Differences In Reaction Time Research Articles

Mediating effect of amygdala activity on response to fear vs. happiness in youth with significant levels of irritability and disruptive mood and behavior disorders.

Irritability, characterized by a tendency to exhibit increased anger, is a common clinical problem in youth. Irritability is a significant clinical issue in youth with various psychiatric diagnoses, especially disruptive behavior, and mood disorders (Attention-Deficit/Hyperactivity Disorder, Oppositional Defiant Disorder, Conduct Disorder, and Disruptive Mood Dysregulation Disorder). Although there have been previous studies focusing on functional alteration in the amygdala related to irritability, there is no comprehensive model between emotional, neuronal, and behavioral characteristics. Using an functional magnetic resonance imaging (fMRI) procedure, we investigated the relationships between behavioral irritability, selective impairments in processing facial emotions and the amygdala neural response in youth with increased irritability. Fifty-nine youth with disruptive mood and behavior disorder completed a facial expression processing task with an event-related fMRI paradigm. The severity of irritability was evaluated using the Affective Reactivity Index. In the result of behavioral data, irritability, and reaction time (RT) differences between interpreting negative (fear) and positive (happiness) facial expressions were positively correlated. In the fMRI result, youth showed higher activation in the right cingulate gyrus, bilateral cerebellum, right amygdala, right precuneus, right superior frontal gyrus, right middle occipital gyrus, and middle temporal gyrus, during the happiness condition vs. fear condition. No brain region exhibited greater activation in the fear than in the happiness conditions. In the result of the mediator analysis, increased irritability was associated with a longer RT toward positive vs. negative facial expressions. Irritability was also positively associated with the difference in amygdala blood oxygen level-dependent responses between the two emotional conditions (happiness > fear). This difference in amygdala activity mediated the interaction between irritability and the RT difference between negative and positive facial expressions. We suggest that impairment in the implicit processing of facial emotional expressions with different valences causes distinct patterns of amygdala response, which correlate with the level of irritability. These results broaden our understanding of the biological mechanism of irritability at the neural level and provide information for the future direction of the study.

Reliability of a shortened single-target implicit association Test (ST-IAT) as an implicit measure of attitudes towards inclusion. Replication and extension of “implicitly measuring attitudes towards inclusive Education: a new attitude Test based on single-target implicit associations” (Lüke and Grosche, 2018, European journal of special needs Education)

ABSTRACT Attitudes towards inclusion (ATI) are regarded as an important aspect for the implementation of inclusive education. Yet, explicit measures of ATI have some limitations. Single-target implicit association tests (ST-IAT) provide an opportunity to an implicit ATI measure based on differences in reaction times. However, this can be a time-consuming procedure. The present study is a replication and extension of the study ‘Implicitly measuring attitudes towards inclusive education: a new attitude test based on single-target implicit associations’ by investigating reliability of a shortened version of the ST-IAT Inclusion. Prior studies did not investigate the reliability continuously, nor did they consider different ways of calculating the ST-IAT effect size (D-score). In this study, data from 594 university students are analysed to evaluate the reliability of a shortened ST-IAT Inclusion. Results show that the reliability of the shortened ST-IAT is good and in line with findings on reliability of other ST-IAT procedures. However, the difference between several D-score procedures was rather marginal. Altogether, the shortened ST-IAT Inclusion can provide an economic and reliable measure for ATI.

Cognitive inflexibility is linked to abnormal frontoparietal-related activation and connectivity in obsessive-compulsive disorder.

Although it was acknowledged that patients with obsessive-compulsive disorder (OCD) would exhibit cognitive inflexibility, the underlying neural mechanism has not been fully clarified. Therefore, this study aimed to investigate the neural substrates involved in cognitive inflexibility among individuals with OCD. A total of 42 patients with OCD and 48 healthy controls (HCs) completed clinical assessment and functional magnetic resonance imaging (fMRI) data collection during cued task switching. Behavioral performances and fMRI activation were compared between the OCD group and the HC group. Psychophysiological interactions (PPIs) analyses were applied to explore functional connectivity related to task switching. Pearson correlation was used to investigate the relationships among behavioral performance, fMRI activity, and obsessive-compulsive symptoms in OCD. The OCD group had a greater switch cost than HCs (χ2 = 5.89, p < .05). A significant difference in reaction time was found during switch (χ2 = 17.72, p < .001) and repeat (χ2 = 16.60, p = .018) between the two groups, while there was no significant difference in group accuracy. Comparison of group differences showed that the OCD group had increased activation in the right superior parietal cortex (rSPL) during task switching, and exhibited increased connectivity of frontoparietal network/default mode network (FPN-DMN; i.e., middle frontal gyrus [MFG]/inferior parietal cortex-precuneus, MFG-middle/posterior cingulate gyrus) and within the FPN (inferior parietal cortex-postcentral gyrus). In the OCD group, the compulsion score was positively correlated with accuracy during switch (r = .405, p = .008, FDRq <.05), and negatively correlated with activation of rSPL (r = -.328, p = .034, FDRq >.05). Patients with OCD had impaired cognitive flexibility and cautious response strategy. The neural mechanism of cognitive inflexibility in OCD may involve increased activation in the rSPL, as well as hyperconnectivity within the FPN and between the FPN and DMN.

