Comparable attenuation of facial emotion recognition in adults with ASD or ADHD

Abstract

People with autism spectrum disorder (ASD) or attention deficit/hyperactivity disorder (ADHD) have been shown to take longer to recognise emotions associated with facial expressions. While this effect has been sufficiently documented, less attention has been given to its specificity. Since both disorders lead to increased reaction times on a wide variety of tasks, it is unclear whether differences in reaction times are specific to emotion recognition processes or due to attenuations of more basic sensory or motor processes. Therefore, we pair the use of a sensitive morphing task assessing emotion discrimination threshold, i.e. how much information is needed to correctly recognise an emotion, with a control task measuring species discrimination threshold. We hypothesise specific increases of emotion discrimination threshold in adults with ADHD or ASD, and differences in gaze patterns, specifically in dwell times and number of saccades. Our data supports differences in facial emotion recognition between adults with ADHD or ASD and a comparison group without any neurological or psychiatric disorders. Importantly, emotion discrimination thresholds were equivalent in adults with ADHD and ASD when including performance in the control task in the model. However, there were no differences between groups in terms of gaze patterns, suggesting that differences in facial emotion recognition were not due to differences in attention to facial landmarks or information gathering strategies.