ATTENTIONAL MODULATION OF VISUAL-MOTION PROCESSING IN CORTICAL AREAS MT AND MST

THE visual system is constantly inundated with information received by the eyes, only a fraction of which seems to reach visual awareness. T his selection process is one of the functions ascribed to visual atten tion(1-6). Although many studies have investigated the role of attenti on in shaping neuronal representations in the visual cortex, few have focused on attentional modulation of neuronal signals related to visua l motion. Here we report that the responses of direction-selective neu rons in monkey visual cortex are greatly influenced by attention, and that this modulation occurs as early in the cortical hierarchy as the level of the middle temporal visual area (MT). Our finding demonstrate s a stronger and earlier influence of attention on motion processing a long the dorsal visual pathway than previously recognized.