Improved intraindividual variability in cognitive performance following cognitive and exercise training in older adults

OBJECTIVE

Increased intraindividual variability (IIV) of cognitive performance is a marker of cognitive decline in older adults. Whether computerized cognitive training (CCT) and aerobic exercise counteracts cognitive decline by reducing IIV is unknown. We investigated the effects of CCT with or without aerobic exercise on IIV in older adults.

METHODS

This was a secondary analysis of an 8-week randomized controlled trial. Older adults (aged 65-85 years) were randomized to CCT alone (n = 41), CCT with aerobic exercise (n = 41), or an active control group (n = 42). The CCT group trained using the Fit Brains® platform 3×/week for 1 hr (plus 3×/week of home-based training). The CCT with aerobic exercise group received 15 min of walking plus 45 min of Fit Brains® 3×/week (plus 3×/week of home-based training). The control group received sham exercise and cognitive training (3×/week for 1 hr). We computed reaction time IIV from the Dimensional Change Card Sort Test, Flanker Inhibitory Control and Attention Test (Flanker), and Pattern Comparison Processing Speed Test (PACPS).

RESULTS

Compared with the control group, IIV reduced in a processing speed task (PACPS) following CCT alone (mean difference [95% confidence interval]: -0.144 [-0.255 to -0.034], p < 0.01) and CCT with aerobic exercise (-0.113 [-0.225 to -0.001], p < 0.05). Attention (Flanker congruent) IIV was reduced only after CCT with aerobic exercise (-0.130 [-0.242 to -0.017], p < 0.05).

CONCLUSIONS

A CCT program promoted cognitive health via reductions in IIV of cognitive performance and combining it with aerobic exercise may result in broader benefits.

Implicit and explicit motor imagery ability after SCI: Moving the elbow makes the difference

Cervical spinal cord injury (SCI) causes dramatic sensorimotor deficits that restrict both activity and participation. Restoring activity and participation requires extensive upper limb rehabilitation focusing elbow and wrist movements, which can include motor imagery. Yet, it remains unclear whether MI ability is impaired or spared after SCI. We investigated implicit and explicit MI ability in individuals with C6 or C7 SCI (SCIC6 and SCIC7 groups), as well as in age- and gender-matched controls without SCI. Inspired by previous studies, implicit MI evaluations involved hand laterality judgments, hand orientation judgments (HOJT) and hand-object interaction judgments. Explicit MI evaluations involved mental chronometry assessments of physically possible or impossible movements due to the paralysis of upper limb muscles in both groups of participants with SCI. HOJT was the paradigm in which implicit MI ability profiles differed the most between groups, particularly in the SCIC6 group who had impaired elbow movements in the horizontal plane. MI ability profiles were similar between groups for explicit MI evaluations, but reflected task familiarity with higher durations in the case of unfamiliar movements in controls or attempt to perform movements which were no longer possible in persons with SCI. Present results, obtained from a homogeneous population of individuals with SCI, suggest that people with long-term SCI rely on embodied cognitive motor strategies, similar to controls. Differences found in behavioral response pattern during implicit MI mirrored the actual motor deficit, particularly during tasks that involved internal representations of affected body parts.

Risk assessment of driver performance in the oil and gas transportation industry: Analyzing the relationship between driver vigilance, attention, reaction time, and safe driving practices

The increasing use of road traffic for land transportation has resulted in numerous road accidents and casualties, including those involving oil and gas tanker vehicles. Despite this, little empirical research has been conducted on the factors influencing tanker drivers' performance. This study aims to address this knowledge gap, particularly in the energy transportation industry, by examining the driving performance factors that affect tanker drivers and incorporating risk assessment measures. The model variables were identified from the literature and used to develop a survey questionnaire for the study. A total of 307 surveys were collected from Malaysian oil and gas tanker drivers, and the driving performance factors were contextually adjusted using the Exploratory Factor Analysis (EFA) approach. The driving performance model was developed using partial least squares structural equation modeling (PLS-SEM). The EFA results categorized driving performance into two constructs: 1) drivers' reaction time with β = 0.320 and 2) attention and vigilance with β value = 0.749. The proposed model provided full insight into how drivers' reaction time, attention, and vigilance impact drivers' performance in this sector, which can help identify potential risks and prevent accidents. The findings are significant in understanding the factors that affect oil and gas drivers' performance and can aid in enhancing oil and gas transportation management by including effective risk assessment measures to prevent fatal crashes.

Discrimination of the moving direction is improved depending on the pattern of the mechanical tactile stimulation intervention

BACKGROUND

The mechanical tactile stimulation, such as plastic pins and airflow-driven membrane, induces cortical activity. The cortical activity depends on the mechanical tactile stimulation pattern. Therefore, the stimulation pattern of mechanical tactile stimuli intervention may influence its effect on the somatosensory function. However, the effect of the mechanical tactile stimulation input pattern on the somatosensory function has not yet been investigated at the behavioral level. The present study aimed to clarify the effects of mechanical tactile stimuli intervention with different stimulation patterns on the ability to discriminate moving directions.

RESULTS

Twenty healthy adults participated in the experiment. Three conditions were used for mechanical tactile stimuli intervention: (1) the whole stimulus surface was stimulated, (2) the stimulus moved within the stimulus surface, and (3) a no-stimulus condition. The effects of mechanical tactile stimuli intervention on tactile discrimination were evaluated using a simple reaction task and a choice reaction task to discriminate the movement direction. Reaction time, correct rate, and rate correct score were calculated to measure task performance. We examined the effects of mechanical tactile stimuli intervention on the ability to discriminate the moving direction for a certain period under three intervention conditions. The results showed that the mean reaction time during the simple reaction task did not differ significantly before and after the intervention under all intervention conditions. Similarly, we compared the data obtained before and after the intervention during the choice reaction task. Our results revealed that the mean reaction time and correct rate did not differ significantly under vertical and horizontal conditions. However, the rate correct score showed a significant improvement after the horizontal moving tactile stimulation intervention under both vertical and horizontal conditions.

CONCLUSIONS

Our results showed that the effect of mechanical tactile stimuli intervention on mechanical tactile stimulation moving direction discrimination function depended on the input pattern of mechanical tactile stimuli intervention. Our results suggest the potential therapeutic benefits of sustained tactile stimulation intervention. This study revealed that it is possible to change behavioral levels via mechanical tactile stimuli intervention as well as the potential of mechanical tactile stimuli intervention in the field of rehabilitation.

On the importance of transparent reporting of reaction time data pre-processing

In behavioral, cognitive, and social sciences, reaction time measures are an important source of information. However, analyses on reaction time data are affected by researchers' analytical choices and the order in which these choices are applied. The results of a systematic literature review, presented in this paper, revealed that the justification for and order in which analytical choices are conducted are rarely reported, leading to difficulty in reproducing results and interpreting mixed findings. To address this methodological shortcoming, we created a checklist on reporting reaction time pre-processing to make these decisions more explicit, improve transparency, and thus, promote best practices within the field. The importance of the pre-processing checklist was additionally supported by an expert consensus survey and a multiverse analysis. Consequently, we appeal for maximal transparency on all methods applied and offer a checklist to improve replicability and reproducibility of studies that use reaction time measures.

Deficits in neurocognitive performance in patients with chronic ankle instability during a neurocognitive balance task - A retrospective case-control study

OBJECTIVES

To assess the neurocognitive performance while maintaining balance of patients experiencing CAI compared to healthy controls. In patients with CAI, the affected limb was also compared to the contralateral limb.

DESIGN

A retrospective case-control study.

SETTING

Laboratory study.

PARTICIPANTS

We included 27 patients with CAI and 21 healthy controls.

METHODS

The study consisted of two sessions, namely familiarisation and experimentation, which were scheduled with a gap of at least one week between them. During the experimental trial, both groups performed the Y-Balance Test and Reactive Balance Test once on each limb.

MAIN OUTCOME MEASURES

The main outcome measures are accuracy and visuomotor response time (VMRT) calculated via video-analysis and with the Fitlight™-hardware and software respectively during the Reactive Balance Test (RBT).

RESULTS

No data was excluded from the final analysis. Patients with CAI exhibited significantly lower accuracy than healthy controls, with a mean difference of 8.7% (±3.0)%. There were no differences for VMRT between groups. Additionally, no significant differences were observed between the affected and contralateral limb of the patient group for both accuracy and VMRT.

CONCLUSIONS

Patients with CAI showed lower accuracy, but similar VMRT compared to healthy controls during a neurocognitive balance task, indicating impaired neurocognitive function. Patients exhibit comparable speed to healthy individuals when completing neurocognitive balance tasks, yet they display a higher frequency of accuracy errors in accurately perceiving their environment and making decisions under time constraints. Future research should gain more insights in which other cognitive domains are affected in patients with CAI for a better grasp of this condition's underlying mechanism.

Effects of six-week stroboscopic training program on visuomotor reaction speed in goal-directed movements in young volleyball players: a study focusing on agility performance

BACKGROUND

In team sports, deficits in visuomotor reaction speed are considered a significant and modifiable risk factor that can lead to decreased performance and an increased risk of injuries. Thus, identifying effective methods to enhance visuomotor abilities is crucial. The main objective of this research was to investigate the impact of a six-week stroboscopic intervention on visuomotor reaction speed in goal-directed specific movements based on agility among young volleyball players. Additionally, the study aimed to explore the impact of saccade dynamics on visuomotor reaction speed performance throughout the experiment.

