Reaction Time Measures Research Articles

The Effects of Participating in Recreational Games on Health Markers and Reaction Time in Middle-aged Tribal Women

Background: Taking part in recreational activities, especially outdoors, can greatly improve physical health. People, who take part in park activities such as walking, hiking, or skiing, schedule fewer office visits, maintain lower body fat percentages, and have lower blood pressure and cholesterol levels. Although recreational games was proven to be a useful physical activity to stimulate some health benefits, we do not know if there are significant benefits of recreational games played on a smaller area with fewer players in the middle-age population. Because exercise is known to increase blood flow and oxygen to the skeletal muscles and the brain, it was inferred that exercise would also affect an individual’s reaction time.
 Aims: The present study aimed to investigate whether recreational games could improve health and reaction time of middle-aged tribal women after 16 weeks of training. To determine this, twenty subjects gave baseline blood pressure, heart rate, and simple reaction time measurements.
 Methodology: Twenty healthy middle-aged tribal women aged 50–55 were randomized in a group to involve in recreational games training (n = 20; age: 52.4 ± 2.48 years). The participants performed 3 training sessions of 40 min per week.
 Results: Results from a repeated measure ANOVA indicated a time interaction (pre training, mid training and post training) for Blood Pressure (Systolic), Blood Pressure (Diastolic), Resting Heart Rate and Reaction Time (Audio) in favor of the participants. The results concluded that Recreational games can be an effective training modality to stimulate a decrease in resting HR and reaction time with small improvements in systolic and diastolic Blood Pressure.
 Conclusion: To participate in Recreational games only three times per week shows helpful health-related adaptations and decreased reaction time, means there was significant improvement in health markers and reaction time abilities, which may be an affirmative impact to the reduction of the risk of developing lifestyle diseases and is beneficial to people in their daily live.

Tracking Changes in Frontal Lobe Hemodynamic Response in Individual Adults With Developmental Language Disorder Following HD tDCS Enhanced Phonological Working Memory Training: An fNIRS Feasibility Study.

Background: Current research suggests a neurobiological marker of developmental language disorder (DLD) in adolescents and young adults may be an atypical neural profile coupled with behavioral performance that overlaps with that of normal controls. Although many imaging techniques are not suitable for the study of speech and language processing in DLD populations, fNIRS may be a viable option. In this study we asked if fNIRS can be used to identify atypical cortical activation patterns in individual adults with DLD and track potential changes in cortical activation patterns following a phonological working memory training protocol enhanced with anodal HD tDCS stimulation to the presupplementary motor area (preSMA).Objective/Hypothesis: The purpose of this study was two-fold: (1) to determine if fNIRS can be used to identify atypical hemodynamic responses in individual young adults with DLD during active spoken word processing and, (2) to determine if fNIRS can detect changes in hemodynamic response in these same adults with DLD following anodal HD tDCS enhanced phonological working memory training.Methods: Two adult subjects with DLD (female, age 25) completed a total of two sessions of fNIRs working memory task prior to and following one session of a non-word repetition task paired with anodal HD tDCS (1.0 mA tDCS; 20 min) to the preSMA. Standardized z-scores of behavioral measures (accuracy and reaction time) and changes in hemodynamic response during an n-back working memory task for the two participants with DLD was compared to that of a normative sample of 21 age- and gender- matched normal controls (ages 18 to 25) prior to and following phonological working memory training.Results: Individual standardized z-scores for each participant with DLD indicated that prior to training, hemoglobin response in the prefrontal lobe for both participants was markedly different from each other and normal controls. Following training, standard scores showed that the hemodynamic response for both participants moved within normal limits for ROIs.Conclusion: These findings highlight the feasibility of fNIRS to establish individual differences in the link between behavior and neural patterns in single subjects with DLD, as well as track individual differences in changes in brain activity following working memory training.

