Abstract
In humans, damage of posterior parietal and frontal cortices often induces a neglect of the contralateral visual field. In cats, unilateral deactivation of the posterior middle suprasylvian (pMS) sulcus in the posterior inferior parietal region also results in an equally severe contralateral neglect, as assessed by a visual orienting task. Since attention is likely based upon a widespread network, we tested the contributions of the pMS sulcus and 14 other cortical regions to visual orienting in 31 adult cats. Unilateral cooling deactivation of three adjacent regions along the posterior bend of the suprasylvian sulcus (posterior middle suprasylvian sulcus, posterior suprasylvian sulcus, and dorsal posterior ectosylvian gyrus at the confluence of the occipital, parietal and temporal cortices) eliminated visual orienting responses into the contralateral hemifield, while orienting responses into the ipsilateral hemifield remained highly proficient. Additional cortical loci critical for visual orienting include the anterior suprasylvian gyrus (lateral area 5, anterior inferior parietal cortex) and medial area 6. Cooling deactivation of: 1) dorsal or 2) ventral posterior suprasylvian gyrus; 3) ventral posterior ectosylvian gyrus, 4) middle ectosylvian gyrus; 5) anterior or 6) posterior middle suprasylvian gyrus (area 7); 7) anterior middle suprasylvian sulcus; 8) medial area 5; 9) the visual portion of the anterior ectosylvian sulcus (AES); 10) or lateral area 6 were all without impact on orienting Therefore, three adjoining regions at the junction of temporal, parietal and occipital cortices are critical for mediating visual attention into the contralateral visual field. In addition, one anterior inferior parietal and one medial frontal region contribute importantly to visually-guided orienting.