Group Differences In Reaction Time Research Articles

Similar Gap-Overlap Profiles in Children with Fragile X Syndrome and IQ-Matched Autism.

Fragile X syndrome (FXS) is a single-gene disorder characterized by moderate to severe cognitive impairment and a high association with autism spectrum disorder (ASD) and Attention-Deficit/Hyperactivity Disorder (ADHD). Atypical visual attention is a feature of FXS, ASD, and ADHD. Thus, studying early attentional patterns in young children with FXS can offer insight into early emerging neurocognitive processes underlying challenges and contribute to our understanding of common and unique features of ASD and ADHD in FXS. The present study examined visual attention indexed by the gap-overlap paradigm in children with FXS (n = 39) compared to children with ASD matched on intellectual ability and age (n = 40) and age-matched neurotypical controls (n = 34). The relationship between gap-overlap performance and intellectual ability, ASD, and ADHD across groups was characterized. Saccadic reaction times (RT) were collected across baseline, gap, and overlap conditions. Results indicate no group differences in RT for any conditions. However, RT of the ASD and NT groups became slower throughout the experiment whereas RT of the FXS group did not change, suggesting difficulties in habituation for the FXS group. There was no relationship between RT and intellectual ability, ADHD, or ASD symptoms in the FXS and ASD groups. In the NT group, slower RT was related to elevated ADHD symptoms only. Taken together, findings suggest that the social attention differences documented in FXS and ASD may be due to other cognitive factors, such as reward or motivation, rather than oculomotor control of visual attention.

Alcohol use disorder and fitness to drive: Discrepancies between health professionals' evaluations and objective measures of alcohol use and cognitive functioning.

Aims: In this study, we investigated if health professionals' evaluations of driving ability corresponded with measures of severity of alcohol use and measures of cognitive functions necessary for safely driving a car. Methods: A total of 90 participants from a multicentre study were included. Participants were categorised into three groups: (1) the group judged fit to drive (FIT); (2) the group judged not fit to drive (UNFIT); and (3) the group who had lost their driver's licence due to legal sanctions (LEGAL). The participants' AUDIT scores, earlier treatment episodes and results from neuropsychological tests of reaction time, attention and visuospatial ability were included in the analyses. Results: We found a significant difference in the severity of alcohol use disorder (AUD) and visuospatial abilities between the FIT and UNFIT groups. Half of the UNFIT group had at least mild visuospatial difficulties, compared to only a quarter in the FIT group. There were no group differences in reaction time or attentional measures. The LEGAL group had more severe AUD than the other groups. Conclusion: The FIT group did not perform differently from the UNFIT group on attention and reaction time measures. The UNFIT group had more visuospatial impairments, but even half of this group had normal scores. It is uncertain whether the differences between the two groups are of practical significance. The quality of health professionals' evaluations may be questioned, and the results highlight the need for more reliable and valid criteria for doing fitness to drive evaluations.

The role of sleep disturbance in reduced accuracy on a divided attention task among patients with fibromyalgia.

Patients with fibromyalgia show impaired cognitive performance compared with healthy, pain-free controls. Sleep disturbance, anxiety, and depression are highly prevalent among patients with fibromyalgia, and each is associated with impaired cognitive performance. Yet, limited work has explored whether psychosocial factors contribute to group differences in cognitive performance. This secondary data analysis investigated differences in cognitive performance between patients with fibromyalgia and healthy controls, and whether psychosocial factors accounted for these differences. Adults with fibromyalgia (N = 24) and healthy, pain-free controls (N = 26) completed 2 cognitive tasks and the Patient-Reported Outcomes Measurement Information System sleep disturbance, anxiety, and depression short forms. Independent samples t tests were used to test for differences in cognitive performance between patients with fibromyalgia and healthy controls. Pearson correlations were conducted to examine associations between psychosocial factors and cognitive performance. Psychosocial factors significantly related to cognitive performance were explored as potential mediators of group differences in cognitive performance. Patients with fibromyalgia demonstrated poorer accuracy for divided attention compared with healthy controls, and sleep disturbance mediated this group difference. On the attentional switching task, healthy controls showed a greater switch-cost for accuracy compared with patients with fibromyalgia, but there was no group difference in reaction time. Anxiety and depression were not related to cognitive performance. We found that patients with fibromyalgia reported greater sleep disturbance and, in turn, had poorer accuracy on the divided attention task. Sleep disturbance is modifiable with behavioral interventions, such as cognitive behavioral therapy, and may be a target for improving sleep quality and cognitive performance among patients with fibromyalgia.

