Abnormal Visual Scanning of Emotionally Evocative Natural Scenes in Huntington’s Disease

Abstract

Huntington’s disease (HD) is a neurodegenerative movement disorder associated with deficits in the processing of emotional stimuli, including alterations in the self-reported subjective experience of emotion when presented with pictures of emotional scenes. The aim of this study was to determine whether individuals with HD, compared to unaffected controls, display abnormal visual scanning of emotionally evocative natural scenes. Using eye-tracking, we recorded eye-movements of 25 HD participants (advanced pre-symptomatic and early symptomatic) and 25 age-matched unaffected control participants during a picture viewing task. Participants viewed pictures of natural scenes associated with different emotions: anger, fear, disgust, happiness, or neutral, and evaluated those pictures on a valence rating scale. Individuals with HD displayed abnormal visual scanning patterns, but did not differ from controls with respect to their valence ratings. Specifically, compared to controls, HD participants spent less time fixating on the pictures and made longer scan paths. This finding highlights the importance of taking visual scanning behavior into account when investigating emotion processing in HD. The visual scanning patterns displayed by HD participants could reflect a heightened, but possibly unfocussed, search for information, and might be linked to attentional deficits or to altered subjective emotional experiences in HD. Another possibility is that HD participants may have found it more difficult than controls to evaluate the emotional valence of the scenes, and the heightened search for information was employed as a compensatory strategy.

Visual scanning of the eye region of human faces predicts emotion recognition performance in Huntington’s disease.

“…Our finding of altered visual scanning of human faces is consistent with oculomotor impairments (e.g., Avanzini et al, 1979; Leigh et al, 1983), abnormal visual scanning behavior during nonsocial cognitive tasks (Blekher et al, 2009; Henderson et al, 2011) and during emotional tasks in HD (Kordsachia et al, 2017b), as well as with neurophysiological research suggesting that facial emotion recognition in HD is associated with altered visual processing (Croft et al, 2014; Dogan et al, 2014; Harrington et al, 2014). Nevertheless, the only previous study in HD examining visual scanning of facial expressions did not find differences between HD and control participants in fixation number or duration for the eye, nose, and mouth regions (van Asselen et al, 2012).…”

“…Abnormal visual scanning of faces is expected given that the basal ganglia, which are dramatically affected in HD, play a role in eye-movement control (Hikosaka, Takikawa, & Kawagoe, 2000). Additionally, oculomotor impairments (Avanzini, Girotti, Caraceni, & Spreafico, 1979; Leigh, Newman, Folstein, Lasker, & Jensen, 1983), abnormal visual scanning patterns during cognitive tasks (Blekher et al, 2009; Henderson et al, 2011), and abnormal visual scanning of emotionally evocative natural scenes (Kordsachia, Labuschagne, & Stout, 2017b) have been reported in HD. Interestingly, the emotion recognition deficit in HD is not specific to the facial or visual domain, as emotion recognition impairments also affect body language (de Gelder, Van den Stock, Balaguer, & Bachoud- Lévi, 2008) and nonverbal vocalizations (Bora et al, 2016; Sprengelmeyer et al, 2006).…”