Emotion Recognition after Traumatic Brain Injury (TBI) - A General or a Selective Impairment?

Abstract

Moderate-severe Traumatic Brain Injury (TBI) has been shown to reduce the ability to correctly recognise the emotions expressed by others. Perception of negative emotions (sadness, disgust, fear, and anger) is reportedly affected more than positive (happiness and surprise) ones. The overarching aim of this thesis was to re-examine emotion recognition in individuals with TBI, and specifically, to explore whether TBI impairs the recognition of some emotions more than others. This was done by applying the Emotion Recognition Task (ERT; Montagne, Kessels, De Haan, & Perrett, 2007), and the Complex Audio-Visual Emotion Assessment Task (CAVEAT), a novel measure of emotion recognition which was designed to overcome the limitations of the conventional emotion recognition measures. The role of neuropsychological functioning in emotion recognition was also examined in light of the dynamic nature of the tasks used in this thesis. The psychometric properties of the CAVEAT and its ecological validity were also examined. These were addressed by eight studies, which together constitute an empirical endeavour to explore emotion recognition deficits in TBI. Study 1 and 2 used the ERT to investigate the recognition of the six basic emotions across varying intensity. Studies 3A-3C described the development and pilot testing of CAVEAT, and Study 3D tested performance on the six basic emotions from the CAVEAT. Study 4 explored the psychometric properties of the CAVEAT, and Study 5 examined the role of neuropsychological functioning in CAVEAT performance and its ecological validity. Combined, these findings suggest that moderate-severe TBI results in an overall impairment in emotion recognition, which is largely independent from neuropsychological functioning. The evidence of selective impairment in recognising some emotions compared to others (e.g., negative compared to positive), might be an artefact of the conventional measures of facial affect recognition used, which do not examine variance in the difficulty of emotions and which, consequently, may produce erroneous conclusions about differential impairment. These findings weaken arguments that emotion recognition is mediated by separate neural pathways underlying the recognition of positive and negative emotions and which are differentially affected by TBI. Finally, they strengthen the role of emotion recognition in the social dysfunction following TBI.