Standard Deviation Of Reaction Time Research Articles

Neurocognitive Profiles of Early Adulthood Attention-Deficit/Hyperactivity Disorder.

This study examined the neurocognitive profiles of early adulthood attention-deficit/hyperactivity disorder (ADHD) patients using the Korean version of the Wechsler Adult Intelligence Scale, 4th Edition (K-WAIS-IV) and Continuous Performance Test 3rd Edition (CPT-3) assessment results. A total of 105 individuals underwent the K-WAIS-IV assessment, and 68 participants completed the CPT-3. We examined the differences between intelligence subindex scores using paired t-tests and applied Pearson's correlation analysis to determine the correlation between the K-WAIS-IV and CPT-3 scores. Working Memory Index scores were significantly lower than Verbal Comprehension Index scores, whereas Processing Speed Index (PSI) scores were significantly lower than all three other subindex scores. Significant negative correlations were found between all four K-WAIS-IV subindex scores and the CPT-3 scores for Detectability, Omissions, Commissions, Perseverations, Hit Reaction Time, Hit Reaction Time Standard Deviation, and Variability. The PSI of the K-WAIS-IV can be considered a useful predictor in early adulthood ADHD patients combined with the CPT-3 examination.

Effects of a 1-year piano intervention on cognitive flexibility in older adults.

We analyzed the data of a randomized controlled trial to examine the effects of piano practice on cognitive flexibility in healthy older adults. Participants (N = 153, 69.5 ± 3.5 years of age, 57.5% females) were randomly assigned to a piano practice group (PP) or a control group engaged in active music listening (MC). Both groups underwent a year-long intervention with weekly 60-min lessons and daily homework. We assessed switch and mixing costs in terms of speed (mean reaction times) and variability (standard deviation of reaction times) with a number switch and a perceptual switch task. We employed scale analysis based on musical instrument digital interface to assess pianistic performance. Tests were conducted at baseline, after 6 months, postintervention (12 months), and at follow-up (18 months). Results revealed more pronounced improvements in pianistic performance in the PP group compared with the MC group over the course of the intervention. Both groups exhibited gains in several cognitive flexibility outcomes, which originated primarily in the latter half of the intervention. For mixing costs of the number switch test, the PP group showed greater improvements compared with the MC group. Changes in pianistic performance were not related to changes in cognitive flexibility. Additionally, the findings indicated a compensation account in both groups, which was more pronounced in the PP group for mixing costs. This study suggests that both piano practice and active music listening-with piano practice to a higher degree-enhance cognitive flexibility, particularly in sustained control mechanisms linked to mixing costs. Both interventions potentially require longer than 6 months to induce behavioral transfer effects and are especially beneficial for individuals with lower cognitive flexibility levels. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Effects of one night of sleep deprivation on whole brain intrinsic connectivity distribution using a graph theory neuroimaging approach

Neuroimaging studies have revealed disturbances in brain functional connectivity (FC) after one night of sleep deprivation (SD). These researches explored the alterations of FC using classical regions of interest (ROI)-based analysis or functional connectivity density. However, these methods need for a priori information about the selected ROIs and a specific correlation threshold to define a connection between two ROIs or voxels, which may bring inconsistent results. In the present study, we adopted a data-driven, whole brain voxel-based graph-theoretical approach, intrinsic connectivity distribution (ICD) analysis, to examine changes of brain connectivity after SD in 52 normal young subjects without any prior knowledge. The cross-hemisphere ICD (ch-ICD) analysis was also performed to discover the effect of SD on cerebral lateralization. We found that sleep-deprived subjects showed significant reduced ICD in default mode network (DMN) and limbic network, and increased ICD in sensorimotor network. Furthermore, after SD, the ICD in the right precuneus showed significant correlation with psychomotor vigilance test (PVT) performance following the stepwise regression analysis after Bonferroni correction (ICD = 0.43 - 0.62∗10 % fast reaction time + 0.31∗the standard deviation of reaction time, p = 0.0012). Follow-up seed-based FC analyses in the right precuneus revealed decreased FC to regions in DMN, visual network, ventral attentional network and frontal-parietal network. Nevertheless, no striking difference of ch-ICD was found following SD. In conclusion, these findings suggested that DMN, especially precuneus may be hubs of FC disturbances associated with vigilance after SD, and may provide new insights into the intervention for SD.

