Towards objectively quantifying sensory hypersensitivity: a pilot study of the “Ariana effect”

In everyday life, people are usually capable of performing two tasks simultaneously. However, in a previous study we showed that during a fatiguing motor task, cognitive performance declined progressively. There is extensive literature on the (positive) effects of caffeine on cognitive and motor performance. These effects are most pronounced under suboptimal conditions, for example during fatigue. However, little is known about the effects of caffeine on cognitive performance during a fatiguing motor task. This study was aimed to investigate whether a moderate dose of caffeine could attenuate the decline in cognitive performance during a fatiguing motor task. The study consisted of a placebo and a caffeine (3 mg/kg) session. A total of 23 subjects completed these sessions in a semi-randomized and double-blind order. In each session, subjects performed maximal voluntary contractions of the index finger, a choice reaction time (CRT) task and a dual task consisting of a fatiguing motor task concomitantly with the same CRT task. After the fatiguing dual task, the CRT task was repeated. Caffeine improved cognitive task performance, in both the single and dual task, as shown by decreased reaction times together with unchanged accuracy. Cognitive performance in the dual task deteriorated with increasing fatigue. However, the decrease in cognitive performance in the beginning of the dual task, as observed in the placebo condition, was partly prevented by caffeine administration (i.e., no increase in reaction times). We found no effects of caffeine on motor parameters (absolute force, endurance time or electromyographic amplitude). Caffeine improved cognitive performance. This effect also extends under demanding situations, as was shown by the performance during the dual task, even during progressive motor fatigue.

Activation-interference association for finger responses in choice reaction time tasks

This study investigated the effects of stimuli that vary in erotic content on performance during a choice reaction time (CRT) task. Eighty subjects, 20 from each of four groups—heterosexual men, heterosexual women, gay men, and lesbian women—completed the study. Participants were required to locate the position of a dot on slides of nude and clothed men and women as well as neutral stimuli as rapidly as possible. It was hypothesized that sexual interest would influence cognitive processes and cause longer latencies to preferred‐gender stimuli. Subjects also completed an incidental learning task to determine if a relationship existed between stated sexual orientation and memory for stimuli. Results indicate that reaction times were longest with nude stimuli of the preferred gender for each group. The nude stimuli had the highest accuracy rate for correctly classifying groups based on sexual orientation with the possible exception of heterosexual women. Results for clothed stimuli on the CRT task were similar but not as strong. Results of the incidental learning task indicate that participants had the greatest memory for nude preferred‐gender stimuli. The data indicate that sexual interest in a stimulus may cause distraction during performance of a cognitive task but may facilitate memory for the stimulus during a memory task.

Sensory hypersensitivity in Tourette syndrome: A review

A gender difference in choice reaction time (RT) has been reported in the literature (e.g., Adam et al., 1999; Noble et al., 1964). Noble, Baker and Jones found that females had slower choice RT than their male counterparts many years ago. Later study by Adam et al. also reported a faster choice RT for male participants. Since Weiss (1965) introduced the measurement of RT components with electromyography (EMG), pre-motor time (PMT) and motor time (MT) have been used to identify the central (cognitive) and peripheral (neuromuscular) processing of the initiation of voluntary movement in human performance research. PURPOSE: To examine whether choice reaction time and its fractionated components differ between genders and dominant and non-dominant hands. METHODS: Twenty right-hand dominant college students (10 male, 26.0 ± 3.06 yrs; 10 female, 25.4 ± 2.27 yrs) were tested for their visual-manual choice reaction time for four consecutive days using both left and right hands. Based on the EMG activity of the pronator teres and biceps brachii, fractionated RTs of pronation and supination were measured for each hand. The learning effect was identified and a reliable measure was obtained. A 2 (gender) by 2 (hand) two-way mixed design analysis of variance (ANOVA) was used to analyze possible gender and hand difference as well as their interaction. RESULTS: Choice RT decreased across days (p < .05), however, no significant change was found between days 3 and day 4. No Gender x Hand interaction or hand difference was observed for choice RT. A significant gender difference was observed for total choice RT (F1,18 = 6.43, p < .05). The mean choice RT for the males was 278 ms, and for the females it was 308 ms. A further analysis of PMT and MT indicated that male participants had a faster PMT (218 ms) than female (246 ms) participants (F1,18 = 6.51, p < .05), but no MT difference was observed between the gender groups. CONCLUSIONS: There is no choice reaction time difference between dominant and non-dominant hands for the college students. Male participants demonstrated a faster choice RT than female participants, and the difference in total choice RT can be attributed to the PMT component, but not MT. The finding supports the proposed explanations that males might have employed a binary strategy while females used a serial strategy in choice reaction time tasks.

Focused attention deficits in patients with Alzheimer’s disease and mild cognitive impairment

Relation between the time-course of Hoffmann-reflexes and the foreperiod duration in a reaction-time task

Reaction times and anticipatory skills of karate athletes

Reaction times measured in a choice reaction time and a double task condition: A small twin study

Perception-action coupling in choice reaction time tasks

Many studies have found that cigarette smoking or nicotine improves mental functioning in abstinent smokers. An unresolved issue is whether this improvement is due primarily to a direct facilitation of performance or to relief of the impairment caused by nicotine withdrawal. We evaluated the performance of 12 non-smokers before and twice (15 and 45 min) after a subcutaneous injection of 0.8 mg nicotine, 0.8 ml saline, and a control no treatment, on a choice reaction time (RT) task. Each treatment was given on a separate day; the control day was given on the first session. The order of nicotine and saline was balanced between subjects, and injections were given double-blind. The RT task manipulated stimulus and response processing. These manipulations consisted of two levels of stimulus complexity and two levels of response complexity, resulting in four task conditions. These manipulations along with latency measures of the event-related potential were used to identify the components of processing that mediated nicotine's effects on performance. During each active drug session blood nicotine levels, cardiovascular, and subjective responses were measured before and after each of the three tests (pre-drug, 15 min and 45 min post-drug). For the information processing measures only the comparisons of the pre- and 15-min post-test showed significant drug effects. Nicotine compared to saline significantly increased the number of responses at the fast end of the RT distribution. However, there were no changes in accuracy. Nicotine also speeded mean RT compared with saline or the control day, but the effects were only significant for the control-nicotine comparison.(ABSTRACT TRUNCATED AT 250 WORDS)

