptual cues offer more accurate recommendations than aids that use only one type of cue. Automatic analysis of linguistic cues improved both the decision aid's recommendations and the users' credibility assessment accuracy. Challenging the generalizability of past findings, the elicitation of perceptual cues did not improve the decision aid's recommendations or the users' assessment accuracy. Elicitation of perceptual cues, however, did improve user acceptance of the decision aid's recommendations. These findings provide guidance for future development of credibility assessment decision aids. [ABSTRACT FROM AUTHOR]

We measured psychometric (i.e. concentration-response) functions for the detection of odor, nasal pungency and eye irritation from butyl acetate and toluene. Olfactory detection was measured in subjects with normal olfaction (i.e. normosmics) for whom nasal trigeminal detection does not interfere because it requires much higher concentrations. Nasal trigeminal detection, called nasal pungency, was measured only in subjects lacking olfaction (i.e. anosmics) in order to avoid odor interference. Ocular trigeminal detection, called eye irritation, was measured in both groups. The method employed entailed a two-alternative, forced-choice procedure with presentation of increasing concentrations. The outcome showed, for both chemicals, similar ocular trigeminal chemosensitivity in normosmics and anosmics and similar overall ocular and nasal trigeminal chemosensitivity. Olfactory sensitivity was much higher than both forms of trigeminal sensitivity by concentration differences of six and four orders of magnitude for butyl acetate and toluene, respectively. Detectability plots (i.e. detection performance vs log concentration) for the three sensory endpoints followed an S-shaped function with a middle range section that showed a robust linear fit (r > 0.94) on graphs of z-score vs log concentration. These detectability functions allow the calculation of olfactory and trigeminal thresholds at various levels of performance. At a point half-way between random and perfect detection, trigeminal and olfactory threshold concentrations were, respectively, 0.67 (+/-0.32) and 2.28 (+/-1.77) log units lower than those measured by us in the past for the same chemicals using an analogous procedure but under just one, fixed, level of performance. The available data suggest that, although considerably laborious, detectability functions provide chemosensory thresholds of closer relevance to environmentally realistic conditions (e.g. whole-body exposures).

Perception likely results from the interplay between sensory information and top-down signals. In this electroencephalography (EEG) study, we utilised the hierarchical frequency tagging (HFT) method to examine how such integration is modulated by expectation and attention. Using intermodulation (IM) components as a measure of nonlinear signal integration, we show in three different experiments that both expectation and attention enhance integration between top-down and bottom-up signals. Based on a multispectral phase coherence (MSPC) measure, we present two direct physiological measures to demonstrate the distinct yet related mechanisms of expectation and attention, which would not have been possible using other amplitude-based measures. Our results link expectation to the modulation of descending signals and to the integration of top-down and bottom-up information at lower levels of the visual hierarchy. Meanwhile, the results link attention to the modulation of ascending signals and to the integration of information at higher levels of the visual hierarchy. These results are consistent with the predictive coding account of perception. [ABSTRACT FROM AUTHOR]

Introduction: Models from signal detection theory are commonly used to score neuropsychological test data, especially tests of recognition memory. Here we show that certain item response theory models can be formulated as signal detection theory models, thus linking two complementary but distinct methodologies. We then use the approach to evaluate the validity (construct representation) of commonly used research measures, demonstrate the impact of conditional error on neuropsychological outcomes, and evaluate measurement bias. Method: Signal detection-item response theory (SD-IRT) models were fitted to recognition memory data for words, faces, and objects. The sample consisted of U.S. Infantry Marines and Navy Corpsmen participating in the Marine Resiliency Study. Data comprised item responses to the Penn Face Memory Test (PFMT; N = 1,338), Penn Word Memory Test (PWMT; N = 1,331), and Visual Object Learning Test (VOLT; N = 1,249), and self-report of past head injury with loss of consciousness. Results: SD-IRT models adequately fitted recognition memory item data across all modalities. Error varied systematically with ability estimates, and distributions of residuals from the regression of memory discrimination onto self-report of past head injury were positively skewed towards regions of larger measurement error. Analyses of differential item functioning revealed little evidence of systematic bias by level of education. Conclusions: SD-IRT models benefit from the measurement rigor of item response theory—which permits the modeling of item difficulty and examinee ability—and from signal detection theory—which provides an interpretive framework encompassing the experimentally validated constructs of memory discrimination and response bias. We used this approach to validate the construct representation of commonly used research measures and to demonstrate how nonoptimized item parameters can lead to erroneous conclusions when interpreting neuropsychological test data. Future work might include the development of computerized adaptive tests and integration with mixture and random-effects models. [ABSTRACT FROM AUTHOR]

Recently, we have proposed the degree of satisfaction-difference (DOSD) method to measure changes in consumer product acceptance (Kim, van Hout, Dessirier, et al., 2018). The DOSD method utilizes A-Not A with reminder format to improve the stability and validity of the consumer evaluation by reminding consumers of the evaluative criteria with the reference sampling and by controlling the sequence effects on each sampling of the blind test product. Using the data obtained from DOSD method, in this paper, a way to compute a measure of the absolute degree of satisfaction for a product based on signal detection theory (SDT), referred to as d' SAT (d-prime satisfaction), is suggested. This new measure is compared to the comparative distance measure of d' , the degree of satisfaction difference of a product from the reference product, which has been already described in the previous study. The absolute satisfaction degree is a value indicating each product’s degree of consumer satisfaction as in the hedonic score. However, the degree of satisfaction measure presented herein is superior to the hedonic score because it enables easy interpretation of whether a group of consumers are satisfied or not with a product. In practical situations, the two measures of the degree of satisfaction difference from the reference and the degree of satisfaction, which are computed using the data from DOSD method, can be used complementarily in order to reveal information about consumer perception and evaluation. [ABSTRACT FROM AUTHOR]

