Figure 3. Spatial attention modulates activity in cortical ROIs in the occipital, temporal, parietal, and frontal lobes. A, β Values of the GLM for monkey Q (BOLD, top) and monkey M (Sinerem, bottom) across ROIs (left to right: V1, V2, V3a, V3, V4d, V4t, MT, MST, FST, PITd, 7a, VIP, LIP, and FEF) in the attentive discrimination task with central bar cue (Fig. 1A, var1). Responses during the attend contralateral (Attend contra) condition are shown in gray; responses during the attend ipsilateral (Attend ipsi) condition in black. Significant activation differences in the two conditions: *p < 0.01 (ANOVA, multiple-comparison corrected); ***, most significant differences; **, differences with at least half the F value of the most significant difference. B, β Values for the motion-discrimination task with color cue (Fig. 1A, var3; averaged across monkeys Q and M, Sinerem both). Responses to the passive fixation task condition (neutral) are shown in white. Significant activation differences between the two attention conditions (Attend contra and Attend ipsi) are indicated by asterisks following the same convention as in A. FEF modulation was marginally significant (p = 0.03). C, Left, Scatter plot of activation differences (Attend contra vs Attend ipsi, vertical axis) for each ROI versus mean activation during the two attention conditions (horizontal axis) averaged across attentive motion-discrimination tasks variant 1 (vars1) and variant 3 (vars3; A and B). Areas MST, FST, VIP, and 7a show weak and insignificant activation and attention modulation across tasks and animals. The dotted line indicates conditions with response enhancement during the Attend contra condition that is enhanced by 67% (corresponding to an AI of 0.25) relative to the response during the Attend ipsi condition. Right, Bar graph of AIs of ROIs with both visual activation and attentional modulation. Areas V1, V2, V3a, and V3 show similar and lower levels of attentional modulation; motion-selective areas V4t and MT show more; and area PITd, area LIP, and the FEF show the strongest. The AI for the FEF, which typically exhibited little mean activation, was the largest of these three areas, and was cutoff at the top for display purposes.