Braun C, Mailhoux C, Dufresne A
Département de Psychologie of L'Université du Québec à Montréal, Canada.
Acta Psychol (Amst). 1996 Feb;91(1):3-14. doi: 10.1016/0001-6918(94)00051-4.
Modulation of stimulus luminance in a tachistoscopic face discrimination task has been found to significantly invert visual hemifield advantage in reaction time (RT) (Sergent, 1982a, Sergent, 1982b). However, there is no more physiological rationale for that than for a similar effect, say, of retinal adaptation, and it is even conceivable that the latter may have confounded the former in past experiments. The experiments reported here were therefore designed to tease out the relative contributions of stimulus luminance and of background illumination (i.e., retinal adaptation) in a simple RT task. Two equally difficult conditions of dim targets were set up, one with light-adapted subjects and one with dark-adapted subjects. Similarly, two equally difficult conditions of bright targets were set up with light and dark-adapted subjects. It was found that dim targets (near detection threshold) yielded a significant right visual field RT advantage in light-adapted subjects and that dim targets (equally near detection threshold) yielded a significant left visual field RT advantage in dark-adapted subjects. Future experiments will determine whether cone-mediated RT to detection is left hemisphere dominant and whether rod-mediated RT to detection is right hemisphere dominant.
在速示面孔辨别任务中，刺激亮度的调节已被发现会显著反转反应时（RT）中的视觉半视野优势（塞尔让，1982a，塞尔让，1982b）。然而，对此现象的生理学原理并不比对类似效应（比如视网膜适应）的原理更多，甚至可以想象，在过去的实验中，后者可能混淆了前者。因此，此处报告的实验旨在在简单反应时任务中梳理出刺激亮度和背景照明（即视网膜适应）的相对贡献。设置了两个难度相当的暗目标条件，一个针对明适应受试者，另一个针对暗适应受试者。同样，针对明适应和暗适应受试者设置了两个难度相当的亮目标条件。结果发现，暗目标（接近检测阈值）在明适应受试者中产生了显著的右视野反应时优势，而暗目标（同样接近检测阈值）在暗适应受试者中产生了显著的左视野反应时优势。未来的实验将确定锥体介导的检测反应时是否以左半球为主导，以及杆体介导的检测反应时是否以右半球为主导。