Analysis of task-based fMRI data is conventionally carried out using a hypothesis-driven approach, where blood-oxygen-level dependent (BOLD) time courses are correlated with a hypothesized temporal structure. In some experimental designs, this temporal structure can be difficult to define. In other cases, experimenters may wish to take a more exploratory, data-driven approach to detecting task-driven BOLD activity. In this study, we demonstrate the efficiency and power of an inter-subject synchronization approach for exploratory analysis of task-based fMRI data. Combining the tools of instantaneous phase synchronization and independent component analysis, we characterize whole-brain task-driven responses in terms of group-wise similarity in temporal signal dynamics of brain networks. We applied this framework to fMRI data collected during performance of a simple motor task and a social cognitive task. Analyses using an inter-subject phase synchronization approach revealed a large number of brain networks that dynamically synchronized to various features of the task, often not predicted by the hypothesized temporal structure of the task. We suggest that this methodological framework, along with readily available tools in the fMRI community, provides a powerful exploratory, data-driven approach for analysis of task-driven BOLD activity. [ABSTRACT FROM AUTHOR]

Alcohol and other pharmacologically similar sedatives (i.e., GABAA positive allosteric modulators or PAMs) impair the encoding of new episodic memories but retroactively facilitate the consolidation of recently encoded memories. These effects are consistent for recollection (i.e., the retrieval of details) but some mixed results have been reported for familiarity (i.e., a feeling of knowing a stimulus was presented). Here, with dual-process models, we reanalyzed prior work testing the effects of GABAA PAMs at encoding or consolidation. Contrary to previous conclusions, we show that GABAA PAMs at encoding consistently impair both recollection and familiarity when an independence correction is applied to familiarity-based responses. These findings were further confirmed and extended in a dual-process signal detection analysis of a recent study on the effects of alcohol during encoding or consolidation: Alcohol at encoding impaired both recollection and familiarity, whereas alcohol at consolidation enhanced both recollection and familiarity. These findings speak to the ability of alcohol and other GABAA PAMs to induce ‘blackouts,’ highlighting the importance of dual-process approaches when analyzing drug manipulations at different phases of episodic memory. [ABSTRACT FROM AUTHOR]

Despite the ubiquity of go/no-go tasks in the study of behavioral inhibition, there is a lack of evidence regarding the impact of key design characteristics, including the go/no-go ratio, intertrial interval, and number of types of go stimuli, on the production of different response classes of central interest. In the present study we sought to empirically determine the optimal conditions to maximize the production of a rare outcome of considerable interest to researchers: false alarms. As predicted, the shortest intertrial intervals (450 ms), intermediate go/no-go ratios (2:1 to 4:1), and the use of multiple types of go stimuli produced the greatest numbers of false alarms. These results are placed within the context of behavioral changes during learning. [ABSTRACT FROM AUTHOR]

Creating and maintaining accurate bindings of elementary features (e.g., color and shape) in visual short-term memory (VSTM) is fundamental for veridical perception. How are low-level features bound in memory? The present work harnessed a multivariate model of perception - the General Recognition Theory (GRT) - to unravel the internal representations underlying feature binding in VSTM. On each trial, preview and target colored shapes were presented in succession, appearing in either repeated or altered spatial locations. Participants gave two same/different responses: one with respect to color and one with respect to shape. Converging GRT analyses on the accuracy confusion matrices provided substantial evidence for binding in the form of violations of perceptual independence at the level of the individual stimulus, such that positive correlations were obtained when both features repeated or alternated together, while negative correlations were obtained when one feature repeated and the other alternated. This “cloverleaf” GRT pattern of binding was similar whether the spatial location of the preview and target repeated or altered. The current results are consistent with: (a) the discrete memory “slots” model of VSTM, and (b) the notion that spatial location is not necessary for the formation of “object files.” The GRT approach presented here offers a viable quantitative model for testing various questions regarding feature binding in VSTM. [ABSTRACT FROM AUTHOR]

Relative to younger adults, older adults appear to exhibit greater use of schema-based, as opposed to detailed, processing strategies. This relationship is investigated in an experimental study that examines the moderating influences of two marketing-relevant variables, incongruity of message items and optimal time of day. Signal detection analysis performed on recognition measures serves as a basis for assessing strategy use. Both older and younger adults, during their optimal times of day (morning and evening, respectively), engage in detailed processing, but this tendency is particularly pronounced for the elderly when exposed to high-incongruity cues. By contrast, during their nonoptimal time of day, older adults seem to rely on schema-based processing regardless of the level of incongruity, whereas younger adults remain relatively detailed in their processing strategies. Theoretical and practical implications for marketing are discussed. [ABSTRACT FROM AUTHOR]

Singh and Cole (12) recently reviewed attempts by advertising researchers to develop an accurate measure of correct recognition for use in examining an ad's likely effectiveness, and they provided an alternative measure that entails an adjustment for likely guessing. In this paper, several additional recognition formulations are discussed, and empirical and qualitative comparisons of available measures are provided. Results of the empirical comparisons revealed reasonable convergence among the alternative recognition formulations. Conclusions and recommendations for research application are given. [ABSTRACT FROM AUTHOR]

Most marketing applications of signal detection theory (SDT) produce an estimate of the respondent's memory accuracy based on exposure to a number of advertisements. Marketing practitioners, however. are usually more interested in the performance of an individual advertisement, or elements of that ad. Moreover, advertising recognition paradigms are typically limited to single observations per respondent. The authors present and compare two alternative methodologies that estimate SDT parameters for such designs by pooling recognition performance across respondents. They present two simulations that explore the most efficient methodology and suggest guidelines for selecting appropriate accuracy indices. [ABSTRACT FROM AUTHOR]

