How expectation shapes perception: from cortical layers to brain-wide networks (360G-Wellcome-218535_Z_19_Z)
The way we perceive the world is strongly influenced by our expectations about what we are likely to see at any given moment. However, the neural mechanisms by which the brain integrates sensory inputs and expectations, and thereby generates the contents of perception, have yet to be established. I propose that, upon presentation of a predictive cue (e.g., a siren), memory systems pre-activate templates of expected stimuli (an ambulance) in the deep layers of visual cortex, leading to biased processing of sensory inputs from the very moment they arrive. Such biased processing then leads naturally to biases in perception, in extreme cases even hallucinations. I will test this proposal by addressing three complimentary questions: 1) How do the neural computations underlying perception unfold over time? 2) What is the fundamental computational architecture of visual cortex? 3) What is the neural source of expectations? I will combine psychophysical tasks probing participants’ perception with neuroimaging tools with exquisite temporal (MEG) and spatial (high-field fMRI) resolution to address these questions. The overarching aim of my research is to provide a mechanistic account of subjective perception. Ultimately, these insights may improve our understanding of clinical disorders characterised by aberrations in perception, such as psychosis.
£1,098,771 16 Oct 2019