Involvement of the human frontal eye field and multiple parietal areas in covert visual selection during conjunction search.

摘要: Searching for a target object in cluttered visual scene requires active attention if the differs from distractors not by elementary features but rather feature conjunction. We used functional magnetic resonance imaging (fMRI) human subjects to investigate neuroanatomy of attentional mechanisms employed during conjunction search. In experimental condition, searched defined colour and orientation. baseline uniquely coloured target, regardless its Eye movement recordings outside scanner verified subjects' ability maintain fixation Reaction times indicated that condition was attentionally more demanding than condition. Differential activations between conditions were therefore ascribed top-down modulation neural activity. The frontal eye field, ventral precentral sulcus following posterior parietal regions consistently activated: (i) postcentral sulcus; (ii) posterior; (iii) anterior part intraparietal (iv) junction with transverse occipital sulcus. Parietal spatially distinct displayed differential amplitudes signal increase maximal amplitude Less consistent activation found lateral fusiform gyrus. These results suggest an involvement field covert selection potential targets also provide evidence subdivision cortex multiple areas participating selection, major contribution