Effect of different sport environments on proactive and reactive motor inhibition: A study on open- and closed-skilled athletes via mouse-tracking procedure.

This study aimed to investigate the effect of different sport environments (open-and closed-skill sports) on proactive and reactive inhibitory processes as two distinct components of motor inhibition. A mouse-tracking procedure was employed to compare behavioral performance among three groups of participants (tennis players, swimmers and non-athletes) in non-sport-specific cued Go/No-Go (GNG) and Stop Signal Task (SST), which mainly engage proactive and reactive inhibitory control, respectively. Reaction times (RTs), inhibitory failures, and Stop Signal Reaction Times (SSRTs) were measured. To investigate dynamic aspects of inhibitory control, movement trajectories classified as one-shot (absence of trajectory alteration reflected in a steep slope) or non-one-shot (non-linear/multipeaked trajectory, with one or multiple corrections) were analyzed and compared among groups. Results showed no group differences in RTs in Go/No-Go and Stop conditions. SSRTs were significant shorter for the athletes than non-athletes in SST, but no differences emerged for inhibitory failures in cued GNG. During inhibitory failures athletes showed higher proportion of non-one-shot movements than non-athletes. Higher proportion of non-one-shot profiles was observed in cued GNG compared to SST. Finally, no differences between open-and closed-skilled athletes were found in both tasks. Our findings suggest that both proactive and reactive inhibitory controls do benefit from sport practice, but open-and closed-skill sports do not differ in influencing inhibitory processes. Movement profile analysis could be a promising, complementary behavioral analysis to integrate for more fine-grained evaluation and differentiation of inhibitory motor control in athletes, specifically when using GNG tasks.

Viés Atencional em Faces Emocionais no Transtorno de Personalidade Borderline

O transtorno de personalidade borderline (TPB) tem como uma característica principal uma dificuldade de relacionamento interpessoal. O viés atencional (VA) seria a locação diferencial a estímulos considerados ameaçadores em detrimento a estímulos neutros. Saber se as pessoas com TPB tem um processamento atencional enviesado frente a expressões faciais torna-se relevante para ajudar compreender a psicopatologia e dar foco em intervenções clínicas. Objetivo: Investigar VA em faces emocionais em pessoas com TPB na tarefa dot-probe utilizando o eye tracking. Método: Participaram n=12 pessoas com funcionamento de TPB (grupo clínico) e n=13 com depressão (grupo controle-clínico) que responderam a uma tarefa de dot-probe com faces emocionais nos tempos de 250ms e 1000ms. Resultados: Houve diferenças no tempo de reação para a face emocional de raiva em 250ms, em que grupo clínico foi mais rápido para responder os ensaios do que grupo controle. Em relação ao eye tracking, houve diferenças de grupos, indicando que grupo controle olhou mais para os olhos das faces neutras do que o grupo clínico em ensaios incongruentes. Conclusões: Estudo sugere que há um VA para faces emocionais de raiva em pessoas com TPB em estágio de processamento automático. É sugerido intervenções terapêuticas específicas para TPB.