Kannada akshara knowledge in primary school children: measurement of accuracy and reaction time using a cross-sectional study design

Background: Reading acquisition varies between languages, as languages differ in terms of phonology and orthography. Orthographic knowledge is demonstrated to be crucial in literacy acquisition in most orthographies. The literature on acquisition of orthographic knowledge has focused more on alphabetic orthographies and less is understood in alphasyllabary Kannada language. The present study aimed to understand the akshara knowledge acquisition by measuring akshara identification accuracy and reaction time in typically developing Kannada medium primary school children. Methods: The study consisted of 315 typically developing children, 45 each from Grade I through Grade VII between the age range of 5 years 6 months to 12 years 6 months. The children were assessed for akshara identification accuracy and reaction time using a representative sample of 67 akshara selected at four different levels of complexity: vowels in primary form, consonant with inherent vowels, consonant with vowel diacritics, and consonant clusters. The mean performance was compared between the groups using one-way ANOVA with post-hoc Bonferroni test. Results: One-way ANOVA revealed significant main effect (p≤0.05) of Grade on akshara identification accuracy and reaction time. The post-hoc Bonferroni test revealed that the mean akshara identification accuracy improved significantly (p≤0.05) from Grade I to Grade V and reached a plateau at Grade VI. The reaction time significantly reduced from Grade I to Grade IV and there was no significant change beyond Grade V. Conclusion: The children learning to read alphasyllabary Kannada gain mastery over the majority of aksharas during the initial years of formal schooling, which develops completely by Grade VI. The automaticity in naming akshara develops gradually and reaches a plateau by Grade IV. The present findings indicate that children acquire automaticity in naming akshara early, while the akshara knowledge continues to develop.

Effect of Distance between Marker Agreement Dependencies on Sentence Comprehension in Persons with Aphasia.

Background:Rules and regularities are embedded in all the language structures. Extracting these helps in speech-language acquisition and processing. Sentence processing relies on transitional probability of the dependencies and its distance which are present within the sentence.Aim:To investigate the effect of distance between marker agreement dependencies on sentence comprehension in Persons with Aphasia (PWA) and Neuro- Typical Individuals (NTI).Methods:Ten PWA and Ten NTI were recruited for the study. Participants whose native language was Kannada (a South Indian Language) and received formal education of minimum 10th grade were selected.Materials:A total of 60 Kannada sentences were used and grouped into three categories i.e., short sentence (had short distance between dependencies) (SSD); Longer sentences (had long distance between dependencies) (LLD) and longer sentences (had short distance between dependencies) (LSD). The agreement markers in the sentence were manipulated w.r.t distance among them and grouped it as adjacent (short distance) and non-adjacent (long distance) type of sentences.Procedure:The participants were instructed to read the sentence and judge whether it is grammatically correct or not by pressing the key corresponding to 'yes' or 'no' on the keyboard. In addition, modified N-back task was administered.Results and Discussion:Accuracy and reaction time measures were derived for each sentence types. NTI showed better performance than PWA in sentence judgment task. Both the groups, performed poorly on LSD type of sentence when compared to other sentence types. LSD type was more complex due to the syntactic demands placed by the antecedent preposition, pronoun and adverb placed nearer to the verb and also longer distance between subject agreement to the verb.

A-244 Examining the Effects of Computer Operating Configuration on Automated Neuropsychological Assessment Metrics V 4.0 (ANAM4) Reaction Time: A Repeated Measures Approach with Clinical and Research Implications

Abstract Objective Computerized cognitive tests are vulnerable to measurement error due to hardware and software configurations of the administration computer. Though automatic score corrections are often provided to account for this, they may mask subtle individual variations in test performance. We investigated the group and individual impact of correcting for measurement error while accounting for possible order effects using data from a larger study of computer platform effects on reaction time measurement. Methods ANAM4 TBI Military’s Simple Reaction Time (SRT) subtest was administered repeatedly on three different computer platforms. We compare two of those platforms: Platform 1, a Dell D630 configured for ANAM4 TBI Military administration; Platform 3, a Dell E6540 with default settings. A mechanical arm with a preset RT was first used to capture measurement error on each platform. SRT was then administered to healthy US Army soldiers in a randomly selected administration order, such that platform 1 was first and platform 3 was third for n = 58 and platform 3 was first and platform 1 second for n = 53. Results Platform 3 was on average 43.06 ms slower than Platform 1. Group analyses suggested applying a 43.06 ms correction to Platform 3 scores resulted in scores similar to Platform 1. However, it appears there were subtle practice and fatigue effects for some individuals that were possibly masked by the score correction. Conclusion Correcting for error due to computer configurations is important in RT measurement, though there may be subtle individual statistical and clinical implications that are lost at a group analysis level.

Neural correlates of the Dunning-Kruger effect.

