Test-retest Effects Research Articles

Examining implicit and explicit anti-Black racial bias in children: A repeated measure design using the Function Acquisition Speed Test (FAST)

ABSTRACT Anti-Black bias involves negative evaluations of individuals from African-descendent groups. Researchers use explicit and implicit measures to detect this bias and evaluate intervention effectiveness. However, few behavior analysis studies have focused on identifying and addressing racial bias in children, and none have explored the effects of test-retest on implicit measures in this context. This study aimed to identify implicit and explicit anti-Black racial bias in children and examine the test-retest reliability of these measures over three time points. Thirty-four children (average age 8.60 years, 24 females) rated images of Black and White faces on a five-point Likert scale. The Modified Function Acquisition Speed Test (FAST), an implicit measure, assessed how fluently participants categorized Black and White faces with positive and negative images. Results showed no explicit racial bias in the sample. However, implicit measure results revealed an anti-Black bias, with 11 participants consistently displaying this bias across three repetitions. Regarding test-retest reliability, there were no significant performance differences on the implicit and explicit measures across the three repetitions. These findings suggest that the FAST is a sensitive tool for identifying racial bias in children, and the absence of test-retest effects supports its feasibility for repeated use.

Evaluating the effect of action-like video game play and of casual video game play on anxiety in adolescents with elevated anxiety: protocol for a multi-center, parallel group, assessor-blind, randomized controlled trial

BackgroundAdolescence is a critical period for the onset and maintenance of anxiety disorders, which raises the importance of intervening early; one possibility of doing so is via digital interventions. Within that research field, at least two important research paths have been explored in the past years. On the one hand, the anxiolytic effect of casual video games has been tested as such gaming activity may distract away from anxious thoughts through the induction of flow and redirection of attention toward the game and thus away of anxious thoughts. On the other hand, the bidirectional link between weak attentional control and higher anxiety has led to the design of interventions aiming at improving attentional control such as working memory training studies. Taking stock that another genre of gaming, action video games, improves attentional control, game-based interventions that combines cognitive training and action-like game features would seem relevant. This three-arm randomized controlled trial aims to evaluate the feasibility and the efficacy of two video game interventions to document how each may potentially alleviate adolescent anxiety-related symptoms when deployed fully on-line.MethodsThe study aims to recruit 150 individuals, 12 to 14 years of age, with high levels of anxiety as reported by the parents’ online form of the Screen for Child Anxiety Related Disorders questionnaire. This trial contrasts a child-friendly, “action-like” video game designed to improve attentional control abilities in a progressive and stepwise manner (Eco-Rescue), a casual puzzle video game selected to act as a positive distraction tool (Bejeweled) and finally a control group with no assigned training intervention to control for possible test-retest effects (No-training). Participants will be assigned randomly to one of the three study arms. They will be assessed for main (anxiety) and secondary outcomes (attentional control, affective working memory) at three time points, before training (T1), one week after the 6-week training (T2) and four months after completing the training (T3).DiscussionThe results will provide evidence for the feasibility and the efficacy of two online video game interventions at improving mental health and emotional well-being in adolescents with high levels of anxiety. This project will contribute unique knowledge to the field, as few studies have examined the effects of video game play in the context of digital mental health interventions for adolescents.Trial registrationThe trial is registered on ClinicalTrials.gov (NCT05923944, June 20, 2023).

Longitudinal resting-state network connectivity changes in electroconvulsive therapy patients compared to healthy controls

ObjectiveElectroconvulsive therapy (ECT) is effective for major depressive episodes. Understanding of underlying mechanisms has been increased by examining changes of brain connectivity but studies often do not correct for test-retest variability in healthy controls (HC). In this study, we investigated changes in resting-state networks after ECT in a multicenter study. MethodsFunctional resting-state magnetic resonance imaging data, acquired before start and within one week after ECT, from 90 depressed patients were analyzed, as well as longitudinal data of 24 HC. Group-information guided independent component analysis (GIG-ICA) was used to spatially restrict decomposition to twelve canonical resting-state networks. Selected networks of interest were the default mode network (DMN), salience network (SN), and left and right frontoparietal network (LFPN, and RFPN). Whole-brain voxel-wise analyses were used to assess group differences at baseline, group by time interactions, and correlations with treatment effectiveness. In addition, between-network connectivity and within-network strengths were computed. ResultsWithin-network strength of the DMN was lower at baseline in ECT patients which increased after ECT compared to HC, after which no differences were detected. At baseline, ECT patients showed lower whole-brain voxel-wise DMN connectivity in the precuneus. Increase of within-network strength of the LFPN was correlated with treatment effectiveness. We did not find whole-brain voxel-wise or between-network changes. ConclusionDMN within-network connectivity normalized after ECT. Within-network increase of the LFPN in ECT patients was correlated with higher treatment effectiveness. In contrast to earlier studies, we found no whole-brain voxel-wise changes, which highlights the necessity to account for test-retest effects.

