Visual strategies underpinning social cognition in traumatic brain injury

Impairments in social cognition after traumatic brain injury (TBI) are well documented but poorly understood (McDonald, 2013). Deficits in emotion perception, particularly facial affect recognition, are frequently reported in the literature (Babbage et al., 2011; Knox & Douglas, 2009), as well as mentalizing impairments and difficulty in understanding sincere and sarcastic exchanges (Channon, Pellijeff & Rule, 2005). To fully understand social impairments, both low-level and high-level processes must be explored. Few studies have focused on low-level perceptual processes in regards to facial affect recognition after TBI, and those that do typically use static social stimuli which lack ecological validity (Alves, 2013). This thesis employed eyetracking technology to explore the visual strategies underpinning the processing of contemporary static and dynamic social cognition tasks in a group of 18 TBI participants and 18 age, gender and education matched controls. The group affected by TBI scored significantly lower on the Movie for the Assessment of Social Cognition (MASC; Dziobek, et al., 2006), the Amsterdam Dynamic Facial Expression Set (ADFES; van der Schalk, Hawk, Fischer & Doosje, 2009), and The Assessment of Social Inference Test (McDonald et al., 2003). These findings suggest that, across a range of reliable assessments, individuals with TBI displayed significant social cognition deficits, including emotion perception and theory of mind, thus presenting strong evidence that social cognition is altered post-TBI. Impairments were not related to low-level visual processing as measured through eye-tracking metrics. This important insight suggests that social cognition changes post-TBI is likely associated with impairments in higher-level cognitive functioning. Interestingly, the group with TBI did display some aberrant fixation patterns in response to one static and one dynamic task but gaze patterns were similar between the groups on the remaining tasks. These non-uniform results warrant further exploration of low-level alterations post-TBI. Findings are discussed in reference to academic and clinical implications.