Response inhibition as a critical executive function in differentiating attention-deficit/hyperactivity disorder from autism spectrum disorder: a comprehensive attention test study.

Autism Spectrum Disorder (ASD) and Attention-Deficit/Hyperactivity Disorder (ADHD) are both associated with impairment in executive function, particularly in complex attention. Although previous studies using clinical assessments have attempted to delineate differences between these disorders, the findings have been inconclusive. Our study aims to elucidate the differences of endophenotype between ASD, ADHD, and their co-occurring condition utilizing a uniform computerized test. The study included children diagnosed with ASD, ASD co-occurring with ADHD (ASD+ADHD), or ADHD who completed the comprehensive attention test (CAT) at Severance Hospital between October 2013 to May 2023. We excluded children with intellectual disability and comorbid major psychiatric or neurologic disorders possibly affecting attention measurement. The participants were categorized into three groups for the comparative analysis of CAT measures: (a) ASD (n=112), (b) ASD+ADHD (n=155), and (c) ADHD (n=104). The study also conducted an exploratory analysis utilizing multivariate linear regression analysis to examine the association between the CAT measures and parent-reported scales. Notably, the ASD+ADHD and ADHD groups exhibited higher frequency of commission errors (CE) and perseveration errors (PE) compared to the ASD group. In the exploratory analysis, a significant negative association was observed between reaction time (RT) and both the social communication questionnaire (SCQ) and the child behavior checklist (CBCL) externalization scores in the ASD+ADHD and ADHD groups. The ASD+ADHD group tended to show higher standard deviation of reaction time (RTSD) compared to the ASD group. Our findings suggest that impaired response inhibition is more pronounced in ADHD compared to ASD. We propose altered visual attention, reflecting response inhibition, may serve as potential endophenotypic markers differentiating ADHD from ASD in attentional assessment. Elevated RTSD in the ASD+ADHD group demonstrates additive pathology, suggesting that the neurological mechanisms underpinning impaired sustained attention may differ between the two conditions.

Validity of specific CPT indices in differentiating school-aged children previously diagnosed with attention deficit/hyperactivity disorder from school-aged children with non-attention deficit/hyperactivity disorder in general education classrooms: a case control study

BackgroundContinuous performance tests (CPTs) are a popular tool for evaluating the symptoms of attention-deficit/hyperactivity disorder (ADHD). Performance measurements are typically linked to the biological features and cognitive functions of individuals. To determine the validity of specific CPT indices in differentiating between school-aged children with ADHD from with non-ADHD, each student’s sex, chronological age, and cognitive abilities should be considered.MethodsIn this prospective case–control study, a total of 30 non-ADHD students and 26 with ADHD who were aged 6 to 12 years were from general education classrooms. All students completed the Continuous Performance Tests (CPTs) and the Peabody Picture Vocabulary Test-revised (Mandarin-Chinese version). Demographic data were collected from the students’ parents.ResultsDetectability, Omissions, Commissions, and Hit Reaction Time Standard Deviation (HRT SD) yielded higher T-scores in children with ADHD than those without. Compared with non-ADHD students, those with ADHD had higher classification scores for Detectability, Omissions, Perseverations, and HRT SD. For each CPT index, after individual factors were controlled for, logistic regression revealed that only students with positive scores for Detectability, Omission, and HRT SD (adjusted odds ratios = 4.627, 9.977, and 3.908, Ps < 0.05) were likely to receive a diagnosis of ADHD. Furthermore, after individual characteristics were controlled for, Logistic regression also revealed that the cumulative positive scores of the Detectability, Omission, or and HRT SD remained associated with an increased risk of ADHD (adjusted odds ratio = 3.116, P < 0.01).ConclusionsCompared with school-aged children with non-ADHD in general education classrooms, those with ADHD exhibited significantly lower performance in inattention-related CPT indices. To reach an accurate diagnosis through CPTs, clinicians should pay attention to Detectability, Omission, and HRT SD. Compared with other CPT indices, Detectability, Omission, and HRT SD may function as more suitable indicators for distinguishing between school-aged children with and non-ADHD in general education classrooms. These indicators are robust and unobscured by individual characteristics.