The Dunning-Kruger effect (DKE) is a metacognitive phenomenon of illusory superiority in which individuals who perform poorly on a task believe they performed better than others, yet individuals who performed very well believe they under-performed compared to others. This phenomenon has yet to be directly explored in episodic memory, nor explored for physiological correlates or reaction times. We designed a novel method to elicit the DKE via a test of item recognition while electroencephalography (EEG) was recorded. Throughout the task, participants were asked to estimate the percentile in which they performed compared to others. Results revealed participants in the bottom 25th percentile over-estimated their percentile, while participants in the top 75th percentile under-estimated their percentile, exhibiting the classic DKE. Reaction time measures revealed a condition-by-group interaction whereby over-estimators responded faster than under-estimators when estimating being in the top percentile and responded slower when estimating being in the bottom percentile. Between-group EEG differences were evident between over-estimators and under-estimators during Dunning-Kruger responses, which revealed FN400-like effects of familiarity supporting differences for over-estimators, whereas "old-new" memory event-related potential effects revealed a late parietal component associated with recollection-based processing for under-estimators that was not evident for over-estimators. Findings suggest over- and under-estimators use differing cognitive processes when assessing their performance, such that under-estimators may rely on recollection during memory while over-estimators may draw upon excess familiarity when over-estimating their performance. Episodic memory thus appears to play a contributory role in metacognitive judgements of illusory superiority.

Kannada akshara knowledge in primary school children: measurement of accuracy and reaction time using a cross-sectional study design.

Background: Reading acquisition varies between languages, as languages differ in terms of phonology and orthography. Orthographic knowledge is demonstrated to be crucial in literacy acquisition in most orthographies. The literature on acquisition of orthographic knowledge has focused more on alphabetic orthographies and less is understood in alphasyllabary Kannada language. The present study aimed to understand the akshara knowledge acquisition by measuring akshara identification accuracy and reaction time in typically developing Kannada medium primary school children. Methods: The study consisted of 315 typically developing children, 45 each from Grade I through Grade VII between the age range of 5 years 6 months to 12 years 6 months. The children were assessed for akshara identification accuracy and reaction time using a representative sample of 67 akshara selected at four different levels of complexity: vowels in primary form, consonant with inherent vowels, consonant with vowel diacritics, and consonant clusters. The mean performance was compared between the groups using one-way ANOVA with post-hoc Bonferroni test. Results: One-way ANOVA revealed significant main effect (p≤0.05) of Grade on akshara identification accuracy and reaction time. The post-hoc Bonferroni test revealed that the mean akshara identification accuracy improved significantly (p≤0.05) from Grade I to Grade V and reached a plateau at Grade VI. The reaction time significantly reduced from Grade I to Grade IV and there was no significant change beyond Grade V. Conclusion: The children learning to read alphasyllabary Kannada gain mastery over the majority of aksharas during the initial years of formal schooling, which develops completely by Grade VI. The automaticity in naming akshara develops gradually and reaches a plateau by Grade IV. The present findings indicate that children acquire automaticity in naming akshara early, while the akshara knowledge continues to develop.

Laterality effects in the haptic discrimination of verbal and non-verbal shapes

ABSTRACT The left hemisphere is known to be generally predominant in verbal processing and the right hemisphere in non-verbal processing. We studied whether verbal and non-verbal lateralization is present in haptics by comparing discrimination performance between letters and nonsense shapes. We addressed stimulus complexity by introducing lower case letters, which are verbally identical with upper case letters but have a more complex shape. The participants performed a same-different haptic discrimination task for upper and lower case letters and nonsense shapes with the left and right hand separately. We used signal detection theory to determine discriminability (d′), criterion (c) and we measured reaction times. Discrimination was better for the left hand for nonsense shapes, close to significantly better for the right hand for upper case letters and with no difference between the hands for lower case letters. For lower case letters, right hand showed a strong bias to respond “different”, while the left hand showed faster reaction times. Our results are in agreement with the right lateralization for non-verbal material. Complexity of the verbal shape is important in haptics as the lower case letters seem to be processed as less verbal and more as spatial shapes than the upper case letters.

Comparing Web-Based and Lab-Based Cognitive Assessment Using the Cambridge Neuropsychological Test Automated Battery: A Within-Subjects Counterbalanced Study.