Metaphor processing in autism: A systematic review and meta-analysis

Impairments related to figurative language understanding have been considered to be one of the diagnostic and defining features of autism. Metaphor comprehension and production in autism spectrum disorder (ASD) as compared to typically developing (TD) individuals have been investigated for around thirty years, generally showing an overall advantage for TD groups. We present a preregistered systematic review and meta-analysis including a total of 15 studies that fulfilled our set of inclusion criteria (notably, ASD and TD groups matched in chronological age and verbal- or full-scale IQ). Along with accuracy, we also analyzed group differences in reaction time in the studies that reported them. The results revealed a medium-to-large group difference favoring TD over ASD groups based on accuracy measures, as well as a similar overall advantage for TD groups based on reaction times. There was reliable heterogeneity in effect sizes for group differences in accuracy, which was mostly explained by the effect of verbal intelligence, with differences in metaphor processing being smaller for participants with better verbal skills. Some of the variation in effect sizes may also be attributed to differences in types of metaphor processing tasks. We also evaluated the quality of the studies included in the meta-analysis, and the evidence relating to the potential presence of publication bias.

Altered sensorimotor representations after recovery from peripheral nerve damage in neuralgic amyotrophy

Neuralgic amyotrophy is a common peripheral nerve disorder caused by acute autoimmune inflammation of the brachial plexus. Subsequent weakness of the stabilizing shoulder muscles leads to compensatory strategies and abnormal motor control of the shoulder. Despite recovery of peripheral nerves and muscle strength over time, motor dysfunction often persists. Suboptimal motor recovery has been linked to maladaptive changes in the central motor system in several nervous system disorders. We therefore hypothesized that neuralgic amyotrophy patients with persistent motor dysfunction may have altered cerebral sensorimotor representations of the affected upper limb. To test this hypothesis, 21 neuralgic amyotrophy patients (mean age 45 ± 12 years, 5 female) with persistent lateralized symptoms in the right upper limb and 20 age- and sex-matched healthy controls, all right-handed, performed a hand laterality judgement task in a cross-sectional comparison. Previous evidence has shown that to solve this task, subjects rely on sensorimotor representations of their own upper limb, using a first-person imagery perspective without actual motor execution. This enabled us to investigate altered central sensorimotor representations while controlling for altered motor output and altered somatosensory afference. We found that neuralgic amyotrophy patients were specifically less accurate for laterality judgments of their affected right limb, as compared to healthy controls. There were no significant group differences in reaction times. Both groups used a first-person imagery perspective, as evidenced by changes in reaction times as a function of participants’ own arm posture. We conclude that cerebral sensorimotor representations of the affected upper limb are altered in neuralgic amyotrophy patients. This suggests that maladaptive central neuroplasticity may occur in response to peripheral nerve damage, thereby contributing to motor dysfunction. Therapies focused on altering cerebral sensorimotor representations may help to treat peripheral nerve disorders such as neuralgic amyotrophy.

Gender differences in mental rotation strategy depend on degree of autistic traits

The current study looked at eye movements to assess adults' strategies when mentally rotating three-dimensional cube figures. Adults with varying levels of autistic traits differ in their mental rotation strategies. In addition, gender differences in strategies are observed in adults with the highest level of autistic traits.

Associations Between Physical Fitness Indices and Working Memory in Breast Cancer Survivors and Age-Matched Controls.