Spatiotemporal expectations of apparent motion and the effect of attentional control

An experimental investigation was conducted on whether and how temporal expectation influences visual processing in moving objects, while also considering the role of attention control. Data on reaction times were collected as outcome measures from two behavioural experiments. In experiment 1, participants (n = 36) were asked to monitor the movement of an object until its disappearance and respond quickly when it reappeared. The trajectory of an object before its disappearance generates expectations regarding the position and/or timing of its subsequent reappearance. Results revealed that all states of expectation significantly shortened reaction times compared with no expectation. In experiment 2, participants (n = 34) performed the same reaction time task while simultaneously engaging in a working memory task, which comprised memorising a string of characters. Results indicated that there is no difference in reaction times between the only temporal expectation and no expectation. Taken together, these results provide evidence to suggest that participants could predict the location and/or timing of target onset based on rhythmic moving objects, and that a secondary cognitive task impaired temporal expectation. These findings support the temporal expectation hypothesis regarding moving objects requiring attentional control resources.

Looming sounds as auditory warnings: Uses for enhancing visual contrast sensitivity?

Looming sounds have been shown to influence visual perception, suggesting they may make effective auditory warning tones for use with visual tasks. To explore the use of looming sounds as warning signals and to determine whether the strength of a looming sound will impact its effectiveness, we tested five looming sounds with different amplitude increases as warning tones in a contrast sensitivity task where participants made judgements concerning the orientation of low-contrast sinusoidal gratings. Reaction time, accuracy, and contrast threshold were measured for each sound condition. Our results indicate that accuracy was higher and reaction time was faster when a sound was present compared to when no sound was present, and contrast threshold was significantly lowered in sound trials compared to silent trials. However, there was no difference in accuracy, reaction time, or contrast threshold by strength of looming. These results suggest that while auditory warning sounds do enhance performance on a basic visual task, the benefit was not unique to looming sounds. This experiment will help inform the design of warnings by providing insight into the underlying effects of looming sounds on visual performance.

No evidence for rhythmic sampling in inhibition of return.

When exogenously cued, attention reflexively reorients towards the cued position. After a brief dwelling time, attention is released and then persistently inhibited from returning to this position for up to three seconds, a phenomenon coined 'inhibition of return' (IOR). This inhibitory interpretation has shaped our understanding of the spatio-temporal dynamics of the attentional spotlight after an exogenous visual cue for more than three decades. However, a recent theory refines this traditional view and predicts that attention rhythmically alternates between possible target locations at a theta frequency, implying occasional returns of attention to the cued position. Unfortunately, previous IOR studies have only probed performance at a few, temporally wide-spread cue-target onset asynchronies (CTOAs) rendering a comparison of these contradictory predictions impossible. We therefore used a temporally fine-grained adaptation of the Posner paradigm with 25 equally and densely spaced CTOAs, which yielded a robust IOR effect in the reaction time difference between valid and invalidly cued trials. We modelled the time course of this effect across CTOAs as a linear or exponential decay (traditional IOR model), sinusoidal rhythm (rhythmic model) and a combination of both (hybrid model). Model comparison by means of goodness-of-fit indices provided strong evidence in favor of traditional IOR models, and against theta-rhythmic attentional sampling contributing to IOR. This finding was supported by an FFT analysis, which also revealed no significant theta rhythm. We therefore conclude that the spatio-temporal dynamics of attention following an exogenous cue cannot be explained by rhythmic attentional sampling.