The role of auditory processing in L2 vowel learning: evidence from recasts

Developing adequate second language (L2) speech has increasingly become one of the important goals in today’s globalized world. The current study set out to investigate how the provision of recasts can facilitate English vowels /i/-/ɪ/ learning by Chinese native speakers and how such learning gains resulting from recasts can be tied to individual differences in auditory processing. An experimental group of thirty young adults was engaged in ten treatment sessions of recasts lasting ninety minutes each to notice and practice English vowels /i/-/ɪ/. Their learning gains were tested through a forced-choice identification task, a controlled word-reading task, and a spontaneous picture-narrative task before and after receiving recasts. A control group of the same number of participants was also included to receive comparable sessions without receiving any recasts to check for test-retest effects. Quantitative analysis showed that recasts significantly helped Chinese native speakers facilitate their learning of English vowels /i/-/ɪ/ regardless of time and lexical context. Such learning gains resulting from recasts were significantly correlated with specific constructs of auditory processing. Namely, perceptual acuity was significantly correlated with gains from recasts in identifying L2 vowels, and audio-motor integration with gains from recasts in controlled/spontaneous production of L2 vowels. The findings suggest that recasts can serve as ideal instructional techniques of L2 vowel learning for Chinese native speakers and that the auditory processing profiles of individuals can suggest how they can benefit the most from recasts.

Deep brain stimulation normalizes amygdala responsivity in treatment-resistant depression.

Deep brain stimulation (DBS) of the ventral anterior limb of the internal capsule (vALIC) is a promising intervention for treatment-resistant depression (TRD). However, the working mechanisms of vALIC DBS in TRD remain largely unexplored. As major depressive disorder has been associated with aberrant amygdala functioning, we investigated whether vALIC DBS affects amygdala responsivity and functional connectivity. To investigate the long-term effects of DBS, eleven patients with TRD performed an implicit emotional face-viewing paradigm during functional magnetic resonance imaging (fMRI) before DBS surgery and after DBS parameter optimization. Sixteen matched healthy controls performed the fMRI paradigm at two-time points to control for test-retest effects. To investigate the short-term effects of DBS de-activation after parameter optimization, thirteen patients additionally performed the fMRI paradigm after double-blind periods of active and sham stimulation. Results showed that TRD patients had decreased right amygdala responsivity compared to healthy controls at baseline. Long-term vALIC DBS normalized right amygdala responsivity, which was associated with faster reaction times. This effect was not dependent on emotional valence. Furthermore, active compared to sham DBS increased amygdala connectivity with sensorimotor and cingulate cortices, which was not significantly different between responders and non-responders. These results suggest that vALIC DBS restores amygdala responsivity and behavioral vigilance in TRD, which may contribute to the DBS-induced antidepressant effect.

Mapping the modulating effect of transcutaneous auricular vagus nerve stimulation on voxel-based analyses in patients with first-episode major depressive disorder: a resting-state fMRI study.

Seed-based analysis find that transcutaneous auricular vagus nerve stimulation (taVNS) can modulate the dysfunctional brain network in patients with major depressive disorder (MDD). The voxel-based neuro-psychological mechanism of taVNS on patients with first-episode MDD is poorly understood. Twenty-two first-episode MDD patients accepted 8-week taVNS treatment. Resting-state fMRI were scanned before and after the treatment. Voxel-based analyses were performed to characterize the spontaneous brain activity. Health controls (n = 23) were recruited to minimize the test-retest effects. The analysis of covariance (ANCOVA) was performed to determine the treatment-related changes. Then the correlations between the changes of the brain activity and the Hamilton Depression Rating Scale (HAMD) / Hamilton Anxiety Scale remission rate were estimated. Significant group-by-time interactions on voxel-based analyses were observed in inferior ventral striatum (VSi) and precuneus. Post-hoc analyses showed that taVNS inhibited the higher brain activity in the VSi, while upregulated the precuneus. The functional connectivity (FC) between VSi and precuneus decreased. Positive correlations were found between the HAMD remission rate and the alterant brain activity in the VSi. TaVNS reduced the functional connectivity between VSi and precuneus by normalizing the abnormal spontaneous brain activity of VSi in first-episode MDD patients.

