Choice Reaction Time Performance Research Articles

Effects of Various Caffeine Doses on Cognitive Abilities in Female Athletes with Low Caffeine Consumption.

Caffeine (CAF), a prevalent psychoactive stimulant, is believed to potentially enhance cognitive ability. However, studies on the effects of various doses are limited and yield inconsistent results, particularly in female athletes. Therefore, we aimed to assess the association between three different dosages of CAF intake (low, moderate, and high) and cognitive skills in female athletes with low CAF consumption. This study had a randomized, crossover, double-blind design in which each athlete performed four experimental sessions after ingesting either a placebo (PLAC), 3 mg·kg-1 of CAF (3 mg of CAF), 6 mg·kg-1 of CAF (6 mg of CAF), or 9 mg·kg-1 of CAF (9 mg of CAF) with an in-between washout period of at least 72 h. Following a 60 min window post-capsule consumption, fourteen female athletes (age: 17.4 ± 0.8 years) were assessed through various cognitive tests, namely, simple reaction time (SRT), choice reaction time (CRT), and attentional task (AT) tests, along with the mental rotation test (MRT). Additionally, they were required to complete a questionnaire about the undesirable side effects of CAF. Our results indicated that, compared to those of PLAC, the SRT, CRT, and AT performance were significantly improved following the administration of both 3 mg of CAF and 6 mg of CAF. While the greatest enhancement was observed after consuming 3 mg of CAF, no significant differences were found between the effects of 3 mg and 6 mg of CAF. Interestingly, MRT performance did not improve with any of the CAF dosages. Moreover, the ingestion of 9 mg of CAF did not enhance cognitive skills and was linked to the highest occurrence of CAF-related side effects. In conclusion, our results highlight the recommendation for a low CAF dosage of 3 mg·kg-1, in contrast to a higher dose of 6 mg·kg-1 or 9 mg·kg-1 of CAF, to enhance various aspects of cognitive performance in female athletes with low CAF consumption without adverse side effects.

Impacts of a perinatal exposure to manganese coupled with maternal stress in rats: Learning, memory and attentional function in exposed offspring

The developmental effects of chemicals that co-occur in vulnerable populations with elevated psychological stress are of increasing concern to the public. To investigate these concerns, we developed a rodent model of co-occurring perinatal manipulations and conducted a series of cognitive assessments in male and female offspring. Manganese (Mn), a neurodevelopmental toxicant when exceeding physiological requirements, was delivered in the drinking water (0, 2, or 4 mg Mn/mL) of rats from gestational day (GD) 7 to postnatal day (PND) 22. A variable perinatal stress paradigm was applied to half of the animals from GD13 to PND9. Novel object recognition (NOR), Morris water maze (MWM), differential reinforcement of low-rates procedure (DRL) and cued and uncued choice reaction time (CRT) tests were used to assess cognitive functions in offspring. Mn (4 mg/mL) and stress impaired NOR in adolescent males but facilitated NOR performance in females. However, when stress and Mn were combined these effects were attenuated in both sexes. During training for the DRL, Mn (2 mg/mL) facilitated, while stress impaired, lever press learning in both sexes. Few effects related to the treatments were found on DRL or MWM. During cued CRT, Mn (2 and 4 mg/mL) and stress reduced accuracy in males, while stress and Mn (2 mg/mL) increased anticipatory responding and slowed decision time in both sexes. Stress combined with Mn (2 mg/mL) improved cued accuracy and decision time, and Mn attenuated the effect of stress on anticipatory responding in both sexes. Stress slowed female movement time but when combined with Mn (4 mg/mL) the effect of stress was attenuated. During uncued CRT, except for decision time (which replicated effects observed with the cued task), no other effects of Mn or its combination with stress occurred. Females remained negatively affected by stress in most uncued CRT performance measures, while stressed improved male uncued accuracy. Taken together these data do not support increased cognitive impairment produced by Mn when combined with stress. However, the effects of perinatal stress alone, on these cognitive functions may hinder the detection of effects due to chemical exposures and underscores the need to consider the psychological health and wellbeing of the mother and her environment in risk assessment for developmental neurotoxicity of chemicals.