Recognition tests are a very popular means of assessing the memory effectiveness of advertisements. Unfortunately the recognition scores obtained by current methods reflect both the memory for an advertisement and the response biases of the respondents. The authors introduce the theory of signal detection (TSD) which can be used to secure independent estimates of memory and response bias in recognition tests. They discuss how TSD can be used to improve ad recognition testing. [ABSTRACT FROM AUTHOR]

The salesperson who is engaged in an adaptive selling effort often finds hind herself in a complex circumstance wrought with uncertainty. To negotiate the sales encounter successfully, the individual must call upon perceptual and cognitive skills in order to respond effectively to cues of possible events. The dynamics of this elaborate process are aptly detailed in a framework from psychophysics called "Signal Detection Theory" (SDT). The following article explores the potential contribution that SDT offers for adaptive selling and sales management. Explanations of why SDT is a reasonable addition to the adaptive selling literature are presented, propositions concerning SDT's role in effective selling are posited, and SDT-related sales management issues and implications are examined. [ABSTRACT FROM AUTHOR]

A great deal of interest concerns the study of vigilance performance, and trust in automation, due to their implications for public safety. This work provides an experimental resource for scholars in need of a vigilance style task. The dataset includes 150 X-ray images of luggage, and participants indicate whether or not they believe each image contains a dangerous item (simulating airport security screening). Using a sample of 991 adults recruited via MTurk, we normed these items in terms of difficulty. These stimuli can be used to study vigilance performance, trust in an automated decision aid, and other areas. [ABSTRACT FROM AUTHOR]

The quality or precision of stimulus representations in visual working memory can be characterized by a power law, which states that precision decreases as a power of the number of items in memory, with an exponent whose magnitude typically varies in the range 0.5 to 0.75. The authors show that the magnitude of the exponent is an index of the attentional demands of memory formation. They report 5 visual working memory experiments with tasks using noisy, backward-masked stimuli that varied in their attentional demands and show that the magnitude of the exponent increases systematically with the attentional demands of the task. Recall accuracy in the experiments was well described by an attentionweighted sample-size model that views visual working memory as a resource comprised of noisy evidence samples that are recruited during stimulus exposure and which can be allocated flexibly under attentional control. The magnitude of the exponent indexes the degree to which attention allocates resources to items in memory unequally rather than equally. [ABSTRACT FROM AUTHOR]

Measurement of muscle oxidative metabolism is of interest for monitoring the training status in athletes and the rehabilitation process in patients. Time domain near infrared spectroscopy (TD NIRS) is an optical technique that allows the non-invasive measurement of the hemodynamic parameters in muscular tissue: concentrations of oxy- and deoxy-hemoglobin, total hemoglobin content, and tissue oxygen saturation. In this paper, we present a novel TD NIRS medical device for muscle oxidative metabolism. A custom-printed 3D probe, able to host optical elements for signal acquisition from muscle, was develop for TD NIRS in vivo measurements. The system was widely characterized on solid phantoms and during in vivo protocols on healthy subjects. In particular, we tested the in vivo repeatability of the measurements to quantify the error that we can have by repositioning the probe. Furthermore, we considered a series of acquisitions on different muscles that were not yet previously performed with this custom probe: a venous-arterial cuff occlusion of the arm muscle, a cycling exercise, and an isometric contraction of the vastus lateralis. [ABSTRACT FROM AUTHOR]

Predictions of consumer acceptance are often based on hedonic scores, but these are determined not only by the consumer level of product liking, but also by consumer scale usage, which in turn is affected by thinking style and experimental contexts. To improve the validity and reliability of consumer acceptance measurement, a new indirect scaling method, the ‘Degree of Satisfaction-Difference (DOSD)’, was developed using a reminder design and signal detection theory (SDT). In DOSD, a product-specified ‘cognitive warm-up’ was used to evoke the consumer personal context and the internal evaluative criteria prior to product evaluation. In DOSD, each test product was presented together with a fixed-reference (identified as such) and consumers were asked to evaluate their satisfaction with the reference first with a sureness rating, and then to evaluate the test product for both absolute satisfaction and comparative satisfaction to the reference. The reliability of DOSD was tested against traditional hedonic scaling using an independent samples design of two consumer groups with equivalent cognitive reflection test profiles, each including High Reflection Thinkers (HRTs) and Low Reflection Thinkers (LRTs) in equal proportion. Each group tested two sets of skin lotions differing in product range, either using DOSD or hedonic scaling. When examining the affective discriminations of the two common products in terms of d ′ values between product sets, the LRT subjects generated inconsistent responses with hedonic scaling, but reproducible responses with DOSD. The HRT subjects performed consistently using both scaling methods. These results validate DOSD’s superior reliability in affective tests and demonstrate its potential as an alternative consumer acceptance measurement to hedonic scaling. [ABSTRACT FROM AUTHOR]

The capacity to identify unanticipated abnormal cues in a natural scene is vital for animal survival. Stimulus-specific adaptation (SSA) has been considered the neuronal correlate for deviance detection. There have been comprehensive assessments of SSA in the frequency domain along the ascending auditory pathway, but only little attention given to deviance detection in the spatial domain. We found that thalamic reticular nucleus (TRN) neurons exhibited stronger responses to a tone when it was presented rarely as opposed to frequently at a certain spatial location. Subsequently, we engaged signal detection theory to directly gauge neuronal spatial discriminability and found that discrimination of deviant locations was considerably higher than standard locations. The variability in neuronal spatial discriminability among the TRN population was directly related to response difference (RD) but not variance; meanwhile, further analyses attributed higher spatial sensitivity at deviant locations to larger RD. Astonishingly, a significant correlation was found between the amount of adaptation and deviant discriminability. Collectively, our results suggest that adaptation facilitates rare location discrimination by sharpening the response gap between two locations. [ABSTRACT FROM AUTHOR]

