“.mat” files contain: BUF2: Recording during fixation slide (column 1: time; column 2: right pupil width; column 3: right pupil height; column 4: left pupil width; column 5: left pupil height; column 6: glint data from right eye; column 7: glint data from right eye; column 8: image number) BUF: Recording during stimulus presentation (same columns of BUF2) c: block’s specifics (eye-tracker information, trials number and duration, start and end times of eye-tracker registrations) smile: images code Response: block’s information (first column: stimulus presentation time; variable number of other columns: smile variable; last column: trials number);