Gaze matters! The effect of gaze direction on emotional enhancement of memory for faces in patients with mesial temporal lobe epilepsy

Abstract

The aim of the study was to examine if gaze and emotional expression, both highly self-relevant social signals, affect the recollection accuracy of perceived faces in patients with mesial temporal lobe epilepsy (MTLE). Forty patients with MTLE (twenty-one without surgery and nineteen after anterior temporal lobectomy) as well as twenty healthy controls (HC) took part in the study. We used a set of 64 facial stimuli: 32 neutral and 32 emotional displays (16 fearful; 16 angry) from well-established affective stimuli databases. Half of the faces in each condition had eyes directed straight and half - away from the observer. Participants performed a gender identification task, and then, after a 45-minute delay were asked to identify the previously seen stimuli, presented among a new set of photos. Increased automatic learning of angry and fearful compared to neutral expressions was found in HC. There was no emotional enhancement of memory in MTLE but an increased learning for faces with averted than direct gaze. Our results expand on previous research by demonstrating that emotion expression and gaze direction can affect memory of faces. The study supports the hypothesis that healthy individuals and patients with temporal lobe abnormalities present different patterns of emotional gazes processing. The potential consequences of altered emotional gaze processing and social cognition impairments need to be further investigated to improve the quality of life of patients with MTLE.