We developed a brief (5.5 min), continuous voice-hearing task (VHT) to address the limitations of existing paradigms used to study auditory verbal hallucinations in the laboratory. Correlational analysis of VHT data obtained from ordinary participants indicated that false alarm responses on the task were reliable and had convergent and divergent validity. Advantages of the VHT over other similar tasks include its sound psychometric properties, brevity, flexibility, control over confounding factors, suitability for multi-task study, and potential for broader application. [ABSTRACT FROM AUTHOR]

DNA methyltransferases (MTases) may specifically recognize the short palindromic sequences and transfer a methyl group from S-adenosyl-L-methionine to target cytosine/adenine. The aberrant DNA methylation is linked to the abnormal DNA MTase activity, and some DNA MTases have become promising targets of anticancer/antimicrobial drugs. However, the reported DNA MTase assays often involve laborious operation, expensive instruments, and radio-labeled substrates. Here, we develop a simple and label-free fluorescent method to sensitively detect DNA adenine methyltransferase (Dam) on the basis of terminal deoxynucleotidyl transferase (TdT)- activated Endonuclease IV (Endo IV)-assisted hyperbranched amplification. We design a hairpin probe with a palindromic sequence in the stem as the substrate and a NH2-modified 3' end for the prevention of nonspecific amplification. The substrate may be methylated by Dam and subsequently cleaved by Dpnl, producing three singlestranded DNAs, two of which with 3'-OH termini may be amplified by hyperbranched amplification to generate a distinct fluorescence signal. Because high exactitude of TdT enables the amplification only in the presence of free 3'-OH termini and Endo IV only hydrolyzes the intact apurinic/apyrimidinic sites in double-stranded DNAs, zero background signal can be achieved. This method exhibits excellent selectivity and high sensitivity with a limit of detection of 0.003 U/mL for pure Dam and 9.61 X 10-6 mg/mL for Dam in E. coli cells. Moreover, it can be used to screen the Dam inhibitors, holding great potentials in disease diagnosis and drug development [ABSTRACT FROM AUTHOR]

Background: Action monitoring, the process for evaluating the appropriateness of one’s own actions, is reported to be atypical in individuals with autism spectrum disorder (ASD).Method: We examined the characteristics of action monitoring in 11 children with ASD and 12 children with typical development (TD), analyzing stimulus-locked and response-locked event-related potential components (i.e., N2; error-related negativity, ERN; and error positivity, Pe) related to execution of a flanker task.Results: We found a smaller N2 amplitude in children with ASD than in those with TD. Children with ASD also had a larger amplitude of ERN for partial error responses (electromyographic activity corresponding to the inappropriate hand side before response execution) than did children with TD. Additionally, the ERN amplitude for the partial error response was correlated with the Autistic Mannerisms of the Social Responsiveness Scale. There were no significant differences in Pe amplitudes between children with ASD and those with TD.Conclusion: The results suggest that action monitoring in children with ASD is significantly different both before and after response execution. We hypothesized that the detail-focused processing style of ASD reduces the demands of action monitoring before response execution; however, autistic mannerisms evoke excessive concern regarding trivial mistakes after response execution. [ABSTRACT FROM PUBLISHER]

We examined the role of both suspect race and socioeconomic status (SES) on shooting decisions during a first-person shooter task. Two studies revealed that both suspect race and SES influenced shooting decisions. Non-Black participants shot armed high-SES Black suspects faster than armed high-SES White suspects and responded 'don't shoot' faster for unarmed high-SES White suspects than unarmed high-SES Black suspects. No race differences appeared in the low-SES conditions-responses resembled high-SES Black suspect. Signal detection, misses, and false alarm analyses revealed participants erred toward not shooting high-SES White suspects. The current studies draw attention to considering both race and SES during shooting decisions. [ABSTRACT FROM AUTHOR]

From the perspective of signal detection theory, different lineup instructions may induce different levels of response bias. If so, then collecting correct and false identification rates across different instructional conditions will trace out the receiver operating characteristic (ROC)-the same ROC that, theoretically, could also be traced out from a single instruction condition in which each eyewitness decision is accompanied by a confidence rating. We tested whether the two approaches do in fact yield the same ROC. Participants were assigned to a confidence rating condition or to an instructional biasing condition (liberal, neutral, unbiased, or conservative). After watching a video of a mock crime, participants were presented with instructions followed by a six-person simultaneous photo lineup. The ROCs from both methods were similar, but they were not exactly the same. These findings have potentially important policy implications for how the legal system should go about controlling eyewitness response bias.Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Many cryptic prey have also evolved hidden contrasting colour signals which are displayed to would-be predators. Given that these hidden contrasting signals may confer additional survival benefits to the prey by startling/ intimidating predators, it is unclear why they have evolved in some species, but not in others. Here, we have conducted a comparative phylogenetic analysis of the evolution of colour traits in the family Erebidae (Lepidoptera), and found that the hidden contrasting colour signals are more likely to be found in larger species. To understand why this relationship occurs, we present a general mathematical model, demonstrating that selection for a secondary defence such as deimatic display will be stronger in large species when (i) the primary defence (crypsis) is likely to fail as its body size increases and/or (ii) the secondary defence is more effective in large prey. To test the model assumptions, we conducted behavioural experiments using a robotic moth which revealed that survivorship advantages were higher against wild birds when the moth has contrasting hindwings and large size. Collectively, our results suggest that the evolutionary association between large size and hidden contrasting signals has been driven by a combination of the need for a back-up defence and its efficacy. [ABSTRACT FROM AUTHOR]