METHODS

There were 50 athletes (26 males and 24 females) with an average age of 16.5 years (± 0.6) who participated in this study. Over a six-week training period, athletes performed volleyball-specific training either wearing stroboscopic glasses (intervention) or under normal visual conditions (control). Prior to and after the training period, the agility tests based on change-of-direction speed (CODS) and reactive agility (RA) were used to identify visuomotor reaction speed performance. To measure agility performance a five-repetition shuttle run to gates was conducted. The REAC-INDEX, which represents visuomotor reaction speed, was analyzed as the resulting difference between the CODS test and the RA test. To elicit saccadic dynamics, a laboratory visual search task was performed.

RESULTS

A significant GROUP×TIME interaction was observed for the REAC-INDEX (p = 0.012, ηp2 = 0.13). ANCOVA analyses revealed significant GROUP differences, indicating improved post-training REAC-INDEX results (p = 0.004, d = 0.87), regardless of gender. Training-induced modulations in saccade acceleration did not reach significance, but a significant relationship was observed between changes in saccade acceleration and changes in the REAC-INDEX (r = -0.281, p = 0.048), indicating that higher performance gains following training were associated with a stronger increase in saccade acceleration.

CONCLUSIONS

This study demonstrates that stroboscopic training effectively enhances visuomotor reaction speed in goal-directed movements based on agility. Furthermore, visuomotor reaction speed gains could potentially be mediated by saccade dynamics. These findings provide valuable insights into the effectiveness of stroboscopic eyewear for training sport-specific visuomotor skills among young volleyball players.

EXPRESS: Effects of perceptual redundancy, conceptual redundancy and self-relatedness on categorical responses

A redundancy gain occurs when perceptually identical stimuli are presented together, resulting in quicker categorization of these paired stimuli compared to lone stimuli. Similar effects have been reported for paired stimuli within the same conceptual category, particularly if the category is self-related. We recruited 528 individuals across three related studies to investigate whether, during perceptual and conceptual redundancy, such self-bias effects on foreground stimuli are modulated by natural versus urban backgrounds. Here, we highlight our observations pertaining to perceptual and conceptual redundancy effects of the foreground stimuli. In our first experiment, response options were randomized per trial. Results showed reaction time gains for perceptually identical stimuli, but this advantage was not modulated by self/other categorization. However, slower reaction times were observed for conceptually-related stimulus pairs, and were influenced by self/other categorization. The second experiment replicated the methods of earlier studies of redundancy and observed comparable results to Experiment 1: A perceptual redundancy gain unmodulated by self/other categorization, yet, for conceptual redundancy, no gain/cost but effects of self/other categorization. In the third experiment, self/other categories were substituted with arbitrary A/B categories: Once more, there was a perceptual redundancy gain and no conceptual redundancy gain. Notably, A/B categorisation produced effects equivalent to self/other categorisation. Overall, these findings challenge previous research on the facilitated early processing of conceptually-related stimuli and suggest that self-relatedness may not exert a unique effect on stimulus processing beyond attentional and response preferences during categorization. Our study motivates further research to understand conceptual categorization and redundancy gain effects.

Standardizing norms for 1286 colored pictures in Cantonese

This study established psycholinguistic norms in Cantonese for a set of 1286 colored pictures sourced from several picture databases, including 750 colored line drawings from MultiPic (Duñabeitia et al., 2018) and 536 photographs selected for McRae et al. (2005) concepts. The pictures underwent rigorous normalization processes. We provided picture characteristics including name and concept agreement, familiarity, visual complexity, and frequency of modal responses. Through correlational analyses, we observed strong interrelationships among these variables. We also compared the current Cantonese norming to other languages and demonstrated similarity and variations among different languages. Additionally, we embraced the multilingual diversity within the current sample, and found that higher Cantonese proficiency but lower non-native language proficiency were associated with better spoken picture naming. Last but not least, we validated the predictive power of normed variables calculated from typed responses to spoken picture naming, and the consistency between typed and spoken responses. The present norming provides a timely and valuable alternative for researchers in the field of psycholinguistics, especially those studying Cantonese production and lexical retrieval. All raw data, analysis scripts, and final norming results are available online as psycholinguistic norms for Cantonese in the following link at the Open Science Framework: https://osf.io/dz9j6/?view_only=a452d8a56c92430b9dedf21ac26b1bc1 .

Effects of acute cannabis inhalation on reaction time, decision-making, and memory using a tablet-based application

BACKGROUND

Acute cannabis use has been demonstrated to slow reaction time and affect decision-making and short-term memory. These effects may have utility in identifying impairment associated with recent use. However, these effects have not been widely investigated among individuals with a pattern of daily use, who may have acquired tolerance. The purpose of this study was to examine the impact of tolerance to cannabis on the acute effects as measured by reaction time, decision-making (gap acceptance), and short-term memory.

METHODS

Participants (ages 25-45) completed a tablet-based (iPad) test battery before and approximately 60 min after smoking cannabis flower. The change in performance from before to after cannabis use was compared across three groups of cannabis users: (1) occasional use (n = 23); (2) daily use (n = 31); or (3) no current use (n = 32). Participants in the occasional and daily use group self-administered ad libitum, by smoking or vaping, self-supplied cannabis flower with a high concentration of total THC (15-30%).

RESULTS

The occasional use group exhibited decrements in reaction time (slowed) and short-term memory (replicated fewer shapes) from before to after cannabis use, as compared to the no-use group. In the gap acceptance task, daily use participants took more time to complete the task post-smoking cannabis as compared to those with no use or occasional use; however, the level of accuracy did not significantly change.

CONCLUSIONS

The findings are consistent with acquired tolerance to certain acute psychomotor effects with daily cannabis use. The finding from the gap acceptance task which showed a decline in speed but not accuracy may indicate a prioritization of accuracy over response time. Cognitive and psychomotor assessments may have utility for identifying impairment associated with recent cannabis use.

Reaction Time in Fibromyalgia Patients

BACKGROUND

Fibromyalgia has unknown aetiology and is associated with reduced information processing speed and therefore prolonged reaction time. However, the processes underlying this are unknown.

OBJECTIVES

First, to compare the reaction time in a cohort of fibromyalgia patients and a matched group of normal controls. Second, to assess whether detailed symptoms of pain and autonomic function, as well as measures of tinnitus, fatigue, daytime sleepiness and Mycoplasma pneumoniae infection are predictors of reaction time in fibromyalgia.

METHODS

The between-groups mean serial five-choice reaction time difference was assessed in a cohort of fibromyalgia patients and in a matched group of normal controls in an analytical case-- controlled study. With the mean serial five-choice reaction time as the dependent variable for the fibromyalgia group, a mixed stepwise multiple linear regression was performed with inputs relating to pain, dysautonomia, tinnitus, fatigue, daytime sleepiness and Mycoplasma pneumoniae infection.

RESULTS

The mean (standard error) serial five-choice reaction time for the fibromyalgia group was 448.4 (23.0) ms, compared with 386.3 (8.3) ms for the control group (p = 0.007). The final multiple linear regression model (p < 0.001; adjusted R2 = 0.772) contained 13 predictors: eight sensory pain and three affective pain parameters, and Mycoplasma pneumoniae IgG and IgA assay results.

CONCLUSION

Certain sensory and affective pain parameters, as well as Mycoplasma pneumoniae infection, appear to be predictors of reaction time in fibromyalgia. Further research into the pathophysiological mechanisms by which they affect information processing is warranted and may shed light on the aetiology of fibromyalgia.

Respiratory patterns and physical fitness in healthy adults: a cross-sectional study

BACKGROUND

The altered respiratory patterns have a significant impact on our health. However, the links between respiration patterns during spontaneous breathing and physical fitness remain unknown. Therefore, we sought to examine how the respiratory pattern during spontaneous breathing interacts with physical fitness.

METHODS

A total of 610 participants (aged 20-59 years) were enrolled; 163 men (age = 41 ± 11) and 401 women (age = 42 ± 9) were included for analysis. The parameters of the respiration pattern were respiration rate (RR) and inhalation/exhalation (I/E) ratio. The physical fitness components were body size, visuomotor reaction time, balance, flexibility, hand grip strength, back extension strength, vertical jump height, number of push-ups, number of sit-ups, and the maximum rate of oxygen consumption. The data were analyzed separately for two gender groups. Participants within each gender group were further divided into two age categories (young: 20-39 years, middle-aged: 40-59 years) for the analysis, and both correlational and comparative tests were used to solidify the results.

RESULTS

Neither RRs nor the I/E ratios were substantially correlated with physical fitness in women. In addition, the I/E ratios showed no significant correlation with physical fitness in young men, while the results from correlational and comparative tests were inconsistent in middle-aged men. Consistently, men with lower RRs exhibited significantly shorter visuomotor reaction times in two age groups, and demonstrated significantly higher vertical jump heights in the middle-aged group.

