Emotional and interpersonal difficulties have been widely described in alcohol-dependence [1] and are thought to play a crucial role in the development and maintenance of this disease [2]. In particular, impairments in the decoding of emotional facial expression (EFE) have been repeatedly reported and may have serious deleterious effects for the everyday life of alcohol-dependent individuals (ADI), notably by affecting their interpersonal relationships [3]. However, the large majority of earlier studies that assessed emotional decoding abilities among ADI were interested in the processing of prototypical full-blown EFE while in everyday social life, EFE are usually not entirely straightforward but are rather composed of a mix of different emotions [4]. The aim of this study was therefore to determine whether ADI exhibit the categorical perception effect, which is a critical process observed in healthy populations to efficiently decode ambiguous EFE. Nineteen recently detoxified ADI and 19 healthy controls (HC), matched for age and gender, were presented with facial stimuli depicting [4] EFE (happy, angry, sad, and neutral), morphed along continua between each possible pair of emotions. Participants had to indicate the predominant emotion within the randomly presented facial stimuli. For each EFE, a sigmoid function that estimated the percentage of identifications according to the morph steps was adjusted for each participant's data. While there was no significant group difference regarding the response slope (indicating how abruptly the shift in responses happens), the identification threshold (i.e. the function midpoint) was significantly increased in ADI compared to HC, independently of the EFE category. The categorical perception of EFE per se appeared thus preserved in alcohol-dependence, but ADI exhibited a bias in EFE decoding characterized by a global under-identification. To conclude, this study is the first to evidence an EFE processing deficit in ADI by using this kind of emotional continuum paradigm measuring the categorical perception effect.

Objectives: Concussion is defined as a complex pathophysiological process affecting the brain. Although the cumulative and long-term effects of multiple concussions are now well documented on cognitive and motor function, little is known about their effects on emotion recognition. Recent studies have suggested that concussion can result in emotional sequelae, particularly in females and multi-concussed athletes. The objective of this study was to investigate sex-related differences in emotion recognition in asymptomatic male and female multi-concussed athletes. Methods: We tested 28 control athletes (15 males) and 22 multi-concussed athletes (10 males) more than a year since the last concussion. Participants completed the Post-Concussion Symptom Scale, the Beck Depression Inventory-II, the Beck Anxiety Inventory, a neuropsychological test battery and a morphed emotion recognition task. Pictures of a male face expressing basic emotions (anger, disgust, fear, happiness, sadness, surprise) morphed with another emotion were randomly presented. After each face presentation, participants were asked to indicate the emotion expressed by the face. Results: Results revealed significant sex by group interactions in accuracy and intensity threshold for negative emotions, together with significant main effects of emotion and group. Conclusions: Male concussed athletes were significantly impaired in recognizing negative emotions and needed more emotional intensity to correctly identify these emotions, compared to same-sex controls. In contrast, female concussed athletes performed similarly to same-sex controls. These findings suggest that sex significantly modulates concussion effects on emotional facial expression recognition. (JINS, 2017, 23, 65–77)