Neubauer A C, Freudenthaler H H
University of Graz, Department of Psychology, Austria.
Biol Psychol. 1995 Jun;40(3):281-98. doi: 10.1016/0301-0511(95)05121-p.
In the past, Kleitman's notion of a basic rest-activity cycle (BRAC), which states an approximate 1.5-h rhythm of arousal, has received some empirical support in studies investigating physiological or psychological parameters. Our study investigated this ultradian rhythm in human cognitive performance. Sixty subjects were tested every 10 min for 9 h with an elementary cognitive task, the sentence-verification test (SVT), and provided ratings of alertness and mood. Heart period was always measured during performance of the SVT. Using rather conservative statistical methods, spectral analyses of time series revealed no significant 90-min periodicity for any of the variables. Instead, longer periodicities were the major sources of variance. Reanalyses using detrended and/or smoothed time series suggest that emergence of the BRAC might depend also on statistical methods. In conformity with recent studies it was concluded that several positive reports for the BRAC might be due to lack of conservatism in statistical methods.
过去，克莱特曼提出的基本休息-活动周期（BRAC）概念，即一种约1.5小时的唤醒节律，在研究生理或心理参数的实验中得到了一些实证支持。我们的研究调查了人类认知表现中的这种超日节律。60名受试者在9小时内每隔10分钟接受一次基本认知任务——句子验证测试（SVT），并对警觉性和情绪进行评分。在进行SVT期间始终测量心率周期。使用较为保守的统计方法，对时间序列进行频谱分析，结果显示所有变量均无显著的90分钟周期性。相反，更长的周期性是方差的主要来源。使用去趋势化和/或平滑时间序列进行的重新分析表明，BRAC的出现可能也取决于统计方法。与近期研究一致，得出的结论是，BRAC的一些肯定性报告可能是由于统计方法不够保守所致。