Neural mechanisms of long-term exercise intervention on cognitive performance among short-sleep young adults: A hemodynamic study

ObjectivesShort-sleep is becoming increasingly common and may negatively affect brain function including cognitive ability. Physical exercise has been proved to improve cognitive function while intensity matters. This study was conducted to examine the effects of 12-week exercise interventions on cognitive performance and prefrontal cortex activation related to task performance in short-sleep young adults. MethodsA total of 50 subjects (23.62 ± 5.28 years and 24 men) with regular short-sleep conditions (<7 h per night) participated in this study and were divided into three groups: control, moderate-intensity continuous training (MICT), and high-intensity interval training (HIIT) group. As task performance (congruent and incongruent Stroop) was monitored, changes in prefrontal oxygenated hemoglobin (oxyHb), an indicator of cortical activation, were measured using functional near-infrared spectroscopy (fNIRS) to explore the hemodynamics mechanism. ResultsPost 12-week intervention, significant differences in reaction time for congruent [β (95%CI): −0.045 (−0.088, −0.002), p = 0.039] and incongruent Stroop tests [β (95%CI): −0.058 (−0.113, −0.003), p = 0.038] were found only in the MICT intervention group. However, HIIT did not show significant improvements in cognitive function. Left middle frontal gyrus (Frontal Mid L) and right dorsolateral superior frontal gyrus (Frontal Sup R) were both stimulated by MICT and HIIT. Moreover, left dorsolateral superior frontal gyrus (Frontal Sup L) was stimulated by MICT. ConclusionThe findings indicated that 12-week MICT improved cognition by significantly increasing cortical activity across more brain regions. Thus, we suggested that maintaining moderate-intensity exercise could benefit cognitive function despite short sleep.

Evaluation of driving fitness using driving simulators in patients with right-hemisphere damage: an unmatched case-control study

ABSTRACT Background Patients with right hemisphere damage (RHD) may exhibit mild unilateral spatial neglect (USN), which is difficult to detect in general assessments performed during driving rehabilitation. Objectives We compared driving simulator performance, practical driving performance, and neuropsychological test results between patients with RHD who were able and unable to return to driving to predict driving fitness based on driving simulator performance. Methods This unmatched case-control study included 29 patients with RHD who were able (return-to-driving group, n = 16) and unable (non-return-to-driving group, n = 13) to return to driving. Patient demographics, motor function, attention, driving simulator performance (participants’ reaction time and rate to green lamps appearing in any of the three displays and average lane position), and practical driving performance were compared between the groups. Receiver operating characteristic (ROC) analysis was performed to examine the predictive performance of driving fitness in reaction rate and paper-and-pencil tests. Results The non-return-to-driving group had a significantly lower reaction rate than the return-to-driving group (p = 0.027; 95% confidence interval [CI], 0–7; r = 0.407). No significant difference in reaction time or lane position in either the left or right lane during driving simulation was observed. ROC analysis of the reaction rate in the driving simulator task showed sensitivity of 0.692, specificity of 0.812, and area under the curve of 0.738 [95% CI, 0.541–0.935]. Conclusions Decreases in reaction rates during simulated driving assessments are associated with an inability to resume driving in patients with RHD. Such assessments may aid in predicting fitness for driving in these patients.

Quantitative Distributions of Product Ions and Reaction Times with a Binary Mixture of VOCs in Ambient Pressure Chemical Ionization.

A model to quantitatively predict ion abundances from atmospheric pressure chemical ionization (APCI) between hydrated protons and a volatile organic compound (VOC) was extended to binary mixtures of VOCs. The model includes differences in vapor concentrations, rate coefficients, and reaction times and is enhanced with cross reactions between neutral vapors and protonated monomers. In this model, two specific VOCs were considered, a ketone, 6-methyl-5-hepten-2-one (M, and an amine, 2,6-di-tert-butyl-pyridine (N), with measured "conditional rate coefficients" (in cm3·s-1) of kM = 1.11 × 10-9 and kN = 9.17 × 10-10, respectively. The cross reaction of MH+(H2O)x to NH+(H2O)y was measured as kcr = 1.31 × 10-12 at 60 °C. Cross reactions showed an impact on ion abundances at t > 30 ms for equal vapor concentrations of 100 ppb for M and N. In contrast, this impact was negligible for vapor concentrations of 1 ppb and did not exceed 5% change in product ion abundance up to 1000 ms reaction times. The model was validated with laboratory measurements to within ∼10% using an ion mobility spectrometer and effective reaction time obtained from computational fitting of experimental findings. This was necessitated by complex flow patterns in the ion source volume and was determined as ∼10.5 ms. The model has interpretative and predictive value for quantitative analysis of responses with ambient pressure ion sources for mass spectrometry and ion mobility spectrometry.

