Wesensten N J, Badia P, Harsh J
Walter Reed Army Institute of Research, Washington, DC 20307-5100.
Physiol Behav. 1990 Apr;47(4):653-8. doi: 10.1016/0031-9384(90)90073-d.
Time of day, repeated testing, and interblock interval effects on P300 amplitude were investigated. Subjects (N = 50) were tested using a standard oddball paradigm in either morning or afternoon sessions consisting of six test blocks per session. Amplitude of P300 was significantly higher in the morning than in the afternoon for all test blocks. In addition, amplitude of P300 habituated across test blocks from a mean of 9.59 microV on Block 1 to a mean of 4.98 microV on Block 6. Inserting a one-hour interval between Blocks 2 and 3 attenuated the rate of habituation. The results indicate that time of day, repeated testing, and interblock intervals affect P300 amplitude. Amplitude changes due to time of day may reflect circadian variations in cognitive resources indexed by the P300 component, while decrements due to repeated testing may reflect changes in allocation of resources across test sessions.
研究了一天中的时间、重复测试以及组间间隔对P300波幅的影响。研究对象（N = 50）采用标准的Oddball范式进行测试，测试分上午或下午时段进行，每个时段包含六个测试组块。所有测试组块中，上午的P300波幅显著高于下午。此外，P300波幅在各测试组块间呈现习惯化，从第1组块的平均9.59微伏降至第6组块的平均4.98微伏。在第2组块和第3组块之间插入一小时的间隔减弱了习惯化的速率。结果表明，一天中的时间、重复测试以及组间间隔会影响P300波幅。一天中不同时间导致的波幅变化可能反映了由P300成分所索引的认知资源的昼夜节律变化，而重复测试导致的波幅减小可能反映了各测试时段资源分配的变化。