CONCLUSIONS

In women, respiratory patterns were not correlated with physical fitness. The relationship between middle-aged men's I/E ratios and their physical fitness warrants further investigation. Men with lower RRs may have better visual-motor coordination and/or sustained attention, while middle-aged men with lower RRs may also have greater leg explosive power and neuromuscular coordination, which should be considered for physical assessment and health improvement.

Benefits of multinomial processing tree models with discrete and continuous variables in memory research: an alternative modeling proposal to Juola et al. (2019)

Signal detection theory (SDT) and two-high threshold models (2HT) are often used to analyze accuracy data in recognition memory paradigms. However, when reaction times (RTs) and/or confidence levels (CLs) are also measured, they usually are analyzed separately or not at all as dependent variables (DVs). We propose a new approach to include these variables based on multinomial processing tree models for discrete and continuous variables (MPT-DC) with the aim to compare fits of SDT and 2HT models. Using Juola et al.'s (2019, Memory & Cognition, 47[4], 855-876) data we have found that including CLs and RTs reduces the standard errors of parameter estimates and accounts for interactions among accuracy, CLs, and RTs that classical versions of SDT and 2HT models do not. In addition, according to the simulations, there is an increase in the proportion of correct model selections when relevant DV are included. We highlight the methodological and substantive advantages of MPT-DC in the disentanglement of contributing processes in recognition memory.

Electrophysiological effects of smartphone notifications on cognitive control following a brief mindfulness induction

Smartphone use is nearly ubiquitous, with 93% of adults among economically developed countries, including the United States, Canada, Israel, and South Korea owning a smartphone (Taylor & Silver, 2019). Multiple studies have demonstrated the distracting effects of smartphone notifications on behavioral measures of cognition. Fewer studies have examined the effects of notifications on neural activity underlying higher-level cognitive processes or behavioral inductions to reduce smartphone-related distraction. Using EEG spectral frequency power densities, we assessed the effects of smartphone notifications (vs. control trials) on engagement of attentional shifting processes involved in cognitive control during a Navon Letter visual oddball task. Participants were randomly assigned to a brief mindfulness induction (N = 44) or a neutral narration control condition (N = 43). Overall, participants had lower theta-band power, but higher alpha- and beta-band power densities on target letter trials preceded by smartphone notifications. Additionally, participants in the mindfulness (vs. control) condition had a larger attention shifting oddball assessed via theta power density and theta/beta ratio (TBR) values-reflecting increased engagement of cognitive control-particularly on smartphone notification (vs. control) trials. Altogether, these results provide evidence supporting the idea that smartphone notifications can decrease activity of neural correlates of cognitive control, and offer the promise of a brief mindfulness induction to buffer against the effects of smartphone notifications on cognitive control. The findings indicate a need for further research on mindfulness inductiosn as a means to reduce potential distraction caused by smartphones.

Cathodal HD-tDCS and attention: A study on patients with intractable left lateral frontal lobe epilepsy

OBJECTIVE

Defects in the attentional network in patients with epilepsy are influenced by factors such as the location of epileptic foci. Examining the impact of cathodal high-definition transcranial direct current stimulation (HD-tDCS) on attention components could provide insights into potential attention-related side effects of tDCS. This study aimed to investigate the effect of cathodal HD-tDCS on interictal epileptiform discharges (IEDs), auditory/visual (A/V) attention components, and reaction time (RT) in patients with intractable focal left lateral frontal lobe epilepsy (LFLE).

METHODS

To control for variations in individual epilepsy syndrome, 12 adult participants diagnosed with drug-resistant left LFLE with focal cortical IEDs on C3 underwent repeated measurements at pretest, posttest, and follow-up steps. 4 × 1 ring electrodes (cathode on C3 and four anodes on F3, P3, T3, and Cz) delivered 2 mA DC for 20 min per session for 10 consecutive days. The integrated visual and auditory continuous performance test (IVA+) assessed the A/V attention components and RT. One-way repeated-measure ANOVA was used.

RESULTS

The findings suggest a significant effect in reducing IEDs. The IVA+ results showed a significant improvement in auditory divided attention and visual selective and focused attention (p < 0.05). In the follow-up, these changes demonstrated lasting efficacy. A/V speed scales increased (p < 0.05), showing a significant decrease in reaction time.

CONCLUSIONS

Cathodal HD-tDCS significantly reduced IEDs and improved the components of auditory divided attention, visual focused attention, and visual selective attention, with a reduction in patient reaction time. A significant lasting, side-effect-free positive effect was observed for up to one month after the intervention.

Assessing the predictions from Posner's theory of phasic alertness using data from Los and Schut (2008)

Alertness has been construed as one of three fundamental components of attention. When generated by a warning signal, phasic changes in alertness ubiquitously decrease reaction time. But how does it do so? Based on earlier findings, in 1975, Posner proposed a theory of phasic alertness with two postulates: (i) phasic alertness does not affect the accumulation of information; (ii) phasic alertness accelerates when a response based on the accumulating information will be generated. When targets are continuously presented, this theory predicts that alertness will reduce reaction at the expense of an increase in errors-that is, generate a speed-accuracy trade-off. Los and Schut, Cognitive Psychology, 57, 20-55, (2008), while endorsing Posner's theory, claimed to have failed to replicated the tell-tale trade-off reported by Posner et al. Memory and Cognition, 1, 2-12, (1973, Experiment 1). The primary goal of this commentary was to use all the data from Los and Schut to see if the predicted speed-accuracy trade-off would be verified or not. With the increased power, it was confirmed that the conditions that benefited the most in reaction time from alertness also had higher error rates. It is noteworthy that recent studies have generated replications and extensions of the methods and findings of Posner et al; thus, it appears that the empirical pattern predicted by Posner's theory of phasic alertness is relatively robust.

Effects of plyometric training on measures of physical fitness in racket sport athletes: a systematic review and meta-analysis

Background

Over the past decade, the popularity of racket sports has surged. Plyometric training (PT) has been the focus of extensive research because of the proven benefits it provides to athletes. However, there is a lack of systematic reviews and meta-analyses specifically evaluating the impact of PT on physical fitness metrics in racket sport athletes. This study aimed to conduct a comprehensive review and analysis of evidence derived from randomized controlled trials (RCTs) to evaluate the effects of PT on measures of physical fitness among racket sports athletes.

Methods

The electronic databases PubMed, Web of Science, SCOPUS, and SPORTDiscus were systematically searched up to June 2023 without placing any restrictions on the publication dates. The PICOS method was adopted to establish the inclusion criteria: (a) healthy athletes who participate in racket sports; (b) a PT program; (c) a control group; (d) assessment of physical fitness components pre- and post-PT; and (e) RCTs. The records' methodological quality was assessed utilizing the Physiotherapy Evidence Database (PEDro) scale. The certainty in the evidence related to each outcome was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) assessment. A random-effects model was used to calculate effect sizes (ES; Hedges' g) between experimental and control groups.

Results

There were 14 eligible studies of moderate-to-high-quality, involving 746 athletes in total. The results revealed small-to-moderate effects (p < 0.05) of PT on muscle power (ES = 0.46), muscle strength (ES = 0.50), sprint speed (ES = 0.45), change of direction ability (ES = 0.76), and reaction time (ES = 0.67), while no clear evidence was found on balance and flexibility. The training-induced changes in muscle power showed no significant difference (p > 0.05) between youth (ES = 0.72) and adults (ES = 0.40). There were also similar muscle power improvements (ES = 0.36-0.54 vs 0.38-0.56, all p > 0.05) for a length of ≤7 weeks with ≤14 total PT sessions vs >7 weeks with >14 total PT sessions, and ≤2 weekly sessions vs >2 sessions. No adverse effects were reported in the included studies regarding the PT intervention. The certainty of evidence varied from very low to moderate. Conclusions: Our findings demonstrated that PT has positive effects on important indices of physical fitness among athletes participating in racket sports. Future studies are required to clarify the optimal doses and examine interactions among training variables to further promote the physical fitness of this specific population.

Reaction time and brain oscillations in Go/No-go tasks with different meanings of stimulus color

Color has meaning in particular contexts, and the meaning of color can impact behavioral performance. For example, the meaning of color about traffic rules (blue/green and red mean "go" and "stop" respectively) influences reaction times (RTs) to signals. Specifically, in a Go/No-go task, RTs have been reported to be longer when responding to a red signal and withholding the response to a blue signal (Red Go/Blue No-go task) than when responding to a blue signal and withholding the response to a red signal (Blue Go/Red No-go task). However, the neurophysiological background of this phenomenon has not been fully understood. The purpose of this study was to investigate the brain oscillatory activity associated with the effect of meaning of color on RTs in the Go/No-go task. Twenty participants performed a Blue simple reaction task, a Red simple reaction task, a Blue Go/Red No-go task, and a Red Go/Blue No-go task. We recorded responses to signals and electroencephalogram (EEG) during the tasks and evaluated RTs and changes in spectral power over time, referred to as event-related synchronization (ERS) and event-related desynchronization (ERD). The behavioral results were similar to previous studies. The EEG results showed that frontal beta ERD and theta ERS were greater when signals were presented in blue than red color in both simple reaction and Go/No-go tasks. In addition, the onset of theta ERS was delayed in the Red Go than Blue Go trial in the Go/No-go task. The enhanced beta ERD may indicate that blue signals facilitate motor response, and the delayed onset of theta ERS may indicate the delayed onset of cognitive process when responding to red signals as compared to blue signals in the Go/No-go task. Thus, this delay in cognitive process can be involved in the slow response in the Red Go/Blue No-go task.