A-11 Sex Differences in Performance Validity Testing in the Immediate Post-Concussion Assessment and Cognitive Test

Abstract Purpose Sex differences have frequently been investigated in concussion and poor effort is a known confound in baseline testing. However, research has yet to investigate if insufficient effort is different or has differential effects on baseline cognitive scores between male and female athletes. Methods Collegiate athletes (n=1,505; 43% female) completed ImPACT during their baseline concussion evaluation. Research has identified four embedded effort indicies in ImPACT which were used to estimate effort across a continuum. We evaluated the relationship between effort, sex, memory performance and speed performance using linear regression models. Results We found that athletes who failed one, two, or three+ effort indicators performed worse on all cognitive domains compared to athletes who failed zero effort indicators (p&amp;lt;0.05). More male athletes failed two or three+ effort indicators compared to female athletes (p&amp;lt;0.001). Female athletes performed faster overall on visual-motor speed tasks (p=0.001), but there was no interaction between sex and failed effort indicators. Female athletes also performed faster on reaction time and better verbal memory tasks compared to male athletes, but only when they failed three+ effort indicators (p&amp;lt;0.01). Conclusions These results suggest that as expected, athletes performed worse when they failed more effort indicators. Insufficient or poor effort appears to be different between male and female athletes, with male athletes demonstrating more indicators of poor effort than female athletes. Poor effort also appears to differentially effect cognitive scores with differences in reaction time and verbal memory only identified between groups when athletes failed three or more effort measures.

(A Lack of) Sex Differences in the Effects of Acute Stress on Attentional Bias to Threat

Attentional bias (i.e., a bias toward processing certain stimuli) can be influenced by context, motivation, and state. Prior work has suggested that stress may affect attentional bias to threat, but there is inconsistency in this work with respect to how stress influences it—if it does at all. Some evidence suggests that sex differences may exist in stress effects on attentional bias, but to date no experiment has tested this possibility. We addressed the above by investigating the effects of an acute stressor, a Zoom-adapted Trier Social Stress Test, on attentional bias to threat and positive stimuli using a facial dot-probe task (N=150, 89 women). Salivary cortisol was measured pre- and post-manipulation to verify stress induction and assess the association of cortisol with attentional bias. Although participants showed expected attentional bias to threat, we found no effect of stress nor a stress by sex interaction on attentional bias to threatening or positive stimuli. We did, however, find an interaction between stress and sex in overall reaction time, such that stressed women responded faster than control women. Associations with cortisol and computationally modeled estimates of attention will be presented. Although we observed significant attentional biases to threat as well as stress-induced differences in overall reaction time, we found no evidence indicating that stress affects behavioral indices of attentional bias in either men or women within our paradigm.

Neural basis of the attention bias during addiction stroop task in methamphetamine-dependent patients with and without a history of psychosis: an ERP study.

Attentional bias plays an important role in sustaining various types of drug addiction. No prior studies examined methamphetamine (MA)-associated psychosis (MAP) relationships between ERP time course and performance on an addiction Stroop task in MA abusers. The aim of the present study was to determine whether MA abusers with (MAP+) or without (MAP-) psychosis exhibit alterations of the ERP during the addiction Stroop task. Thirty-one healthy controls (CTRL), 14 MAP-, and 24 MAP+ participants were recruited and completed the addiction Stroop task during EEG recording using 32 electrodes. Group variations were compared on measures of behavioral task performance and event-related potentials (ERP) of performance monitoring (N200, P300, N450). The Barratt impulsiveness scores were analyzed to investigate correlations with ERP changes. MA-related word stimulus elicited a more negative N200 amplitude over left-anterior electrodes in MAP- abusers; furthermore, a positive association between the N200 amplitude and Barratt attentional scores and non-planning scores was observed, while no such differences were found in MAP+ abusers. There were no significant differences in reaction time (RT) and error rate between each group. This is the first study to examine psychosis relationships between ERP time course and performance on an addiction Stroop task in MA abusers with or without psychosis. These findings support the association between attentional bias measured by the MA addiction Stroop task and N200 component as well as indicate the possibility of using this cognitive task in combination with ERP technology to detect psychosis factors among abstinent MA abusers.

