Article Figures & Data
Figures
- Figure 1.
Experimental protocol and behavioral results. A, Illustration of the timing and sequence of events within an example trial. Each trial consisted of a fixation period followed by a memory cue, then by a cue-to-probe interval, and finally by either a visual search display (on standard search trials), a memory probe (on memory catch trials), or no display (on cue-only trials). Trials were separated by a jittered intertrial interval (data not shown, see Materials and Methods, Experimental protocol). In the example trial displayed here, the WM cue would be considered an invalid cue for the visual search, because the WM cue surrounds a search distracter (the search target is the tilted bar). B, Median search response time is plotted as a function of WM cue validity and whether the cue validity was predictable.
- Figure 2.
Neural substrates of WM validity effects on visual selection. A, Parahippocampal areas are more active when WM cue is valid relative to invalid for search across both high and low WM predictability conditions. B, Frontoparietal regions are more active when the WM cue is invalid relative to valid for search. Activated voxel clusters in a whole-brain analysis (Z > 2.3, p < 0.05, corrected).
- Figure 3.
Neural substrates of anticipatory control over WM–attention interaction. A, In green are the areas that are more active during cue-only trials when observers have foreknowledge that the WM cue is a valid predictor of the search target. In red are regions showing increased activity during cue-only trials when the WM content reliably predicted an invalid distracter in search relative to when there was no such foreknowledge. Clusters of activity are derived relative to the 50/50 baseline. B, Signal change (%) is plotted for the peak active cluster (MNI: −36, −48, 38) of the left PPC for cue-related activity in 100% valid blocks and 100% invalid blocks (effects are displayed relative to the 50/50 unpredictable baseline; Z >1.96, p < 0.05, corrected). C, Signal change (%) is plotted for the peak active cluster (MNI 40 −48 3) of the right PPC for cue-related activity in 100% valid blocks and 100% invalid blocks (effects are displayed relative to the 50/50 unpredictable baseline).
- Figure 4.
Neural effects of control over WM–attention interaction during visual search. A, In yellow are activated voxel clusters in a whole-brain analysis (Z > 2.3, p < 0.05, corrected) of cue plus search periods showing areas that are more active when cues predictably coincided with targets or distracters than when cue–target relations were unpredictable (100% valid/invalid > 50% valid/invalid blocks) (rHipp, Right hippocampus; Val, Valid; Inv, invalid). In red are voxels that covaried with within-subject variability in the behavioral effect of foreknowledge about WM validity (Z > 2.3, p < 0.05, corrected). PCC, Posterior cingulate cortex; rOFC, right orbitofrontal cortex). B, Correlation between hippocampal response enhancement by predictable cues (see A) and behavioral search efficiency due to foreknowledge of WM validity (for details, see Results). C, Voxel clusters that were selectively more activated during search in the predictably valid cue condition than in the predictably invalid cue condition. Percent signal change is plotted for the peak of the cluster on the left middle temporal gyrus (lMTg) (Z > 1.96, p < 0.05, corrected).