This study examined the effects of cardiorespiratory fitness, heart rate recovery, and physical activity on working memory in breast cancer survivors and age-matched controls. Using a case-control design, 32 women who had received a breast cancer diagnosis and completed primary treatment within the past 36-months (11 radiation only; 21 chemotherapy) and 30 age-matched women with no previous cancer diagnosis completed a n-back continuous performance task commonly used as an assessment of working memory. In addition, cardiorespiratory fitness and heart rate recovery were measured during a submaximal graded exercise test and physical activity was measured using 7-days of accelerometer monitoring. Breast cancer survivors who had received chemotherapy had poorer heart rate recovery (p = .010) and engaged in less physical activity than women who had received radiation only (p = .004) or non-cancer controls (p = .029). Cancer treatment (radiation; chemotherapy) predicted differences in reaction times on the 1-back working memory task (p = .029). However, more rapid heart rate recovery predicted shorter reaction times on the 1-back task in the age-matched control group (p = .002). All participants with greater cardiorespiratory fitness displayed greater accuracy independent of disease status on the 1-back task (p = .017). No significant group differences in reaction times were observed for 2-back target trials between breast cancer survivors and controls. However, greater total physical activity predicted shorter reaction times in breast cancer survivors (radiation, chemotherapy) on the 2-back task (p = .014). In addition, all participants who exhibited more rapid heart rate recovery demonstrated better greater accuracy regardless of disease status (p = .013). These findings support differences in physical activty participation, heart rate recovery, and 1- and 2-back working memory reaction times between breast cancer survivors and age-matched controls. Greater cardiorespiratory fitness, heart rate recovery, and physical activity were positively associated with better working memory performance across conditions.

Predicting vulnerability to sleep deprivation using diffusion model parameters.

We used diffusion modelling to predict vulnerability to decline in psychomotor vigilance task (PVT) performance following a night of total sleep deprivation (SD). A total of 135 healthy young adults (69 women, age = 21.9 ± 1.7 years) participated in several within-subject cross-over design studies that incorporated the PVT. Participants were classified as vulnerable (lower tertile) or non-vulnerable (upper tertile) according to their change in lapse rate [lapse = reaction time (RT) ≥ 500 ms] between the evening before (ESD) and the morning after SD. RT data were fitted using Ratcliff's diffusion model. Although both groups showed significant change in RT during SD, there was no significant group difference in RT during the ESD session. In contrast, during ESD, the mean diffusion drift of vulnerable subjects was significantly lower than for non-vulnerable subjects. Mean drift and non-decision times were both adversely affected by sleep deprivation. Both mean drift and non-decision time showed significant state × vulnerability interaction. Diffusion modelling appears to have promise in predicting vulnerability to vigilance decline induced by a night of total sleep deprivation.

Electrophysiological assessment of the effects of obstructive sleep apnea on cognition.

We used electrophysiological measures to investigate the effects of obstructive sleep apnea on attention, learning, and memory. Thirty subjects (OSA group, n = 15, control group n = 15) participated in n-back tests, accompanied by P300 recordings, to investigate working memory and attention. The mirror-drawing test was used to study procedural memory, and the trail-making test (TMT) was used to evaluate divided attention and executive function. No significant group difference in reaction time was found in the 0-back and 1-back tests. In the 2-back test, reaction times of patients were longer than those of the control group. No P300 wave was obtained in the OSA group in any (0-, 1-, or 2-back) n-back test. In contrast, in the control group, significant P300 waves were recorded except for the 2-back test. The mirror-drawing scores were unaffected by sleep apnea. There was no difference between groups in the TMT-A test on any of the trials. Although no group difference was found in the first or second trials of the TMT-B test, OSA patients were less successful in learning on the third trial. According to our study results, OSA affects attention and executive function adversely however, we could not detect a significant effect on working or procedural memory.

Impact of total sleep deprivation on behavioural neural processing of emotionally expressive faces

Sleep deprivation impacts subjective mood states, but very little research has examined the impact on processing emotional information. In the current study, we investigated the impact of total sleep deprivation on neural responses to emotional facial expressions as well as the accuracy and speed with which these faces were categorized. Forty-nine participants completed two tasks in which they were asked to categorize emotional facial expressions as Happy, Sad, Angry, or Fearful. They were shown the 'full' expression of the emotions in one task and more subtle expressions in a second task in which expressions were 'morphed' with neutral faces so that the intensity of emotion varied. It was expected that sleep deprivation would lead to greater reactivity (indexed by larger amplitude N170 event-related potentials), particularly for negative and more subtle facial expressions. In the full face task, sleep-deprived (SD) participants were significantly less accurate than controls (C) at identifying Sad faces and slower to identify all emotional expressions. P1 was smaller and N170 was larger for the SD compared to C group, but for all emotions, indicating generalized impairment in low-level visual processing. In the more difficult morphed face task, SD participants were less accurate than C participants for Sad faces; as well, the group difference in reaction time was greatest for Sad faces. For the SD group, N170 increased in amplitude with increasing perceptual difficulty for the Fearful and Angry faces, but decreased in amplitude with increasing difficulty for Sad faces. These data illustrate that sleep deprivation led to greater neural reactivity for the threat-related negative emotions as they became more subtle; however, there was a failure to engage these perceptual resources for the processing of Sad faces. Sleep loss preferentially impacted the processing of Sad faces; this has widespread implications for sleep-deprived groups.