Rapid Dual-Task Decrements After a Brief Period of Manual Tracking in Simulated Weightlessness by Water Submersion.

Investigating dual-task (DT) performance during simulated weightlessness by water submersion, using a manual tracking and a choice reaction task. In contrast to previous work, we focus on performance changes over time. Previous research showed motor tracking and choice reaction impairments under DT and single-task (ST) conditions in shallow water submersion. Recent research analyzed performance as average across task time, neglecting potential time-related changes or fluctuations of task-performance. An unstable tracking and a choice reaction task was performed for one minute under ST and DT conditions in 5m water submersion and on dry land in 43 participants. Tracking and choice reaction time performance for both tasks were analyzed in blocks of 10seconds. Tracking performance deteriorated underwater compared to dry land conditions during the second half while performing one minute in DT conditions. Choice reaction time increased underwater as well, but independent of task time and type. Tracking error increased over time when performing unstable tracking and choice reaction together. Potentially, physiological and psychological alterations under shallow submersion further strain the human system during DT operations, exceeding available recourse capacities such that DT performance deteriorated over time. Humans operating in simulated weightlessness underwater should be aware of substantial performance declines that can occur within a short amount of time during DT situations that include continuous tracking.

Belief in caffeine's ergogenic effect on cognitive function and endurance performance: A sham dose-response study.

This study aimed to determine if belief in caffeine's ergogenic potential influences choice reaction time (CRT) and/or running performance. Twenty-nine healthy individuals (23.7±5 years, 16 males) completed two trials (one week apart). Before the trials, participants indicated their "belief" in caffeine's ergogenic effects and previous "experience" using caffeine for performance. On arrival, participants randomly received either sham "Low (100mg; LD)" or "High (300mg; HD)" dose caffeine capsules 30-min before commencing the CRT test, followed by a 10km run. Paired samples t-tests determined differences between trials for CRT latency (Ex-Gaussian analysis; μ-, σ- and τ-) and running performance using the entire cohort and sub-groups exhibiting strong "beliefs"+/-"experience". Sham caffeine dose did not influence CRT (μ-, σ- and τ-respectively, LD: 400±53ms vs. HD: 388±41ms; LD: 35±18ms vs. HD: 34±17ms; LD: 50±24ms vs. HD: 52±19ms, all p's>0.05). Neither belief (n=6), nor belief+experience (n=4), influenced this effect. Furthermore, caffeine dose did not influence run time (LD: 49.05±3.75min vs. HD: 49.06±3.85min, p=0.979). Belief (n=9) (LD: 48.93±3.71min vs. HD: 48.9±3.52min, p=0.976), and belief+experience (n=6) (LD: 48.68±1.87min vs. HD: 49.55±1.75min, p=0.386) didn't influence this effect. A dose-response to sham caffeine ingestion was not evident on cognitive or endurance performance in healthy individuals, regardless of their convictions about caffeine's ergogenicity.

Carfentanil toxicity in the African green monkey: Therapeutic efficacy of naloxone

Carfentanil is an ultra-potent opioid with an analgesic potency 10,000 times that of morphine but has received little scientific investigation. Three experiments were conducted to evaluate the toxicity of carfentanil and the efficacy of naloxone in adult male African green monkeys. The first experiment determined the ED50 (found to be 0.71 μg/kg) of subcutaneous carfentanil for inducing bradypnea and/or loss of posture. Experiment 2 attempted to establish the ED50 of naloxone for rapidly reversing the bradypnea/loss of posture induced by carfentanil (1.15 μg/kg). Experiment 3 evaluated the effects of carfentanil (0.575 μg/kg) alone, the safety of naloxone (71−2841 μg/kg), and the efficacy of naloxone (71−710 μg/kg) administration at two time points following carfentanil (1.15 μg/kg) on operant choice reaction time. Collectively, these experiments characterized the temporal progression of carfentanil-induced toxic signs, determined the range of naloxone doses that restored respiratory and gross behavioral function, and determined the time course and range of naloxone doses that partially or completely reversed the effects of carfentanil on operant choice reaction time performance in African green monkeys. These results have practical relevance for the selection of opioid antagonists, initial doses, and expected functional outcomes following treatment of synthetic opioid overdose in a variety of operational/emergency response contexts.

