The mind drifts towards the past: how experience shapes the visual system

Cel

Our future behaviour is strongly shaped by our past experience. This can happen explicitly, like the development of a strategy, but other times it happens implicitly and automatically. For instance, we are strongly biased to repeat actions rather than deviate, even when told repetitions are rare. This bias toward repetition extends beyond motor behaviour to cognitive processes themselves, where it is believed to underlie the remarkable human capacity for automatic pattern learning. This has recently become a topic of great interest in the behavioural study of attention, as our attention system is strongly attracted towards past experiences, prioritising locations and features that we recently attended to. No corresponding neuroimaging work has yet attempted to pinpoint how and where experience changes the attentional processing of perceptual signals, leaving a gap between behavioural and neural theories of attention. This project seeks to remedy this gap in two studies testing competing theories of how experience changes the representation of features, and where these experience effects originate in the brain. We will rely heavily on a new method for measuring attention with precision called Rapid Invisible Frequency Tagging (RIFT) and will investigate how experience changes how we process feature information in an MEG study. We will follow-up this project with the first concurrent EEG/fMRI using RIFT to capture a complete spatial and temporal profile of attention, characterising how it influences information propagation through various levels of the human visual system. Specifically, we’ll look at where experience biases originate, comparing feedforward to feedback models to reveal whether experience is stored in dedicated subcortical structures, or is distributed throughout the brain. We will then bring our insights from our two empirical studies into a theoretical review where we will propose the first neural model of attention incorporating experience effects.