The pathogenesis of chronic fatigue syndrome (CFS) remains unknown. Thresholds and latencies of motor evoked potentials (MEPs) in response to transcranial magnetic stimulation (TMS) are normal but intracortical inhibition has not been investigated. Eleven patients with CFS were compared with 11 control subjects. Each patient completed a questionnaire using visual analogue indices of pain, fatigue, anxiety and depression. Subjects released a button to initiate simple (SRTs) and choice reaction time (CRTs) tasks; for each task, movement times were measured between release of the initiation button and depression of a second button 15 cm away. Subjects held a 10 % maximum voluntary contraction in the thenar muscles of their dominant hand while TMS was applied to the motor cortex; the duration and extent of inhibition of surface electromyographic (EMG) activity were assessed at stimulus strengths above and below the threshold for MEPs. Patients had significantly (P < 0.05) higher mean indices of fatigue than of pain, anxiety or depression. Mean (+/- S.E.M.) SRTs (but not CRTs) were longer in patients (309 +/- 45 ms) than in controls (218 +/- 9 ms). Movement times were longer in patients for both SRTs and CRTs. TMS thresholds, expressed as a percentage of the maximum stimulator output, were not significantly (P > 0.05) different in both groups for both MEPs (patients, 34 +/- 3%; controls, 36 +/- 3%) and inhibition of voluntary contraction (patients, 29 +/- 2%; controls, 34 +/- 4%). The duration and extent of inhibition did not differ significantly between groups at any stimulus strength. The pattern of change in duration and extent of inhibition with increasing stimulus intensity was no different in the two groups. The duration and extent of corticospinal inhibition in patients with CFS did not differ from controls, adding further evidence to the notion that the feeling of fatigue and the slowness of movement seen in CFS is not manifest in corticospinal output pathways.

As cognitive dysfunction due to schizophrenia is strongly associated with patients' social rehabilitation, cognitive functions have been examined as a therapeutic target. Although the Brief Assessment of Cognition in Schizophrenia (BACS) has been used to evaluate cognitive function, it is difficult to administer in routine clinical practice due to its time-consuming nature. Therefore, a novel tool is needed to facilitate the assessment of cognitive function. In the present study, we examined whether cognitive function can be assessed effectively by testing psychomotor function in patients with schizophrenia. Test batteries consisting of choice reaction time (CRT) and compensatory tracking task (CTT) and the BACS were examined in 20 schizophrenic patients to evaluate the correlation between the scales by Pearson correlation coefficient. Of the test batteries, the CRT was significantly correlated with attention functions, a subtest of the BACS (r = -0.506, p = 0.023), and the CTT was strongly correlated with attention functions (r = -0.716, p < 0.001) and working memory (r = -0.633, p = 0.003). A multiple regression analysis was performed to clarify the association between psychomotor function tests and the total BACS score, and peripheral awareness task, a component of CTT, was independently associated with the total BACS score (β = -0.59, p = 0.004) with an R2 of 0.37. Thus, of the psychomotor function tests, the CRT and the CTT are highly useful in assessing cognitive functions in schizophrenic patients. However, no having large sample size in this study is a limitation.

Autism spectrum disorder (ASD) is a neurodevelopmental disorder that influences an individual's cognitive functions and social interaction. While most studies have focused on children and adolescents diagnosed with ASD, elevated levels of autistic traits in subclinical populations may also influence individuals' daily functioning. Autistic traits are also linked to the Big Five personality. In particular, neuroticism (emotion instability) has been shown to be positively associated with autistic traits, which may contribute to behavioral symptoms of autistic traits. The present study aimed to investigate the association between autistic symptoms and sensorimotor processing among a subclinical population. One hundred young adults (Mage = 20.32 years; SD = 3.69 years; 69 female) completed a choice reaction time (RT) task, and their behavioral performance was analyzed using the ex-Gaussian modeling. The Autism Quotient (AQ) and the Ten-Item Personality Inventory (TIPI) were used to assess autistic traits and neuroticism, respectively. The mediation analysis was conducted to examine the behavioral mechanism through which autistic traits influence sensorimotor processing. The results showed that the AQ score was negatively correlated with RT and positively correlated with neuroticism score. Importantly, the mediation analysis indicated an indirect effect, suggesting that neuroticism mediates the association between the AQ score and RT. The findings indicated a possible mechanism of the association between autistic traits and sensorimotor responses and suggested that neuroticism should be included as an intervention target for ASD. The present study contributes to the research on autistic traits and has practical implications for future intervention programs to improve daily functioning among individuals with ASD.

Three trained Ss participated in a choice reaction time task under conditions of 0, 1, 2 and 3-bits of stimulus uncertainty. Stimuli were presented in random sequence. Prior to each presentation Ss were required to state a behavioral hypothesis, i.e., guess which stimulus event would occur. The stimulus uncertainty-choice reaction time relationship was linear, confirming previous findings. However, when correct and incorrect behavioral hypothesis trials were separately analyzed, it was found that the positive linear relation was obtained only in the latter case; choice reaction time was independent of stimulus uncertainty when S’s guess was correct.