The role of body mass index and its covariates in emotion recognition

Obesity is a chronic and debilitating medical condition that results from a complex mix of genetic, physiological, psychological, and social factors. Despite a recognized consensus regarding the complexity of obesity, little is known about how various demographic, medical, and cognitive performance variables interact in this population, especially in relation to factors which may contribute to the maintenance of obesity over time. Research has supported that one key aspect of this process is eating in response to psychological rather than physiological cues. Given the increased prevalence of psychopathology, particularly mood disorders, in obese individuals, the question arises as to whether there exists an underlying impairment in emotion recognition. The current study sought to examine the associations among demographic and medical variables as well as performance on cognitive tests of memory, attention, executive function, sensory-motor, and verbal skills. Contrary to the hypothesis that BMI would be inversely related to performance on tests of emotion recognition, results indicated that as BMI increases, reaction time to complete these tasks decreases. This finding was noted even after the effects of age, gender, estimated pre-morbid IQ, pre-existing medical conditions, and performance in all neurocognitive domains was removed. In addition, when examined across BMI categories, it was observed that participants with BMIs greater than 40 kg/m2 showed the fastest reaction times. Overall, these findings provide support for contemporary theories of emotion which generally agree that emotions evolved to facilitate adaptation to environmental threat