Reaction time test

One of six volunteers exposed to 150ppm of Stoddard solvent for 15 minutes had transitory eye irritation at 470ppm (2700mg/m ) all subjects had eye irritation and two had slight dizziness. Eight volunteers exposed at 4000 rag/rcL for 50 minutes had some changes in simple reaction time tests but not in perceptual speed, short-term memory, or manual dexterity compared with pre- and postexposure self controls. ... 

Motor and so-called psychomotor tasks, e.g. reaction-time tests of varying complexity, also respond reliably to sedative and stimulant drug effects (Kunsman et al., 1992) however none of the procedures shows particularly great sensitivity. 

Oscilloscopic observations were made to estimate the mixing and reaction times. Tests with dyes showed that the mixing time was well within the 33-msec, chopping time of the spectrophotometer. Brief observations during the approximately 8-msec, view of the sample beam permitted each cycle allowed an estimate of 15 to 20 msec, for the mixing time. Similar observations with ferrous mercapto-acetate solutions injected into oxygen-containing buffers showed no differences from the tests with dyes. Apparently the oxidation is completed within a few milliseconds or less. 

Numerous studies investigating focused attention have used reaction time tests. Nicotine polacrilex gum (2 mg) produced faster motor reaction time, but did not affect recognition reaction time in overnight deprived smokers,75 nonabstinent smokers,76 and a group of nonabstinent smokers and nonsmokers.78 Le Houezec et al.84 found that SC nicotine (0.8 mg) increased the number of fast... 

Like reaction time tests, nearly all studies have reported that acute administration of benzodiazepines impair performance on the DSST. Lorazepam (1 to 9 mg),125,130,142,147-149 triazolam (0.25 to 0.75 mg),132,134,135,148,150-153 alprazolam (0.5 to 4 mg),129,147 temazepam (15 to 60 mg),119,150 diazepam (5 to 10 mg),147,154 clonazepam,155 and estazolam (1 to 4 mg)152 have been shown to impair response speed and/or accuracy on the DSST in a dose-related manner. However, Kelly et al.156 reported that diazepam (5 or 10 mg) had no effect on DSST performance. It is unlikely that low doses of diazepam accounted for the lack of effect, as suggested by Kelly et al.,156 because numerous studies have reported DSST impairment after 10 mg diazepam.7 In a test similar to the DSST symbol copying, Saano et al.125 reported no effect of diazepam (5 mg) and lorazepam (1 mg). Acute triazolam (0.375 mg) administration decreased the number of trials completed on the DSST task, but tolerance to this decrement developed with each of three subsequent doses.137... 

A relatively large number of studies have investigated the effects of opioids on tests requiring focused attention. Morphine (2.5 to 10 mg, IV)185 and propofol (70 mg, IV)193 impaired an auditory simple reaction time test, and fentanyl (1 to 2.5 ng/ml, IV)182 impaired a visual choice reaction time test. Jenkins et al.197 reported that IV (3 to 20 mg) and smoked (2.6 to 10.5 mg) heroin impaired performance on a simple visual reaction time task. However, other studies reported no effect of butorphanol (0.5 to 2.0 mg, IV),186 fentanyl (25 to 100 pg, IV),191 meperidine (0.25 to 1.0 mg, IV),192 and nalbuphine (2.5 to 10 mg, IV)189 on an auditory simple reaction time test. It may be... 

A relatively large number of studies have investigated the effects of marijuana on focused attention, including reaction time tests and the DSST. Marijuana (1.8 and 3.6% THC) was shown to slow responding on a simple, visual reaction time task 242 however, others have not found marijuana to impair simple reaction time performance.11,40,236 Similarly, some studies have shown that marijuana impairs complex or choice reaction time tasks,11,233 whereas others have shown no effect.234 O Leary et al.243 found no effect of a 20-mg marijuana cigarette on reaction time in a dichotic listening task. 

The MSLT has been performed in patients with UARS, and abnormal results have been reported, but the test is often borderline normal, equating well with the complaint of fatigue. No systematic study of cognitive function has been performed in UARS patients, and investigation of mental lapses using tests such as the psychomotor vigilance task (PVT), a reaction-time test, is also lacking. But reevaluation of subjects treated with nasal CPAP demonstrated that sleep efficiency and MSLT scores improve (28). 

A search of the available literature failed to produce evidence that methylphenidate has been used by the military to counteract fatigue in operational environments. However, the U.S. Navy has conducted laboratory studies in which military personnel were administered 10 mg methylphenidate or 37.5 mg pemoline during 64 hr of continuous wakefulness. The results indicated that methylphenidate did not produce improvements in objective and subjective sleepiness, or in straightforward measures of performance (27,46). However, when the performance data from a choice-reaction-time test were analyzed for trial-to-trial variance, methylphenidate was found to decrease the variance compared to placebo on the first of 2 days of sleep deprivation. The effect did not continue into the second day (51). As was the case with the vigilance studies (above), the nonsignificant or relatively small effects of methylphenidate may have resulted from the low dosage that was studied. 

Although the effects of caffeine on some aspects of performance may be difficult to establish, the impact of this compound on tasks requiring vigilance or sustained attention is clearer. Lieberman et al. (110) evaluated the impact of 32-, 64-, 128-, and 256-mg doses of caffeine on a four-choice visual reaction time test (10 min), a continuous-performance task (variable duration), and the Wilkinson auditory vigilance test (1 hr). Results indicated that every dose of caffeine improved four-... 

How much sleep is needed to repay sleep debt It seems unlikely that exactly 1 extra hr of recovery sleep is needed to repay each hour of accumulated sleep debt (15), although the recovery process needs much more study. Some have suggested that the rate of recovery depends on the age level, with older adults showing improvement in reaction time tests more rapidly than younger adults (16). One experiment showed that older adults had returned to baseline levels on the MSLT after 1 night of recovery sleep, whereas younger adults continued to have shorter MSLT scores (17). 

Reaction time In psychology, the time interval between the application of a stimulus and the detection of a response. In a simple reaction time test, a subject is asked to press a button as soon as a light flashes. 

Jensen Yes that s correct. Even comparing Berkeley students with mentally retarded people in institutions, their fastest reaction times do not differ all that much, but the retarded people produce many more slower reaction times. A more important correlate of g than reaction time is the intra-individual variance in reaction time brighter people show less variation from trial-to-trial of a reaction time test than less bright people. 

Jensen No, but there are hypotheses, such as the theory that there s simply more noise in the nervous systems of lower IQ people, and that this variation from trial-to-trial in reaction time tests reflects neural noise, whatever that may mean. This should be investigated, because it s a more striking correlate of IQ than is reaction time itself. 

The paradigm for measuring information-processing speed is commonly referred to as a reaction time test since the elapsed time (i.e., the processing time) between the onset of a given stimulus and the occurrence of a prescribed response is the basic measurable quantity. To obtain a processing speed measure, the stimulus content in bits, chunks, or simply stimuli is divided by the processing... 

Variations on the dopamine hypothesis have also been proposed. Krause et al. (1985) reported a correlation between increased reaction time and decreased urinary dopamine in patients with PKU. As brain dopamine is concentrated in the corpus striatum, and the choice reaction time test requires a motor response as well as integration of stimuli, they speculate that the nigrocostriatal pathways are affected. Faust (1986-1987) obtained similar results they suspect that the deficits are associated with complex areas of the brain, such as the anterior frontal regions, and in motor areas that represent less advanced functions. 

Automated Psychological Test System (Elithorn and Levander, unpublished) (a) Reaction Time Tests... 

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