Choice Reaction Time (choice + reaction_time)

Distribution by Scientific Domains
Medical Sciences62%

Terms modified by Choice Reaction Time

  • choice reaction time task
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    Selected Abstracts

    Comparing effects of methylphenidate, sertraline and placebo on neuropsychiatric sequelae in patients with traumatic brain injury

    HUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 2 2005
    Hoon Lee
    Abstract Background This study aimed to investigate the effects of methylphenidate and sertraline compared with placebo on various neuropsychiatric sequelae associated with traumatic brain injury (TBI). Methods This was a 4 week, double-blind, parallel-group trial. Thirty patients with mild to moderate degrees of TBI were randomly allocated to one of three treatment groups (n,=,10 in each group) with matching age, gender and education, i.e. methylphenidate (starting at 5,mg/day and increasing to 20,mg/day in a week), sertraline (starting at 25,mg/day and increasing to 100,mg/day in a week) or placebo. At the baseline and at the 4 week endpoint, the following assessments were administered: subjective (Beck Depression Inventory) and objective (Hamilton Depression Rating Scale) measures of depression; Rivermead Postconcussion Symptoms Questionnaire for postconcussional symptoms; SmithKline Beecham Quality of Life Scale for quality of life; seven performance tests (Critical Flicker Fusion, Choice Reaction Time, Continuous Tracking, Mental Arithmetic, Short-Term memory, Digit Symbol Substitution and Mini-Mental State Examination); subjective measures of sleep (Leeds Sleep Evaluation Questionnaire) and daytime sleepiness (Epworth Sleepiness Scale). All adverse events during the study period were recorded and their relationships to the drugs were assessed. Results Neuropsychiatric sequelae seemed to take a natural recovery course in patients with traumatic brain injury. Methylphenidate had significant effects on depressive symptoms compared with the placebo, without hindering the natural recovery process of cognitive function. Although sertraline also had significant effects on depressive symptoms compared with the placebo, it did not improve many tests on cognitive performances. Daytime sleepiness was reduced by methylphenidate, while it was not by sertraline. Conclusions Methylphenidate and sertraline had similar effects on depressive symptoms. However, methylphenidate seemed to be more beneficial in improving cognitive function and maintaining daytime alertness. Methylphenidate also offered a better tolerability than sertraline. Copyright © 2005 John Wiley & Sons, Ltd. [source]

    Choice Reaction Time and cognitive dysfunction following cardiac surgery

    ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 9 2009
    J. Steinmetz
    No abstract is available for this article. [source]

    Interactive effect of central obesity and hypertension on cognitive function in older out-patients with Type 2 diabetes

    DIABETIC MEDICINE, Issue 12 2008
    E. Kim
    Abstract Aim Central obesity, hypertension and diabetes mellitus have been related individually to cognitive dysfunction. We aimed to study the interactive effects of these co-occurring risk factors on cognitive decline, which remain unclear in older patients with diabetes. Methods We assessed metabolic profiles and neuropsychological functions in 60 older out-patients with Type 2 diabetes to examine the associations of central obesity with cognitive functions, while controlling for other confounding factors in these subjects. Results Waist circumference was associated with poor performance in digits forward (r2 = 0.11, P = 0.02), choice reaction time (r2 = 0.08, P = 0.04) and cognitive reaction time (r2 = 0.07, P < 0.05) even after adjustment for potential confounders including age, gender, education and HbA1c. There were also significant interactions between central obesity and hypertension with respect to performance of digits forward (P = 0.04) and delayed verbal cued recall (P = 0.03). Conclusion Our findings suggest that, in addition to glycaemic control, central obesity and hypertension influence cognitive functions, such as attention and psychomotor speed in older patients with Type 2 diabetes. [source]

    Functional specificity of human premotor,motor cortical interactions during action selection

    EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 7 2007
    Jacinta O'Shea
    Abstract Functional connections between dorsal premotor cortex (PMd) and primary motor cortex (M1) have been revealed by paired-pulse transcranial magnetic stimulation (TMS). We tested if such connections would be modulated during a cognitive process (response selection) known to rely on those circuits. PMd,M1 TMS applied 75 ms after a cue to select a manual response facilitated motor-evoked potentials (MEPs). MEPs were facilitated at 50 ms in a control task of response execution, suggesting that PMd,M1 interactions at 75 ms are functionally specific to the process of response selection. At 100 ms, PMd,M1 TMS delayed choice reaction time (RT). Importantly, the MEP (at 75 ms) and the RT (at 100 ms) effects were correlated in a way that was hand-specific. When the response was made with the M1-contralateral hand, MEPs correlated with slower RTs. When the response was made with the M1-ipsilateral hand, MEPs correlated with faster RTs. Paired-pulse TMS confined to M1 did not produce these effects, confirming the causal influence of PMd inputs. This study shows that a response selection signal evolves in PMd early during the reaction period (75,100 ms), impacts on M1 and affects behaviour. Such interactions are temporally, anatomically and functionally specific, and have a causal role in choosing which movement to make. [source]