Entropy, the complexity measures for time series, has found numerous successful applications in brain signal analysis such as detection of epileptic seizure and monitoring the depth of anesthesia. Renyi entropy generalizes the well-known Shannon entropy, and hence providing better flexibility in application to real data. The objective of this paper is to evaluate the effectiveness of Renyi entropy as feature extraction method for motor imagery (MI)-based brain-computer interface (BCI). In this paper, Renyi entropy has been implemented in MI systems of various settings using BCI competition data sets. The classification accuracy of Renyi entropy in all data sets is benchmarked against common spatial pattern (CSP), the state-of-the-art feature extraction method. For common binary class data sets, Renyi entropy achieves an accuracy of approximately 3.4 % higher for BCI Competition II Data Set III and 0.87 % lower for BCI Competition III Data Set I, and there is no difference in accuracy for BCI Competition III Data Set IVc when compared against conventional CSP. In small sample setting, the average classification accuracy using Renyi entropy is approximately 3.4 and 0.3 % higher as compared to conventional CSP and best performing variant of regularized CSP, respectively. In addition, Renyi entropy is also compared to other chaos-inspired feature extraction methods, namely Katz and Higuchi which are implemented for MI systems by earlier researchers. The effect of implementing Renyi entropy on multiple narrower frequency sub-bands is also investigated in this study. In multi-class setting, Renyi entropy shows no statistical difference ( p = 0.6022, paired t test) in accuracy when compared to the algorithm of the BCI competition winner. However, Renyi entropy has an advantage of requiring only one single application of feature extraction regardless of the number of classes, while multiple implementation of CSP is required as CSP is originally designed for binary class problem. The successful application of Renyi entropy in all the aforementioned settings indicates that Renyi entropy is a viable feature extraction alternative for MI-based BCI systems. [ABSTRACT FROM AUTHOR]

The hypothesis that prey organisms can reduce the risk of predation by overtly signalling their unprofitability, or aposematism, has a long history in behavioural and evolutionary biology. To fully understand this longstanding idea, we need to measure and manipulate traits of aposematic prey, such as their distinctiveness from other prey, from the perspective of the potential predator. Specifically, we need measurements that are not anthropomorphic and that are based on the principles of discrimination developed by psychophysicists. This paper utilizes an experimentally tractable measure of discriminability based on signal detection theory as originally studied by psychophysicists. In addition, we develop and experimentally test a model to characterize the predator avoidance advantages derived from being distinct from other prey. By experimentally varying discriminability (and thus distinctiveness) we find that increased discriminability does confer a predator avoidance advantage, but the extent of this effect depends on the unprofitability of prey and the relative frequency of unprofitable prey. [ABSTRACT FROM AUTHOR]

The author presents some reactions to an article concerning vision and signal detection of a drowning victim. He agrees that preventive lifeguard practices and protocols are based on adequate science and experimental research. He emphasized the need for peer-reviewed water-safety research before publication.

Background: Despite on-going efforts to better understand dysregulated eating, the olfactory-gustatory deficits and food preferences in eating disorders (ED), and the mechanisms underlying the perception of and responses to food properties in anorexia nervosa (AN) and bulimia nervosa (BN) remain largely unknown; both during the course of the illness and compared to healthy populations. It is, therefore, necessary to systematically investigate the gustatory perception and hedonics of taste in patients with AN and BN. To this end, we will examine whether aversions to the taste of high-calorie food is related to the suppression of energy intake in restricting-type AN, and whether an increased hedonic valence of sweet, caloric-dense foods may be part of the mechanisms triggering binge-eating episodes in BN. In addition, the role of cognitions influencing these mechanisms will be examined. Method: In study 1, four mixtures of sweet-fat stimuli will be presented in a sensory two-alternative forced-choice test involving signal detection analysis. In study 2, a full-scale taste reactivity test will be carried out, including psychophysiological and behavioral measures to assess subtle and covert hedonic changes. We will compare the responses of currently-ill AN and BN patients to those who have recovered from AN and BN, and also to those of healthy normal-weight and underweight individuals without any eating disorder pathology. Discussion: If taste response profiles are differentially linked to ED types, then future studies should investigate whether taste responsiveness represents a useful diagnostic measure in the prevention, assessment and treatment of EDs. The expected results on cognitive mechanisms in the top-down processes of food hedonics will complement current models and contribute to the refinement of interventions to change cognitive aspects of taste aversions, to establish functional food preferences and to better manage food cravings associated with binge-eating episodes. No trial registration was required for this protocol, which was approved by the Swiss ethics committee (CER-VD, n° 2016-02150) and the Ethics Review Panel of the University of Luxembourg. [ABSTRACT FROM AUTHOR]

The everyday auditory environment is complex and dynamic; often, multiple sounds co-occur and compete for a listener's cognitive resources. 'Change deafness', framed as the auditory analog to the well-documented phenomenon of 'change blindness', describes the finding that changes presented within complex environments are often missed. The present study examines a number of stimulus factors that may influence change deafness under real-world listening conditions. Specifically, an AX (same-different) discrimination task was used to examine the effects of both spatial separation over a loudspeaker array and the type of change (sound source additions and removals) on discrimination of changes embedded in complex backgrounds. Results using signal detection theory and accuracy analyses indicated that, under most conditions, errors were significantly reduced for spatially distributed relative to non-spatial scenes. A second goal of the present study was to evaluate a possible link between memory for scene contents and change discrimination. Memory was evaluated by presenting a cued recall test following each trial of the discrimination task. Results using signal detection theory and accuracy analyses indicated that recall ability was similar in terms of accuracy, but there were reductions in sensitivity compared to previous reports. Finally, the present study used a large and representative sample of outdoor, urban, and environmental sounds, presented in unique combinations of nearly 1000 trials per participant. This enabled the exploration of the relationship between change perception and the perceptual similarity between change targets and background scene sounds. These (post hoc) analyses suggest both a categorical and a stimulus-level relationship between scene similarity and the magnitude of change errors. [ABSTRACT FROM AUTHOR]