A randomized trial of one versus three hyperbaric oxygen sessions for acute carbon monoxide poisoning

Introduction: Hyperbaric oxygen (HBO2) improves outcome in patients with acute carbon monoxide (CO) poisoning, but optimal dose/timing are unknown. In this double-blind, sham-controlled randomized trial, we compared neuropsychological sequelae at 6 weeks and 6 months in patients receiving 3 HBO2 sessions or 1 HBO2 session and 2 sham chamber sessions after acute CO poisoning. Methods: After completing 1 HBO2 session (3.0 ATA, 60 minutes, 2.0 ATA, 65 minutes), CO-poisoned patients were randomized (1:1): 2 sham chamber sessions (1 ATA air, 120 minutes) or 2 additional HBO2 sessions (2.0 ATA, 90 minutes at pressure, 120 minutes in chamber) completed within 24 hours. Eligible patients were <24 hours from accidental poisoning, English-speaking, and not intubated. We planned 150 participants. Results: The study was stopped early for enrollment futility. From 2006-2016, we screened 395 patients, 136 were deemed eligible to participate, and 75 signed informed consent. Two were later withdrawn for past brain injury/PTSD (1 sham, 1 HBO2), and 1 for performance validity (sham). Of the 72 analyzed, mean age was 42±15 years, 40 (56%) were male, 20 (28%) had loss of consciousness, and mean initial carboxyhemoglobin was 22±9%. The rate of 6-week neuropsychological sequelae was 50% in the 1 HBO2 session group and 55% in the 3 HBO2 sessions group (p=0.80), and at 6 months was 42% vs 46%, respectively (p=0.76). Conclusions: There was no difference in the rate of neuropsychological sequelae in those who received 3 HBO2 sessions and those who received 1 HBO2 sessions and 2 sham sessions. The higher rate of neuropsychological sequelae compared to an earlier study may be due to neuropsychological test-retest effects or previously identified risk factors for cognitive sequelae (age, duration of poisoning, cerebellar dysfunction). This study’s rates of cognitive difficulties, affective complaints, and other symptoms suggest brain injury after CO poisoning is common.

Vocabulary changes in adulthood: Main findings and methodological considerations.

Vocabulary scores increase until approximately age 65 years and then remain stable or decrease slightly, unlike scores on tests of other cognitive abilities that decline significantly with age. To review the findings on ageing-related changes in vocabulary, and to discuss four methodological issues: research design; test type; measurement; and vocabulary ability as a proxy for general intelligence. A discussion of cross-sectional and longitudinal research designs shows that cohort membership accounts for some but not all ageing-related changes in vocabulary, and that drop-out and test-retest effects do not alter conclusions regarding these changes. Test type affects age trends in vocabulary, and if researchers use only one test, they should choose a multiple-choice synonym test. While some authors suggest that vocabulary tests do not measure the same underlying ability in younger and older adults, more research of this suggestion is needed. A brief examination of the use of vocabulary ability as a proxy for general intelligence in healthy ageing and for premorbid abilities in dementia indicates that such practice is often questionable. Vocabulary knowledge increases through the mid-60s regardless of measurement method. However, there is little information on how word knowledge serves other verbal skills in old age, how and when adults learn new words, or how much exposure is necessary for meanings to remain in storage for a lifetime. Research of these issues may require new methodologies, as well as novel theoretical accounts of ageing-related effects on vocabulary. What is already known on this subject Unlike many cognitive abilities that decline with ageing, vocabulary knowledge continues to increase until approximately age 65, and then remains stable or decreases slightly. These findings have been replicated in different research designs and across languages. What this paper adds to existing knowledge The article presents a summary of findings on changes in vocabulary across adulthood, and a discussion of four key methodological issues: research design, test type, measurement, and the use of vocabulary ability as a proxy for general intelligence. What are the potential or actual clinical implications of this work? To better understand changes in vocabulary knowledge across adulthood, clinicians must be aware of methodological considerations that affect the field. Such considerations have direct clinical implications regarding the choice of vocabulary tests and their use as a proxy for other abilities in both healthy older adults and in individuals with dementia.

