Naturalistic Hybrid Search in Autism Spectrum Disorder: Co-recording EEG and eye-tracking data to investigate behaviour and brain activity differences

In real life, when searching for friends in crowds, or driving, individuals often look for one of various possible targets kept in memory. Involving searching targets through one's memory, and searching them visually, this is known as hybrid search (HS). In autism spectrum disorder (ASD), some evidence has shown that individuals with ASD may approach search differently compared to typical individuals, however the underlying mechanisms remain unclear. ASD is a neurodevelopmental disorder of rising incidence in the UK that is characterised by social difficulties, sensorimotor abnormalities, and restricted interests and behaviours. A recent theory attempting to reconcile the evidence about the latent cognitive mechanisms in ASD proposes that, rather than abnormal perception, atypical processes in ASD may stem from internal assumptions (also known as "priors") being less used than in typical individuals. When perceiving an experience, individuals are impacted by both inbound sensory information and their prior knowledge about the world. In ASD, the development or usage of this prior knowledge to understand an experience, for instance, a scene where one is searching for a specific friend, can be affected. However, hybrid search experimental paradigms so far have typically involved searching for an abstract stimulus in blank backgrounds, which means they do not capture real-world settings and limit the investigation of such proposal. Natural scenes have contextual information that individuals use to guide their search to specific areas of the scene for different targets. Therefore, research that accounts for contextual information present in real-world scenes is particularly important if we want to better understand the cognitive processes of search in ASD. Thus, this project aims to examine behavioural and brain-imaging data to investigate potential differences in how neurotypical and neurodiverse brains coordinate the complex steps of naturalistic hybrid search, using stimuli and paradigms that are closer to real-world experience. To examine the mechanisms underpinning hybrid search, this project will entail co-recording an electroencephalogram (EEG), a recording of the brain's electrical activity, and eye-tracking data while participants perform a modified HS task that manipulates stimuli type and contextual features. Participants will be adults with and without an autism spectrum condition, matched in age, gender, and non-verbal IQ. Co-recording EEG and eye-tracking to understand hybrid search's mechanisms in the neurotypical and neurodiverse brain is a novel investigation. It will bridge several knowledge gaps as aforementioned. While ASD is a sound population to investigate and contrast mechanisms underpinning hybrid search in general, because they are likely to be atypical, this experimental work also has implications for understanding underlying cognitive and neural mechanisms in ASD. Practically, this project could have real-world implications, such as, helping create ASD targeted training for many critical real-world hybrid search tasks, like driving.