BackgroundComputerized assessments are already used to derive accurate and reliable measures of cognitive function. Web-based cognitive assessment could improve the accessibility and flexibility of research and clinical assessment, widen participation, and promote research recruitment while simultaneously reducing costs. However, differences in context may influence task performance.ObjectiveThis study aims to determine the comparability of an unsupervised, web-based administration of the Cambridge Neuropsychological Test Automated Battery (CANTAB) against a typical in-person lab-based assessment, using a within-subjects counterbalanced design. The study aims to test (1) reliability, quantifying the relationship between measurements across settings using correlational approaches; (2) equivalence, the extent to which test results in different settings produce similar overall results; and (3) agreement, by quantifying acceptable limits to bias and differences between measurement environments.MethodsA total of 51 healthy adults (32 women and 19 men; mean age 36.8, SD 15.6 years) completed 2 testing sessions, which were completed on average 1 week apart (SD 4.5 days). Assessments included equivalent tests of emotion recognition (emotion recognition task [ERT]), visual recognition (pattern recognition memory [PRM]), episodic memory (paired associate learning [PAL]), working memory and spatial planning (spatial working memory [SWM] and one touch stockings of Cambridge), and sustained attention (rapid visual information processing [RVP]). Participants were randomly allocated to one of the two groups, either assessed in-person in the laboratory first (n=33) or with unsupervised web-based assessments on their personal computing systems first (n=18). Performance indices (errors, correct trials, and response sensitivity) and median reaction times were extracted. Intraclass and bivariate correlations examined intersetting reliability, linear mixed models and Bayesian paired sample t tests tested for equivalence, and Bland-Altman plots examined agreement.ResultsIntraclass correlation (ICC) coefficients ranged from ρ=0.23-0.67, with high correlations in 3 performance indices (from PAL, SWM, and RVP tasks; ρ≥0.60). High ICC values were also seen for reaction time measures from 2 tasks (PRM and ERT tasks; ρ≥0.60). However, reaction times were slower during web-based assessments, which undermined both equivalence and agreement for reaction time measures. Performance indices did not differ between assessment settings and generally showed satisfactory agreement.ConclusionsOur findings support the comparability of CANTAB performance indices (errors, correct trials, and response sensitivity) in unsupervised, web-based assessments with in-person and laboratory tests. Reaction times are not as easily translatable from in-person to web-based testing, likely due to variations in computer hardware. The results underline the importance of examining more than one index to ascertain comparability, as high correlations can present in the context of systematic differences, which are a product of differences between measurement environments. Further work is now needed to examine web-based assessments in clinical populations and in larger samples to improve sensitivity for detecting subtler differences between test settings.

The effect of preferred background music on task-focus in sustained attention

Although many people listen to music while performing tasks that require sustained attention, the literature is inconclusive about its effects. The present study examined performance on a sustained-attention task and explored the effect of background music on the prevalence of different attentional states, founded on the non-linear relationship between arousal and performance. Forty students completed a variation of the Psychomotor Vigilance Task—that has long been used to measure sustained attention—in silence and with their self-selected or preferred music in the background. We collected subjective reports of attentional state (specifically mind-wandering, task-focus and external distraction states) as well as reaction time (RT) measures of performance. Results indicated that background music increased the proportion of task-focus states by decreasing mind-wandering states but did not affect external distraction states. Task-focus states were linked to shorter RTs than mind-wandering or external distraction states; however, background music did not reduce RT or variability of RT significantly compared to silence. These findings show for the first time that preferred background music can enhance task-focused attentional states on a low-demanding sustained-attention task and are compatible with arousal mediating the relationship between background music and task-performance.

Effects of a multinutrient-fortified milk drink combined with exercise on functional performance, muscle strength, body composition, inflammation, and oxidative stress in middle-aged women: a 4-month, double-blind, placebo-controlled, randomized trial