Training attentive individuation leads to visuo-spatial working memory improvement in low-performing older adults: An online study.

Cognitive decrements are typical of physiological aging. Among these age-related cognitive changes, visuo-spatial working memory (vWM) decline has a prominent role due to its effects on other cognitive functions and daily routines. To reinforce vWM in the aging population, several cognitive training interventions have been developed in the past years. Given that vWM functioning depends (at least partially) on the efficiency of attention selection of the relevant objects, in the present study we implemented a short (five sessions), online intervention that primarily trained attentive individuation of target items and tested training effects on a vWM task. Attention training effects were compared with practice (i.e., a group that repeatedly performed the same vWM task) and test-retest effects (i.e., a passive group). After the training, the results showed attention training effects of the same magnitude as practice effects, confirming that the enhancement of attentive individuation has a positive cascade influence on maintaining items in vWM. Moreover, training and practice effects were only evident in low-performing older adults. Thus, interindividual differences at baseline crucially contribute to training outcomes and are a fundamental factor to be accounted for in the implementation of cognitive training protocols.

The effect of processing semantic features on spoken word retrieval in a case series of people with aphasia

Purpose: There is a growing body of evidence showing the benefit of Semantic Feature Analysis in the treatment of word finding abilities in people with aphasia. The original technique was grounded in the hypothesis that the activation of semantic features spreads to the target and thereby facilitates its subsequent retrieval. However, it remains unclear the extent to which the focus on semantic features influences the treatment effects. The aim of this study was therefore to shed light on this issue by examining the effect of priming with semantic features (parts and functions) on target retrieval across a case series of people with aphasia. Method: 10 people with aphasia and word retrieval impairments were primed with spoken forms of words that were either the target name (identity condition, e.g. car), parts of the target (e.g. wheel) or functions of the target (e.g. drive) before later being asked to name a picture of that target. An unrelated prime condition (e.g. employ) was used as a control for test-retest effects. Result: At a group level, there was speeding of reaction times in picture naming in the identity condition relative to the unrelated condition; however, no effect of priming was found for either parts or functions. There was significantly better response accuracy in post-priming naming, but this effect did not reach significance for any individual experimental condition (identity, parts, functions) as compared to the unrelated condition, although the identity condition showed numerical improvement while the other two conditions showed decline. Conclusion: Given the lack of evidence for facilitatory effects from parts and functions of a target in a priming task, this research suggests that further research is warranted on the extent to which the improvement in word retrieval subsequent to Semantic Feature Analysis is caused by the emphasis on production of semantic features rather than from the repetition of the target name.

Neuropsychological outcomes after thalamic deep brain stimulation for essential tremor

IntroductionNon-motor DBS outcomes have received little attention in ET relative to PD. This study examines neuropsychological outcomes in ET following thalamic VIM DBS. MethodsFifty patients completed neuropsychological evaluations preoperatively and approximately seven months postoperatively. Cognition and mood changes were analyzed at the group level and individual level. Additional associations with treatment, disease, and demographic characteristics were assessed. ResultsSignificant cognitive decline was not observed at the group level. At the individual level, 46% of patients demonstrated at least subtle overall cognitive decline (≥1SD on at least one test within at least two domains). Mild decline (≥1SD) was seen in 10%–29.17% of patients on individual tests across all cognitive domains, with highest rates in verbal memory. Substantial cognitive decline (≥2SD) occurred in less than 9% of the sample across all tests. Factors related to cognitive decline included higher DBS parameter settings, older age of ET onset, intracranial complications, and inability to reduce ET medications postoperatively. Depression and anxiety did not change when accounting for questionnaire items that could be falsely elevated by tremor. ConclusionSubstantial cognitive decline after VIM DBS is rare in patients with ET. However, subtle decrements can occur across cognitive domains and particularly in verbal memory. DBS parameter settings may relate to cognitive decline. Further research is needed to better understand possible associations with electrode lateralization and other variables that could also relate to disease progression and test-retest effects. Symptoms of depression and anxiety remain stable.