Enhancing pilot vigilance assessment: The role of flight data and continuous performance test in detecting random attention loss in short IFR flights

Situational awareness (SA) and fatigue management are crucial aspects of aviation safety, particularly during demanding flight phases. This study introduces an innovative approach employing flight data, machine learning, and Continuous Performance Test (CPT) metrics to predict pilot performance and SA during instrument approaches under Instrument Meteorological Conditions (IMC). Data were collected from over 10 pilots across more than 40 flights in a high-fidelity Cessna 172 analog flight simulator.Significant correlations were observed between dynamic cognitive performance parameters and the exceedance shape factor, a novel measure of pilot sustained attention introduced in this research. Key variables identified through correlation analysis included variability, interstimulus change, and reaction time standard deviation.Importantly, commission scores and reaction time standard deviation emerged as key predictors in the machine learning model, specifically the Optimizable Gaussian Process Regression (GPR) model with a radial basis function kernel. The model achieved a validation R-squared of 0.90 and a test R-squared of 0.70. These systems could incorporate additional data sources, such as eye-tracking and scan pattern analysis, for a better assessment of pilot SA and fatigue levels. While post-flight measurements are inherently reactive, they are effective for monitoring the degradation of pilot CPT scores after each leg of high-frequency, short-duration flights.Notable limitations include the need to understand individual cognitive differences among pilots, such as age, experience, and cognitive style. The predictive model also requires validation in actual flight conditions to determine its ecological validity. Future research should aim to address these limitations, generalize the findings, and integrate CPT data with other sensor inputs to provide a more comprehensive understanding of pilot performance.

Association between intra-individual variability and prefrontal cortex activity measured by functional Near Infrared Spectroscopy (fNIRS) in children with ADHD

ABSTRACT This study uses fNIRS to determine whether there is a difference in the relationship between intra-individual variability and frontal lobe activity between ADHD patients and typically developing children. A total of 28 subjects (14 in ADHD patient group and 14 in control group) participated in this study. The subjects were tested for K-SADS and intelligence, and then the frontal lobe activity of the subjects was measured by continuous performance test, using functional near-infrared spectroscopy (NIRSIT). Processing speed index was significantly lower in the ADHD patient group than in the control group (p = .04). The CPT test results showed a positive correlation in the activity of the right dorsolateral prefrontal region in the patient group, but not at a statistically significant level. In the control group, activity showed a significant level of negative correlation with commission and hit reaction time standard deviation (p = .023; p = .063 respectively). In contrary to ADHD patient group, activation of the right dorsolateral prefrontal area was significantly correlated with reduction of intra-individual variability. This result showing that the relationship between activation of the right dorsolateral prefrontal area of the ADHD patient group and intra-individual variability shows a different pattern from typically developing children.

The Effect of Rocking Bed on Mood and Attention

Objective: The current study aims to explore the effects of sleep in the rocking bed on mood and attention.Methods: Thirty-nine young adults (14 with insomnia and 25 without insomnia) slept in the Sway Bed under three different conditions; 1) motionless condition, 2) continuously rocking condition, and 3) before-sleep rocking condition. In the motionless condition, participants slept without rocking for all night. In the continuously rocking condition, rocking started when lights out and stopped at wake-up time. In the before-sleep rocking condition, rocking started when lights out, but stopped after sleep onset. The Profile of Mood States and the computerized Comprehensive Attention Test were conducted before and after experimental sleep.Results: Under continuously rocking, depression, tension, anger, fatigue, confusion, and standard deviation of reaction time in divided attention were reduced. Under after-sleep bed condition, depression, tension, fatigue, confusion and omission errors in divided attention were reduced. There were no significant differences in after-sleep mood or attention changes between bed conditions. However, within those with insomnia, after-sleep improvement of depression and divided reduction were larger under continuously rocking conditions than under motionless conditions.Conclusion: Sleeping in the rocking bed improved negative affects and divided attention. The effects of rocking bed on depression and divided attention were prominent especially in those with insomnia. The current findings suggest that the sleep in the rocking bed may improve the depressive mood and the impaired attention of insomnia patients.

