These data were acquired during an experience-sampling task which participants were probed with questions about their thoughts, together with pupil and eyelid diameter measurement using Phasya Drowsimeter R100 glasses. More specifically, they were invited to sit in front of a computer screen with a keyboard to answer, wearing Phasya glasses and ER-3C earphones. They were asked to indicate the type of thinking they were going through at rest among several categories of answer, only when they heard a probe sound. The investigator remained present in the room but out of sight of the participant, behind a fabric-covered plexiglass, the room was quiet with dimmed lights. The probe sound occurred 40 times at fixed random time interval ranging from 30 to 60 sec (Van Calster et al., 2017). 3 categories of mental states were established: i) “Absence” (MB), ii) “Thoughts” (MW), iii) “Sensations” (S). After the experience sampling task, subjects had to complete several questionnaires : - ASQ (Attentional Style Questionnaire) : measures a person’s general tendency of attentional control along two dimensions (bottom-up and top-down), by distinguishing between internal and external of potential distractors. - GAD-7 (Generalized Anxiety Disorder) : it was administrated to see if there was a potential link between the score and the thought process. For example, assess whether a higher score was correlated with greater mental rumination (i.e. high internal attention orientation score). - MMSE (Mini Mental State Examination : it was administrated to aged participants to examine general cognitive functions and check that they did not have any major neurocognitive disorder. FILES: - RAW DATA : keyboard responses + ocular data (drowsilogic) > eye.metrics.csv: measures of pupil + eyelid > flags.csv : flags (MB/MW/S) created on drowsilogic and related to the keyboard responses > - sub(...).csv: all informations about keyboard responses (code PsychoPy) > log ? > psydat ? > glasses.mkv: video of the eye > .dldx : real time eye measurement on drowsilogic software. This file cannot be opened without the software and the USB key (which has the license to use drowsilogic). All dataframes for analyses can be found on this OSF server. Raw data can be asked directly to matthieu.koroma@uliege.be and will be provided without restrictions if it is for research purposes following the open science practices and non-commercial use. All codes for analyses can be found on : https://gitlab.uliege.be/S.Mortaheb/mb_aging.git