Stability and test-retest reliability of different hormonal stress markers upon exposure to psychosocial stress at a 4-month interval

The Trier Social Stress Test (TSST) has been shown to reliably induce physiological stress responses in the hypothalamus-pituitary-adrenal (HPA) and in the sympathetic-adrenal-medullary (SAM) axis in cross-sectional studies. However, it was also reported that repeated exposure to the TSST might be associated with habituation, mainly of the HPA axis responsivity. Thus, in all longitudinal stress studies involving repeated TSST administration, potential habituation of the HPA axis response complicates the interpretation of results. The goal of the present study was therefore to assess stability and test-retest reliability of a number of different endocrinological stress markers as well as subjective stress responses after two exposures to the TSST four months apart. We assessed salivary and plasma cortisol profiles, plasma ACTH and noradrenaline profiles, as well as subjective stress ratings in healthy volunteers before, during, and after the TSST at six time-points both at test-day 1 (TSST_1, n = 42) and test-day 2 (TSST_2, n = 34) 4-months later. Half of the participants received the TSST in the early, the other half in the late afternoon. Discontinuous growth models were applied to model three phases of the stress response (preTSST, reactivity, recovery) for each marker. Subsequently, the stability of these phases was analyzed. Stability and test-retest reliability of standard physiological stress markers such as Area-under-the-Curve (AUCG, AUCI), Absolute Peak Change, and Relative Peak Change (RPC) were analyzed as well. We did not observe strong test-retest effects in any of the endocrinological measures. In contrast, test-retest effects in subjective stress were characterized by a faster drop directly after the second TSST, whereas the initial increase before the test period was the same for both test-days. Regarding test-retest-reliability, AUCG was the most reliable measure across all endocrinological and subjective stress markers (range: r = .606 to .858), while AUCI and RPC (range: r = − .146 to .548) were least reliable. A 4-month interval is a sufficient time interval between two repeated TSST exposures to largely reinstate the physiological stress response, which was also true for the initial psychological stress response. Thus, the TSST is well applicable in longitudinal studies.

Evaluation of Prolonged Walking in Persons with Multiple Sclerosis: Reliability of the Spatio-Temporal Walking Variables during the 6-Minute Walk Test.

Background: Walking disorders represent the most disabling condition in persons with Multiple Sclerosis (PwMS). Several studies showed good reliability of the 6-min walk test (6MWT) (i.e., especially distance traveled), but little is known about the reliability of the Spatio-temporal (ST) variables in the 6MWT. Objective: To evaluate the test-retest reliability of ST variables and perceived exertion during the 6MWT in PwMS and comparable healthy persons. Methods: We explored three 1-min intervals (initial: 0′–1′, middle: 2′30″–3′30″, end: 5′–6′) of the 6MWT. Six ST variables and perceived exertion were measured (respectively, using the GAITRite system and the Borg Scale). These measurements were performed twice, 1 week apart. The test-retest effects were assessed using the intraclass correlation coefficient (ICC) or the weighted kappa. Results: Forty-five PwMS and 24 healthy persons were included. The test-retest reliability of ST variables values was good-to-excellent for PwMS (ICC range: 0.858–0.919) and moderate-to-excellent for healthy persons (ICC range: 0.569–0.946). The test-retest reliability values of perceived exertion were fair for PwMS (weighted kappa range: 0.279–0.376) and substantial for healthy persons (weighted kappa range: 0.734–0.788). Conclusion: The measurement of ST variables during these 6MWT intervals is reliable and applicable in clinical practice and research to adapt rehabilitation care in PwMS.

Applying planned missingness designs to longitudinal panel studies in developmental science: An overview.

Longitudinal panel studies are widely used in developmental science to address important research questions on human development across the lifespan. These studies, however, are often challenging to implement. They can be costly, time-consuming, and vulnerable to test-retest effects or high attrition over time. Planned missingness designs (PMDs), in which partial data are intentionally collected from all or some of the participants, are viable solutions to these challenges. This article provides an overview of several PMDs with potential utilities in longitudinal studies, including the multi-form designs, multi-method designs, varying lag designs, accelerated longitudinal designs, and efficient designs for analysis of change. For each of the designs, the basic rationale, design considerations, data analysis, advantages, and limitations are discussed. The article is concluded with some general recommendations to developmental researchers and promising directions for future research.

Transcranial Direct Current Stimulation Combined With Cognitive Training Induces Response Inhibition Facilitation Through Distinct Neural Responses According to the Stimulation Site: A Follow-up Event-Related Potentials Study.