Rapid withdrawal from a threatening animal is movement-specific and mediated by reflex-like neural processing

Responses to potentially dangerous stimuli are among the most basic animal behaviors. While research has shown that threats automatically capture the attention of human participants, research has failed to demonstrate automatic behavioral responses to threats in humans. Using a novel naturalistic paradigm, we show that two species of animals humans often report fearing trigger rapid withdrawal responses: participants withdrew their arm from photos of snakes and spiders faster, and with higher acceleration when compared to bird and butterfly stimuli. The behavior was specific to withdrawal as approach movements or button-press/release tasks failed to detect a similar difference. Moreover, between-participant differences in how aversive they found the stimuli predicted the participant's withdrawal speed, indicating that the paradigm was also sensitive to trait-level differences between individuals. Using electroencephalography (EEG), we show that the fast withdrawal was mediated by two attentional processes. First, fast withdrawal responses were associated with early amplification of sensory signals (40-110 ms after stimulus). Second, a later correlate of feature-based attention (early posterior negativity, EPN, 200-240 ms after stimulus) revealed the opposite pattern: Stronger EPN was associated with slower behavioral responses, suggesting that the deployment of attention towards the threatening stimulus features, or failure to "disengage" attention from the stimulus, was detrimental for withdrawal speed. Altogether, the results suggest that rapid behavioral withdrawal from a threatening animal is mediated by reflex-like attentional processing, and later, conscious attention to stimulus features may hinder escaping the treat.

Slower Processing Speed in Autism Spectrum Disorder: A Meta-analytic Investigation of Time-Based Tasks

Autism spectrum disorder (ASD) is a complex neurodevelopmental condition affecting information processing across domains. The current meta-analysis investigated whether slower processing speed is associated with the ASD neurocognitive profile and whether findings hold across different time-based tasks and stimuli (social vs. nonsocial; linguistic vs. nonlinguistic). Mean RTs of ASD and age-matched neurotypical comparison groups (N = 893 ASD, 1063 neurotypical; mean age ASD group = 17 years) were compared across simple RT, choice RT, and interference control tasks (44 studies, 106 effects) using robust variance estimation meta-analysis. Simple RT tasks required participants to respond to individual stimuli, whereas choice RT tasks required forced-choice responses to two or more stimuli. Interference control tasks required a decision in the context of a distractor or priming stimulus; in an effort to minimize inhibitory demands, we extracted RTs only from baseline and congruent conditions of such tasks. All tasks required nonverbal (motor) responses. The overall effect-size estimate indicated significantly longer mean RTs in ASD groups (g = .35, 95% CI = .16; .54) than comparison groups. Task type moderated effects, with larger estimates drawn from simple RT tasks than interference control tasks. However, across all three task types, ASD groups exhibited significantly longer mean RTs than comparison groups. Stimulus type and age did not moderate effects. Generalized slowing may be a domain-general characteristic of ASD with potential consequences for social, language, and motor development. Assessing processing speed may inform development of interventions to support autistic individuals and their diverse cognitive profiles.

Hypoxia impairs reaction time but not response accuracy in a visual choice reaction task

We investigated the effect of hypoxia on the reaction time (RT) and response accuracy of pilots performing a visual choice reaction task that corresponded to the scanning of helmet mounted display (HMD) symbology. Eighteen male military pilots performed the task in a hypobaric chamber at two simulated altitudes (92 m and 4572 m) in a single-blinded repeated measures and counter-balanced design. The visual stimuli were displayed in low and high contrast and at a 30- and 50-degree field of view (FoV). We measured the pilots' RT and response accuracy. Using an eye tracker, we measured the pilot's glance time at each stimulus location. Finally, we collected subjective ratings of alertness. The results show that hypoxia increased the RT and glance time. Lowering the stimulus contrast and increasing the FoV further increased the RT, independent of hypoxia. These findings provide no evidence for hypoxia-induced changes in visual contrast sensitivity or visual field. Instead, hypoxia seemed to affect RT and glance time by reducing alertness. Despite the increased RT, the pilots maintained their accuracy on the visual task, suggesting that visual scanning of HMD symbology may be resistant to the effects of acute hypoxia.

A simple 100% normobaric oxygen treatment can substantially enhance sequence learning processes

Motor learning processes are crucial for our everyday life, and improving skills by tailored interventions is of great clinical interest and value. Our previous work revealed a positive effect of normo-baric oxygen treatment on visuomotor adaptation. Here, we investigate whether it could positively affect sequence learning (SL) processes as well. Sixty-four healthy young adults were divided into a 100% oxygen treatment (NbOxTr; N = 32, M=20.7 ± 1.63 yrs.) and a normal air treatment (AirTr; N = 32, M=20.8 ± 0.95 yrs.) group. Participants performed a standardized SL task by pressing the spatial-compatible key on a keyboard according to four visual stimuli with two pre-determined 8-item sequences with different training depths. Following a baseline session (10 trials), both groups received a gas treatment (5 L/min, via nasal cannula) during the next training session (4 blocks, 45 trials each block), followed by a testing session (30 trials) without gas treatment. On day two, participants completed another 30 trials, similar to the first-day testing session, also without gas treatment. ANOVA revealed no significant group differences during baseline (p > 0.05) but a significantly faster response time (+45.5%) in the NbOxTr than AirTr group in the training session with gas treatment for all training depths (p < 0.05). The positive NbOxTr effect consolidated into the following testing session without gas treatment for deeply trained sequences (+17%; p < 0.05), and for all training depth on day-two testing (+45.2%; p < 0.05). Results suggest that the NbOxTr substantially improved participants' SL processing speed. Notably, improvements consolidated after an overnight sleep. The present work confirms a beneficial effect of a single, simple NbOxTr on fundamental motor learning processes. This treatment approach may provide promising implications for practice in neurological rehabilitation and other motor learning-related scenarios and should be further investigated in future research.

A robot-based interception task to quantify upper limb impairments in proprioceptive and visual feedback after stroke

BACKGROUND

A key motor skill is the ability to rapidly interact with our dynamic environment. Humans can generate goal-directed motor actions in response to sensory stimulus within ~ 60-200ms. This ability can be impaired after stroke, but most clinical tools lack any measures of rapid feedback processing. Reaching tasks have been used as a framework to quantify impairments in generating motor corrections for individuals with stroke. However, reaching may be inadequate as an assessment tool as repeated reaching can be fatiguing for individuals with stroke. Further, reaching requires many trials to be completed including trials with and without disturbances, and thus, exacerbate fatigue. Here, we describe a novel robotic task to quantify rapid feedback processing in healthy controls and compare this performance with individuals with stroke to (more) efficiently identify impairments in rapid feedback processing.

METHODS

We assessed a cohort of healthy controls (n = 135) and individuals with stroke (n = 40; Mean 41 days from stroke) in the Fast Feedback Interception Task (FFIT) using the Kinarm Exoskeleton robot. Participants were instructed to intercept a circular white target moving towards them with their hand represented as a virtual paddle. On some trials, the arm could be physically perturbed, the target or paddle could abruptly change location, or the target could change colour requiring the individual to now avoid the target.

RESULTS

Most participants with stroke were impaired in reaction time (85%) and end-point accuracy (83%) in at least one of the task conditions, most commonly with target or paddle shifts. Of note, this impairment was also evident in most individuals with stroke when performing the task using their unaffected arm (75%). Comparison with upper limb clinical measures identified moderate correlations with the FFIT.

CONCLUSION

The FFIT was able to identify a high proportion of individuals with stroke as impaired in rapid feedback processing using either the affected or unaffected arms. The task allows many different types of feedback responses to be efficiently assessed in a short amount of time.

Reaction time as an outcome measure during online fear conditioning: Effects of number of trials, age, and levels of processing

Recent studies have shown that fear conditioning experiments can be successfully conducted online. However, there is limited evidence that measures other than subjective ratings of threat expectancy can be collected, which means that online research may not be able to adequately replace laboratory experiments. In the current study, we conducted an online fear conditioning experiment consisting of habituation, acquisition, extinction and 48 h delayed extinction recall using ratings of threat expectancy and conditional stimulus pleasantness, and probe reaction time as outcome measures. The conditional stimuli were categories of words and a levels of processing manipulation explored whether words that were processed at a deeper level during extinction evoked smaller differential threat responses during extinction recall. Although the levels of processing manipulation did not produce a significant outcome, we found that extinction recall was successfully operationalised in our study. Reaction time indicated differential responding during both acquisition and extinction recall, and age of participants was correlated in one of two experiments with differential threat expectancy and reaction time, such that older participants showed better safety learning. The outcomes of this experiment provide multiple novel tools for researchers to explore fear conditioning, especially in an online environment.