The Impact of Sex on Cognitive Control in ADHD: Girls Slow to Inhibit, Boys Inhibit Less, and Both Show Higher Response Variability

Objective: To determine whether girls and boys with ADHD show distinct impairments in components of cognitive control across multiple tasks (go/no-go, stop signal, and flanker) and performance metrics (response speed, variability, and errors). Method: A total of 300 children, ages 8 to 12 years with ADHD (n = 210, 58 girls) or typically developing (TD; n = 99, 37 girls), completed all tasks. Traditional response measures (e.g., mean and standard deviation of reaction time, inhibition errors, and stop signal reaction time) and ex-Gaussian modeling of reaction times (mu, sigma, and tau) were analyzed. Results: Girls showed intact response inhibition in the context of slower response speed, while boys made more inhibition errors and did not slow their response speed. Both girls and boys with ADHD showed higher response variability and poorer interference control than TD children. Conclusion: Girls and boys with ADHD show distinct impairments in cognitive control that may be important for understanding the pathophysiology of ADHD.

Time-frequency neural dynamics of ADHD children and adolescents during a Working Memory task

The present report analyzed the time-frequency changes in Event-Related Spectral perturbations (ERSP) in a sample of ADHD children and adolescents compared to a normodevelopment (ND) sample. A delayed match-to-sample (DMTS) test of working memory (WM) was presented to a group of ADHD subjects (N = 29) and compared with ND group (N = 34) with ages between 6 and 17 years old. Time-frequency decomposition was computed through wavelets. ADHD subjects presented higher Reaction Time (RT), Standard Deviation of RT (Std of RT), and a reduced percentage of correct responses. The results showed a complex pattern of oscillatory bursts during the encoding, maintenance, and recognition phases with similar dynamics in both groups. ADHD children presented a reduced Event-Related Synchronization (ERS) in the Theta range during the encoding phase, and also a reduced Alpha ERS during the late period of the maintenance phase. S1 Early theta ERS was positively correlated with Std of RT. Behavioral data, early Theta, and late Alpha ERS classified correctly above 70 % of ADHD and ND subjects when a linear discriminant analysis was applied. The reduced encoding and maintenance impaired brain dynamics of ADHD subjects would justify the poorer performance of this group of subjects.

Auditory Attention Ability under Dichotic Dual-Task Situation in Adults with Listening Difficulties

Introduction: Recent studies have reported poor cognition, such as attention and working memory, in adults with listening difficulties (LiD). However, they do not adequately describe the actual state of poor attention ability in adults with LiD. We examined the state of auditory attention in adults with and without LiD in tasks requiring multiple attention controls. Methods: Twenty-one adults who had normal hearing but complained about LiD encountered during everyday life and 22 healthy controls were included. We presented a target detection task using an odd-ball format for one ear and a sentence repetition task for the other ear. In the target detection task, participants listened to the 1,000-Hz tone served as the standard stimulus, while they had to accept a 2,000-Hz tone presented as the deviant stimulus. In the sentence repetition task, short sentences were presented. The stimuli presented to them were played on a personal computer at the most comfortable level. The participants heard these stimuli through headphones. They were required to press a key for standard stimuli in the target detection task and repeat what they heard immediately in the repetition task. We compared the response accuracy for each ear task between adults with and without LiD. Results: Our results showed that there were significant differences between the participant groups in the auditory dual-task under the dichotic listening situation. When examined individually, four adults with LiD had decreased scores in both the sentence repetition and target detection task, while the other nine participants showed a bias toward either task. Furthermore, the analysis of reaction time for pressing button revealed that the standard deviation of reaction time was extended in participants who scored poorly in either of the ear tasks. On the other hand, all adults without LiD were able to conduct the auditory dual-task exactly and promptly. Conclusion: The results suggest that adults with LiD have difficulties in appropriately allocating various cognitive abilities required for each task. We concluded that auditory attention is an important ability to conduct the auditory dual-task, and this is applicable for adults with LiD. Therefore, we believe that it is necessary to use auditory tests that require complex attentional abilities in listening, such as those required in daily life, to assess adults with LiD.

Information-based multivariate decoding reveals imprecise neural encoding in children with attention deficit hyperactivity disorder during visual selective attention.