We investigated whether the mid-term impact (1 week posttraining) of a "combined cognitive rehabilitation (CRP)/transcranial direct current stimulation (tDCS) program" on the performance of a Go/No-go task was enhanced compared with isolated CRP and whether it varied according to the stimulation site (right inferior frontal gyrus [rIFG] vs right dorsolateral prefrontal cortex [rDLPFC]). A total of 150 healthy participants were assigned to (1) an Inhibition Training (IT) group, (2) a group receiving active tDCS over the rIFG in combination with IT (IT + IF), (3) a group receiving active tDCS over the rDLPFC in combination with IT (IT + DL), (4) a group receiving IT with sham tDCS (ITsham), and (5) a No-Training (NT) group to control for test-retest effects. Each group undertook 3 sessions of a Go/No-go task concomitant with the recording of event-related potentials (T0, before training; T1, at the end of a 4-day training session [20 minutes each day]; T2, 1 week after T1). With the exception of the NT participants, all the groups exhibited improved performances at T2. The IT + DL group exhibited the best improvement profile, indexed by faster response times (RTs) (T0 > T1 = T2), with a reduced rate of errors at the posttraining sessions compared with both T0 and T1. This "inhibitory learning effect" was neurophysiologically indexed by shorter No-go N2d latencies and enhanced No-go P3d amplitudes. CRP combined with active tDCS over the rDLPFC appears to be optimal for boosting long-term (one week) inhibitory skills as it induced specific and robust neural changes.

The interactive effects of test-retest and methylphenidate administration on cognitive performance in youth with ADHD: A double-blind placebo-controlled crossover study

Studies have shown that Methylphenidate (MPH) affects cognitive performance on the neuropsychological tests and clinical symptoms of individuals diagnosed with attention deficit/hyperactivity disorder (ADHD). This study investigated the acute effects of MPH on neuropsychological tests to explore the interaction between MPH and test-retest effects. Twenty youths with ADHD were tested before and after MPH intake in a double-blind placebo-controlled crossover design and compared to twenty matched controls. Participants were tested on a range of standardized tasks including sustained attention to response, N-Back, and Word/Color Stroop. Identical tasks were administered twice each testing day, before and 1 hour after MPH/Placebo administration. Healthy controls were tested similarly with no intervention. Decreases in response time (RT) variability across tasks and in commission errors were found in ADHD after MPH. Conversely, a significant increase in RT variability and increase in omission errors were observed after the placebo. In the control group, RT variability and omission errors increased whereas commission errors decreased, suggesting fatigue and practice effects, respectively. Test-retest reliability was higher in controls than ADHD. It is suggested that cognitive tests are sensitive objective measures for the assessment of responses to MPH in ADHD but are also affected by repetition and fatigue.

Deep brain stimulation modulates directional limbic connectivity in obsessive-compulsive disorder.

Deep brain stimulation is effective for patients with treatment-refractory obsessive-compulsive disorder. Deep brain stimulation of the ventral anterior limb of the internal capsule rapidly improves mood and anxiety with optimal stimulation parameters. To understand these rapid effects, we studied functional interactions within the affective amygdala circuit. We compared resting state functional MRI data during chronic stimulation versus 1 week of stimulation discontinuation in patients, and obtained two resting state scans from matched healthy volunteers to account for test-retest effects. Imaging data were analysed using functional connectivity analysis and dynamic causal modelling. Improvement in mood and anxiety following deep brain stimulation was associated with reduced amygdala-insula functional connectivity. Directional connectivity analysis revealed that deep brain stimulation increased the impact of the ventromedial prefrontal cortex on the amygdala, and decreased the impact of the amygdala on the insula. These results highlight the importance of the amygdala circuit in the pathophysiology of obsessive-compulsive disorder, and suggest a neural systems model through which negative mood and anxiety are modulated by stimulation of the ventral anterior limb of the internal capsule for obsessive-compulsive disorder and possibly other psychiatric disorders.

Six Sessions of Sprint-Interval Training Did Not Improve Endurance and Neuromuscular Performance in Untrained Men.