An early fMRI marker of semantic memory deficits in people with amnestic mild cognitive impairment

Semantic memory deficits in Alzheimer's disease have often been reported. However, the nature of changes in semantic memory at pre-dementia stage is less extensively studied. By acquiring functional magnetic resonance imaging (fMRI) during a semantic memory task, we examined brain activity that could be affected by early disease processes in patients with amnestic Mild Cognitive Impairment (aMCI). We applied fMRI during the Semantic Object Retrieval Task (SORT), a task where subjects answered at each trial whether a pair of words presented would bring to mind a particular object. Trials of “Binds” probe object memory (e.g., humps and desert) whereas “NonBinds” do not (e.g., humps and mirror). We thus compared blood oxygen level dependent (BOLD) signal recorded from aMCI patients (N=6; mean age: 72.7±8.3 yr; CDR=0.5) to that of age-matched normal control (NC) subjects (N=6; mean age: 67.3±9.8 yr; CDR=0). Participants in both groups took longer to respond to NonBinds compared to Binds. No group differences in reaction time or accuracy were observed (p > .05). FMRI data showed that NC subjects demonstrated greater BOLD signal during Binds compared to NonBinds in left supramarginal gyrus and precuneus whereas no such differences were observed in the aMCI group (FWE < .05). Overall, NC subjects had greater activations than aMCI patients during Binds in bilateral medial frontal lobe, left insula, left caudate, and left post-central gyrus (p < .005, corrected at cluster size > 50 voxels), but NonBind-associated activations did not differ between groups. NC subjects had greater brain response elicited by trials that required retrieval of object memory compared to trials that did not. In contrast, aMCI patients showed no such differential brain activation while demonstrating less brain activity than NC subjects during memory retrieval. Our findings suggest that neural integrity in the regions involved in object memory retrieval is compromised in individuals with aMCI even when behavioral performance is not impaired. Presumably, changes in these brain regions indicate an early sign of semantic memory deficits that may become behaviorally measurable only at a later stage.

Recognizing Biological Motion and Emotions from Point-Light Displays in Autism Spectrum Disorders

One of the main characteristics of Autism Spectrum Disorder (ASD) are problems with social interaction and communication. Here, we explored ASD-related alterations in ‘reading’ body language of other humans. Accuracy and reaction times were assessed from two observational tasks involving the recognition of ‘biological motion’ and ‘emotions’ from point-light displays (PLDs). Eye movements were recorded during the completion of the tests. Results indicated that typically developed-participants were more accurate than ASD-subjects in recognizing biological motion or emotions from PLDs. No accuracy differences were revealed on two control-tasks (involving the indication of color-changes in the moving point-lights). Group differences in reaction times existed on all tasks, but effect sizes were higher for the biological and emotion recognition tasks. Biological motion recognition abilities were related to a person’s ability to recognize emotions from PLDs. However, ASD-related atypicalities in emotion recognition could not entirely be attributed to more basic deficits in biological motion recognition, suggesting an additional ASD-specific deficit in recognizing the emotional dimension of the point light displays. Eye movements were assessed during the completion of tasks and results indicated that ASD-participants generally produced more saccades and shorter fixation-durations compared to the control-group. However, especially for emotion recognition, these altered eye movements were associated with reductions in task-performance.