Decision-making accuracy typically increases through collective integration of people's judgments into group decisions, a phenomenon known as the wisdom of crowds. For simple perceptual laboratory tasks, classic signal detection theory specifies the upper limit for collective integration benefits obtained by weighted averaging of people's confidences, and simple majority voting can often approximate that limit. Life-critical perceptual decisions often involve searching large image data (e.g., medical, security, and aerial imagery), but the expected benefits and merits of using different pooling algorithms are unknown for such tasks. Here, we show that expected pooling benefits are significantly greater for visual search than for single-location perceptual tasks and the prediction given by classic signal detection theory. In addition, we show that simple majority voting obtains inferior accuracy benefits for visual search relative to averaging and weighted averaging of observers' confidences. Analysis of gaze behavior across observers suggests that the greater collective integration benefits for visual search arise from an interaction between the foveated properties of the human visual system (high foveal acuity and low peripheral acuity) and observers' nonexhaustive search patterns, and can be predicted by an extended signal detection theory framework with trial to trial sampling from a varying mixture of high and low target detectabilities across observers (SDT-MIX). These findings advance our theoretical understanding of how to predict and enhance the wisdom of crowds for real world search tasks and could apply more generally to any decision-making task for which the minority of group members with high expertise varies from decision to decision. [ABSTRACT FROM AUTHOR]

There is a conflicting literature on facial emotion processing in autism spectrum disorder (ASD): both typical and atypical performance have been reported, and inconsistencies in the literature may stem from different processes examined (emotion judgment, face perception, fixations) as well as differences in participant populations. Here we conducted a detailed investigation of the ability to discriminate graded emotions shown in morphs of fear-happy faces, in a well-characterized high-functioning sample of participants with ASD and matched controls. Signal detection approaches were used in the analyses, and concurrent high-resolution eye-tracking was collected. Although people with ASD had typical thresholds for categorical fear and confidence judgments, their psychometric specificity to detect emotions across the entire range of intensities was reduced. However, fixation patterns onto the stimuli were typical and could not account for the reduced specificity of emotion judgment. Together, our results argue for a subtle and specific deficit in emotion perception in ASD that, from a signal detection perspective, is best understood as a reduced specificity due to increased noise in central processing of the face stimuli. [ABSTRACT FROM AUTHOR]

The vast range and complexity of glycan structures and their dynamic variations in health and disease have presented formidable challenges toward understanding the biological significance of these molecules. Despite these limitations, compelling evidence highlights a major role for galectins, a family of soluble glycan-binding proteins, as endogenous decoders that translate glycan-containing information into a broad spectrum of cellular responses by modulating receptor clustering, reorganization, endocytosis, and signaling. Here, we underscore pioneer findings and recent advances in understanding the biology of galectin–glycan interactions in myeloid, lymphoid, and endothelial compartments, highlighting important pathways by which these multivalent complexes control immune and vascular programs. Implementation of novel glycoanalytical approaches, as well as the use of genetically engineered cell and organism models, have allowed glycans and galectins to be explored across a range of cellular processes. [ABSTRACT FROM AUTHOR]

Receiver Operating Characteristic (ROC) analysis has recently come in vogue for assessing the underlying discriminability and the applied utility of lineup procedures. Two primary assumptions underlie recommendations that ROC analysis be used to assess the applied utility of lineup procedures: (a) ROC analysis of lineups measures underlying discriminability, and (b) the procedure that produces superior underlying discriminability produces superior applied utility. These same assumptions underlie a recently derived diagnostic-feature detection theory, a theory of discriminability, intended to explain recent patterns observed in ROC comparisons of lineups. We demonstrate, however, that these assumptions are incorrect when ROC analysis is applied to lineups. We also demonstrate that a structural phenomenon of lineups, differential filler siphoning, and not the psychological phenomenon of diagnostic-feature detection, explains why lineups are superior to showups and why fair lineups are superior to biased lineups. In the process of our proofs, we show that computational simulations have assumed, unrealistically, that all witnesses share exactly the same decision criteria. When criterial variance is included in computational models, differential filler siphoning emerges. The result proves dissociation between ROC curves and underlying discriminability: Higher ROC curves for lineups than for showups and for fair than for biased lineups despite no increase in underlying discriminability. [ABSTRACT FROM AUTHOR]

Facial features differ in the amount of expressive information they convey. Specifically, eyes are argued to be essential for fear recognition, while smiles are crucial for recognising happy expressions. In three experiments, we tested whether expression modulates the perceptual saliency of diagnostic facial features and whether the feature’s saliency depends on the face configuration. Participants were presented with masked facial features or noise at perceptual conscious threshold. The task was to indicate whether eyes (experiments 1-3A) or a mouth (experiment 3B) was present. The expression of the face and its configuration (i.e. spatial arrangement of the features) were manipulated. Experiment 1 compared fearful with neutral expressions, experiments 2 and 3 compared fearful versus happy expressions. The detection accuracy data was analysed using Signal Detection Theory (SDT), to examine the effects of expression and configuration on perceptual precision (d’) and response bias (c), separately. Across all three experiments, fearful eyes were detected better (higher d’) than neutral and happy eyes. Eyes were more precisely detected than mouths, whereas smiles were detected better than fearful mouths. The configuration of the features had no consistent effects across the experiments on the ability to detect expressive features. But facial configuration affected consistently the response bias. Participants used a more liberal criterion for detecting the eyes in canonical configuration and fearful expression. Finally, the power in low spatial frequency of a feature predicted its discriminability index. The results suggest that expressive features are perceptually more salient with a higher d’ due to changes at the low-level visual properties, with emotions and configuration affecting perception through top-down processes, as reflected by the response bias. [ABSTRACT FROM AUTHOR]