Pilots' Spatial Visualization Ability Assessment Based on Virtual Reality.

BACKGROUND: The aim of this study was to investigate the effectiveness of the mental rotation test (MRT) based on virtual reality (VR) in predicting pilots' spatial visualization ability (SVA).METHODS: Based on VR, 118 healthy pilots' SVA were evaluated by MRT. The pilot flight ability evaluation scale was used as the criterion of test validity. According to the scale score, pilots were divided into high, middle, or low spatial ability groups pursuant to the 27% allocation principle. Differences in reaction time (RT), correct rate (CR), and correct number per second (CNPS) of MRT between groups were compared. Correlations between scale scores and MRT scores were analyzed. RT, CR, and CNPS of MRT among different age groups and between genders were also compared.RESULTS: The RT of the high spatial ability group was remarkably slower than that of the low spatial ability group (363.4 ± 140.2 s, 458.1 ± 151.7 s). The CNPS of the high spatial ability group was dramatically higher than that of the low spatial ability group (0.111 ± 0.045 s, 0.086 ± 0.001 s). There were no significant differences in RT, CR, and CNPS between different genders. Pilots in the 29-35 yr old age group had considerably slower RT than those in the 22-28 yr old age group (330.8 ± 140.3 s, 417.2 ± 132.7 s). Pilots in the 29-35 yr old age group had conspicuously higher CNPS than pilots in the 22-28 yr old age group (0.119 ± 0.040 s, 0.096 ± 0.036 s). All pilots' scale scores were positively correlated with CNPS (r = 0.254) and negatively correlated with RT (r = -0.234).DISCUSSION: MRT based on VR has a good discrimination efficacy for SVA of pilots and is a good indicator for the SVA component measurement.Zhang M, Wang M, Feng H, Liu X, Zhai L, Xu X, Jin Z. Pilots' spatial visualization ability assessment based on virtual reality. Aerosp Med Hum Perform. 2023; 94(6):422-428.

Robust intuition? Exploring the difference in the strength of intuitions from perspective of attentional bias

The logical intuition hypothesis proposes a difference in the strength between logical and heuristic intuitions. The labels of logical and heuristic intuitions are exclusive to conventional reasoning research. This paper reports the result of testing intuition strength using the dot-probe methodology in a novel multiplication paradigm. Here, “logical intuition” and “heuristic intuition” were relabeled as “weaker intuition” (-1 × 5 = 5) and “stronger intuition” (1 × 5 = 5), respectively, to assess the assumptions about the difference in the strength of “Chinese multiplication mnemonics” intuitions. The dot-probe paradigm was utilized in the following experiments to measure attentional bias. This was assessed by calculating the difference in reaction time between incongruent (the target location is opposite to the probe location) and congruent (the target location is the same as the probe location) conditions. Experiment 1 found attentional bias directed attention to the correct answer for both weaker and stronger intuitions. Experiment 2 replicated and extended Experiment 1 with a secondary task to manipulate high and low cognitive loads. Consequently, stronger intuitions were unaffected by cognitive load and participants were biased toward the correct answer, whereas attentional bias for weaker intuitions only occurred in low load conditions. These results revealed that although both intuitions can guide attention, stronger intuition may guide attention bias in a high-load situation due to its robust automation. Our findings extend the logical intuition hypothesis that proposes a difference in the automated strengths of intuitions to mathematical and analytic thinking.

Multi-faceted Commercially Sourced Pd-Supported Reduction: A View from Practical Experience