Previous research demonstrated that six sessions of cycling sprint-interval training (SIT) within a duration of only 2 weeks can increase endurance performance considerably. Primarily muscular mechanisms have been under investigation explaining such performance improvements. However, it has been shown in other exercise tasks that training-induced changes also occur at the level of the central nervous system. Therefore, we hypothesized to observe an enhanced neuromuscular performance in conjunction with an increase in endurance performance after 2 weeks of SIT. Therefore, we randomly assigned 19 healthy men (26 ± 5 years) to a control (n = 10) or a training group (n = 9), the latter performing a replication of the SIT protocol from Burgomaster et al. Before and after the training intervention, both groups performed a cycling endurance test until exhaustion. Neuromuscular function of the right vastus lateralis muscle was assessed before and after each endurance task by the means of maximal voluntary isometric contractions (MVCs). The variables of interest being MVC, voluntary activation was measured by peripheral nerve stimulations (VAPNS), by transcranial magnetic stimulation (VATMS), as well as potentiated resting twitches (Qtw,pot). We did not find any significant differences between the groups in the control variable time to exhaustion in the endurance task. In addition, we did not observe any time × group interaction effect in any of the neuromuscular parameters. However, we found a significant large-sized time effect in all neuromuscular variables (MVC, = 0.181; VATMS, = 0.250; VAPNS, = 0.250; Qtw,pot, = 0.304) as well as time to exhaustion = 0.601). In contrast to other studies, we could not show that a short-term SIT is able to increase endurance performance. An unchanged endurance performance after training most likely explains the lack of differences in neuromuscular variables between groups. These findings demonstrate that replication studies are needed to verify results no matter how strong they seem to be. Differences over time for the variables of neuromuscular fatigue irrespective of group (MVC, + 9.3%; VATMS, + 0.2%; VAPNS, + 6.3%; Qtw,pot, + 6.3%) demonstrate test-retest effects that should be taken into consideration in future training studies and emphasize the inevitable necessity for controlled experiments.

Training Inhibitory Control Induced Robust Neural Changes When Behavior Is Affected: A Follow-up Study Using Cognitive Event-Related Potentials.

Cognitive training results in significant, albeit modest, improvements in specific cognitive functions across a range of mental illnesses. Inhibitory control, defined as the ability to stop the execution of an automatic reaction or a planned motor behavior, is known to be particularly important for the regulation of health behaviors, including addictive behaviors. For example, several studies have indicated that inhibitory training can lead to reduced alcohol consumption or a loss of weight/reduced energy intake. However, the exact neurocognitive mechanisms that underlie such behavioral changes induced by training are still matter of debate. In the present study, we investigated the long-term impact (ie, at 1 week posttraining) of an inhibitory training program (composed of 4 consecutive daily training sessions of 20 minutes each) on the performance of a Go/No-go task. Healthy participants were randomly assigned to 1 of 3 designated groups: (1) an Inhibition Training (IT) group that received training based on a hybrid flanker Go/No-go task; (2) a group that received a noninhibition-based (ie, episodic memory; EM) training; and (3) a No-Training (NT) group to control for test-retest effects. Each group underwent 3 sessions of a Go/No-go task concomitant with the recording of event-related potentials. Our results revealed a specific impact of the Inhibitory Training on the Go/No-go task, indexed by a faster process compared with the other 2 groups. This effect was neurophysiologically indexed by a faster N2 component on the difference NoGo-Go waveform. Importantly, effects at both the behavioral and at the neural level were still readily discernible 1 week posttraining. Thus, our data clearly corroborate the notion that cognitive training is effective, while also indicating that it may persist over time.

Neurocognitive assessment on a tablet device: Test–retest reliability and practice effects of ANAM Mobile

New technology has allowed for the transition of computerized neurocognitive assessments to increasingly user-friendly mobile platforms. While this increased portability facilitates neurocognitive assessment in a wider variety of settings, this transition necessitates further examination of the psychometric properties of tests that have been previously validated on alternate platforms. The present study evaluated the test-retest reliability and practice effects for a new version of the Automated Neuropsychological Assessment Metrics (ANAM), ANAM Mobile, designed to be administered on a tablet computer. A total of 108 undergraduate students completed ANAM Mobile and returned after one week for repeated testing. Observed test–retest reliabilities were consistent with previously established estimates across similar time intervals and ranged from .55 (Simple Response Time) to .87 (Matching to Sample). Modest practice effects were observed. Base rates of reliable decline were low and suggested that declines on two or more tests are uncommon among healthy college students. The present study demonstrates that ANAM Mobile subtests have good-to-excellent reliability across a 7-day retest interval with minimal practice effects. Future research should explore within-subject reliability across repeated ANAM administrations on a tablet device and further examine retest reliabilities over varying time courses and in more diverse samples.