Introduction:Auditory hallucinations are associated with signal detection biases. We examine the extent to which suggestions influence performance on a signal detection task (SDT) in highly hallucination-prone and low hallucination-prone students. We also explore the relationship between trait suggestibility, dissociation and hallucination proneness. Method:In two experiments, students completed on-line measures of hallucination proneness (the revised Launay–Slade Hallucination Scale; LSHS-R), trait suggestibility (Inventory of Suggestibility) and dissociation (Dissociative Experiences Scale-II). Students in the upper and lower tertiles of the LSHS-R performed an auditory SDT. Prior to the task, suggestions were made pertaining to the number of expected targets (Experiment 1,N = 60: high vs. low suggestions; Experiment 2,N = 62, no suggestion vs. high suggestion vs. no voice suggestion). Results:Correlational and regression analyses indicated that trait suggestibility and dissociation predicted hallucination proneness. Highly hallucination-prone students showed a higher SDT bias in both studies. In Experiment 1, both bias scores were significantly affected by suggestions to the same degree. In Experiment 2, highly hallucination-prone students were more reactive to the high suggestion condition than the controls. Conclusion:Suggestions may affect source-monitoring judgments, and this effect may be greater in those who have a predisposition towards hallucinatory experiences. [ABSTRACT FROM PUBLISHER]

There is some evidence that short interstimulus intervals (ISIs) on the Psychomotor Vigilance Test (PVT) are associated with longer and more varied reaction times (RTs). Preparation processes may impede RT following short ISIs, resulting in additional unexplained variance. The aims of this study were to investigate whether there is an effect of ISI on RT and errors within the PVT, and whether such an effect changes with three elements of fatigue: time of day, prior wake and time on task. Twelve male participants completed 49 PVTs across 7× 28 h periods of forced desynchrony. For analysis, RTs, reciprocal reaction times (1/RT), false starts and lapse responses within each 10 min session were assigned to a 1-s ISI group, a 2-min time of task group, a 2.5-h PW level and a 60° phase of the circadian rhythm of core body temperature (as a measure of time of day). Responses following short ISIs (2–5 s) were significantly slower and more varied than responses following longer ISIs (5–10 s). The likelihood of a lapse was also higher for short ISIs, while the probability of a false start increased as a function of ISI. These effects were independent of the influences of time of day, prior wake and time on task. Hence, mixed model ANOVAs comprising only long ISIs (5–10 s) contained stronger effect sizes for fatigue than a model of all ISIs (2–10 s). Including an ISI variable in a model improved the model fit and explained more variance associated with fatigue. Short ISIs resulted in long RTs both in the presence and absence of fatigue, possibly due to preparation processes or ISI conditioning. Hence, omitting short ISI trials from RT means or including an ISI variable in analysis can reduce unwanted variance in PVT data, improving the sensitivity of the PVT to fatigue. [ABSTRACT FROM AUTHOR]

Purpose Clinical psychologists and other health professionals are often requested to act as expert witnesses in Court. They are required to assess, and report upon, the reliability of the accounts of physical and psychological symptoms made by their clients. This study investigated the effectiveness of a checklist drawing upon relevant literature on lying and malingering to aid the detection of exaggeration of physical symptoms. Method Sixty-four participants were cast as interviewers and assigned to either a 'checklist' or 'no checklist' condition. Another 64 volunteers were assigned to either a 'truth teller' or 'malingerer' role and, after undergoing a cold pressor procedure, were interviewed about their experience. The interviewers with a checklist drawn from the literature were asked to rate the presence of 28 checklist items on 5-point Likert scales and to indicate whether or not they believed their interviewee was truthful or exaggerating his or her symptoms. The interviewers without the checklist were asked to simply indicate whether their interviewee was truthful or exaggerating. Results Evaluators who were not given the checklist did not classify their interviewees at a level significantly better than chance. Those using the checklist achieved an overall hit rate of 70%. Signal detection analysis supported the finding that those with the checklist showed greater discriminability. Nine checklist items significantly discriminated between truth tellers and malingerers. Furthermore, the total checklist score was significantly higher for exaggerated accounts than for truthful accounts. Conclusions Results suggest that a checklist based on the literatures into lying and malingering warrants further investigation. Such a tool would be useful as an aid for expert witnesses called to provide informed opinion on the likelihood that a claimant is exaggerating, malingering or otherwise misrepresenting difficulties. [ABSTRACT FROM AUTHOR]

Distinct networks in the forebrain and the midbrain coordinate to control spatial attention. The critical involvement of the superior colliculus (SC)--the central structure in the midbrain network--in visuospatial attention has been shown by four seminal, published studies in monkeys (Macaca mulatta) performing multialternative tasks. However, due to the lack of a mechanistic framework for interpreting behavioral data in such tasks, the nature of the SC's contribution to attention remains unclear. Here we present and validate a novel decision framework for analyzing behavioral data in multialternative attention tasks. We apply this framework to re-examine the behavioral evidence from these published studies. Our model is a multidimensional extension to signal detection theory that distinguishes between two major classes of attentional mechanisms: those that alter the quality of sensory information or "sensitivity," and those that alter the selective gating of sensory information or "choice bias." Model-based simulations and model-based analyses of data from these published studies revealed a converging pattern of results that indicated that choice-bias changes, rather than sensitivity changes, were the primary outcome of SC manipulation. Our results suggest that the SC contributes to attentional performance predominantly by generating a spatial choice bias for stimuli at a selected location, and that this bias operates downstream of forebrain mechanisms that enhance sensitivity. The findings lead to a testable mechanistic framework of how the midbrain and forebrain networks interact to control spatial attention. [ABSTRACT FROM AUTHOR]