Degrading stimuli by reducing image resolution impairs performance in a rodent continuous performance test

Attention is a cognitive domain often disrupted in neuropsychiatric disorders and continuous performance tests (CPTs) are common clinical assays of attention. In CPTs, participants produce a behavioral response to target stimuli and refrain from responding to non-target stimuli. Performance in CPTs is measured as the ability to discriminate between targets and non-targets. Rodent versions of CPTs (rCPTs) have been validated with both anatomical and pharmacological studies, providing a translational platform for understanding attention function. In humans, stimulus degradation, the inclusion of visual noise in the image to reduce resolution, in CPTs impairs performance. Reduced image contrast, changes in the relative luminescence of elements in the image, has been used in rCPTs to test similar constructs, but, to our knowledge, reduced image resolution has not been tested in an rCPT. In this study, we tested multiple levels of stimulus degradation in a touchscreen version of the rCPT in mice. We found that stimulus degradation significantly decreased performance in males and females. Specifically, we found decreased stimulus discrimination and increases in hit reaction time and reaction time variability. These findings are in line with the effects of stimulus degradation in human studies. These data extend the utility and translational value of the family of rCPTs by demonstrating that stimulus degradation in the form of reduced image resolution produces qualitatively similar behavioral responses in mice as those in previous human studies.

Is there an association between daytime napping, cognitive function, and brain volume? A Mendelian randomization study in the UK Biobank

OBJECTIVES

Daytime napping has been associated with cognitive function and brain health in observational studies. However, it remains elusive whether these associations are causal. Using Mendelian randomization, we studied the relationship between habitual daytime napping and cognition and brain structure.

METHODS

Data were from UK Biobank (maximum n = 378,932 and mean age = 57 years). Our exposure (daytime napping) was instrumented using 92 previously identified genome-wide, independent genetic variants (single-nucleotide polymorphisms, SNPs). Our outcomes were total brain volume, hippocampal volume, reaction time, and visual memory. Inverse-variance weighted was implemented, with sensitivity analyses (Mendelian randomization-Egger and Weighted Median Estimator) for horizontal pleiotropy. We tested different daytime napping instruments to ensure the robustness of our results.

RESULTS

Using Mendelian randomization, we found an association between habitual daytime napping and larger total brain volume (unstandardized ß = 15.80 cm3 and 95% CI = 0.25; 31.34) but not hippocampal volume (ß = -0.03 cm3 and 95% CI = -0.13;0.06), reaction time (expß = 1.01 and 95% CI = 1.00;1.03), or visual memory (expß = 0.99 and 95% CI = 0.94;1.05). Additional analyses with 47 SNPs (adjusted for excessive daytime sleepiness), 86 SNPs (excluding sleep apnea), and 17 SNPs (no sample overlap with UK Biobank) were largely consistent with our main findings. No evidence of horizontal pleiotropy was found.

CONCLUSIONS

Our findings suggest a modest causal association between habitual daytime napping and larger total brain volume. Future studies could focus on the associations between napping and other cognitive or brain outcomes and replication of these findings using other datasets and methods.

The influence of selected anthropometric parameters on psychomotor abilities among professional Rugby Union players

BACKGROUND

One of the most popular varieties of rugby is Rugby Union, in which a team consists of 15 players. Rugby Union is a full-contact sport, and players must demonstrate strength, endurance, speed and agility. During the match, players participate in multiple physical collisions and tackles, short-duration and high-intensity sprinting efforts. In addition, one of the elements affecting the effectiveness of the player's game can be the reaction time of the rugby player to the visual stimulus and the ability to read the game and react to the situations on the pitch. The level of psychomotor abilities of a person or a player practising sports can be influenced by various factors, including age, body height, body weight, type of sport practised or level of training. The study aimed to analyse the psychomotor abilities of professional rugby union players, investigate the relationship between the selected anthropometric characteristics and psychomotor abilities, and compare obtained results with the control group.

METHODS

The study covered 22 players of the Polish National Team (age: 29.3 ± 5.4) and 27 students in the control group (age: 24.3 ± 3.9). The tests were carried out using the Test2Drive computer system of tests. For psychomotor abilities analysis, four tests were used: Simple Reaction Test, Choice Reaction Time Test, Hand-Eye Coordination Test and Spatial Orientation Test. The statistical analysis compares groups using basic statistical measures, and statistically significant differences between groups were checked. In addition, multiple linear regression was used.

RESULTS

The analysis showed statistically significant differences between the groups in the simple reaction time test and the movement time for the test assessing reaction time with choice and eye-hand coordination. Multiple regression analysis conducted for both groups showed a statistically significant influence of some anthropometric parameters on the examined psychomotor abilities. The calculated multiple regression models had a high fit.

CONCLUSIONS

The analysis showed that professional Rugby Union players have shorter movement time than the control group. For reaction time, statistically significant differences were observed only for simple reaction time. Moreover, linear regression analysis showed that body height and weight affect the selected psychomotor abilities.

Applying the Accumulator model to predict driver's reaction time based on looming in approaching and braking conditions

INTRODUCTION

The prediction of when the driver will react to a change in the lead vehicle motion is critical for assessing rear-end crash risk using car-following models. Past studies have assumed constant reaction time and driver's continuous reaction. However, these assumptions are not valid as the driver's reaction time can vary in different car-following situations and the driver does not continuously react to the lead vehicle motion. Thus, this study predicted the driver's reaction time using the Wiedemann car-following model and the Accumulator model. The Accumulator model assumes the driver's start of reaction based on the accumulation of looming and thereby reflects the driver's intermittent reaction.

METHOD

Fifty drivers' behavior was observed using a driving simulator in two scenarios: (1) approach and follow a moving lead vehicle and (2) approach a stopped lead vehicle. The Accumulator model predicted the reaction times based on different looming variables (angular velocity and tau-inverse), lead vehicle type (car and truck), and lead vehicle brake lights (on or off).

RESULTS

The Accumulator model showed lower prediction errors of the reaction time than the Wiedemann model, which assumes reaction based on the fixed looming threshold. The Accumulator model predicted the reaction times more accurately when it was calibrated with the angular velocity due to width and height of lead vehicles. Moreover, the Accumulator model with tau-inverse produced the smallest prediction error of reaction times among different Accumulator models and the Wiedemann model when lead vehicle brake lights were on.

CONCLUSIONS

This study demonstrates that the Accumulator model is a promising method of predicting the driver's reaction time in car-following situations, which affects rear-end crash risk.

PRACTICAL APPLICATIONS

The Accumulator model can be incorporated into a car-following model for the prediction of reaction times and can estimate the rear-end collision risk of vehicles more accurately.

Tradeoffs of estimating reaction time with absolute and relative thresholds

Measuring the duration of cognitive processing with reaction time is fundamental to several subfields of psychology. Many methods exist for estimating movement initiation when measuring reaction time, but there is an incomplete understanding of their relative performance. The purpose of the present study was to identify and compare the tradeoffs of 19 estimates of movement initiation across two experiments. We focused our investigation on estimating movement initiation on each trial with filtered kinematic and kinetic data. Nine of the estimates involved absolute thresholds (e.g., acceleration 1000 back to 200 mm/s2, micro push-button switch), and the remaining ten estimates used relative thresholds (e.g., force extrapolation, 5% of maximum velocity). The criteria were the duration of reaction time, immunity to the movement amplitude, responsiveness to visual feedback during movement execution, reliability, and the number of manually corrected trials (efficacy). The three best overall estimates, in descending order, were yank extrapolation, force extrapolation, and acceleration 1000 to 200 mm/s2. The sensitive micro push-button switch, which was the simplest estimate, had a decent overall score, but it was a late estimate of movement initiation. The relative thresholds based on kinematics had the six worst overall scores. An issue with the relative kinematic thresholds was that they were biased by the movement amplitude. In summary, we recommend measuring reaction time on each trial with one of the three best overall estimates of movement initiation. Future research should continue to refine existing estimates while also exploring new ones.

Stop-signal delay reflects response selection duration in stop-signal task

The stop-signal task (SST) is widely used for studying the speed of the latent process of response inhibition. The SST patterns are typically explained by a horse-race model (HRM) with supposed Go and Stop processes. However, HRM does not agree with the sequential-stage model of response control. As a result, the exact relationship between the response selection, the response execution stages, and the Stop process remains unclear. We propose that response selection occurs within the stop-signal delay (SSD) period, and that the competition between the Go and Stop processes occurs within the response execution period. To confirm this, we conducted two experiments. In Experiment 1, participants carried out a modified SST task with an additional stimulus category - Cued-Go. In the Cued-Go trials, cues were followed by imperative Go signals. The Cue-Go period duration was dynamically adjusted by an adaptive algorithm based on the response times reflecting the individual response selection duration. In Experiment 2, Cued-Go stimuli were followed by Stop Signals in half of the trials and response inhibition efficiency was calculated. The results of Experiment 1 indicate that SSD reflects the duration of the response selection process. The results of Experiment 2 show that this process has an independent and small effect on the effectiveness of controlled inhibition of the target response. Based on our findings, we propose a two-stage model of response inhibition in SST, with the first stage including response selection process and the second stage response inhibition following the SS presentation.

