Figure 2

Pupil size is increased in response to free recall of remembered words. (a) Example of pupil area modulation during free recall of remembered words from one recall trial. Red lines mark the start time of word vocalization. Notice that recall of words is associated with pupil dilation with no changes in the screen display. (b) Mean pupil responses from all recalled word epochs in one patient are aligned to the onset of vocalization (left). Notice the consistent dilation starting before and peaking at the time of vocalization. Mean pupil area in ±1 s epochs around the word vocalization (‘during recall’) is significantly greater than in the remaining recall epochs (‘outside recall’) with no vocalization (**p < 0.01). (c) Across-subject comparison (colors are different subjects) of the pupil area in the two epoch types shows consistently more dilated pupil during recall of remembered words (*p < 0.05).