EVENT-RELATED POTENTIAL STUDY OF ATTENTION REGULATION DURING ILLUSORY FIGURE CATEGORIZATION TASK IN ADHD, AUTISM SPECTRUM DISORDER, AND TYPICAL CHILDREN.

Autism spectrum disorders (ASD) and attention deficit/hyperactivity disorder (ADHD) are very common developmental disorders which share some similar symptoms of social, emotional, and attentional deficits. This study is aimed to help understand the differences and similarities of these deficits using analysis of dense-array event-related potentials (ERP) during an illusory figure recognition task. Although ADHD and ASD seem very distinct, they have been shown to share some similarities in their symptoms. Our hypothesis was that children with ASD will show less pronounced differences in ERP responses to target and non-target stimuli as compared to typical children, and to a lesser extent, ADHD. Participants were children with ASD (N=16), ADHD (N=16), and controls (N=16). EEG was collected using a 128 channel EEG system. The task involved the recognition of a specific illusory shape, in this case a square or triangle, created by three or four inducer disks. There were no between group differences in reaction time (RT) to target stimuli, but both ASD and ADHD committed more errors, specifically the ASD group had statistically higher commission error rate than controls. Post-error RT in ASD group was exhibited in a post-error speeding rather than corrective RT slowing typical for the controls. The ASD group also demonstrated an attenuated error-related negativity (ERN) as compared to ADHD and controls. The fronto-central P200, N200, and P300 were enhanced and less differentiated in response to target and non-target figures in the ASD group. The same ERP components were marked by more prolonged latencies in the ADHD group as compared to both ASD and typical controls. The findings are interpreted according to the "minicolumnar" hypothesis proposing existence of neuropathological differences in ASD and ADHD, specifically minicolumnar number/width morphometry spectrum differences. In autism, a model of local hyperconnectivity and long-range hypoconnectivity explains many of the behavioral and cognitive deficits present in the condition, while the inverse arrangement of local hypoconnectivity and long-range hyperconnectivity in ADHD explains some deficits typical for this disorder. The current ERP study supports the proposed suggestion that some between group differences could be manifested in the frontal ERP indices of executive functions during performance on an illusory figure categorization task.

List context manipulation reveals orthographic deficits in Italian readers with developmental dyslexia

We tested the influence of list context on word frequency and length effects on the reading aloud of Italian developmental dyslexics and skilled peers. The stimuli were presented either in mixed blocks (alternating words and nonwords) or in pure blocks. The analyses based on the rate-and-amount model (Faust et al., 1999) indicated that group differences in reaction times between dyslexic and skilled readers (a) were well accounted for in terms of global components and (b) were modulated by context in the case of words but not in the case of nonwords. ANOVAs on z-transformed reaction time data further indicated the influence of stimulus length. Importantly, the frequency effect interacted with context: Controls showed a list context effect for high- and low-frequency words, while dyslexics showed a list context effect only for high-frequency words. The effect of length on reading times remained unaffected by context manipulation. It is proposed that this pattern of results may be accounted for by hypothesizing two separate deficits: An early graphemic impairment affecting performance independently of context and a later inefficiency in activating entries in the orthographic lexicon as a function of context demands.

Functional Cortical and Subcortical Abnormalities in Pedophilia: A Combined Study Using a Choice Reaction Time Task and fMRI

