Time perception in autistic adults: Duration and relative timing judgements do not differ from non-autistics

It has previously been proposed that autistic people have problems with timing which underlie the behavioural and cognitive differences in the condition. However, the nature of this postulated timing issue has not been well specified and the existing experimental literature has generated mixed findings. In the current study, we attempted a systematic investigation of timing processes in autistic adults using Scalar Expectancy Theory as a theoretical framework. Autistic (n = 58) and non-autistic (neurotypical; n = 91) adults matched for age, sex and full-scale IQ completed a battery of auditory and visual timing tasks measuring basic sub-second duration perception (temporal difference thresholds), clock processes (verbal estimation), clock and memory processes (temporal generalisation), and relative timing (temporal order judgements). Participants also completed supra-second retrospective duration estimates where the participant was not warned in advanced that they would be required to make a timing judgement, and questionnaires measuring self-reported timing behaviours in daily life. The groups reported differences on questionnaires, but measures of timing performance were comparable overall. In an exploratory analysis, we performed principal components analysis to investigate the relationship between timing judgements and participants’ self-reported social-communicative, sensory and motor traits. Measures of timing performance were not well correlated with these questionnaire scores. The current study is not supportive of reduced timing performance in autistic adults, nor of a relationship between sub-second timing perception and social-communicative, sensory or motor traits.