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Perception is the process by which our brains interpret sensory information. Our brains are constantly evaluating sensory signals in our environments, which shapes how we experience the world and, ultimately, our physical and mental well-being. When this develops differently, it may lead to atypical sensory perception as seen in autism. The addition of sensory symptoms to the most recent diagnostic criteria for autism highlights the need to understand its underlying mechanisms. This thesis used methods from experimental psychology and brain imaging to investigate the neurocognitive mechanisms of perceptual inference in autistic individuals. Chapter 1 introduces the topic of sensory perception, its neurocomputational framework, and its role in autism. It provides an overview of the theories and models of perception in autism and presents the overarching aims of this research. Chapter 2 reports a study of how autistic adults make perceptual decisions on two visual similarity judgment tasks. Signal detection theory analyses indicated that, in both tasks, when compared to typical people, autistic individuals used different decision criteria during conditions of uncertainty. Chapter 3 addresses the limited neuroimaging research on non-social features of autism. Using activation likelihood estimation, findings were condensed from non-social perception task-based functional MRI studies examining differences between autistic and typical participants. Overall, autistic people, compared to typical controls, showed less activity in the prefrontal cortex during perception tasks. More refined analyses revealed that, when compared to typical controls, autistic people showed greater recruitment of the extrastriate cortex during visual processing. Chapters 4 and 5 report findings from a visuomotor probabilistic reversal learning task used to examine how adults with varying levels of autistic traits evaluate sensory information, build, and update sensory expectations. A positive relationship was found between autistic traits and the learning of probable sequences before the reversal. In addition, there were separate main effects of autistic traits and intolerance to uncertainty on the ability to update expectations following the reversal. These findings suggest that, while people with different levels of autistic traits identify statistical regularities at a comparable level to one another, autistic traits play a role in how individuals update their expectations once a change is introduced. Chapter 5 examined how these behavioural findings relate to inhibitory neurotransmitters. In this 7-Tesla MR spectroscopic investigation, γ-Aminobutyric acid (GABA) was measured in the occipital and motor cortices to investigate its role in visuomotor sequential learning and its interactions with autistic traits. Previous findings of a negative relationship between sensorimotor GABA and sequence learning were replicated. At the same time, there were no clear links between autistic traits and occipital and motor GABA. Finally, Chapter 6 ties these findings together and evaluates how they contribute to our understanding of autistic perception. Some of the challenges of cognitive neuroscience research in autism are highlighted alongside clear directions for future work.