Internal precooling decreases forehead and core temperature but does not alter choice reaction time during steady state exercise in hot, humid conditions

This study aimed to determine if precooling via crushed ice ingestion reduces forehead skin temperature (Thead) and core temperature (Tcore) during exercise in the heat and whether it has an effect on choice reaction time (CRT). Ten males commenced a 30 min precooling period, ingesting either 7 g kg−1 of crushed ice (ICE) or room temperature water (CON) prior to cycling 60 min at 55% V̇O2peak in hot, humid conditions (35.0 ± 0.3 °C, 50.2 ± 2.1% Relative Humidity). The CRT task was completed upon arrival and after the precooling period in the lab, then at 15 min intervals during exercise in the heat. Precooling reduced Thead and Tcore to a greater degree in ICE (Thead: −0.8 ± 0.31 °C; Tcore: −0.9 ± 0.3 °C) compared with CON (Thead: −0.2 ± 0.3 °C; Tcore: −0.2 ± 0.2 °C) (p ≤ 0.001). Choice reaction time performance improved throughout the cycle for both conditions (p ≤ 0.05). Ice ingestion lowered thermal sensation (p = 0.003) and skin temperature (d = 0.88; Tskin), while heart rate, ratings of perceived exertion and thirst were similar between conditions (p > 0.05). Precooling effectively reduced Thead and Tcore but did not provide additional improvement in CRT during moderate exercise in the heat. Further investigation is required to determine whether the lower central and peripheral temperature after ice ingestion is beneficial for tasks of greater cognitive effort.

Distinct Populations of Motor Thalamic Neurons Encode Action Initiation, Action Selection, and Movement Vigor.

Motor thalamus (Mthal) comprises the ventral anterior, ventral lateral, and ventral medial thalamic nuclei in rodents. This subcortical hub receives input from the basal ganglia (BG), cerebellum, and reticular thalamus in addition to connecting reciprocally with motor cortical regions. Despite the central location of Mthal, the mechanisms by which it influences movement remain unclear. To determine its role in generating ballistic, goal-directed movement, we recorded single-unit Mthal activity as male rats performed a two-alternative forced-choice task. A large population of Mthal neurons increased their firing briefly near movement initiation and could be segregated into functional groups based on their behavioral correlates. The activity of "initiation" units was more tightly locked to instructional cues than movement onset, did not predict which direction the rat would move, and was anticorrelated with reaction time (RT). Conversely, the activity of "execution" units was more tightly locked to movement onset than instructional cues, predicted which direction the rat would move, and was anticorrelated with both RT and movement time. These results suggest that Mthal influences choice RT performance in two stages: short latency, nonspecific action initiation followed by action selection/invigoration. We discuss the implications of these results for models of motor control incorporating BG and cerebellar circuits.SIGNIFICANCE STATEMENT Motor thalamus (Mthal) is a central node linking subcortical and cortical motor circuits, though its precise role in motor control is unclear. Here, we define distinct populations of Mthal neurons that either encode movement initiation, or both action selection and movement vigor. These results have important implications for understanding how basal ganglia, cerebellar, and motor cortical signals are integrated. Such an understanding is critical to defining the pathophysiology of a range of BG- and cerebellum-linked movement disorders, as well as refining pharmacologic and neuromodulatory approaches to their treatment.

