Eye-movement patterns during emotion recognition in focal epilepsy: An exploratory investigation.

Background: Eye-movement patterns during facial emotion recognition are under-researched in patients with focal epilepsy (PWFE). Previous studies including other neurological patients indicate that bilateral mesiotemporal damage could be associated with impaired emotion recognition and abnormal eye-movement patterns.

Aims: The current study addresses the question whether PWFE, in whom fronto-(mesio-)temporal networks are often disturbed, also show abnormal eye-movement patterns during facial emotion recognition.

Method: 24 PWFE and a group of 29 healthy controls (HC) performed a facial emotion recognition task and a gender recognition task while eye movements were recorded with an eye-tracker. For this purpose, Areas of Interest (AOI) were defined in the presented faces: the eye region and the mouth region. In addition to the proportion of correctly recognized emotions, the following eye-tracking parameters were recorded: Relative fixation duration (FD)/fixation count (FC) in the mouth region/eye region (relative to the FD/FC on the entire screen).

Results: PFWE showed an emotion recognition deficit compared to HC, whereas gender recognition performance did not differ between groups. In addition, PWFE showed significantly fewer and shorter fixations in the mouth region than HC, in both the emotion recognition task and the gender recognition task.

Conclusions: When looking at faces, PFWE show eye-movement patterns different from those of healthy controls. Behaviorally, PWFE are only impaired in emotion recognition. Hence, PWFE possibly scan facial regions that are relevant to successful emotion recognition more diffusely and less efficiently than healthy control subjects. Future studies should investigate the etiology of such abnormal eye-movement patterns in PWFE.