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Simple Reaction Time (simple + reaction_time)

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Medical Sciences40%

Terms modified by Simple Reaction Time

  • simple reaction time task
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    Selected Abstracts

    MEG reveals different contributions of somatomotor cortex and cerebellum to simple reaction time after temporally structured cues

    HUMAN BRAIN MAPPING, Issue 7 2006
    Tim Martin
    Abstract Magnetoencephalography (MEG) was used to measure brain activity while participants performed a simple reaction to targets after either a random interval (uncued targets) or a series of isochronous warning stimuli with 200-ms intervals that acted as a countdown. Targets could arrive "on time" or "early" relative to the preceding warning stimuli. Cerebellar activity before any stimulus onset predicted uncued simple reaction time. Onset of activity in somatomotor cortex relative to the target predicted reaction time after two warning stimuli when the target arrived on time or early. After three warning stimuli, when the target arrived on time and was certain to occur, prestimulus cerebellar activity and somatomotor onset were significant predictors of reaction time. When the target arrived early after three warning stimuli, prestimulus cerebellar and cingulate activity were predictive. The cerebellar results may reflect a number of possible factors, including a role in timing, response readiness, prediction and attention. Hum. Brain Mapping 2005. © 2005 Wiley-Liss, Inc. [source]

    Psychomotor speed in hypertension: Effects of reaction time components, stimulus modality, and phase of the cardiac cycle

    PSYCHOPHYSIOLOGY, Issue 3 2007
    Louisa Edwards
    Abstract Hypertension is characterized by cognitive deficits. As evidence for impaired psychomotor speed, including slower reaction times, is mixed, we aimed to provide a detailed investigation of simple reaction time in hypertension. Pre-motor and motor reaction times were measured across the cardiac cycle in 30 hypertensives and 29 normotensives to determine the effects of phasic and tonic blood pressure on performance. Auditory, visual, and tactile simple reaction time tasks were completed with stimuli presented 0, 300, and 600 ms after the R-wave of the electrocardiogram. Reaction times did not differ between hypertensives and normotensives. Although pre-motor reaction times were faster during the late phase than the early phase of the cardiac cycle whereas motor reaction times were unchanged, this effect was similar for hypertensives and normotensives. No sensory-motor deficits were evident in these hypertensives regardless of baroreceptor activity. [source]

    Assessment of cognitive function in systemic lupus erythematosus, rheumatoid arthritis, and multiple sclerosis by computerized neuropsychological tests

    ARTHRITIS & RHEUMATISM, Issue 5 2010
    John G. Hanly
    Objective Computerized neuropsychological testing may facilitate screening for cognitive impairment in systemic lupus erythematosus (SLE). This study was undertaken to compare patients with SLE, patients with rheumatoid arthritis (RA), and patients with multiple sclerosis (MS) with healthy controls using the Automated Neuropsychological Assessment Metrics (ANAM). Methods Patients with SLE (n = 68), RA (n = 33), and MS (n = 20) were compared with healthy controls (n = 29). Efficiency of cognitive performance on 8 ANAM subtests was examined using throughput (TP), inverse efficiency (IE), and adjusted IE scores. The latter is more sensitive to higher cognitive functions because it adjusts for the impact of simple reaction time on performance. The results were analyzed using O'Brien's generalized least squares test. Results Control subjects were the most efficient in cognitive performance. MS patients were least efficient overall (as assessed by TP and IE scores) and were less efficient than both SLE patients (P = 0.01) and RA patients (P < 0.01), who did not differ. Adjusted IE scores were similar between SLE patients, RA patients, and controls, reflecting the impact of simple reaction time on cognitive performance. Thus, 50% of SLE patients, 61% of RA patients, and 75% of MS patients had impaired performance on ,1 ANAM subtest. Only 9% of RA patients and 11% of SLE patients had impaired performance on ,4 subtests, whereas this was true for 20% of MS patients. Conclusion ANAM is sensitive to cognitive impairment. While such computerized testing may be a valuable screening tool, our results emphasize the lack of specificity of slowed performance as a reliable indicator of impairment of higher cognitive function in SLE patients. [source]

    Is there progressive cognitive dysfunction in Sjögren Syndrome?

    ACTA NEUROLOGICA SCANDINAVICA, Issue 3 2010
    A preliminary study
    Martínez S, Cáceres C, Mataró M, Escudero D, Latorre P, Dávalos A. Is there progressive cognitive dysfunction in Sjögren Syndrome? A preliminary study. Acta Neurol Scand: 122: 182,188. © 2010 The Authors Journal compilation © 2010 Blackwell Munksgaard. Objective,,, The aim of this study was to determine the progression of cognitive dysfunction in primary Sjögren Syndrome (SS). Methods,,, Twelve subjects with SS were compared with ten subjects with migraine and ten healthy controls on neuropsychological, mood and fatigue tests at baseline and 8 years later. Results,,, At follow-up, SS subjects performed below subjects with migraine on the Continuous Performance Test (CPT) but did not differ on other tasks. Compared with controls, both clinical groups obtained lower scores on simple reaction time, patients with SS obtained lower scores on the Wisconsin Card Sorting Test (WCST) and patients with migraine performed below controls on the Benton's Judgment of Line Orientation Test (JOLO). Clinical groups did not differ on cognitive changes over time, except that migraine subjects improved on verbal fluency. Compared with baseline, both SS and migraine patients were more impaired on simple reaction time, Trail Making Test part B, Stroop and JOLO. However, they showed higher scores on verbal and visual memory, WCST and CPT reaction time. SS also showed higher levels of depression and fatigue than migraine and controls, with no significant changes over time. Discussion,,, Preliminary evidence indicates some cognitive deficits in both SS and migraine following a pattern of fronto-subcortical dysfunction without a significant cognitive decline over time. [source]