Multinutrient protein-enriched supplements are promoted to augment the effects of exercise on muscle mass and strength, but their effectiveness in middle-aged women, or whether there are any additional benefits to physical function, remains uncertain. We aimed to evaluate whether a multinutrient-fortified milk drink (MFMD) could enhance the effects of exercise on functional muscle power (stair climbing) in middle-aged women. Secondary aims were to evaluate the intervention effects on physical function, muscle strength, lean mass (LM), fat mass (FM), bone mineral content (BMC), muscle cross-sectional area (CSA), muscle density, balance, flexibility, aerobic fitness, inflammation, oxidative stress, bone and cartilage turnover, blood pressure, and blood lipids. In this 4-mo, double-blind, placebo-controlled, randomized trial, 244 women (45-65 y) participated in a multimodal resistance-type exercise program 3 d/wk, with random allocation to a twice-daily MFMD containing added protein, vitamin D, calcium, milk fat globule membrane (phospholipids and other bioactives), and other micronutrients (Ex+MFMD, n=123) or an energy-matched placebo (Ex+placebo, n=121). A total of 216 women (89%) completed the study. After 4 mo, both groups experienced similar 3.6%-4.3% improvements in the primary outcomes of fast-pace 5- and 10-step stair ascent power. In contrast, Ex+MFMD experienced greater improvements in 5-step regular-pace stair descent time [net difference (95% CI): -0.09 s (-0.18, 0.00 s), P=0.045], countermovement jump height [0.5 cm (0.04, 1.0 cm), P=0.038], total body LM [0.3 kg (0.04, 0.60 kg), P=0.020], FM [-0.6 kg (-1.0, -0.2 kg), P=0.004], BMC [0.4% (0.1%, 0.6%), P=0.020], muscle CSA [thigh: 1.8% (0.6%, 2.9%), P=0.003; lower leg: 0.9% (0.3%, 1.6%), P=0.005], balance eyes closed [3.3 s (1.1, 5.4 s), P=0.005], 2-min step performance [8 steps (3, 12 steps), P=0.003], and sit-and-reach flexibility [1.4 cm (0.6, 2.2 cm), P=0.026]. MFMD did not enhance the effects of exercise on any measures of muscle strength, gait speed, dynamic balance, reaction time, or blood lipids, and there was no effect of either intervention on blood pressure, markers of inflammation, or cartilage turnover. Ex+placebo had a greater improvement in the oxidative stress marker protein carbonyls (P<0.01). In middle-aged women, daily consumption of an MFMD did not enhance the effects of a multimodal exercise program on the primary outcome of stair climbing ascent power, but did elicit greater improvements in multiple secondary outcomes including various other measures of functional performance, LM, muscle size, FM, balance, aerobic capacity, flexibility, and bone metabolism.This trial was registered at www.anzctr.org.au as ACTRN12617000383369.

Evidence of Sleep Cycle Analogous to Vertebrate SWS/REM Alternation in the Octopus

The combination of body quiescence and skin pattern changes displayed periodically by Sepia officinalis, as well as the high threshold for arousal upon stimulation and increased brain activity in quiescent Octopus vulgaris, suggest the existence of a state akin to rapid-eye-movement sleep (REM) in cephalopods. Would be possible that cephalopods, as amniotes, sleep through the alternation of distinct quiescent states, analogous to slow-wave sleep (SWS) and REM? To investigate this possibility, we video-recorded 4 adult specimens of Octopus insularis and quantified in detail their behavioral states and transitions. We also performed sensory stimulation to measure reaction times across all behavioral states. Two distinct quiescent states occurred in tandem, both quite unresponsive to stimulation (median reaction time: 50 s). The first state was SWS-like, characterized by uniformly pale skin, closed pupils, and long episode durations (median 415.2 s). The second state was REM-like, characterized by dynamic skin patterns, rapid eye movements and short episode durations (median 40.8 s). The REM-like state was periodic (60% of all recurrences between 26.85-39.15 min) and occurred mostly after the SWS-like state (82% of all transitions). These observations support the existence in cephalopods of an ultradian sleep cycle analogous to the SWS/REM alternation.

Where is an emotion? Using targeted visceroception as a method of improving emotion regulation in healthy participants to inform suicide prevention initiatives: a randomised controlled trial