Attention deficit hyperactivity disorder (ADHD) is a common neurodevelopmental disorder in school-age children. Attentional orientation is a potential clinical diagnostic marker to aid in the early diagnosis of ADHD. However, the underlying pathophysiological substrates of impaired attentional orienting in childhood ADHD remain unclear. Electroencephalography (EEG) was measured in 135 school-age children (70 with childhood ADHD and 65 matched typically developing children) to directly investigate target localization during spatial selective attention through univariate ERP analysis and information-based multivariate pattern machine learning analysis. Compared with children with typical development, a smaller N2pc was found in the ADHD group through univariate ERP analysis. Children with ADHD showed a lower parieto-occipital multivariate decoding accuracy approximately 240-340 ms after visual search onset, which predicts a slower reaction time and larger standard deviation of reaction time. Furthermore, a significant correlation was found between N2pc and decoding accuracy in typically developing children but not in children with ADHD. These observations reveal that impaired attentional orienting in ADHD may be due to inefficient neural encoding responses. By using a personalized information-based multivariate machine learning approach, we have advanced the understanding of cognitive deficits in neurodevelopmental disorders. Our study provides potential research directions for the early diagnosis and optimization of personalized intervention in children with ADHD.

Examining reaction time variability on the stop-signal task in the ABCD study.

Reaction time variability (RTV) has been estimated using Gaussian, ex-Gaussian, and diffusion model (DM) indices. Rarely have studies examined interrelationships among these performance indices in childhood, and the use of reaction time (RT) computational models has been slow to take hold in the developmental psychopathology literature. Here, we extend prior work in adults by examining the interrelationships among different model parameters in the ABCD sample and demonstrate how computational models of RT can clarify mechanisms of time-on-task effects and sex differences in RTs. This study utilized trial-level data from the stop signal task from 8916 children (9-10 years old) to examine Gaussian, ex-Gaussian, and DM indicators of RTV. In addition to describing RTV patterns, we examined interrelations among these indicators, temporal patterns, and sex differences. There was no one-to-one correspondence between DM and ex-Gaussian parameters. Nonetheless, drift rate was most strongly associated with standard deviation of RT and tau, while nondecisional processes were most strongly associated with RT, mu, and sigma. Performance worsened across time with changes driven primarily by decreasing drift rate. Boys were faster and less variable than girls, likely attributable to girls' wide boundary separation. Intercorrelations among model parameters are similar in children as has been observed in adults. Computational approaches play a crucial role in understanding performance changes over time and can also clarify mechanisms of group differences. For example, standard RT models may incorrectly suggest slowed processing speed in girls that is actually attributable to other factors.

Test-retest reliability of the 5-minute psychomotor vigilance task in working-aged females

BackgroundThe psychomotor vigilance task (PVT) is a commonly used test that effectively assesses neurobehavioral alertness. The originally developed PVT is 10 minutes in duration, which presents practical and logistical issues, particularly when administered to large samples or on a repetitive basis. More recently the PVT has been used in both 3- and 5-minute formats. While both of these durations have been shown to be field sensitive to identify impairments from sleep- and fatigue-related interventions, the 5-minute version has been suggested to be more valid than the 3-minute. However, while these have shown field-validity in a number of working populations, there is a paucity of data reporting the test-retest reliability statistics of the 5-minute PVT, particularly in working-aged females. The purpose of the study was to examine the test-retest reliability of a comprehensive set of PVT variables for the 5-minute PVT in a population of working-aged females (20–63 years). New methodParticipants reported to the laboratory on two separate days and performed a 5-minute PVT on each occasion. Outcome measures included the mean reaction time (MRT), fastest and slowest 10% of reaction times (F10RT% and S10RT%, respectively), standard deviation of reaction times (SDRT) as well as error-based metrics including major and minor lapses, anticipations, and false starts. In addition, total errors (ERR) were computed as a composite of all types of errors. Reliability statistics were reported as intraclass correlation coefficients (ICCs), standard error of measurement (SEM, SEM%), and minimal difference to be considered real (MD, MD%). Systematic error was also evaluated between sessions. ResultsOverall high reliability was shown for the MRT (ICC = 0.79, SEM% = 4.14%) and F10RT% (ICC = 0.83, SEM% = 4.43%) variables, with moderate relative reliability (based on ICCs) for the false starts, ERR, and sleepiness scale (ICC = 0.50 – 0.70) variables but these all exhibited poor absolute reliability (based on SEM% values of 32.60 – 168.69%). Poor relative reliability was found for the SDRT and S10RT% variables (ICCs < 0.50) but the S10RT% variable had good absolute reliability (SEM% = 7.12%). The minor and major lapses and anticipations variables had too few of event occurrences for a confident determination of the reliability. ConclusionsThe finding that the MRT variable displayed systematic error (P = 0.01) indicating that a learning curve may have been present, but the F10RT% did not show systematic error, suggests the F10RT% may be the most reliable PVT variable in a 5-minute duration test. These findings provide researchers and practitioners with reliability statistics that may help in determining which variable(s) to use, and which to avoid when specifically conducting 5-minute PVT assessments, particularly in a population of working-aged females. These results suggest that the 5-minute PVT can be used in place of the 10-minute version, if used appropriately.

