Auditory Choice Reaction Time Task Research Articles

A comparative study of gender difference in reaction time in response to exam stress among first-year medical students

Background: Different studies conducted worldwide among medical students have reported the prevalence of stress ranging from 27% to 73%. Exam stress acts as an acute stressor which affects cognitive functions. It is found that the exam stress elicits elevated activity in the hypothalamic-pituitary-adrenal axis and increased release of cortisol. Aims and Objective: The study was planned to investigate gender difference in perceptions of exam stress and reactions to it among first-year medical students. Choice reaction time (CRT) was used to evaluate the cognitive performance of students during stress-free and stress (exam) conditions. Materials and Methods: The study was conducted on 60 healthy first year MBBS students (30 boys and 30 girls) between the age group of 18 and 20 years. Digital reaction time was used. Randomly occurring visual and auditory CRT tasks were presented to students. First set of readings was taken during stress-free period, and the second and third sets were taken 20 min before first and second terminal practical examination, respectively. Results: The readings were analyzed by unpaired Student’s t-test. Results showed that visual and auditory reaction times were increased in both boys and girls with statistically significant difference between boys and girls in stress (exam) condition, but no difference during stress-free condition. Conclusion: The observation shows that girls tend to perceive more stress than boys which might affect the cognitive functions more, as slower reaction time was observed in girls than boys when they were exposed to stress.

The effect of age on postural and cognitive task performance while using vibrotactile feedback.

Vibrotactile feedback (VTF) has been shown to improve balance performance in healthy people and people with vestibular disorders in a single-task experimental condition. It is unclear how age-related changes in balance affect the ability to use VTF and if there are different attentional requirements for old and young adults when using VTF. Twenty younger and 20 older subjects participated in this two-visit study to examine the effect of age, VTF, sensory condition, cognitive task, duration of time, and visit on postural and cognitive performance. Postural performance outcome measures included root mean square of center of pressure (COP) and trunk tilt, and cognitive performance was assessed using the reaction time (RT) from an auditory choice RT task. The results showed that compared with younger adults, older adults had an increase in COP in fixed platform conditions when using VTF, although they were able to reduce COP during sway-referenced platform conditions. Older adults also did not benefit fully from using VTF in their first session. The RTs for the secondary cognitive tasks increased significantly while using the VTF in both younger and older adults. Older adults had a larger increase compared with younger adults, suggesting that greater attentional demands were required in older adults when using VTF information. Future training protocols for VTF should take into consideration the effect of aging.

Sequential effects in auditory choice reaction time tasks.

This paper concerns sequential effects in choice reaction time tasks. Performance in two interleaved auditory tasks was examined, and two general types of sequential effects were revealed. First, a response repetition effect occurred: Subjects were facilitated in responding when both the stimulus and the response were immediately repeated. Generally, it appeared that subjects were operating according to the bypass rule--that is, repeat the response if the stimulus or some aspect thereof is repeated from the preceding trial; otherwise, change the response. In addition, the experiment also revealed a second type of sequential effect, known as a task-switching effect Subjects were overall slower to respond when the task changed between adjacent trials than when there was no task change. A final result was that subjects were markedly impaired when the stimulus changed but the same response had to be repeated. This finding has been reported elsewhere when purely visual tasks have been used. Hence, it seems that particular difficulties arise, in such sequential testing situations, when type-distinct stimuli are grouped into the same response categories.

A Controlled Crossover Trial of Fenfluramine in Autism

We report a 12 month double-blind randomized crossover trial of fenfluramine in 20 children with the syndrome of autism. On active drug most of the children lost weight and blood serotonin levels fell by an average of 60%. There was a fall in urinary dopamine (DA) and noradrenaline (NA) levels and increased excretion of homovanillic acid (HVA). Some of the children showed improvement in tests of cognitive and language function, although the results did not achieve overall statistical significance. Event-related brain potentials (ERPs) were obtained in seven subjects on an auditory choice reaction time task. Side effects of the drug included irritability and lethargy. Fenfluramine may have a limited place in the management of some patients with autistic disorder.