BackgroundWilliam James’ 1884 paper “What is an emotion?” has generated much recent interest in affective science regarding somatic contributions to emotion. Studies of interoception (“sensing the physiological condition of the body”) suggest that sensing specific parts of the body contributes to the production of emotion, namely when sensing the viscera (i.e. “visceroception” of the heart, gut or lungs). Improved visceroception has, for instance, been linked to increased emotional intensity, suggesting a role for interoception in emotion regulation that may pertain specifically to visceral bodily locations. Thus, in addition to asking James’ question, “What is an emotion?”, we ask, “Where is an emotion?”. Further, there is an evidence base pointing to the connections between emotion regulation and suicide, and between interoception and suicide. This is a preliminary trial investigating whether targeted interoception/visceroception improves emotion regulation. Ultimately, the overall project aims to inform suicide prevention efforts.MethodsThe trial utilises a pre-test/post-test control group design, with two experimental groups undergoing visceroceptive interventions (focussing on areas pertaining to the gut or heart) and a control group. The interventions will run for 8 weeks. A spatial cueing task will measure reaction times to bodily changes relating to lower abdomen or chest focus. A stop/signal task will measure emotional inhibition, which is hypothesised to obscure awareness of active bodily locations. Visceroceptive ability will be tracked using a heartbeat estimation task, a water load test, and by self-report questionnaire. The sample will consist of healthcare professionals and healthcare students. Despite these being groups that represent a relatively high suicide risk among professional and student groups, all participants will be healthy, given the preliminary nature of this trial.DiscussionTo our knowledge, this will be the first project to address whether emotional feeling presents as a localised bodily phenomenon and whether trained awareness of emotional localisation can improve emotion regulation. It will also be the first to investigate relationships between interoception and emotional inhibition (i.e. whether a sustained interoceptive practice leads to the disinhibition of bodily emotional sensations, which can positively contribute to emotion regulation). These empirical findings on emotion regulation from a healthy sample will be used to inform a desk-based enquiry into the role of embodied emotion in suicide prevention, which may make a significant contribution to a growing evidence base on interoception and suicide.Trial registrationACTRN12619000324112. Registered on 4 March 2019. Universal Trial Number (UTN): U1111-1221-0201.

Better Executive Function Is Associated With Faster On-Transition Aerobic Metabolism Among Older Adults.

The present study aimed to examine relationships between executive function (EF) and variables of aerobic fitness. Participants were 32 healthy older adults (M age = 65.1, SD = 6.6 years). We measured the first ventilatory threshold (VeT1) and the kinetics of oxygen uptake (O2), heart rate (HR), and muscle deoxygenation [HHb] during treadmill walking of either constant, moderate intensity, or increasing intensity. We assessed EF with a computerized Stroop test and Stroop measures of correct answers, reaction time, and percent interference. We found the Stroop interference score to be negatively associated with the VeT1 (r = -0.387, p = 0.031) and positively associated with the on-transition aerobic metabolism time constant (τ) of HR (r = 0.519, p = 0.003), O2 (r = 0.454; p = 0.010), and [HHb] (r = 0.644, p = 0.001). Correct responses were negatively related with τHR (r = -0.372, p = 0.039) and τO2 (r = -0.500, p = 0.004). The Stroop average reaction time, congruent reaction time and incongruent reaction time were positively related to τ[HHb] (r = 0.507, p = 0.010; r = 0.437, p = 0.029; r = 0.558, p = 0.004, respectively). Better EF was associated with faster on-transition aerobic metabolism and higher aerobic fitness among older adults.

Visual vs. Tactile Reaction Testing Demonstrates Problems with Online Cognitive Testing

Reaction time is one of the most commonly used measures in online cognitive assessments. However, there are significant technical problems with the methods that are commonly deployed for obtaining this measure. Most online cognitive toolkits obtain reaction time measures with a visual cue and some type of mechanical response (keyboard, mouse or touchscreen). Both the hardware and software involved in the computer systems that these online cognitive tests depend on introduce significant delays and more significantly, variation in these delays. The variability that is introduced by these systems leads to inaccurate results that health care professionals have come to rely on. In this report, a comparison is made between the reaction time data collected with a tactile based device that is accurately calibrated to sub-millisecond accuracy (the Brain Gauge) to a visual reaction time test that relies on consumer grade computer systems in a manner that parallels the methods commonly used in online cognitive testing. Forty healthy controls took both the tactile based and visually based reaction time test, and the results demonstrated a significant difference in both reaction time and reaction time variability. Most significant was the difference in reaction time variability, which was 16 msec for the tactile test and 81 msec for the visual test. While the differences could be partially accounted for by tactile vs. visual biological pathways, the variability of the results from the visual task are in the range predicted by error measured from previous reports that performed robotic testing to derive differences between the two modalities of testing.

A clinical method of evaluating simple reaction time and reaction accuracy is sensitive to a single dose of lorazepam.

