Figure 7.

Sustained signal modulations are not required to encode the locus of attention. A, Average signal modulation in FEF and the portion of visual cortex representing the target location, averaged across subjects and hemispheres. Prestimulus activity in FEF is sustained whereas activity in visual cortex returns nearly to baseline by the end of the preparatory period. B, Time point-by-time point attention discriminability indices for the same regions. The regions indicate the locus of attention equally well at the end of the preparatory period. This suggests that sustained BOLD activity is neither necessary nor sufficient as a marker of attention to a particular location.