The effects of exercise on a choice reaction time task in individuals with post-concussion syndrome

ABSTRACTPurpose: To assess cognitive performance differences pre- and post-exercise in individuals without concussion (non-concussed, NC) and individuals with post-concussion syndrome (PCS). Methods: A total of 30 participants completed a choice reaction time (CRT) task in the form of an iPad application, measuring each individual’s decision-making capabilities, while wearing a head-mounted eye tracker system. Participants completed four blocks of testing; the time interval between the first two blocks of trials and the last two blocks of trials was 10 minutes. Between the completion of block 2 and the start of block 3, the participants completed a 15-minute bout of exercise. Results: Individuals with PCS at rest and following exercise displayed greater average reaction time (RT) (p<.01), lower overall accuracy (p<.01) and shorter final fixation durations (p<.05) than NC. Combined influence of learning and exercise resulted in a significant difference (p<.05) in RT from block 1 to block 3 and block 1 to block 4. Conclusion: Persistent concussion-based symptoms may be indicative of deficits in higher-level cognitive processing, as indicated by both decreased CRT performance and differences in gaze behaviours between groups. Therefore, individuals with PCS may not elicit appropriate decisions when navigating through an environment, potentially leading to further risk of injury.

Relationship Between Arousal and Choice Reaction Time

Traditional Inverted-U hypothesis had been the primary model used by sport psychologists to describe the arousal-performance relationship. However, many sport psychology researchers have challenged this relationship. The aim of the present study was to determine the relationship between arousal and Choice Reaction Time (RT) performance .28 non-athlete female undergraduate students (mean age: 20 years and 6 months) voluntary participated in this study. They were asked to produce responses by depressing buttons with two fingers of one hand in choice RT task. Skin Conductance Level (SCL) as arousal index was recorded continuously during performance. Results indicated that arousal did not correlate with performance. This finding provides no support for the Inverted-U hypothesis in relation to choice RT performance.

An Association of Reaction Time with Bone Quantitative Ultrasound

Requirement of artificial bone materials is high, which demands us to consider many factors of human body. Evidence exists that estrogen influences neuronal physiology and cognitive function. Bone mineral density has been proposed as a marker for cumulative estrogen exposure. This study examined whether choice reaction time (CRT) would be related to calcaneus quantitative ultrasound (QUS). 222 ethnic Han Chinese men were recruited. Besides age and body mass index (BMI), cigarette smoking, as an important environment factor influencing cognition and bone health, was included in covariants. Results showed that CRT performance was statistically significantly positively correlated with bone quality index (p &lt; 0.01) and speed of sound (SOS) (p &lt; 0.001) before controlling covariants. After adjustment for age, BMI, and smoking, CRT remained significantly related to SOS (p &lt; 0.05). Our findings indicate that CRT may be associated with bone status, which suggests an effect of artificial bone on nervous system should be considered when it is produced.

Breakfast consumption and exercise interact to affect cognitive performance and mood later in the day. A randomized controlled trial

The current study assessed the interactive effect of breakfast and exercise on cognition and mood. Twelve active males completed four trials; no breakfast-rest, breakfast-rest, no breakfast-exercise or breakfast-exercise in a randomized, cross-over design. The trials consisted of; breakfast or fast, a 2h rest, exercise (treadmill run) or equivalent rest, a chocolate milk drink, a 90 min rest and an ad libitum lunch. Cognitive performance and mood were recorded frequently throughout each trial. Data was analysed as pre-exercise/rest, during and immediately post exercise/rest and post-drink. No effects were found prior to consumption of the drink. Post-drink, fasting before exercise increased mental fatigue compared to consuming breakfast before exercise and fasting before rest. Tension increased when breakfast was consumed at rest and when exercise was undertaken fasted compared to omitting breakfast before rest. Breakfast before rest decreased rapid visual information processing task speed and impaired Stroop performance. Breakfast omission improved Four Choice Reaction Time performance. To conclude, breakfast before exercise appeared beneficial for post-exercise mood even when a post-exercise snack was consumed. Exercise reversed post-breakfast cognitive impairment in active males.

Does variability in cognitive performance correlate with frontal brain volume?