Benzodiazepines are useful and commonly prescribed. Unfortunately, they are associated with subtle but functionally significant neurocognitive side effects that increase the risk of motor vehicle accidents and falls. The objective of this study was to determine whether clinically feasible measures of simple reaction time and reaction accuracy are sensitive to a single dose of lorazepam. Using a randomized, double-blind, crossover design, 26 healthy adults (13 women; age = 26.9 ± 8.2 yr) were given 1.0 mg lorazepam or placebo 90 minutes prior to two data collection sessions. Participants completed simple and reaction accuracy tasks using a standardized "ruler drop" testing paradigm during each session. Outcomes were mean and variability of simple reaction time and reaction accuracy, which evaluates a participant's ability to catch the device solely on the random 50% of trials that lights affixed to it illuminate on release. Reaction accuracy requires a go/no-go decision within 420 ms before the falling device strikes the floor. As compared with placebo, lorazepam increased simple reaction time variability (range = 43 ± 18 vs. 60 ± 23 ms, respectively; p = 0.004 and standard deviation = 14.6 ± 5.7 vs. 19.7 ± 7.3 ms, respectively; = 0.006) and decreased reaction accuracy (90 ± 7% vs. 84 ± 11%, respectively; p = 0.010). Given prior work demonstrating associations between simple reaction time and reaction accuracy and functional outcomes such as self-protection, response to perturbations, and fall risk, these clinically available measures may have a role in identifying subtle, functionally significant cognitive changes related to short-term benzodiazepine use.

An Accurate Measure of Reaction Time can Provide Objective Metrics of Concussion

There have been numerous reports of neurological assessments of post-concussed athletes and many deploy some type of reaction time assessment. However, most of the assessment tools currently deployed rely on consumer-grade computer systems to collect this data. In a previous report, we demonstrated the inaccuracies that typical computer systems introduce to hardware and software to collect these metrics with robotics (Holden et al, 2020). In that same report, we described the accuracy of a tactile based reaction time test (administered with the Brain Gauge) as approximately 0.3 msec and discussed the shortcoming of other methods for collecting reaction time. The latency errors introduced with those alternative methods were reported as high as 400 msec and the system variabilities could be as high as 80 msec, and these values are several orders of magnitude above the control values previously reported for reaction time (200-220msec) and reaction time variability (10-20 msec). In this report, we examined the reaction time and reaction time variability from 396 concussed individuals and found that there were significant differences in the reaction time metrics obtained from concussed and non-concussed individuals for 14-21 days post-concussion. A survey of the literature did not reveal comparable sensitivity in reaction time testing in concussion studies using alternative methods. This finding was consistent with the prediction put forth by Holden and colleagues with robotics testing of the consumer grade computer systems that are commonly utilized by researchers conducting reaction time testing on concussed individuals. The significant difference in fidelity between the methods commonly used by concussion researchers is attributed to the differences in accuracy of the measures deployed and/or the increases in biological fidelity introduced by tactile based reaction times over visually administered reaction time tests. Additionally, while most of the commonly used computerized testing assessment tools require a pre-season baseline test to predict a neurological insult, the tactile based methods reported in this paper did not utilize any baselines for comparisons. The reaction time data reported was one test of a battery of tests administered to the population studied, and this is the first of a series of papers that will examine each of those tests independently.

An Investigation of the Accuracy of Reaction Time Measurements on ANAM4 TBI-MIL Across Three Computer Platforms.

Using two observational methods and a within-subjects, counterbalanced design, this study aimed to determine if a computer's hardware and software settings significantly affected reaction time (RT) on the Automated Neuropsychological Assessment Metrics (Version 4) Traumatic Brain Injury Military (ANAM4 TBI-MIL). Three computer platforms were investigated: Platform 1-older computers recommended for ANAM4 TBI-MIL administration, Platform 2-newer computers with settings downgraded to run like the older computers, and Platform 3-newer computers with default settings. Two observational methods were used to compare measured RT to observed RT on all three platforms: 1, a high-speed video analysis to compare the timing of stimulus onset and response to the measured RT and 2, comparing a preset RT delivered by a robotic key actuator activated by optic detector to the measured RT. Additionally, healthy active duty service members (n=169) were administered a brief version of the ANAM4 TBI-MIL battery on each of the three platforms. RT differences were observed with both the high-speed video and robotic arm analyses across all three computer platforms, with the smallest discrepancies between observed and measured RT on Platform 1, followed by Platform 2, then Platform 3. When simple reaction time (SRT) raw and standardized scores obtained from the participants were compared across platforms, statistically significant and clinically meaningful differences were seen, especially between Platforms 1 and 3. A computer's configurations have a meaningful impact on ANAM SRT scores. The difference in an individual's performance across platforms could be misinterpreted as clinically meaningful change.