Pedophiles show sexual interest in prepubescent children but not in adults. Research into the neurofunctional mechanisms of paraphilias has gathered momentum over the last years. To elucidate the underlying neural processing of sexual interest among pedophiles and to highlight the differences in comparison with nonparaphilic sexual interest in adults. Nine pedophilic patients and 11 nonpedophilic control subjects underwent functional magnetic resonance imaging (fMRI) while viewing pictures of nude (prepubescents, pubescents, and adults) and neutral content, as well as performing a concomitant choice reaction time task (CRTT). Brain blood oxygen level-dependent (BOLD) signals and response latencies in the CRTT during exposure to each picture category. Analysis of behavioral data showed group differences in reaction times regarding prepubescent and adult but not pubescent stimuli. During stimulation with pictures displaying nude prepubescents, pedophiles showed increased BOLD response in brain areas known to be involved in processing of visual sexual stimuli. Comparison of pedophilic patients with the control group discovered differences in BOLD responses with respect to prepubescent and adult but not to pubescent stimuli. Differential effects in particular occurred in the cingulate gyrus and insular region. The brain response of pedophiles to visual sexual stimulation by images of nude prepubescents is comparable with previously described neural patterns of sexual processing in nonpedophilic human males evoked by visual stimuli depicting nude adults. Nevertheless, group differences found in the cingulate gyrus and the insular region suggest an important role of these brain areas in pedophilic sexual interest. Furthermore, combining attention-based methods like CRTT with fMRI may be a viable option for future diagnostic procedures regarding pedophilia.

Updating positive and negative stimuli in working memory in depression.

Difficulties in the ability to update stimuli in working memory (WM) may underlie the problems with regulating emotions that lead to the development and perpetuation of mood disorders such as depression. To examine the ability to update affective material in WM, the authors had diagnosed depressed and never-disordered control participants perform an emotion 2-back task in which participants were presented with a series of happy, sad, and neutral faces and were asked to indicate whether the current face had the same (match-set) or different (break-set or no-set) emotional expression as that presented 2 faces earlier. Participants also performed a 0-back task with the same emotional stimuli to serve as a control for perceptual processing. After transforming reaction times to control for baseline group differences, depressed and nondepressed participants exhibited biases in updating emotional content that reflects the tendency to keep negative information and positive information, respectively, active in WM. Compared with controls, depressed participants were both slower to disengage from sad stimuli and faster to disengage from happy facial expressions. In contrast, nondepressed controls took longer to disengage from happy stimuli than from neutral or sad stimuli. These group differences in reaction times may reflect both protective and maladaptive biases in WM that underlie the ability to effectively regulate negative affect.

Effects of anxiety on visuospatial pattern discrimination and decision-making processes: what can we learn from brain dynamics?

Event Abstract Back to Event Effects of anxiety on visuospatial pattern discrimination and decision-making processes: what can we learn from brain dynamics? Catherine Brandner1*, S. Tapparel1, L. Grabherr1 and Julie Palix1 1 Department of Psychology, University of Lausanne, Switzerland Detection and discrimination of visuospatial input involve at least extracting, selecting and encoding relevant information and decision-making processes allowing selecting a response. These two operations are altered, respectively, by attentional mechanisms that change discrimination capacities, and by beliefs concerning the likelihood of uncertain events. Information processing is tuned by the attentional level that acts like a filter on perception, while decision-making processes are weighed by subjective probability of risk. In addition, it has been shown that anxiety could affect the detection of unexpected events through the modification of the level of arousal. Consequently, purpose of this study concerns whether and how decision-making and brain dynamics are affected by anxiety. To investigate these questions, the performance of women with either a high (12) or a low (12) STAI-T (State-Trait Anxiety Inventory, Spielberger, 1983) was examined in a decision-making visuospatial task where subjects have to recognize a target visual pattern from non-target patterns. The target pattern was a schematic image of furniture arranged in such a way as to give the impression of a living room. Non-target patterns were created by either the compression or the dilatation of the distances between objects. Target and non-target patterns were always presented in the same configuration. Preliminary behavioral results show no group difference in reaction time. In addition, visuo-spatial abilities were analyzed trough the signal detection theory for quantifying perceptual decisions in the presence of uncertainty (Green and Swets, 1966). This theory treats detection of a stimulus as a decision-making process determined by the nature of the stimulus and cognitive factors. Astonishingly, no difference in d’ (corresponding to the distance between means of the distributions) and c (corresponds to the likelihood ratio) indexes was observed. Comparison of Event-related potentials (ERP) reveals that brain dynamics differ according to anxiety. It shows differences in component latencies, particularly a delay in anxious subjects over posterior electrode sites. However, these differences are compensated during later components by shorter latencies in anxious subjects compared to non-anxious one. These inverted effects seem indicate that the absence of difference in reaction time rely on a compensation of attentional level that tunes cortical activation in anxious subjects, but they have to hammer away to maintain performance. Conference: 10th International Conference on Cognitive Neuroscience, Bodrum, Turkey, 1 Sep - 5 Sep, 2008. Presentation Type: Poster Presentation Topic: Emotional Processing Citation: Brandner C, Tapparel S, Grabherr L and Palix J (2008). Effects of anxiety on visuospatial pattern discrimination and decision-making processes: what can we learn from brain dynamics?. Conference Abstract: 10th International Conference on Cognitive Neuroscience. doi: 10.3389/conf.neuro.09.2009.01.208 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 08 Dec 2008; Published Online: 08 Dec 2008. * Correspondence: Catherine Brandner, Department of Psychology, University of Lausanne, Lausanne, Switzerland, Catherine.Brandner@unil.ch Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Catherine Brandner S. Tapparel L. Grabherr Julie Palix Google Catherine Brandner S. Tapparel L. Grabherr Julie Palix Google Scholar Catherine Brandner S. Tapparel L. Grabherr Julie Palix PubMed Catherine Brandner S. Tapparel L. Grabherr Julie Palix Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Neurobehavioral Performance of Residents After Heavy Night Call vs After Alcohol Ingestion

