Differences Between Autistic and Non-autistic Adults in the Recognition of Anger From Dynamic Expressions Remain After Controlling for Alexithymia.

Abstract

BackgroundFor many years, research has suggested that autistic individuals have difficulties recognising the emotions of other people. However, a burgeoning literature argues that these difficulties may be better explained by co-occurring alexithymia rather than autistic characteristics. Importantly, extant studies in this field have focused on the recognition of emotion from static images. Here we investigated whether there are differences with respect to emotion recognition from dynamic facial stimuli between autistic and non-autistic groups matched on alexithymia.Methods29 control and 31 autistic adults, matched on age, gender, non-verbal reasoning ability and alexithymia, completed a facial emotion recognition task which employed dynamic point light displays of happy, angry and sad facial expressions. Stimuli were manipulated such that expressions were reproduced at 50%, 100% and 150% of their normal speed and spatial extent. ResultsThe ASD group exhibited significantly lower emotion recognition accuracy for angry, but not happy or sad, expressions at the normal (100%) spatial and speed level. Whilst the control group exhibited increasing accuracy across all levels of the speed manipulation, the ASD group only showed improvement from the 100% to 150% level. Non-verbal reasoning and level of autistic traits (and not age, gender or alexithymia) were significant predictors of accuracy for angry videos at the 100% spatial and speed level. LimitationsDue to COVID-19 restrictions, only 22 members of the ASD group completed the ADOS-2 assessments and 7 of those who did, scored below threshold for an autism or ASD diagnosis. Therefore, our ASD group may display less frequent or lower intensity autistic behaviours than would typically be seen in an ASD population. The TAS, which has recently been questioned for its construct validity, was used to measure alexithymia. ConclusionsSince our participants were matched on alexithymia, and we identified that level of autistic traits (and not alexithymic traits) was a significant predictor of the accuracy of angry expression recognition at the normal level, we conclude that a difficulty with recognising angry expressions is relevant to autism and cannot be explained by alexithymia. Future research should elucidate why autistic individuals exhibit differences with angry expressions in particular.