Department of Human Sciences, Sleep Research Centre, Loughborough University, Leicestershire, UK.
Sleep. 2010 Feb;33(2):197-204. doi: 10.1093/sleep/33.2.197.
A lapse during the psychomotor vigilance task (PVT) is usually defined as a response longer than 500 ms; however, it is currently unknown what psychobiological phenomena occur during a lapse. An assessment of what a participant is doing during a lapse may depict varying levels of "disengagement" during these events and provide more insight into the measurement of both a lapse and sleepiness.
Repeated measures.
Participants underwent extended 30-min PVT sessions twice, at 22:00 and 04:00, under: (i) typical non-distractive laboratory conditions, and (ii) an additional distractive condition.
Twenty-four healthy young adults (mean age: 23.2 y +/- 2 y; range 21-25 y [12 m; 12 f]) without any sleep or medical problems and without any prior indication of daytime sleepiness.
One night of sleep loss. Distraction comprised a TV located at 90 degrees in the visual periphery showing a popular TV program. For the non-distraction condition, the TV was turned off.
MEASUREMENTS & RESULTS: Video data (bird's-eye and frontal view) were used to classify each lapse (> or = 500 ms) as occurring with eyes open (EO), eyes closed (EC), or due to a head turn (HT). EO lapses were more prevalent, with all lapses (EO, EC, and HT) increasing with sleepiness. There was a significant effect of distraction for HT lapses which was exacerbated when sleepy. For lapse duration there was little effect of sleepiness for EO lapses but a significant effect for EC and HT. The 95% confidence intervals for lapse duration and associated behavior showed those lapses greater than 2669 ms were 95% likely to be EC, whereas those 500-549 ms were 95% likely to be EO. Response times of 1217 ms had a 50:50 probability of being EO:EC.
Discriminating the varying causes of lapses whether due to visual inattention (eyes open), microsleep (eyes closed), or distraction (head turn) may provide further insight into levels of disengagement from the PVT and further insight into developing sleepiness.
在精神运动警觉任务（PVT）中，通常将反应时间超过 500 毫秒定义为失误；然而，目前尚不清楚在失误期间会发生哪些心理生物学现象。评估参与者在失误期间的行为可能会描绘出这些事件中不同程度的“脱离”，并为失误和嗜睡的测量提供更多的深入了解。
重复测量。
参与者在 22:00 和 04:00 进行了两次扩展的 30 分钟 PVT 测试，在以下两种情况下进行：（i）典型的非分散实验室条件，和（ii）附加的分散条件。
24 名健康的年轻成年人（平均年龄：23.2 岁 +/- 2 岁；年龄范围 21-25 岁[12 个月；12 名女性]），无睡眠或医疗问题，且无日间嗜睡的既往史。
一夜睡眠剥夺。分心包括位于视觉外围 90 度的电视，播放一个受欢迎的电视节目。在非分散条件下，电视关闭。
视频数据（鸟瞰和正面视图）用于将每个大于或等于 500 毫秒的失误分类为睁眼（EO）、闭眼（EC）或由于转头（HT）。EO 失误更为常见，所有失误（EO、EC 和 HT）都随着嗜睡而增加。HT 失误存在显著的分心影响，在困倦时加剧。对于失误持续时间，EO 失误的困倦影响很小，但 EC 和 HT 失误有显著影响。对于失误持续时间和相关行为的 95%置信区间表明，大于 2669 毫秒的失误 95%可能是 EC，而 500-549 毫秒的失误 95%可能是 EO。1217 毫秒的反应时间有 50:50 的概率是 EO:EC。
区分由于视觉注意力不集中（睁眼）、微睡眠（闭眼）或分心（转头）引起的各种失误原因，可能会进一步深入了解从 PVT 中脱离的程度，并进一步深入了解嗜睡的发展。
