STUDY OBJECTIVES The Psychomotor Vigilance Test (PVT) is frequently used to measure behavioral alertness in sleep research on various software and hardware platforms. In contrast to many other cognitive tests, PVT response time shifts of a few milliseconds can be meaningful. It is therefore important to use calibrated systems, but calibration standards are currently missing. This study investigated the influence of system latency bias and its variability on two frequently used PVT performance metrics, attentional lapses (response times [RT] ≥500 milliseconds) and response speed, in sleep-deprived and alert subjects. METHODS PVT data from one acute total (N=31 subjects) and one chronic partial (N=43 subjects) sleep deprivation protocol were the basis for simulations in which response bias (±15 milliseconds [ms]) and its variability (0-50 ms) were systematically varied and transgressions of pre-defined thresholds (i.e., ±1 for lapses, ±0.1/s for response speed) recorded. RESULTS Both increasing bias and its variability caused deviations from true scores that were higher for the number of lapses in sleep deprived subjects and for response speed in alert subjects. Threshold transgressions were typically rare (i.e., <5%) if system latency bias was less than ±5 ms and its standard deviation was ≤10 ms. CONCLUSIONS A bias of ±5 ms with a standard deviation of ≤10 ms could be considered maximally allowable margins for calibrating PVT systems for timing accuracy. Future studies should report the average system latency and its standard deviation in addition to adhering to published standards for administering and analyzing the PVT.

中文翻译：

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心理运动警觉性测试的响应速度测量：如何精确才足够精确？

研究目标心理运动警觉性测试 (PVT) 经常用于在各种软件和硬件平台上测量睡眠研究中的行为警觉性。与许多其他认知测试相比，几毫秒的 PVT 响应时间偏移可能是有意义的。因此，使用校准系统很重要，但目前缺少校准标准。本研究调查了系统延迟偏差及其对两个常用 PVT 性能指标的影响，注意力失误（响应时间 [RT] ≥ 500 毫秒）和响应速度，在睡眠剥夺和警觉的受试者中。方法 来自一名急性总（N=31 名受试者）和一名慢性部分（N=43 名受试者）睡眠剥夺方案的 PVT 数据是模拟的基础，其中响应偏差（±15 毫秒 [ms]）及其变异性（0-50 ms) 被系统地改变，并记录了对预定义阈值的违反（即，±1 表示失误，±0.1/s 表示响应速度）。结果 增加的偏差及其可变性都会导致与真实分数的偏差，这些偏差在睡眠不足的受试者中的失误次数和警觉受试者的反应速度方面更高。如果系统延迟偏差小于 ±5 ms 且其标准偏差≤10 ms，则阈值违规通常很少见（即 <5%）。结论 ±5 ms 的偏差和 ≤ 10 ms 的标准偏差可以被认为是校准 PVT 系统以实现计时精度的最大允许余量。