title: Social Reward Responsivity, Predictive Processing, and Anxiety in Autistic and Non-Autistic People
Creators: name: Brett, Simon
Publisher: name: University of Reading
Year: 2024

description: Many theories have been proposed to explain the social characteristics of autistic people. 
In this thesis, I aimed to test claims of two theoretical accounts: one that proposes domain-specific differences in social reward responsivity, and another that proposes broader, domain-general differences in predictive processing. In addition, given the increased risk of autistic 
people experiencing anxiety, and the often-reported overlap between autistic social 
characteristics and features of social anxiety, I aimed to examine whether features of anxiety 
moderated either of these constructs as assessed through behavioural tasks. To address these 
aims, in Chapter 1, I begin by reviewing the evidence for atypical social reward responsivity and 
predictive processing in autistic people and how these associate with anxiety. In Chapter 2, I 
outline my positionality and the methodological approach of this thesis, as well as the challenges 
and mitigations that occurred in the conduct of the research. In Chapter 3, I sought to understand 
social reward responsivity in neurotypical adolescents and its relationships to autistic traits and 
anxiety. I found increased social reward responsivity in neurotypical adolescents and reduced 
social orienting and simple social choice in adolescents with elevated autistic traits, however 
autistic traits were not related to making less effort to choose social stimuli. Additionally, social 
orienting and seeking behaviours were not associated with features of social anxiety. In Chapter 
4, I aimed to examine both social reward responsivity and predictive processing in autistic and 
non-autistic adolescents, and the relationships of these constructs to autistic traits and anxiety. I 
used a modified social orienting task to index a component of social reward responsivity, and a 
non-social associative learning task to index predictive processing. I found that autistic 
adolescents and those with higher autistic traits showed reduced social orienting, and some 
evidence that autistic and non-autistic adolescents had similar predictive processing. Again, in 
both tasks, there were no significant moderating effects of anxiety on task behaviour. In Chapter 
5, I sought to investigate whether there were differences in social predictive processing between 
autistic and non-autistic adults. I used a social associative learning task and found that autistic 
adults adjusted their behaviour based on environmental context to a lesser extent than non-autistic adults. However, this was not the case for learning about social information. There were
some differences in autistic adults’ predictive processing, but these were strongly influenced by 
the type of information and task design. Once more, there were no significant effects of anxiety. 
Finally, in Chapter 6, I discuss findings from Chapters 3-5 and how they relate to these theories 
and what the implications are for future research. In sum, this PhD presents some evidence for 
reduced social reward responsivity in autistic adolescents and atypical predictive processing in 
autistic adults. Yet, evidence for each theory is notably influenced by task design and there was 
strikingly no significant effect of anxiety across tasks. Therefore, several recommendations are 
made on how future studies should consider social reward responsivity, predictive processing, 
and anxiety in relation to autistic social differences. Namely, (1) carefully consider component 
processes of reward responsivity when designing tasks and follow-up findings with autistic 
adolescents to see whether reduced social orienting is related to effortful social seeking; (2) 
consider whether it is useful to measure traits of anxiety when task designs are rewarding in 
nature, instead follow up as to whether state anxiety influences social responsivity and predictive 
processing; (3) conduct predictive processing based tasks under social and non-social contexts to 
understand the effects of completing a task with another person.