Article Figures & Data
Figures
- Figure 1.
Target objects, task timeline, and activity from two example sessions. During each trial, any one of 20 target stimuli (A) could appear along with three distractors, each located randomly at the four search array locations (B). While maintaining fixation on the central spot, the monkeys classified the target with a left or a right lever turn based on a learned arbitrary association. C, An illustration of spatial relationships during a hypothetical experimental session. Black spots represent the search array locations. The region of the saccadic deficit was measured using a memory-guided saccade task. IT neurons have large receptive fields that typically encompass multiple array locations (hypothetical IT receptive field is indicated by a circle). IT neuron activity and behavior performance before and during FEF inactivation were compared for trials in which the preferred target was inside the saccadic deficit region and for trials in which it was outside the saccade deficit region. D, Average activity (±SEM) during correct trials from two example IT neurons before (black trace) and during (red trace) FEF inactivation when the preferred target was presented at array locations inside the saccade deficit region (left) and outside the saccade deficit region (right). Scatters show fixation positions for correct trials from the two example sessions, before (black) and during (red) inactivation. The neuronal data for neutral and cued trials was combined. E, A structural MRI showing an electrode in the inferotemporal cortex of Monkey 2. This coronal image was sliced at an angle that followed the electrode's trajectory. F, The timeline of a single experimental session.
- Figure 2.
Performance accuracy for trials during which the target to be identified appeared IN (A) and OUT (B) of the region of the saccadic deficit before and during FEF inactivation. Because the IN trials were trials in which the target appeared in the contralesional horizontal position, for comparison, we also show performance accuracy for the ipsilesional horizontal position separately (C). Performance accuracy before inactivation in the IN trials (A) was almost identical to the performance accuracy before and during FEF inactivation in the ipsilesional horizontal location (p > 0.4) shown in C. Error bars indicate SEM. The statistical comparisons are indicated above the bar plots. Asterisk indicates significant difference in performance accuracy before and during FEF inactivation when the target appeared within the region of saccadic deficit.
- Figure 3.
Pooled average IT activity from correct trials during which the preferred target was presented aligned on the time of the search array presentation. A, Activity from search trials in which the target appeared inside the saccade deficit region (IN trials), before and during FEF inactivation. B, Activity from trials in which a single preferred target appeared inside the saccade deficit region before and during FEF inactivation. C, Activity from search trials in which the target appeared outside of the saccade deficit region (OUT trials). D, Activity from trials in which a single preferred target appeared outside the saccade deficit region before and during FEF inactivation. E, Neuronal discrimination index (ROC: preferred vs nonpreferred responses) for search and single-target trials before and during FEF inactivation for the IN and OUT trials. AUC stands for area under ROC curve. Error bars indicate SEM. p values for paired two-tailed sign rank tests comparing before and during conditions are indicated above the error bars. The dotted-line indicates chance (50%) neuronal discriminability (0.5 ROC). Asterisk indicates significant difference in neuronal discrimination of the target before and during FEF inactivation in search trials in which the target appeared within the region of saccadic deficit.
- Figure 4.
A–D show activity during correct trials in which the preferred target was the target to be classified; E–H show activity during correct trials in which the nonpreferred target was the target to be classified. A, Cued IN trials before (black trace) and during (red trace) FEF inactivation. B–D, Cued OUT trials (B), neutral cued IN trials (C), and neutral cued OUT trials (D). E–H, All conventions are the same as in A–D. Time windows for the statistical comparisons for the cue- and target-array responses are indicated by gray bars below the activity traces. The results of paired two-tailed sign-rank tests are indicated above the gray bars. All activity is aligned on the time of the target array presentation—time 0.
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