Aim. To share our experience when working with the Pd-catalyzed hydrogenation and discuss reactions occurred contrary to our expectations, as well as express our vision of the causes for such an unusual reactivity.Results and discussion. Catalysis is a key technology and among the central themes of both petrochemical and fine chemical industries. Although extremely useful and reliable, it can sometimes astonish researchers. The paper discusses 17 intriguing cases of the catalytic hydrogenation and hydrogenolysis reactions from our practice in the High-pressure Synthesis Laboratory (Enamine Ltd.). All examples presented are characterized by peculiar performance of commercially sourced heterogeneous palladium-containing catalysts (Pd/C or Pd(OH)2). Thus, some cases were characterized by reduced activity of the catalyst (or even its complete loss), meaning that reaction conditions found before to be suitable for reduction appeared to be “broken”, and we had to search for a new, often harsher reaction setup. Curiously, it is a matter of classical Pd-catalyzed hydrogenations of N+–O– and C=C fragments. Apparently, these results indicate the heterogeneity of commercially available catalysts and are related to their fine internal structure, in particular the surface morphology. Another interesting issue the article deals with is chemoselectivity of the catalytic hydrogenation. Sometimes some reactions led to astonishing results going across theoretical views and expectations. Saturation of benzene rings instead of (or accompanying) debenzylation, breaking of the common order of hydrogenation for compounds containing several aromatic parts with different resonance energies, irreproducible experiment, obtaining of different products under the same conditions, uncommon results of Pd-catalyzed reactions is the list of interesting results, which we observed and discussed in the article. Analyzing the information available in the literature and considering all the results gathered we tend to believe that the presence of impurities of noble metals (Rh, Ru, Pt) in the catalysts used to be a possible reason for these strange findings. The study supports the general idea that commercial palladium catalysts differ in efficiency, resulting in significant differences in selectivity, reaction time, and yields. Elucidating the regularities behind such empirical results is undoubtedly an interesting area of research in the field of catalysis.Experimental part. All starting compounds exposed to hydrogenation were synthesized in Enamine Ltd. and had purity of not less than 95 %. The palladium-containing catalysts used in the experiment were purchased from 6 commercial sources within 2011 – 2022. The structure and purity of the compounds synthesized were characterized by 1H NMR spectroscopy, liquid chromatography coupled with the mass spectrometry method, elemental analysis. Chromatographic experiments revealed the purity of all compounds obtained being not less than 95 %.Conclusions. In the paper we have summarized our experience with the Pd-catalyzed hydrogenation and presented cases of unusual reactivity or unexpected outcomes of the reactions encountered in our practice. In general, complications we faced were of three types: (1) irreproducibility of the procedures most likely as the result of a changeable activity of the catalysts; (2) chemoselectivity issues when two or multireducible functional groups were present in the substrate; (3) undesirable Pd-catalyzed defunctionalization reactions. In turn, these complications led to increase in production costs, loss of time and resources. Therefore, because of this variability in the efficiency of Pd catalysts, far more efforts are required to find out the key differences between commercial sources of Pd catalysts, as well as to create protocols clearly defining the catalytic activity of each batch of the catalyst allowing to identify high-quality catalysts immediately prior to the use without wasting precious time and synthetic materials.

The Relationship between Diurnal Measures of Tonic Alertness and Self-Reported Fatigue in Persons with Multiple Sclerosis-A Retrospective Data Analysis.

Fatigue in multiple sclerosis (MS) is common, burdensome, and usually assessed by self-report measures. This retrospective data analysis of the twice-daily Alertness test (Test battery of Attentional Performance) examined the extent to which this assessment procedure is associated with MS-related fatigue. Two-hundred and thirteen German inpatients (136 women) aged 18-69years with predominantly relapsing MS (72.8%) were included. Based on reaction time (RT) differences between morning tonic alertness (8:30-11:00a.m.) and afternoon tonic alertness (3:00-4:30p.m.), patients were divided into an "improver," "maintainer," or "decliner" group. Multinomial logistic regression (MLR) was calculated to predict the likelihood of belonging to one of these performance groups, taking into account cognitive fatigue (Fatigue Scale of Motor and Cognition, FSMCcog), disease severity (Expanded Disability Status Scale, EDSS), depression (Center for Epidemiologic Studies Depression Scale, CES-D), gender, and tonic alertness (a.m.). The final MLR model (R2 = .30) included tonic alertness (a.m.) (<.001), FSMCcog (.008), EDSS (.038), CES-D (.161), and gender (.057). Using this model, correct assignment to alertness performance groups was 56.8%. Tonic alertness (p.m.) demonstrated the greatest potential for differentiation among the three performance groups (<.001). These results show a relationship between subjective fatigue and tonic alertness. However, other variables also contribute to this association, suggesting that the RT differences between twice-daily measures of tonic alertness is not related to increased subjective fatigue in a substantial number of pwMS, which diminishes the diagnostic value. Further studies including relevant variables such as sleepiness are urgently needed.