Event-related potentials and monoamines in autistic children on a clinical trial of fenfluramine

In a double blind, crossover study of the response of autistic subjects to fenfluramine, event-related potentials (ERPs) were recorded from 7 subjects on an attention-demanding auditory choice reaction time task (ACRT). ACRT, IQ and biochemical measures were taken after 5 months placebo and 5 months fenfluramine treatment. After fenfluramine treatment blood serotonin levels fell, urinary catecholamine levels fell and the HVA/DA ratio rose. IQ and ACRT performance improved. On the ACRT subjects were asked to press a button to a rate target (500 H Z, P = 0.14) and to ignore higher pitched rare (2000 H Z, P = 0.14) and frequent non-targets (1000 H Z). After fenfluramine treatment N1 latencies increased. The scalp distribution of ERP maxima changes slightly with treatment. P3 maxima elicited by rare non-targets were recorded more rostrally after fenfluramine treatment. After rare non-targets N1 amplitudes at F Z decreased but P3 amplitudes at P Z increased. Early negativity after the rare non-target (particularly on the right side) was negatively correlated with the HVA/DA ratio. Subtraction of the P3 component elicited in a passive condition where no response was required from the active condition showed that P3 positivity to targets was halved with treatment. (In contrast Nd increased on fenfluramine treatment). Overall, N1 and P3 components showed greatest responsivenes to rare non-targets on fenfluramine. N1 but not P3 changes may represent slight improvement of attention-related function with treatment. Small changes in ERP latency and distribution, associated with the neuroleptic action of fenfluramine may be partly responsible for a mild improvement of IQ and ACRT performance on medication.

Event-related potentials in autistic and healthy children on an auditory choice reaction time task

Event-related potentials (ERPs) were recorded from midline (Fz, Cz, Pz) and lateral sites (F 3, F 4, P 3, P 4) in autistic children ( n = 7) and age-matched controls ( n = 9) on an auditory choice reaction time task. Subjects were asked to press a button to an infrequent target (500 Hz, P = 0.14) and to ignore higher pitched infrequent (2000 Hz, P = 0.14) and frequent (1000 Hz) non-targets. Autistic subjects made twice as many errors of omission as controls and showed a higher criterion (beta) for targets. Maximum ERP peak amplitudes showed a more varied scalp distribution in the autistic group. N1 latencies were consistently shorter in the autistic group and in 3 subjects the target P3 latencies were markedly longer than for the controls. Compared to controls, the N1 amplitude of the autistic response was larger to the rare stimuli (particularly to non-targets). The amplitude of the P3 component was smaller in the autistic group (particularly to the target). The stimuli were also presented in a passive condition requiring no response. After subtraction of the waveform obtained in the passive condition from that obtained in the active condition or subtraction of the waveform elicited by the rare non-target from that elicited by the target, N1 target amplitude was larger in control than in autistic children. Autistic subjects showed more early negativity to the rare non-target at left frontal and a larger P3 to the target at right parietal sites. ERPs of autistic children are more responsive to stimulus features (e.g. high/rare non-target tone) and less responsive to their associations or meaningfulness (e.g. target P3). Attention-related ERPs of autistic children show signs of precocious (right dominance for P3) and delayed development (P3 not maximal at parietal sites).

Voluntary blood pressure reductions measured with pulse transit time: training conditions and reactions to mental work.

ABSTRACTBlood pressure reductions aided by exteroceptive feedback were compared with those produced with simple instructions in two groups of 10 subjects. The degree of environmental stimulation during sessions was equated in the two conditions. Additionally, the effect of feedback on blood pressure reactions to an auditory choice reaction time task was studied. Pressure changes were monitored with the pulse wave velocity method.Feedback training led to greater modifications than instructions during pressure control trials. Associated adjustments in interbeat interval and respiration rate were also observed, but were of similar magnitude in the two groups. Some carryover of training effects to the reaction time task was found, but this comparison was confounded by larger initial reactions in the feedback group.