Conjoint fluctuations of PFC-mediated processes and behavior: An investigation of error-related neural mechanisms in relation to sustained attention

The ability to detect errors, which derives from the medial prefrontal cortex (mPFC), is crucial to maintain attention over a long period of time. While impairment of this ability has been reported in patients with sustained attention disruption, the role mPFC-mediated processes play in the intra-individual fluctuation of sustained attention remains an open question. In this context, we computed the variance time course of reaction time (RT) of 42 healthy individuals to distinguish intra-individual periods of low and high performance instability, assumed to represent optimal and suboptimal attentional states, when performing a sustained Go/NoGo task. Analysis of the neurophysiological mechanisms of response monitoring revealed a specific reduction in the error-related negativity (ERN) amplitude and frontal midline theta power during periods of high compared to low RT variability, but only in individuals with a higher standard deviation of reaction time (SD-RT). Concerning post-error adaptation, an increase in the correct-related negativity (CRN) amplitude as well as the frontal lateral theta power on trials following errors was observed in individuals with lower SD-RT but not in those with higher SD-RT. Our results thus show that individuals with poor sustained attention ability exhibit altered post-error adaptation and attentional state-dependent efficiency of error monitoring. Conversely, individuals with good sustained attention performances retained their post-error adaptation and response monitoring regardless of the attentional periods. These findings reveal the critical role of the action-monitoring system in intra-individual behavioral stability and highlight the importance of considering attentional states when studying mPFC-mediated processes, especially in subjects with low sustained attention ability.

Polysomnographic Sleep and Attentional Deficits in Traumatized North Korean Refugees.

IntroductionAttentional deficits and sleep problems are common in refugees who have experienced trauma. In the present study, we used polysomnography (PSG) to investigate the relationship between attentional deficits and objective measures of sleep structure in traumatized North Korean refugees.MethodsWe recruited 32 North Korean refugees (mean age = 33.78 ± 14.33 years) and 39 South Korean participants (mean age = 35.03 ± 11.08 years). Sustained attention and divided attention were assessed using the Computerized Attention Test. We conducted an overnight PSG to objectively assess sleep structure. The participants also completed the Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI), Impact of Event Scale-Revised (IES-R), Epworth Sleepiness Scale (ESS), Pittsburgh Sleep Quality Index (PSQI), and Insomnia Severity Index (ISI).ResultsThe North Korean refugees showed more commission errors (CEs, p < 0.05) and a larger standard deviation (SD) of the reaction time (RT) (p < 0.05) in the sustained attention task compared to the South Korean participants. Furthermore, the North Korean refugees showed a shorter period of wake after sleep onset (WASO, p < 0.01), less time spent in N1 (p < 0.05), and more time spent in N2 (p < 0.05). The larger SD of RT in the sustained attention task in the North Korean refugees was positively correlated with WASO (r = 0.62, p < 0.01) and N1 stage (r = 0.47, p < 0.05) after controlling for age, sex, BDI, BAI, and IES-R.ConclusionThe North Korean refugees showed poorer performance on the sustained attention task. Nocturnal PSG revealed shorter WASO and time spent in N1 in this population, which are independently associated with the preservation of attentional capacity. These data suggest that traumatized refugees may compensate for attentional deficits induced by their traumatic experiences via increased sleep continuity.

Spatial variability of low frequency brain signal differentiates brain states.

