Biomedical subjects

R Pigeau

Publications and source records attributed to R Pigeau.

4 recordsLinked to original sources

PubMed1995

Modafinil, d-amphetamine and placebo during 64 hours of sustained mental work. I. Effects on mood, fatigue, cognitive performance and body temperature.

Modafinil is an alerting substance that is considered safer than amphetamine with fewer side effects. Although modafinil has been used successfully to treat narcolepsy, relatively little is known about its ability to ameliorate fatigue and declines in mental performance due to sleep deprivation (SD) in a normal population. Forty-one military subjects received either 300 mg of modafinil, 20 mg of d-amphetamine, or placebo on 3 separate occasions during 64 hours of continuous cognitive work and sleep loss. Three drug treatments were given: at 23.30 hours and 05.30 hours during the first and second SD nights, respectively, and once at 15.30 hours during the third day of continuous work. Subjective estimates of mood, fatigue and sleepiness, as well as objective measures of reaction time, logical reasoning and short-term memory clearly showed better performance with both modafinil and amphetamine relative to placebo. Both modafinil and amphetamine maintained or increased body temperature compared to the natural circadian cycle observed in the placebo group. Also, from subject debriefs at the end of the study, modafinil elicited fewer side-effects than amphetamine, although more than the placebo group. Modafinil appears to be a good alternative to amphetamine for counteracting the debilitating mood and cognitive effects of sleep loss during sustained operations.

Journal Article↗

PubMed1995

Modafinil, d-amphetamine and placebo during 64 hours of sustained mental work. II. Effects on two nights of recovery sleep.

Polysomnograms were obtained from 37 volunteers, before (baseline) and after (two consecutive recovery nights) a 64-h sleep deprivation, with (d-amphetamine or modafinil) or without (placebo) alerting substances. The drugs were administered at 23.00 hours during the first sleep deprivation night (after 17.5 h of wakefulness), to determine whether decrements in cognitive performance would be prevented; at 05.30 hours during the second night of sleep deprivation (after 47.5 h of wakefulness), to see whether performance would be restored; and at 15.30 hours during the third day of continuous work, to study effects on recovery sleep. The second recovery night served to verify whether drug-induced sleep disturbances on the first recovery night would carry over to a second night of sleep. Recovery sleep for the placebo group was as expected: the debt in slow-wave sleep (SWS) and REM sleep was paid back during the first recovery night, the rebound in SWS occurring mainly during the first half of the night, and that of REM sleep being distributed evenly across REM sleep episodes. Recovery sleep for the amphetamine group was also consistent with previously published work: increased sleep latency and intrasleep wakefulness, decreased total sleep time and sleep efficiency, alterations in stage shifts, Stage 1, Stage 2 and SWS, and decreased REM sleep with a longer REM sleep latency. For this group, REM sleep rebound was observed only during the second recovery night. Results for the modafinil group exhibited decreased time in bed and sleep period time, suggesting a reduced requirement for recovery sleep than for the other two groups. This group showed fewer disturbances during the first recovery night than the amphetamine group. In particular, there was no REM sleep deficit, with longer REM sleep episodes and a shorter REM latency, and the REM sleep rebound was limited to the first REM sleep episode. The difference with the amphetamine group was also marked by less NREM sleep and Stage 2 and more SWS episodes. No REM sleep rebound occurred during the second recovery night, which barely differed from placebo. Hence, modafinil allowed for sleep to occur, displayed sleep patterns close to that of the placebo group, and decreased the need for a long recovery sleep usually taken to compensate for the lost sleep due to total sleep deprivation.

Journal Article↗

PubMed1986

Dream self-reflectiveness as a learned cognitive skill.

This research was directed toward the contradiction sustained by cognitive dream psychology, which on the one hand regards dreaming as higher symbolic activity and, on the other, sees its organizational and functional characteristics as derivative and/or inferior to those of waking consciousness. Study 1 evaluates the degree of self-reflective meta-cognition in dreams from different sleep stages. Subjects were 24 college students selected such that half were self-reported high-frequency dream recallers and half were low-frequency recallers. Both groups were composed equally of men and women. Greater self-reflectiveness (SR) was found in REM dreams as compared with those from stages 2 and 4, which did not differ. High-frequency recallers showed more dream SR than did low-frequency recallers. Study 2 assessed the extent to which self-reflective and lucid dreaming can be learned as a cognitive skill by varying levels of intention and attention paid to dreaming. After 3 weeks of home dream collection, results showed that four experimental groups had greater dream SR than did a baseline group. The most effective treatment was the mnemonic, wherein attention patterning schemas learned in waking resulted in more self-reflective and lucid dreaming than did either baseline or attention-control conditions. These results provide evidence that dreaming is not single-minded but variable along a self-reflective process continuum, and suggest functional and organizational levels that are consistent with the conception of dreaming as higher order cognitive activity.

Adult↗

PubMed1984

Quantitative description of sleep stage electrophysiology using digital period analytic techniques.

The purpose of the current study was to assess the overlap in variance of two procedures for the quantification of sleep electrophysiology: conventional stage scoring and computer quantification of tonic activity. Data were collected on 24 nights from eight subjects and were scored according to a modified set of Rechtschaffen and Kales criteria and submitted to a period-analytic computer analysis. Following this, discriminant function analyses were performed on the data for each night to predict the visual stage scores from the computer-generated data. The results indicate a very high degree of predictive accuracy (91.05%) supporting the contention that the computer-quantified data set includes the variance normally captured by stage scoring. The implications of computer quantification of sleep electrophysiology are discussed.

Adolescent↗