Choice reaction time

Smith, D., Tong, J. and Leigh, G., Combined effects of caffeine and tobacco on the components of choice reaction time, heart rate and hand steadiness. Perc and Motor Skills 45(2), 635-639, 1977. 

Cognitive effects Human nonsmokers Administration of nicotine to tobacco nonusers produces small cognitive enhancements. Studies in tobacco nonusers have primarily measured attention, information processing speed, and memory. Nicotine improves perceptual speed, choice reaction time, and digit recall (Stough et al. 1995 Le Houezec et al. 1994 Foulds et al. 1996). Improvements also occur in digit symbol substitution and continuous performance tests without reducing accuracy (Petrie and Deary 1989 Levin et al. 1998). 

Opioids are sedating and cause a reduction in processing speed in clinical populations (e.g.. Digit Symbol Substitution Test) (Wood et al. 1998). However, a study in healthy subjects did not confirm these effects on digit substitution (Walker and Zacny 1998). Improvements are seen in choice reaction time after morphine administration (Hanks et al. 1995). Deficits have been reported in early-stage visual processing (O Neill et al. 1995 Hanks et al. 1995). By comparison, morphine s cognitive effects are lesser than those of lorazepam, but milder than hydromorphone (Rapp et al. 1996 Hanks et al. 1995). 

Cognitive and subjective effects The effects of LSD on attention have been examined in animal paradigms. LSD reduces accuracy on a multiple-choice reaction time task, which is reversed by a 5-HT2 antagonist (Carli and Samanin 1992). LSD produces gross alterations in time perception, which holds true in animal models as well as human reports (Frederick et al. 1997). 

After 30 50 g of alcohol (consumed as 70 110 ml of cognac or whisky or 250 400 ml of wine) a biphasic action was observed. Some 30 45 min after the alcohol had been ingested, simpler mental activities such as reading and speed of simple reactions were often improved but there was no change in the more difficult tasks. Later on, i.e. more than 45 min after intake, performance was in general reduced, particularly for higher doses of alcohol and more complex activities (choice reaction times, wealth of word associations). 

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. 

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. 

As mentioned earlier, the U.S. Naval Health Research Center has investigated the efficacy of pemoline over long periods without sleep. Naitoh et al. (59) compared four groups of subjects exposed to 64 hr of continuous wakefulness who received either a 20-min nap every 6 hr, no nap for the duration of the study, 37.5 mg pemoline every 12 hr, or placebo. Performance effects were measured using a four-choice reaction time task administered every 3 hr. While both pemoline and a nap were successful at attenuating fatigue-related degradations in accuracy, response speed, and number of stimuli attempted, the effects on these latter two variables were more robust under pemoline (compared to naps). 

Kamimori et al. (129) tested the effects of approximately 150, 300, and 600 mg caffeine on noradrenaline and adrenaline levels, sleep latency, Stanford Sleepiness Scale ratings, and choice reaction time in volunteers who were dosed after 49 hr of continuous wakefulness (and kept awake for an additional 12 hr). 

Babkoff, H., Kelly, TL, Naitoh, P. Trial-to-trial variance in choice reaction time as a measure of the effect of stimulants during sleep deprivation. Milit Psychol 2001 13(1) 1-16. 

Naitoh et al. (45) employed a sleep/wake schedule of 20-min naps every 6 hr during a 64-hr period of continuous work, comparing this experimental condition against a second condition comprising total sleep deprivation for the entire 64-hr period. Compared to the sleep deprivation condition, the 20-min naps significantly reduced the cumulative effects of sleep loss on a four-choice reaction time task. 

Response accuracy reflects the animal s capacity to remember the lever previously presented and therefore represents a measure of short-term memory. Simple reaction times reflect the animal s rapidity to respond to an unpredictable spatial stimulus and therefore represent a measure of attention. Choice reaction times reflect the animal s rapidity to choose between two levers and therefore represent a measure of decision taking or information processing speed. Performance on all parameters improves over the acquisition period and therefore indicates the animal s capacity to learn the new task. 

Fig. 14. Effects of diazepam and scopolamine on the 3 parameters measured during the acquisition of a delayed alternation task in the rat (mean performance over 10 sessions). Note that both diazepam and scopolamine significantly decrease the number of correct responses (impairment of learning/memory). Diazepam has no effect on simple reaction times whereas scopolamine significantly increases it (impairment of attention). Diazepam significantly decreases choice reaction times whereas choice reaction times are clearly increased by scopolamine. The increased choice reaction times with scopolamine probably reflect an impairment of information processing speed, whereas the decrease observed with diazepam probably reflects the disinhibitory effects of diazepam.

Visual search reaction time 4-choice reaction time Continuous attention IM 10 vs. 25 mg... 

Guillermain Y, Micallef J, Possamai C, Blin O, Hasbroucq T. 2001. N-methyl-D-aspartate receptors and information processing Human choice reaction time under a subanaesthetic dose of ketamine. Neurosci Lett 303 29-32. 

Skilled motor control has been evaluated in tests of manipulative ability, such as a paw reaching for food, in tests of lever pressing, and in simple and choice reaction time tasks in operant test apparatuses. 

Fig. 8. Nine-hole box test apparatus for assessing serial and choice reaction time. A. Perspective view. B. Schematic plan view.

Brown VJ, Robbins TW (1991) Simple and choice reaction time performance following unilateral striatal dopamine depletion in the rat. Impaired motor readiness but preserved response preparation. Brain 774 513-525. 

There have now been parallel studies of 6-OHDA-induced lesions of the mesostriatal and mesocortical DA systems (Robbins et al., 1998 Baunez and Robbins, 1999). Both studies produced results that were different from those of mesolimbic DA loss, in that there were impairments in choice accuracy when the visual stimuli were presented in a temporally unpredictable manner. The impaired choice accuracy resulting from mesostriatal DA depletion was found in the context of many other behavioral deficits, including slowed responding and large increases in response latency (similar to those seen following mesolimbic DA loss). However, despite these effects, no deficits in accuracy were observed under baseline conditions. The selective disruption produced by the variable intertrial intervals may be related to the basic impairments in the readiness to respond described in earlier studies on simple and choice reaction time (Brown and Robbins, 1991). 

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