According to HIPPEA (High, Inflexible Precision of Prediction Errors in Autism), in autism, neural processes are putting inflexibly high precision on prediction errors, irrespective of context. We used an apparent motion paradigm to test this prediction. This dataset contains the anonymised data from 11 autistic and 9 non-autistic participants, who took part in an apparent motion paradigm similar to the one presented by Sanders et al., 2012) to participants with Schizophrenia. The participants had to detect a flashing stimulus, that appeared either in-time (predictable) or out-of-time (unpredictable) with the apparent motion. We observed that 66% (6/9) neurotypical and (64%) 7/11 autistic participants were better at detecting predictable targets. Thus, autistic participants were likely able to use the apparent motion to establish a predictive model of the stimuli, benefiting their ability to detect the predictable over the unpredictable target. Additionally, 55% (6/11) of autistic participants had faster responses for unpredictable targets, whereas only 22% (2/9) neurotypicals had faster responses to unpredictable compared to predictable targets. Thus, it appears that for autistic participants unpredictable events are given special treatment in the brain, even if those targets are not detected more often. This data does not fulfill the power calculations for a robust effect, thus all of the data is being shared including experiment and data analysis pre-processing and final analysis scripts. Moreover, a pre-registered analysis is available for researchers to finish off the results of this study - https://osf.io/729crAutism Spectrum Disorder (ASD) is a developmental condition with recognised impact on social functioning. Dysfunctional processing of sensory information has recently been acknowledged as a key diagnostic criterion (APA, 2013). Hence, understanding how sensory information is processed in autism is a crucial part of understanding and improving the way we treat it. The larger project associated with this dataset aims to test an important new approach for modelling sensory and cognitive processing in autism (Van de Cruys et al., 2014). This approach uses a predictive coding framework to examine how mismatches between expectations and internally generated models of the world can lead to an abundance of error signals in the brains of individuals with ASD. These error signals lead to differences in processing that have the potential for creating anxiety and difficulty in perceiving social signals. To test this framework in ASD we use behavioural and brain imaging experiments that involve observing object and human (biological) motion. This enabled us to investigate the processing of sensory information with and without a social component.

Data was collected through an experimental design and additional behavioural measurements. Participants provided data on their Autism Quotient scores, their handedness (Edinburgh Handedness Scale). Participants' visual acuity was tested using FrACT and a Landolt C procedure, and participants were required to have visual acuity of 0.5 as per the UK driving regulations. Participants' cognitive abilities were measured using the Wechsler Abbreviated Scale of Intelligence (WASI) and their full-scale, verbal and non-verbal IQ is recorded. The majority of Autistic participants also took part in an ADOS assessment carried out by a trained researcher. After these tests, participants took part in the apparent motion experiment, which contained 2 blocks of 15min each - one experimental (apparent motion) and one control condition (no apparent motion, but similar stimulation). The experiment was carried out while an eye tracker recorded the participants' right eye movements. Participants were instructed to fixate in the centre during the task, but during the between-trial breaks, they were allowed to move their eyes, but not their head from the chinrest. Calibration of the eye-tracker was done before each block, thus participants were allowed to move their head freely between blocks. Participants were individuals who have disclosed they have been diagnosed with an autism spectrum condition and had no history of epilepsy. Neurotypical participants were participants who matched the autistic participants closely in age and full-scale IQ, had an Autism Quotient score below 26 and had no psychological or neurological conditions. Left-handed participants were not included in the experiment.