Test-retest reliability of a smartphone-based approach-avoidance task: Effects of retest period, stimulus type, and demographics

The approach-avoidance task (AAT) is an implicit task that measures people's behavioral tendencies to approach or avoid stimuli in the environment. In recent years, it has been used successfully to help explain a variety of health problems (e.g., addictions and phobias). Unfortunately, more recent AAT studies have failed to replicate earlier promising findings. One explanation for these replication failures could be that the AAT does not reliably measure approach-avoidance tendencies. Here, we first review existing literature on the reliability of various versions of the AAT. Next, we examine the AAT's reliability in a large and diverse sample (N = 1077; 248 of whom completed all sessions). Using a smartphone-based, mobile AAT, we measured participants' approach-avoidance tendencies eight times over a period of seven months (one measurement per month) in two distinct stimulus sets (happy/sad expressions and disgusting/neutral stimuli). The mobile AAT's split-half reliability was adequate for face stimuli (r = .85), but low for disgust stimuli (r = .72). Its test-retest reliability based on a single measurement was poor for either stimulus set (all ICC1s < .3). Its test-retest reliability based on the average of all eight measurements was moderately good for face stimuli (ICCk = .73), but low for disgust stimuli (ICCk = .5). Results suggest that single-measurement AATs could be influenced by unexplained temporal fluctuations of approach-avoidance tendencies. These fluctuations could be examined in future studies. Until then, this work suggests that future research using the AAT should rely on multiple rather than single measurements.

Reaction Time Variability in Children Is Specifically Associated With Attention Problems and Regional White Matter Microstructure

BACKGROUND

Increased intraindividual variability (IIV) in reaction times (RTs) has been suggested as a key cognitive and behavioral marker of attention problems, but findings for other dimensions of psychopathology are less consistent. Moreover, while studies have linked IIV to brain white matter microstructure, large studies testing the robustness of these associations are needed.

METHODS

We used data from the Adolescent Brain Cognitive Development (ABCD) Study baseline assessment to test the associations between IIV and psychopathology (n = 8622, age = 8.9-11.1 years) and IIV and white matter microstructure (n = 7958, age = 8.9-11.1 years). IIV was investigated using an ex-Gaussian distribution analysis of RTs in correct response go trials in the stop signal task. Psychopathology was measured by the Child Behavior Checklist and a bifactor structural equation model was performed to extract a general p factor and specific factors reflecting internalizing, externalizing, and attention problems. To investigate white matter microstructure, fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity were examined in 23 atlas-based tracts.

RESULTS

Increased IIV in both short and long RTs was positively associated with the specific attention problems factor (Cohen's d = 0.13 and d = 0.15, respectively). Increased IIV in long RTs was also positively associated with radial diffusivity in the left and right corticospinal tract (both tracts, d = 0.12).

CONCLUSIONS

Using a large sample and a data-driven dimensional approach to psychopathology, the results provide novel evidence for a small but specific association between IIV and attention problems in children and support previous findings on the relevance of white matter microstructure for IIV.

Choice of end-state comfort is dependent upon the time spent at the beginning-state and the precision requirement of the end-state

Choice of posture while grasping an object typically depends upon several factors including the time spent in that posture, what postures were held prior to choosing that posture, and the precision required by the posture. The purpose of this study was to test choice of end-state thumb-up posture based on time spent at the beginning-state and the precision requirement of the end-state. To determine choice of thumb-up based on time or precision, we varied how long a subject had to hold the beginning state before moving an object to an end location. We made end-state precision either small or large and eliminated the precision needed to stand the object up at the end of the movement. A choice between "comfort" at the beginning or precision at the end-state would be demanded by the conditions with long beginning-state hold times and high precision demands. We aimed to determine which aspect of movement was of greater importance to individuals, overall "comfort" or precision. When the requirement was to hold the initial grasp longer, and the end-target was large, we predicted that we would see more thumb-up postures adopted at the beginning state. When the final placement was small and the initial posture was not constrained, we predicted we would see thumb-up postures adopted at the end state. On average, we found that, as beginning-state grasp time increased, more individuals chose beginning-state thumb-up postures. Perhaps, not surprisingly, we found distinct individual differences within our sample. Some individuals seemed to choose beginning-state thumb-up postures nearly 100% of the time, while other individuals chose end-state thumb-up postures nearly 100% of the time. Both the time spent in a posture and its precision requirements influenced planning, but not necessarily in a systematic way.

Prefrontal activation during simulated driving in people with schizophrenia: A functional near-infrared spectroscopy study

People with schizophrenia (PWS) could be at risk when driving, yet this remains to be confirmed. In this study, we used functional near-infrared spectroscopy (fNIRS) and a driving simulator to assess potential driving skill difficulties as reflected by brain activity in PWS and compared them with those of healthy controls (HCs). Twenty PWS and 20 HCs were evaluated. Four tasks were performed: 50-kph and 100-kph sudden braking and 50-kph left and right curve tasks. The hemodynamic activity and driving performance of the two groups were compared. No significant differences were found in the performance of the four tasks. However, significant differences in hemodynamic activity were observed in the left and right dorsolateral prefrontal cortex (DLPFC) during the 100-kph sudden braking task. In addition, a significant negative correlation was found between brake reaction time and brain activity in the left DLPFC during the 100-kph sudden braking task in both groups. The brain mechanisms involved in processing the mental load associated with driving a car are possibly similar in PWS and HCs. Our results suggest that PWS may be able to drive their vehicles safely in the community.

Effects of in-situ stroboscopic training on visual, visuomotor and reactive agility in youth volleyball players

Background

Stroboscopic training is based on an exercise with intermittent visual stimuli that force a greater demand on the visuomotor processing for improving performance under normal vision. While the stroboscopic effect is used as an effective tool to improve information processing in general perceptual-cognitive tasks, there is still a lack of research focused on identifying training protocols for sport-specific settings. Therefore, we aimed at assessing the effects of in-situ stroboscopic training on visual, visuomotor and reactive agility in young volleyball players.

Methods

Fifty young volleyball athletes (26 males and 24 females; mean age, 16.5 ± 0.6 years) participated in this study and were each divided randomly into an experimental group and a control group, who then both performed identical volleyball-specific tasks, with the experimental group under stroboscopic influence. The participants were evaluated three times using laboratory based tests for simple and complex reaction speed, sensory sensitivity and saccade dynamics; before the after the 6-week-long training (short-term effect) and 4 weeks later (long-term effect). In addition, a field test investigated the effects of the training on reactive agility.

Results

A significant TIME vs GROUP effect was observed for (1) simple motor time (p = 0.020, ηp² = 0.08), with improvement in the stroboscopic group in the post-test and retention test (p = 0.003, d = 0.42 and p = 0.027, d = 0.35, respectively); (2) complex reaction speed (p < 0.001, ηp² = 0.22), with a large post-test effect in the stroboscopic group (p < 0.001, d = 0.87) and a small effect in the non-stroboscopic group (p = 0.010, d = 0.31); (3) saccade dynamics (p = 0.011, ηp² = 0.09), with post-hoc tests in the stroboscopic group not reaching significance (p = 0.083, d = 0.54); and (4) reactive agility (p = 0.039, ηp² = 0.07), with a post-test improvement in the stroboscopic group (p = 0.017, d = 0.49). Neither sensory sensitivity nor simple reaction time was statistically significantly affected as a result of the training (p > 0.05). A significant TIME vs GENDER effect was observed for saccadic dynamics (p = 0.003, ηp² = 0.226) and reactive agility (p = 0.004, ηp² = 0.213), with stronger performance gains in the females.

Conclusions

There was a larger effectiveness from the 6-week volleyball-specific training in the stroboscopic group compared to the non-stroboscopic group. The stroboscopic training resulted in significant improvements on most measures (three of five) of visual and visuomotor function with more marked enhancement in visuomotor than in sensory processing. Also, the stroboscopic intervention improved reactive agility, with more pronounced performance gains for short-term compared to the long-term changes. Gender differences in response to the stroboscopic training are inconclusive, therefore our findings do not offer a clear consensus.

Magnetoencephalographic neurofeedback training decreases β-low-γ phase-amplitude coupling of the motor cortex of healthy adults: A double-blinded randomized crossover feasibility study

Objective&#xD;The coupling between the beta (13-30 Hz) phase and low gamma (50-100 Hz) amplitude in the motor cortex is thought to regulate motor performance. Abnormal phase-amplitude coupling (PAC) of beta-low gamma (β-low-γ PAC) is associated with motor symptoms of Parkinson's disease. However, the causal relationship between β-low-γ PAC and motor performance in healthy subjects is unknown. We hypothesized that healthy subjects could change the strength of the β-low-γ PAC in the resting state by neurofeedback training (NFT) to control the β-low-γ PAC, such that the motor performance changes in accordance with the changes in β-low-γ PAC in the resting state. &#xD;Methods&#xD;We developed an NFT to control the strength of the β-low-γ PAC in the motor cortex, which was evaluated by magnetoencephalography (MEG) using a current source estimation technique. Twenty subjects were enrolled in a double-blind randomized crossover trial to test the feasibility of the MEG NFT. In the NFT for 2 days, the subjects were instructed to reduce the size of a black circle whose radius was proportional (down-training) or inversely proportional (up-training) to the strength of the β-low-γ PAC. The reaction times (RTs) to press a button according to some cues were evaluated before and after training. This study was registered at ClinicalTrials.gov (***) and UMIN-CTR (***).&#xD;Results&#xD;The β-low-γ PAC during the resting state was significantly decreased after down-training, although not significantly after up-training. RTs tended to decrease after both trainings, however the differences were not statistically significant. There was no significant correlation between the changes in β-low-γ PAC during rest and RTs.&#xD;Conclusion&#xD;The proposed MEG NFT was demonstrated to change the β-low-γ PAC of the motor cortex in healthy subjects. However, a relationship between PAC and RT has not yet been demonstrated.