Contemporary cognitive science attempts to provide computational models that describe how consciousness and emotion constitute adaptive behavior. Given the recent neurobiological view that highlights the fact that the cognitive and emotional regions of the brain work together to achieve conscious behavior, it was shown that signal-detection theory (SDT) can effectively capture the notion of the consciousness-emotion interactions that underlie emotional experience. In particular, I have demonstrated that the hierarchical SDT model is capable of estimating different levels of the hierarchical organization of emotional experience. I have also shown that the threshold SDT model predicts that the formation of emotion experience requires a discrete decision space, which implies that the neural representations of emotion are mediated by thresholds to be experienced consciously. The application of both computational SDT models seems to be a promising advance for studying consciousness--emotion interactions. [ABSTRACT FROM AUTHOR]

The present study investigated true and false memory manifestations of adaptive and maladaptive perfectionism using the DRM (Deese-Roediger-McDermott) word lists paradigm. Ninety-seven college students were administered the DRM paradigm and completed the Almost Perfect Scale-Revised (Slaney, Rice, Mobley, Trippi, & Ashby, 2001). Signal detection analyses revealed that perfectionism strivings was associated with more accurate memory, whereas perfectionistic concerns was associated with higher levels of false memories and higher confidence ratings about the accuracy of these memories. Moreover, individuals high in perfectionistic concerns manifested a lower memory discriminative ability, suggesting poor working memory capacity. These findings corroborate previous studies suggesting a working memory involvement in false memories and call for further investigation into the cognitive and emotional processes underlying false memories. [ABSTRACT FROM AUTHOR]

Metacognition, or the capacity to reflect upon one’s own knowledge, is a key trait in our cognitive repertoire which is developed during childhood. Here, a direct comparison of metacognitive ability in children ( N = 188; 6–9 years old) and adults, ( N = 47) using a single perceptual task, was made. Results showed that 6–9 years old children have a level of metacognitive access similar to that of adults. Further, a signal detection theory model was applied in order to distinguish metacognitive ability from the propensity towards risk taking, two factors that have so far been confounded in studies. Children presented a suboptimal tendency towards risky decisions and a natural predisposition to overconfidence that can be partially mitigated by imposing a conservative normative strategy. [ABSTRACT FROM AUTHOR]

With neurological processes involving multiple neurotransmitters and neuromodulators, it is important to have the ability to directly map and quantify multiple signaling molecules simultaneously in a single analysis. By utilizing a molecular-specific approach, namely desorption electrospray ionization mass spectrometry imaging (DESI-MSI), we demonstrated that the technique can be used to image multiple neurotransmitters and their metabolites (dopamine, dihydroxyphenylacetic acid, 3-methoxytyramine, serotonin, glutamate, glutamine, aspartate, γ-aminobutyric acid, adenosine) as well as neuroactive drugs (amphetamine, sibutramine, fluvoxamine) and drug metabolites in situ directly in brain tissue sections. The use of both positive and negative ionization modes increased the number of identified molecular targets. Chemical derivatization by charge-tagging the primary amines of molecules significantly increased the sensitivity, enabling the detection of low abundant neurotransmitters and other neuroactive substances previously undetectable by MSI. The sensitivity of the imaging approach of neurochemicals has a great potential in many diverse applications in fields such as neuroscience, pharmacology, drug discovery, neurochemistry, and medicine. [ABSTRACT FROM AUTHOR]

The idea that costly signals are more credible is a long-standing hypothesis in international politics. However, little is known on how costly signaling actually works. Causal evidence is elusive because the effect of a costly signal is almost always confounded with the effects of other previous or simultaneous information. I design three controlled experiments to study how the logic of sinking costs operates. I find that signalers randomly assigned with high resolve are more likely to sink costs, but receivers do not acquiesce in line with signaler expectations, despite the sunk costs suffered. The logic of sunk-cost signaling is strong at the signaler's end but not at the receiver's end. There is a sender-receiver gap in how the same deterrence interaction is perceived at the two ends of the signaling mechanism, contrary to what the theory of costly signaling automatically assumes. [ABSTRACT FROM AUTHOR]

Viewing the body can influence pain perception, even when vision is non-informative about the noxious stimulus. Prior studies used either continuous pain rating scales or pain detection thresholds, which cannot distinguish whether viewing the body changes the discriminability of noxious heat intensities or merely shifts reported pain levels. In Experiment 1, participants discriminated two intensities of heat-pain stimulation. Noxious stimuli were delivered to the hand in darkness immediately after participants viewed either their own hand or a non-body object appearing in the same location. The visual condition varied randomly between trials. Discriminability of the noxious heat intensities ( d′) was lower after viewing the hand than after viewing the object, indicating that viewing the hand reduced the information about stimulus intensity available within the nociceptive system. In Experiment 2, the hand and the object were presented in separate blocks of trials. Viewing the hand shifted perceived pain levels irrespective of actual stimulus intensity, biasing responses toward 'high pain' judgments. In Experiment 3, participants saw the noxious stimulus as it approached and touched their hand or the object. Seeing the pain-inducing event counteracted the reduction in discriminability found when viewing the hand alone. These findings show that viewing the body can affect both perceptual processing of pain and responses to pain, depending on the visual context. Many factors modulate pain; our study highlights the importance of distinguishing modulations of perceptual processing from modulations of response bias. [ABSTRACT FROM AUTHOR]