The issue of work-related sleep loss and consequent fatigue in medical residents continues to cause concern. Some, but not all, studies point to postcall deficits in performance. In this prospective study of 34 pediatric residents, postcall performance was compared during a heavy call rotation (defined as every fourth or fifth night) with light call, light call combined with a blood alcohol concentration of 0.04 gm% to 0.05 gm% per 100 mL, and heavy call with a placebo. The study group included 18 women and 16 men with a mean age of 29 years who worked at an academic medical center. An hour-long test battery was administered during the final week of a light call rotation (nonpostcall); in the final week of a heavy call rotation (postcall); and after alcohol (in the light call group) or placebo (in the heavy call group). Each test session ended with a self-assessment of performance. Outcome measures included the Stanford Sleepiness Scale, a visual analog scale, the Psychomotor Vigilance Task, the Continuance Performance Test, and a simulated driving task. Heavy and light call rotations averaged 90 and 44 hours per week, respectively. Nocturnal sleep averaged approximately 7–1/2 hours during light call and 6–1/4 hours during heavy call. Compared with light call, heavy call reaction times were 7% slower, commission errors were 40% higher, and performance on the driving simulator was substantially poorer. One driving parameter, speed variability, was greater in heavy call with placebo than in light call with alcohol. There were, however, no significant group differences in reaction time, omission errors, lapses, or off-road riving. Self-assessments correlated with actual performance in heavy call residents with respect to commission errors, lane variability, and speed variability, but not reaction time. In both heavy call groups, more participants rated their performance on the Psychomotor Vigilance Task to be poor. Performance on the Continuous Performance Test did not relate to training year. Residents on heavy call or light call with alcohol made more commission errors on this test, and self-ratings showed the same trend. Far more heavy call residents than light call residents rated their simulated driving performance as poor or worse. Using a variety of performance tests, medical residents in this study were about as impaired postcall after 4 weeks on a heavy call rotation as were those on light call who had blood alcohol levels of 0.04 to 0.05 gm%. Residents must be aware of postcall performance impairment and the consequent risk to both themselves and their patients. Sleepy residents may not recognize that they are impaired. Residency programs should include discussions of sleep loss, fatigue, and effective countermeasures. Residency programs might consider adopting such measures as alternative call schedules and postcall quarters in which residents can nap.