    Dissociation between objective psychomotor impairment and subjective sleepiness after diazepam administration in the aged people

    HUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 6 2007
    Masaru Echizenya
    Abstract The aim of the present study was to clarify whether subjective sleepiness accurately reflects benzodiazepine-related decline in psychomotor function after taking benzodiazepines (BZPs) in aged people. Subjects were eight healthy, young (mean age, 19.8,years) and seven healthy, older (mean age, 60.9,years) men. Placebo and diazepam (DZP) were administered orally in a single-blind crossover manner to the young subjects (placebo, 5,mg DZP and 10,mg DZP) and to the older subjects (placebo and 5,mg DZP). Plasma drug concentration, choice reaction time (CRT) as an objective measure of psychomotor function, and the Stanford Sleepiness Scale (SSS) as a measure of subjective sleepiness were monitored every 20,min from 1000 until 1600,h, being the drug administered at 1200,h. Pharmacokinetic variables did not differ significantly between the two age groups. DZP at 10,mg in young subjects induced significant increases in both the CRT and SSS score. DZP at 5,mg induced no significant increase in SSS score in either age group but did induce a significant increase in CRT only in the older subjects that matched that in young subjects given 10,mg DZP. The older subjects suffered from dissociation between subjective sleepiness and objective psychomotor impairment under DZP treatment. Such individuals may underestimate the detrimental effects on brain function. Copyright © 2007 John Wiley & Sons, Ltd. [source]

    Precues enable multiple response preprogramming: Evidence from startle

    PSYCHOPHYSIOLOGY, Issue 2 2009
    Anthony N. Carlsen
    Abstract When one or more response dimensions in a choice reaction time (RT) task are provided beforehand (or precued), RT decreases, indicating that the precued part of a response was prepared in advance. In this study, a startling acoustic stimulus was used to investigate the amount of preprogramming that occurs when part of the response is precued because a startling stimulus has been shown to directly trigger preprogrammed responses. Participants performed wrist flexion/extension movements in a precued one to four choice RT paradigm. A control auditory stimulus (82 dB) or a startling acoustic stimulus (124 dB) accompanied the visual "go" signal on each trial. Although RT latencies were significantly reduced by the startle, many more errors were observed in the startled conditions. Importantly, the errors seen at short RT latencies largely reflected multiple movements to the cued response alternatives, suggesting that multiple responses were preprogrammed. [source]

    An electromyographic investigation of the effect of stimulus,response mapping on choice reaction time

    PSYCHOPHYSIOLOGY, Issue 1 2001
    Thierry Hasbroucq
    The activity of the agonist muscles was recorded during the performance of a two-choice visual reaction time (RT) task in which the compatibility of the stimulus,response mapping was manipulated. Correct trials were distinguished according to whether or not the activation of the agonist of the required response was preceded by an activation of the agonist of the nonrequired response. Double activation trials were more numerous for the incompatible than for the compatible mapping. Furthermore, these trials yielded longer RTs than the single muscular activation trials. These results suggest that initial activations of nonrequired responses are more frequently aborted and corrected when the mapping is incompatible than when it is compatible. This finding supports the dimensional overlap model of stimulus,response compatibility (S. Kornblum, T. Hasbroucq, & A. Osman, 1990). [source]

    Antiepileptic monotherapy significantly impairs normative scores on common tests of executive functions

    ACTA NEUROLOGICA SCANDINAVICA, Issue 3 2009
    E. Hessen
    Background,,, Understanding how antiepileptic (AED) monotherapy influences normative test scores is of importance in the clinic for correct interpretation of neuropsychological profiles. Previous studies have primarily reported minor influence on neuropsychological raw scores, and the clinical relevance of these findings is unclear. Aim of the study ,To obtain a clinical valid answer to this question, we analysed changes in T-scores after AED withdrawal in a large group of well-controlled epilepsy patients, for tests previously shown to be sensitive to AED withdrawal. Methods ,We report outcomes on measures of choice reaction time from the California Computerized Assessment Package, on the Controlled Oral Word Association Test and on the Stroop Color-Word Interference Test. Results ,Significantly improved T-scores were revealed after AED withdrawal on five of the six tests of executive functions with mean improvement of 5 T-scores. Comparable results were achieved in the subgroup taking carbamazepine, with a mean improvement of 6.2 T-scores. Conclusion ,The present results suggest that T-scores for computerized tests of choice reaction time and tests of verbal fluency and response inhibition may be significantly impaired as a consequence of AED monotherapy, and that careful interpretation of these scores is required in diagnostic assessment of patients receiving AED monotherapy. [source]