Little is known about the neural correlates of within-person variability in cognitive performance. We investigated associations between regional brain volumes and trial-to-trial, block-to-block, and day-to-day variability in choice-reaction time, and episodic and working memory accuracy. Healthy younger (n=25) and older (n=18) adults underwent 101 daily assessments of cognitive performance, and their regional brain volumes were measured manually on magnetic resonance images. Results showed that smaller prefrontal white matter volumes were associated with higher block-to-block variability in choice-reaction time performance, with a stronger association observed among older adults. Smaller volumes of the dorsolateral prefrontal cortex covaried with higher block-to-block variability in episodic memory (number-word pair) performance. This association was stronger for younger adults. The observed associations between variability and brain volume were not due to individual differences in mean performance. Trial-to-trial and day-to-day variability in cognitive performance were unrelated to regional brain volume. We thus report novel findings demonstrating that block-by-block variability in cognitive performance is associated with integrity of the prefrontal regions and that between-person differences in different measures of variability of cognitive performance reflect different age-related constellations of behavioral and neural antecedents.

Paradoxical enhancement of choice reaction time performance in patients with major depression

The Cued Reinforcement Reaction Time (CRRT) task is a choice reaction time task in which rewards (points) are available if the subject responds quickly enough and are signalled with a certain probability by stimuli. Reaction times (RTs) are faster following stimuli predicting reward with a high probability than with a low probability. This RT difference is sensitive to manipulations and individual differences in the serotonin (5-HT) system, but the CRRT task performance has not yet been examined in patients with depression. We observed that patients performed better on the task than controls, as evidenced by a greater points score, a greater likelihood of reaching their reinforcement threshold and fewer errors. RT variability was reduced in the patients. No group differences in the effect of the conditioned stimuli on RTs were observed. Accounts of these surprising data are discussed, considering possible effects of antidepressant medication or task-dependent differences in selective attention. Regardless of precise mechanism, the results do indicate that depressed patients are not invariably impaired in motivational paradigms and that their RT performance in certain situations can be superior to that of controls.

Effects of Musically-Induced Emotions on Choice Reaction Time Performance

The main objective of the current study was to examine the impact of musically induced emotions on athletes’ subsequent choice reaction time (CRT) performance. A random sample of 54 tennis players listened to researcher-selected music whose tempo and intensity were modified to yield six different music excerpts (three tempi × two intensities) before completing a CRT task. Affective responses, heart rate (HR), and RTs for each condition were contrasted with white noise and silence conditions. As predicted, faster music tempi elicited more pleasant and aroused emotional states; and higher music intensity yielded both higher arousal (p &lt; .001) and faster subsequent CRT performance (p &lt; .001). White noise was judged significantly less pleasant than all experimental conditions (p &lt; .001); and silence was significantly less arousing than all but one experimental condition (p &lt; .001). The implications for athletes’ use of music as part of a preevent routine when preparing for reactive tasks are discussed.

Coupling Between Cognitive and Motor Function following Mild Traumatic Brain Injury

PURPOSE: Mild traumatic brain injury (mTBI) causes deficits in motor and cognitive function. There is a dearth of research examining the association between these deficits. The purpose of this investigation was to examine the effect of mTBI on the coupling between cognitive and motor function. METHODS: Thirty-six individuals completed a neurocognitive test battery and postural control assessment at baseline and 24-hours post physician diagnosed mTBI. Reaction time and accuracy to various cognitive tasks was accessed. Postural control was indexed with the somatosenory organization test. This test allows for the decomposition of postural control resulting from the integration of visual, somatosensory and vestibular information. Coupling between cognitive and motor function was assessed with correlational analyses. RESULTS: As expected, mTBI resulted in prolonged simple and choice reaction time performance as well as deficits in verbal and visual memory. mTBI was also found to reduce overall postural control, especially when visual information was utilized. Prior to injury correlational analyses indicated there was no association between cognitive and motor function - suggesting minimal cognitive-motor coupling. Following injury significant positive correlations between an individual's cognitive function and their postural sway were observed - indicating increased cognitive-motor coupling. CONCLUSIONS: These longitudinal findings suggest that a transient neural insult, such as mTBI, leads to increased cognitive-motor coupling. These findings support the proposal that a shared neural process, such as visuospatial attention, is impaired following injury and results in deficits in both cognitive and motor function.