Neck strength and force in reaction time task of adolescent athletes with and without concussion history: A pilot study

OBJECTIVES

Assess the impact of concussion by comparing reaction time, peak force recruitment, and rate of force development of adolescent athletes returning from concussion against age- and sex-matched controls in visual-elicited neck movement.

DESIGN

Athletes sat secured in a custom-built isometric device with their heads secured in a helmet and attached to a 6-axis load cell. They performed neck flexion, extension, and lateral flexion in response to a visual cue. Three trials in each direction were used for statistical analyses; peak force and rate of force development were normalized against athlete mass.

SETTING

Laboratory.

PARTICIPANTS

26 adolescent/young adult athletes (8F/18M), either recently concussed (and cleared for return to sport) or an age- and sex-matched healthy control.

MAIN OUTCOME MEASURES

Reaction time, angle, standard deviation of angle, deviation from target angle, peak force, and RFD over 50, 100, 150,and 200 ms of movement were measured for each trial.

RESULTS

Concussed athletes had decreased normalized peak force (P = 0.008) and rate of force development (P < 0.001-0.007). In neck extension, concussed athletes also had decreased movement precision (P = 0.012).

CONCLUSIONS

Concussion is associated with alterations of neck biomechanics that decrease overall neck strength.

Channeling of Brain Towards Engaging Sensorimotor Tasks for Inducing Hedonic Pleasure to Alleviate Blood Pressure in Hypertension

Background

Hypertension is a modifiable risk factor for cardiovascular disease and is responsible for major deaths due to stroke and coronary heart disease. Several pharmacological and non-pharmacological interventions for reducing blood pressure have been tried earlier. Modulating brain regions such as prefrontal cortex (PFC) to channelize activities is an effective tool to target blood pressure.

Purpose

Prefrontal cortex (PFC) exerts inhibitory control over sympathoexcitatory circuits, which was explored using a novel reaction time paradigm.

Methods

Thirty participants of both genders in the age group 40-70 years with established hypertension were included. A structured reaction time paradigm was designed to include psychomotor and visuomotor elements with integrated sensory attention and motor performance tasks. Blood pressure, Lead II ECG, and EEG from F3 and F4 were recorded. A paired t-test was used to examine the variations in these parameters across tasks.

Results

A significant reduction in mean arterial pressure by 4.04 mmHg (p = .0232) during the visuomotor task and a reduction of 3.38 mmHg during the auditory cue task (p = .0446) were observed. Analysis of the difference in heart rate has shown a profound decrease after passive listening tasks by 3.7 beats (p < .0001*). Spectral analysis from F3 and F4 shows high power in low-frequency zone of EEG indicating a relaxed state during auditory cues and passive listening.

Conclusion

The reaction time paradigm, when applied to hypertensives, helped decrease blood pressure and heart rate and improved the high frequency (HF) component of heart rate variability, indicating parasympathetic dominance. Such reward-oriented paradigms may act as biofeedback modules that cause hyperactivity of the PFC to suppress the sympathoexcitatory circuit with increased parasympathetic activity beneficial to hypertensive individuals.

How Exergaming with Virtual Reality Enhances Specific Cognitive and Visuo-Motor Abilities: An Explorative Study

Virtual reality (VR) is the computer simulation of a three-dimensional environment that a person can interact with using special electronic equipment, such as a headset with an integrated display. Often coupled with VR, exergames are video games that involve physical exercise. Little is known regarding the chronic effects of exergaming through VR chon cognitive functions. Eleven young participants were enrolled in this crossover exploratory study. They had to follow two trainings of 5 consecutive days, 15 min per day, interspaced by a 1-month washout period. Trainings were performed in a random order: (1) a video training using shadow boxing fitness videos (SBV) and (2) a VR training using a three-dimensional game where the aim is to cut moving cubes with a sword in each hand. Before and after each training period, a battery of cognitive tests was performed to assess executive functions, such as attention (change blindness), reaction time, response inhibition (go/no-go, Stroop task), or flexibility (trail making test). Fine motor skills were also evaluated through a Fitt's task. No effect of the SBV training was observed on any of the cognitive functions tested. On the contrary, a significant increased performance in selective attention and observation tests was found after VR training, as well as in inhibitory processes (Stroop and go/no-go). Other performances were unaffected by either VR or SBV training. The present study argues that VR exergaming is a promising tool to promote cognitive enhancement but targets specific functions according to the type of interface/game that is used.

Selective processing in attention and memory in schizophrenia: A meta-analysis of the negative priming effect

Individuals with schizophrenia show impairments in a variety of selective attention tasks. Research on the negative priming (NP) effect in schizophrenia has yielded mixed evidence. This meta-analysis aimed to examine the NP effect exhibited by patients with schizophrenia and the impact of study methodology on findings. The methods and reporting of this meta-analysis followed the PRISMA guideline. Eligible studies were identified through primary literature search in MEDLINE, PsycInfo, PsycArticles, and Embase and secondary search based on included studies and important reviews. Three-level random effects-models were used to summarize between-group differences in the raw NP score, as well as the NP ratio and baseline reaction time (RT) as secondary outcomes. We identified 1383 studies published between 1966 and 2022 and reviewed 27 studies that consist of 627 patients with schizophrenia and 653 controls in total. Compared to healthy controls, patients with schizophrenia showed a mildly reduced raw NP score with marginal significance, Hedges' g = -0.16, 95% confidence interval (CI) -0.35 to 0.02, p = 0.084. However, analysis of a subsample of studies indicated a significant, moderate reduction in the NP ratio among patients, g = -0.52, 95% CI -0.91 to -0.14; p = 0.014. Moderator analyses revealed a longer illness duration as predictive of a more reduced NP effect. This meta-analysis lends tentative evidence to impaired attention or memory process as measured by the NP task in schizophrenia. More research is needed to substantiate our results and clarify the impact of study design and patient characteristics on findings.

Investigating motor preparation in synchronous hand and foot movements under reactive vs. predictive control

Synchronizing hand and foot movements under reactive versus predictive control results in differential timing structures between the responses. Under reactive control, where the movement is externally triggered, the electromyographic (EMG) responses are synchronized, resulting in the hand displacement preceding the foot. Under predictive control, where the movement is self-paced, the motor commands are organized such that the displacement onset occurs relatively synchronously, requiring the EMG onset of the foot to precede that of the hand. The current study used a startling acoustic stimulus (SAS), which can involuntarily trigger a prepared response, to investigate whether these results are due to differences in a pre-programmed timing structure of the responses. Participants performed synchronous movements of the right heel and right hand under both reactive and predictive modes of control. The reactive condition involved a simple reaction time (RT) task, whereas the predictive condition involved an anticipation-timing task. On selected trials, a SAS (114 dB) was presented 150 ms prior to the imperative stimulus. Results from the SAS trials revealed that while the differential timing structures between the responses was maintained under both reactive and predictive control, the EMG onset asynchrony under predictive control was significantly smaller following the SAS. These results suggest that the timing between the responses, which differs between the two control modes, is pre-programmed; however, under predictive control, the SAS may accelerate the internal timekeeper, resulting in a shortened between-limb delay.

Choice reaction time in pigeons fails to increase as predicted by Hick's law

Being able to correctly identify a target when presented with multiple possible alternatives, or increasing uncertainty, is highly beneficial in a wide variety of situations. This has been intensely investigated with human participants and results consistently demonstrated that participant reaction time (RT) increases linearly with the number of response alternatives, described as Hick's Law. Yet, the strength of this relationship is impacted by a variety of parameters, including stimulus-response compatibility, stimulus intensity, and practice. Different theories attempt to explain why these parameters affect the time to detect the target, but thus far these theories almost exclusively rely on human and nonhuman primate research. Therefore, it is unclear if these theories are universal or unique to primates, due to the scarcity of other animal models. A previous investigation showed that pigeon RT will increase in accordance with Hick's Law though not as steeply as human RT, potentially due to differences in the procedure used on pigeons. To better understand pigeon RT under uncertainty and facilitate cross species comparisons, these experiments used a procedure that was more similar to what has been given to humans. Surprisingly, pigeon RT did not follow Hick's Law as predicted. In Experiment 1, subjects showed an 'anti-Hick's' effect due to an artefact of stimulus location on the monitor. Subsequent experiments controlled for location, still RT did not increase with the number of choices as predicted by Hick's Law. Procedural changes that may have been responsible for this difference and the role of stimulus-response compatibility are discussed.

