Nash A J, Fernandez M
Department of Psychology, Florida Atlantic University, Boca Raton 33431, USA.
Int J Psychophysiol. 1996 Oct;23(3):171-80. doi: 10.1016/s0167-8760(96)00049-9.
P300 in dual-tasks has been reported to be distributed reciprocally across the tasks, i.e. larger P300 associated with one task implies smaller P300 associated with the other (Wickens et al., 1983; Sirevääg et al., 1989). In these studies, however, the dual-tasks stimuli were either presented simultaneously, precluding a direct, within-trial assessment of relative magnitudes of P300, or they were separated by intervals of 1 s or more, thereby minimizing overlap of the ERP epochs, but at the cost of reduced competition for shared processing resources. The present experiment used an inter-stimulus interval of 400 ms between the auditory (tones) and visual (colored LEDs) stimuli that defined the dual-task and found that, when deviant tones elicited a prominent auditory P300, they were followed by a greatly reduced P300 for the deviant LED. The findings were interpreted from viewpoints that considered the effects of neural inhibition versus neural recovery cycles on the amplitude of P300.
据报道，在双重任务中，P300在各项任务之间呈反向分布，即与一项任务相关的较大P300意味着与另一项任务相关的较小P300（威肯斯等人，1983年；西雷瓦格等人，1989年）。然而，在这些研究中，双重任务刺激要么同时呈现，这排除了对P300相对幅度进行直接的、试验内评估的可能性；要么它们被1秒或更长时间的间隔分开，从而使事件相关电位（ERP）时段的重叠最小化，但代价是共享处理资源的竞争减少。本实验在定义双重任务的听觉（音调）和视觉（彩色发光二极管）刺激之间使用了400毫秒的刺激间隔，并发现，当异常音调引发显著的听觉P300时，随后异常发光二极管的P300会大幅降低。这些发现是从考虑神经抑制与神经恢复周期对P300幅度影响的角度来解释的。