Cocaine Seeking Habits Depend upon Dopamine-Dependent Serial Connectivity Linking the Ventral with the Dorsal Striatum

A neuroanatomical principle of striatal organization has been established through which ventral domains, including the nucleus accumbens, exert control over dorsal striatal processes mediated by so-called "spiraling," striato-nigro-striatal, circuitry. We have investigated the functional significance of this circuitry in the control over a cocaine-seeking habit by using an intrastriatal disconnection procedure that combined a selective, unilateral lesion of the nucleus accumbens core and infusion of a dopamine receptor antagonist into the contralateral dorsolateral striatum, thereby disrupting striato-midbrain-striatal serial connectivity bilaterally. We show that this disconnection selectively decreased drug-seeking behavior in rats extensively trained under a second-order schedule of cocaine reinforcement. These data thereby define the importance of interactions between ventral and dorsal domains of the striatum, mediated by dopaminergic transmission, in the neural mechanisms underlying the development and performance of cocaine-seeking habits that are a key characteristic of drug addiction.

Choice reaction time performance correlates with diffusion anisotropy in white matter pathways supporting visuospatial attention.

Humans exhibit significant interindividual variability in behavioral reaction time (RT) performance yet the underlying neural mechanisms for this variability remain largely unknown. It has been proposed that interindividual variability in RT performance may be due to differences in white matter (WM) physiological properties, although such a relationship has never been demonstrated in cortical projection or association pathways in healthy young adults. Using diffusion tensor MRI (DTI), we sought to test whether diffusion tensor fractional anisotropy (FA), a measure of the orientational coherence of water self-diffusion, is regionally correlated with RT on a visual self-paced choice RT (CRT) task. CRT was found to be significantly correlated with FA in projection and association pathways supporting visuospatial attention including the right optic radiation, right posterior thalamus, and right medial precuneus WM. Significant correlations were also observed in left superior temporal sulcus WM and the left parietal operculum. The lateralization of the CRT-FA correlation to right visual and parietal WM pathways is consistent with the specialization of right visual and parietal cortices for visuospatial attention. The localization of the CRT-FA correlations to predominantly visual and parietal WM pathways, but not to motor pathways or the corpus callosum indicates that individual differences in visual CRT performance are associated with variations in the WM underlying the visuospatial attention network as opposed to pathways supporting motor movement or interhemispheric transmission.

Biomarkers, Health, Lifestyle, and Demographic Variables as Correlates of Reaction Time Performance in Early, Middle, and Late Adulthood

We aimed to identify demographic, health, and biomarker correlates of reaction time performance and to determine whether biomarkers explained age differences in reaction time performance. TIhe sample comprised three representative cohorts aged 20-24, 40-44, and 60-64 years, including a total of 7,485 participants. Reaction time measures of intraindividual variability and latency were used. The measure of intraindividual variability used was independent of mean reaction time. Older adults were more variable than younger adults in choice reaction time performance but not simple reaction time performance. The most important correlates of reaction time performance after gender and education were biological markers such as forced expiratory volume at one second, grip strength, and vision. Few measures of physical or mental health or lifestyle were associated with poorer performance on reaction time measures. Biomarkers explained the majority of age-related variance in simple reaction time and a large proportion of variance in choice reaction time. We conclude that for the ages studied, biomarkers are more important than health factors for explaining age differences in reaction time performance.

Long-term consequences of repeated pentobarbital anaesthesia on choice reaction time performance in ageing rats

Recent studies have suggested that anaesthesia may be a factor in cognitive decline with age. We examined the effect of repeated (eight times) anaesthesia with pentobarbital on reaction time performance in rats in a longitudinal study. Treated rats had faster response times and made more premature responses than the control rats when they were older than 21 months. The results suggest that repeated anaesthesia during the lifespan can lead to an increase in impulsivity, as assessed by a choice reaction time test, during the later stages of life in the rat. These findings support the theory that repeated anaesthesia is a biological factor that affects cognitive ageing.

Functional disconnection of a prefrontal cortical–dorsal striatal system disrupts choice reaction time performance: Implications for attentional function.

Functional disconnection of a prefrontal cortical–dorsal striatal system disrupts choice reaction time performance: Implications for attentional function.