Temporal variability of the neural signal has been demonstrated to be closely related to healthy brain function. Meanwhile, the evolving brain functions are supported by dynamic relationships among brain regions. We hypothesized that the spatial variability of brain signal might provide important information about brain function. Here we used the spatial sample entropy (SSE) to investigate the spatial variability of neuroimaging signal during a steady-state presented face detection task. Lower SSE was found during task state than during resting state, associating with more repetitive functional interactions between brain regions. The standard deviation (SD) of SSE during the task was negatively related to the SD of reaction time, suggesting that the spatial pattern of neural activity is reorganized according to particular cognitive function and supporting the previous theory that greater variability is associated with better task performance. These results were replicated with reordered data, implying the reliability of SSE in measuring the spatial organization of neural activity. Overall, the present study extends the research scope of brain signal variability from the temporal dimension to the spatial dimension, improving our understanding of the spatiotemporal characteristics of brain activities and the theory of brain signal variability.

Dissociating Slow Responses From Slow Responding.

Increased Intra-Subject Variability (ISV) is a candidate endophenotype of ADHD. ISV’s relationship with response speed is highly relevant for ADHD as patients are highly variable but typically no slower than controls. This brief report addresses the relationship between variability and speed by employing dimensional analyses for differentiated performance measures, with a particular focus on the ex-Gaussian measures, across relevant ADHD studies and in young healthy adults (N = 70). For both patients with ADHD and healthy adults, we found that reaction time standard deviation and mean reaction time were strongly correlated, thus failing to dissociate, but ex-Gaussian tau (τ) shared only little variance with Gaussian mu (μ), thus dissociating slow responses (τ) from response speed or—if given—slow responding (μ). Our results highlight the utility of employing the ex-Gaussian measures to disentangle ISV and speed, particularly for ADHD data as patients make more slow responses but are not overall slower than typical controls.

Economical Assessment of Working Memory and Response Inhibition in ADHD Using a Combined n-back/Nogo Paradigm: An ERP Study

The development of cognitive interventions in attention-deficit/hyperactivity disorder (ADHD) often requires the assessment of multiple cognitive functions. However, experimental settings consisting of various tasks are particularly strenuous for patients and can thus result in poor data quality. For the economical assessment of working memory and response inhibition, this study aims to validate a combined n-back/nogo paradigm by comparing it to single task versions and to demonstrate its applicability for ADHD research. Twenty-five healthy individuals and 34 ADHD patients between 9 and 16 years participated in this event-related potential (ERP) study. Healthy controls underwent single task versions of a 2-back working memory task and a go/nogo response inhibition task as well as the introduced combined 2-back/nogo task. This combined task demonstrated a comparable ERP structure for working memory and response inhibition aspects as single task versions. Behaviorally, higher working memory performance during the combined paradigm indicated lower task difficulty, while high correlations between combined and single task versions still indicated valid working memory measures. For response inhibition performance, different task versions resulted in similar outcomes. The application of the combined n-back/nogo paradigm in ADHD patients revealed the expected working memory and response inhibition deficits, increased omission errors, reaction times, and standard deviation of reaction time, as well as diminished n-back P3 and nogo P3 amplitudes. We conclude that the combined n-back/nogo task is an effective paradigm for the economical assessment of working memory and response inhibition deficits in ADHD on a behavioral and neurophysiological level.

Changes in attention variables in those who treated with anticholinergic agents for nonmonosymptomatic enuresis.

PurposeBrain dysfunction related to areas regarding attention and arousal may occur not only in patients with attention-deficit/hyperactivity disorder (ADHD) but also in patients with enuresis and daytime symptoms. This study aimed to investigate changes in computerized comprehensive attention tests (CATs), a psychometric test for ADHD when patients with nonmonosymptomatic enuresis (NME) were treated with anticholinergic agents.Materials and MethodsThirty patients with NME featuring overactive bladder were prospectively enrolled. They were treated with 5 mg of solifenacin to control daytime symptoms. Using CATs, patients were evaluated during 12 weeks of treatment. Four subtests of attention (visual and auditory selective attention, sustained attention, and flanker tests) were measured. For each subtest, four domains (omission error, commission error, response time [RT], and standard deviation of RT) were assessed.ResultsOnly one domain of the flanker test was in the deficient range at baseline. The presence of urge incontinence affected follow-up results on the sustained attention tests. Treatment with anticholinergic agents did not significantly affect attention variables but changes in several variables were correlated with bladder symptoms and enuresis.ConclusionsMinimal baseline defects in attention function were seen in patients with NME. Follow-up results for some attention variables were affected by daytime symptoms and enuresis. These results suggest that altered brain function in enuretic patients influences improvement in both attention and bladder function.