A method for diagnosing depression: Facial expression mimicry is evaluated by facial expression recognition

BACKGROUND

Considerable evidence has shown that facial expression mimicry is impaired in patients with depression. We aimed to evaluate voluntary expression mimicry by facial expression recognition for diagnosing depression.

METHODS

A total of 168 participants performed voluntary expression mimicry task, posing anger, disgust, fear, happiness, neutrality, sadness, and surprise. 9 healthy raters performed facial expression recognition task through the observer scoring method, and evaluated seven expressions imitated by participants. Emotional scores were calculated to measure any differences between two groups of participants and provided a basis for clinical diagnosis of depression.

RESULTS

Compared with the control group, the depression group had lower accuracy in imitating happiness. Compared with the control group, the depression group imitated a higher neutrality bias for sadness, surprise, happiness and disgust, while sadness and surprise had a lower happiness bias; for imitating happiness, the depression group showed higher anger, disgust, fear, neutrality, and surprise bias; for imitating neutrality, the depression group showed higher sadness bias, and lower happiness bias. Compared with the control group, the raters had a higher reaction time to recognize the happiness imitated by depression group, and it was positively correlated with severity of depression. The severity of depression was also negatively correlated with accuracy in imitating happiness, and positively correlated with neutrality bias of imitating surprise.

LIMITATIONS

The ecological effectiveness of static stimulus materials is lower than that of dynamic stimuli. Without synchronized functional imaging, there is no way to link brain activation patterns.

CONCLUSION

The ability of patients with depression to voluntarily imitate facial expressions declines, which is mainly reflected in accuracy, bias and recognizability. Our experiment has discovered deficits in these aspects of patients with depression, which will be used as a method for diagnosising depression.

Reaction Time "Mismatch Costs" Change with the Likelihood of Stimulus-Response Compatibility

Dyadic interactions require dynamic correspondence between one's own movements and those of the other agent. This mapping is largely viewed as imitative, with the behavioural hallmark being a reaction-time cost for mismatched actions. Yet the complex motor patterns humans enact together extend beyond direct-matching, varying adaptively between imitation, complementary movements, and counter-imitation. Optimal behaviour requires an agent to predict not only what is likely to be observed but also how that observed action will relate to their own motor planning. In 28 healthy adults, we examined imitation and counter-imitation in a task that varied the likelihood of stimulus-response congruence from highly predictable, to moderately predictable, to unpredictable. To gain mechanistic insights into the statistical learning of stimulus-response compatibility, we compared two computational models of behaviour: (1) a classic fixed learning-rate model (Rescorla-Wagner reinforcement [RW]) and (2) a hierarchical model of perceptual-behavioural processes in which the learning rate adapts to the inferred environmental volatility (hierarchical Gaussian filter [HGF]). Though more complex and hence penalized by model selection, the HGF provided a more likely model of the participants' behaviour. Matching motor responses were only primed (faster) in the most experimentally volatile context. This bias was reversed so that mismatched actions were primed when beliefs about volatility were lower. Inferential statistics indicated that matching responses were only primed in unpredictable contexts when stimuli-response congruence was at 50:50 chance. Outside of these unpredictable blocks the classic stimulus-response compatibility effect was reversed: Incongruent responses were faster than congruent ones. We show that hierarchical Bayesian learning of environmental statistics may underlie response priming during dyadic interactions.

The Effects of Over- and Under-Specified Linguistic Input on L2 Online Processing of Referring Expressions

Via two reading experiments, this exploratory study examined the effects of over-and under-specified linguistic input on L2 online processing of Chinese referring expressions (REs). In each experiment, a group of advanced L2 Chinese speakers (all with Uyghurs as L1) and a control group of native Chinese speakers read 48 sets of 4 sentence pairs with each set including one sentence pair containing referential underspecification (ambiguity) and one pair containing overspecification (redundancy). An analysis of the two groups' reaction time (RT) using mixed-effects linear modelling reveals that underspecification had no effect on native Chinese speakers in both experiments, and overspecification also had no effect in the form of a redundant size noun modifier in Experiment 1 but showed a facilitating effect in the form of a color noun modifier in Experiment 2. In contrast, L2 Chinese speakers were significantly disrupted by underspecification in both experiments but not by overspecification. The results seem to support the hypothesis that L2 processing is constraint-based. Tentative research and pedagogical implications of the findings are discussed.

Within-individual variability in cognitive performance in schizophrenia: A narrative review of the key literature and proposed research agenda

Schizophrenia is a neurodevelopmental disorder and a leading cause of disability worldwide. Deficits in cognitive function are characteristic of schizophrenia and are predictors of functional outcomes in the disorder. Within-individual variability (WIV) in cognitive performance is elevated in schizophrenia and has been suggested to provide additional insight into cognitive function over and above mean performance measures. Despite growing interest in WIV in schizophrenia, research on the clinical significance and neural correlates of WIV in the disorder remains sparse. The present narrative review summarizes the key literature linking WIV in schizophrenia to clinical, neural, and genetic correlates. Here, we aim to highlight key knowledge gaps and provide directions for future research into WIV in schizophrenia.

Extending reaction duration has minor influence on nitrite production in partial-denitrification process

Partial denitrification (PD) is another important pathway producing nitrite for anammox, however, whether its performance is affected by overlong reaction time, a situation that often takes place is still unknown. Three sequencing batch reactors were operated for PD to evaluate this factor on nitrite production. Results indicated effluent nitrite was very close despite reaction time even extending to four times longer than control (i.e., nitrate-to-nitrite transformation ratio (NTR) of 94.4%-89.8%). Meanwhile, it was found PD could recover to the normal after suffering from high organics shocking. Cycle studies suggested produced nitrite would not be further reduced with prolonged time, as indicated by changing trend of pH and alkalinity. Microbial analysis revealed PD functional bacteria, Thauera, slightly decreased with prolonged reaction, while it was always predominated. Taken together, this study indicated overlong reaction time had minor influence on PD, demonstrating its robustness with great technological superiority in supplying nitrite for anammox.

Neonatal Behavioral Screen for Mouse Models of Neurodevelopmental Disorders

Behavioral phenotyping approaches for neonatal mice are important for investigating early alterations in brain development and function, relevant to neurodevelopmental disorders in humans. This chapter describes a behavioral screen that can provide an overall profile of function across the neonatal and preweaning period while also minimizing pup stress and disturbance of the maternal environment. Testing begins when mice are between 6 and 8 days in age, with additional evaluations at discrete time points until postnatal day (PD) 20-21, using tests for negative geotaxis, surface righting reflex, activity in an open field, acoustic startle responses and sensorimotor gating, and limb clasp.

Test re-test reliability of virtual acoustic space identification (VASI) test in young adults with normal hearing

Background

Recent developments in virtual acoustic technology has levered promising applications in the field of auditory sciences, especially in spatial perception. While conventional auditory spatial assessment using loudspeakers, interaural differences and/or questionnaires are limited by the availability and cost of instruments, the use of virtual acoustic space identification (VASI) test has widespread applications in spatial test battery as it overcomes these constraints.

Purpose

The lack of test-retest reliability data of VASI test narrows its direct application in auditory spatial assessment, which is explored in the present study.

Methods

Data from 75 normal-hearing young adults (mean age: 25.11 y ± 4.65 SD) was collected in three sessions: baseline, within 15 min of baseline (intra-session), and one week after baseline session (inter-session). Test-retest reliability was assessed using the intra-class correlation coefficient (ICC), coefficient of variation (CV), and cluster plots.

Results

The results showed excellent reliability for both accuracy and reaction time measures of VASI, with ICC values of 0.93 and 0.87, respectively. The CV values for overall VASI accuracy and reaction time 9.66% and 11.88%, respectively. This was also complemented by the cluster plot analyses, which showed 93.33% and 96.00% of temporal stability in the accuracy and reaction time measures, indicative of high test-retest reliability of VASI test in auditory spatial assessment.

Conclusions

The high temporal stability (test-retest reliability) of VASI test validates its application in spatial hearing test battery.

Slow tempo music preserves attentional efficiency in young children

Past research has shown that listening to slow- or fast-tempo music can affect adults' executive attention (EA) performance. This study examined the immediate impact of brief exposure to slow- or fast-tempo music on EA performance in 4- to 6-year-old children. A within-subject design was used, where each child completed three blocks of the EA task after listening to fast-tempo music (fast-tempo block), slow-tempo music (slow-tempo block), and ocean waves (control block), with block-order counterbalanced. In each block, children were also asked to report their pre-task subjective emotional status (experienced arousal and valence) before listening to music and their post-task emotional status after the EA task. Three major results emerged. First, reaction time (RT) was significantly faster in the slow-tempo block than in the fast-tempo, suggesting that listening to slow-tempo music preserves processing efficiency, relative to fast-tempo music. Second, children's accuracy rate in the EA task did not differ across blocks. Third, children's subjective emotional status did not differ across blocks and did not change across the pre- and post-task phases in any block, suggesting the faster RT observed in the slow-tempo block cannot be explained by changes in arousal or mood.