Location vs feature: reaction time reveals dissociation between two visual functions.
Reaction time in a detection or a location discrimination task was longer when a target appeared at the same location as in the previous trial (inhibition of return; IOR). However, it became shorter when the task was color or orientation discrimination (facilitation of return: FOR). This dichotomy was observed in the single target as well as in the popout displays. In additional experiments, vernier, size, and luminance discriminations all led to FOR, whereas eye-movement and arm-reaching tasks led to IOR. Moreover, identical stimuli could lead to the opposite patterns of result depending on the nature of the task: inhibition in global location tasks, and facilitation in feature analysis tasks. These may correspond to "where" vs "what" or "action" vs "recognition" pathways neurophysiologically.
Tanaka
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Y
Department of Neurobiology, Brain Research, Weizmann Institute of Science, Rehovot, Israel. yasuto@nisan.weizmann.ac.il
Shimojo
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S
D000704:Analysis of Variance; D003118:Color Perception / Q000502:physiology; D003463:Cues; D004192:Discrimination, Psychological / Q000502:physiology; D005403:Fixation, Ocular; D006801:Humans; D009431:Neural Conduction; D009433:Neural Inhibition; D011930:Reaction Time; D012399:Rotation; D012438:Saccades / Q000502:physiology; D014796:Visual Perception / Q000502:physiology