LUMINANCE CHANGE DOES NOT AFFECT THE ATTENTIONAL ORIENTING TO AN EXOGENOUS CUE

This study aimed to examine whether the abrupt-onset feature or luminance of an exogenous cue was responsible for triggering the orienting response. The luminance level of an abrupt-onset cue was manipulated. A dim peripheral flash was made of luminance of 18.9 fL. A bright peripheral flash was made of luminance of 33.7 fL. Both types of peripheral cues were against a display background of 9.2 fL. Using EOG electrodes to monitor eye movements, the allocation of spatial attention was measured with response times to recognition of the targets that are presented at different locations following a cue. The results showed that the reaction time costs of the uncued locations for the bright cue was about the same as for the dim cue. The findings suggest that the dynamic changes of a peripheral flash, rather than luminance of the flash, may trigger the attentional orienting system.