Clinical Use of the Automated Neuropsychological Assessment Metrics TBI-Mil Expanded Battery in Evaluating Concussion Recovery: A Retrospective Study

This retrospective study evaluated the use of the Automated Neuropsychological Assessment Metrics (ANAM4) Expanded battery in a clinical setting to determine if the resolution of physiological symptoms, in the absence of neurocognitive assessment, was sufficient data in the return-to-duty (RTD) determination. In this study, 508 U.S. Naval Academy midshipmen were diagnosed with concussion and prescribed a standard treatment protocol. As directed by the protocol, they were evaluated and tracked by medical providers until determined to have normal balance and to be asymptomatic at rest and with exertion. Upon the resolution of these physiological symptoms, the midshipmen were referred for neurocognitive (ANAM4) testing. When results indicated a return to neurocognitive baseline, a RTD determination was made. The analysis of data in this study indicated that RTD determinations based solely on the resolution of physiological symptoms would have resulted in 25.1% of the sample being returned to duty before neurocognitive recovery. Additional analysis of the ANAM4 reliable change index (RCI) data for each of the concussed patients revealed a pattern of scores that correlated with an expected length of recovery. Individuals with at least one RCI greater than or equal to -1.64 returned to neurocognitive baseline in 8.92 days, whereas individuals with 2 or more RCIs greater than or equal to -1.25 (but less than -1.64) returned to baseline in 5.78 days, and those with a difference in measured reaction times that were greater or equal to -1.25 returned to baseline in 3.20 days. Furthermore, findings indicated that female service members required additional time for the resolution of physical symptoms as compared to their male counterparts. The mean number of days from injury to being deemed symptoms free in males was approximately 14, as compared to females who were deemed symptom free in 21 days. This difference is statistically significant. Findings of this investigation revealed three specific outcomes. First, a computerized neurocognitive assessment instrument should be used as an adjunct measure in evaluating the resolution of physiological symptoms following a concussive injury. Second, results revealed that based on the RCIs of postinjury ANAM4 assessments, it is possible to estimate the remaining recovery time needed for a return to neurocognitive baseline. Third, results of this analysis revealed that gender appears to be a factor in time between concussive injury and resolution of symptoms.

Risk-Taking Patterns of Children, Associated Cognitive Weaknesses, and Prevention of Negative Outcomes.

ObjectiveAccidents, drug use, and unsafe sex associated with greater propensity for risk‐taking are leading causes of illness and death among adolescents. This study aimed to help identify and further characterize children with maladaptive risk‐taking to improve primary prevention interventions.MethodsTwo scores from the Bubblegum Analog Risk‐Taking Task for Children (BART‐C), total points and average inflations of unpopped bubbles, were used in a cluster analysis to identify distinct patterns of risk‐taking among 6,267 kindergarten through eighth‐grade children. Clusters were compared with the Flanker Test of Focused Attention, the Go/No‐Go test of inhibition, and the List Sorting Working Memory Test.ResultsBoth BART‐C scores made significant (p<0.001) contributions in defining three clusters of children: reckless, risk avoidant, and adaptive risk‐taking. Clusters differed significantly on Flanker Test measures of incongruent accuracy (p=0.004) and reaction time (p<0.001), Go/No‐Go inhibition (p=0.001), and List Sorting Working Memory Test scores (p<0.001). The reckless cluster had lower Flanker accuracy and Go/No‐Go inhibition than did the other groups and lower working memory than the adaptive risk‐taking group. Compared with adaptive risk‐takers, the risk‐avoidant group was slower (p<0.001), showed a nonsignificant trend toward greater accuracy on the Flanker test, and had lower working memory scores (p<0.001).ConclusionsThe BART‐C defined two maladaptive risk‐taking clusters: reckless and risk avoidant. Significant differences in cognitive function between these groups and the adaptive risk‐taking group provides external validation of and further characterizes the clusters. Early intervention may prevent future health‐compromising behaviors among reckless children and may promote fuller learning and development among risk‐avoidant children.