Psychostimulants and sleep-dependent memory consolidation_WhitehurstLN

This is a within-subject, double-blind, placebo-controlled design, where we investigated the impact of morning administration (9AM) of dextroamphetamine on recognition memory for negative and neutral pictures after 12 hours of wake and 24 hours with sleep. Stimulants provided a 6% memory enhancement for neutral pictures after 12-hrs of wake. However, stimulants impaired sleep (decreased total sleep time and minutes in slow wave sleep (SWS) and increased sleep latencies). In addition, recognition for neutral pictures showed significant reductions at 24 hours in the stimulant compared to the placebo condition, and this memory impairment was statistically mediated by SWS latency. No performance differences between drug conditions were found for negative pictures at any time point. We tested the hypothesis that stimulant-driven performance impairment was related to poor sleep by introducing a hypnotic drug (i.e. zolpidem) at night which, when paired with the stimulant during the day, restored both the sleep and, critically, the memory performance deficit, compared with the stimulant alone.

本实验采用被试内双盲安慰剂对照设计，探究了上午（9点）给予右旋安非他明（dextroamphetamine）后，被试在12小时清醒状态与24小时睡眠状态下对负性及中性图片的再认记忆表现。在12小时清醒状态下，该兴奋剂可使中性图片的再认记忆成绩提升6%。但兴奋剂会损害睡眠：降低总睡眠时间与慢波睡眠（slow wave sleep, SWS）时长，并延长睡眠潜伏期。此外，与安慰剂组相比，兴奋剂组在24小时时的中性图片再认记忆成绩出现显著下降，且该记忆损伤在统计上由慢波睡眠潜伏期介导。而针对负性图片，任意时间点下不同药物组间均未发现行为表现差异。本研究通过在夜间给予催眠药物唑吡坦（zolpidem），检验了“兴奋剂引发的行为表现损伤与睡眠质量受损相关”这一假说：与单独使用兴奋剂的组别相比，日间联用兴奋剂与夜间唑吡坦的组别，其睡眠状态与记忆表现缺陷均得到恢复，且该恢复效果尤为关键。