Task-relevant social cues affect whole-body approach-avoidance behavior

Positively evaluated stimuli facilitate approach and negatively evaluated stimuli prompt avoidance responses, as typically measured by reaction time differences when moving a joystick toward the own body or away from it. In this study, we explore whether a whole-body response (forward and backward leaning can serve as a better indicator of approach-avoidance behavior; AA). Thirty-two subjects were presented with pictures of males and females with angry or happy facial expressions. Subjects had to perform approach or avoidance responses by leaning forward or backward, either based on the facial expression of the stimulus or the gender of the stimulus. Leaning responses were sensitive to angry faces for explicit decision cues. Here, angry facial expressions facilitated backward leaning but not when responding to the gender of the stimulus. We compare this to the established manual measure of AA and discuss our results with regard to response coding.

The role of cerebellum in timing processing: A contingent negative variation study

Time management is an important aspect of human behaviour and cognition. Several brain regions are thought to be involved in motor timing and time estimation tasks. However, subcortical regions such as the basal nuclei and cerebellum seem to play a role in timing control.The aim of this study was to investigate the role of the cerebellum in temporal processing. For this purpose, we transitorily inhibited cerebellar activity by means of cathodal transcranial direct current stimulation (tDCS) and studied the effects of this inhibition on contingent negative variation (CNV) parameters elicited during a S1-S2 motor task in healthy subjects.Sixteen healthy subjects underwent a S1-S2 motor task prior to and after cathodal and sham cerebellar tDCS in separate sessions. The CNV task consisted of a duration discrimination task in which subjects had to determine whether the duration of a probe interval trial was shorter (800 ms), longer (1600 ms), or equal to the target interval of 1200 ms.A reduction in total CNV amplitude emerged only after cathodal tDCS for short and target interval trials, while no differences were detected for the long interval trial. Errors were significantly higher after cathodal tDCS than at baseline evaluation of short and target intervals. No reaction time differences were found for any time interval after the cathodal and sham sessions.These results point to a role of the cerebellum in time perception. In particular, the cerebellum seems to regulate temporal interval discrimination for second and sub-second ranges.

Differences in Selective Attention and Inhibitory Control in Patients with Major Depressive Disorder and Healthy Controls Who Do Not Engage in Sufficient Physical Activity.

Patients with major depressive disorder (MDD) are characterized by neurocognitive impairments and show deficits in various cognitive performance indicators, including executive function. We examined whether sustained attention and inhibitory control differ between patients with MDD and healthy controls, and whether differences exist between patients with mild, moderate, and severe depression. Clinical in-patients (N = 212) aged 18-65 years with a current diagnosis of MDD and 128 healthy controls were recruited. Depression severity was assessed using the Beck Depression Inventory, and sustained attention and inhibitory control were assessed using the oddball and flanker tasks. The use of these tasks promises insights into executive function in depressive patients that are not biased by verbal skills. Group differences were tested via analyses of covariance. Patients with MDD showed slower reaction times in both the oddball and flanker task, independent of the executive demands of the trial types. Younger participants achieved shorter reaction times in both inhibitory control tasks. After correcting for age, education, smoking, BMI, and nationality, only differences in reaction times in the oddball task were statistically significant. In contrast, reaction times were not sensitive to the symptom severity of depression. Our results corroborate deficits in basic information processing and specific impairments in higher-order cognitive processes in MDD patients. As difficulties in executive function underlie problems in planning, initiating, and completing goal-directed activities, they may jeopardize in-patient treatment and contribute to the recurrent nature of depression.

Does CUD measure interhemispheric transfer time? The allocation of attention influences the Poffenberger effect

A simple reaction time (SRT) difference between responses to visual stimuli presented ipsilaterally and contralaterally to the responding hand, known as the Poffenberger effect or the crossed–uncrossed difference (CUD), has been commonly interpreted as a measure of interhemispheric transfer time (IHTT). However, the validity of this interpretation and the measure's reliability have been debated. The present study aimed at obtaining reliable evidence of the influence of spatial attention on the CUD, which would provide an argument against the classical interpretation of CUD. To meet the high statistical power requirements, over 100 thousand SRTs in total were collected from 12 participants. The task had three stimulus presentation conditions differing in the degree of stimulus location uncertainty: blocked (no uncertainty), randomized (full uncertainty), and mixed (25% uncertainty). The results showed robust effects of location uncertainty, proving spatial attention's contribution to the CUD. Further, we observed a strong visual-field asymmetry reflecting the right hemisphere specialization in target detection and spatial reorienting. Lastly, despite exceptional reliability of the component SRT measures, the CUD reliability was still too low to justify using this measure as an index of individual differences.