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How the striatum contributes to visual-selection

Periodic Reporting for period 2 - STRIAVISE (How the striatum contributes to visual-selection)

Reporting period: 2020-10-01 to 2021-09-30

Humans are very good at learning predictive relationships between sensory signals and their outcomes, such as how a siren predicts from where a fast emergency vehicle will appear, or how a sweet wrapper predicts the location of a possible tasty treat. Knowledge of these relationships is useful if they can be exploited to control the neural processes that drive cognition and behaviour; for example choosing where to allocate attention in a busy sensory world to influence subsequent decision-making. Elucidating how the brain uses predictive information to shape attention and perception will offer insights into how individual learning shapes sensory experience, and may pave the way for interventions for individuals who suffer from atypical function of the brain’s prediction and attention networks. The results from the action show that modulations to striatal-cortical connections underpin the influence of learning on attention allocation, that individuals differ in how they leverage predictive information to guide their attention, and that multiple computations underpin the influence of expectations on attention, spatial expectations induce anticipatory attention shifts, whereas reward affects attention counterfactually; i.e. visual processing models missed as well as attained rewards.
1) To understand how subcortical structures that encode reward predictions, and cortical structures that underpin visual attention operations, interface when sensory cues predict future decision-related outcomes.
The fellow has successful applied state-of-the-art modelling of neural circuitry to determine that the striatum modulates its influence on cortical activity when expectations predict decision-related outcomes. The fellow has compared theories for how the brain may encode and combine distinct expectations to guide visual selection, and has found that that expectations are encoded independently to influence visual selection, suggesting summation of expectations to build priorities for visual exploration across any scene. She has further identified that individuals for systematic subtypes in how they are influenced by value cues, with some people showing a reactive, counterfactual response, rather than an anticipatory coding of the visual scene. The fellow has completed data collection for a high-resolution imaging study that assesses the extent to which information pertaining to visual expectations is present in the striatum.

2) To ascertain whether a causal role can be established for subcortical brain regions when such predictions guide visual-selection
The fellow has developed a paradigm and a methodology to assess the causal role of the systems governed by the basal ganglia, in healthy participants, using a dopamine-intervention study. This has resulted in the formation of a novel collaboration. The study is registered on the open science framework.

3) To understand the scope of striatal influence on the cortical dynamics (i.e. ongoing neural communication) that underpin visual attention operations
The fellow has established the protocols for this study and has run a development version using EEG (in preparation for MEG). The results of this project have established that the brain normalises across learned value associations to influence visual priorities across a visual scene, and that this occurs to update violated expectations, rather than in anticipation to upcoming visual events. These results are currently being written up for publication. The fellow has also collaborated to identify that asymmetries in striatal structure predict visual attention biases as captured in the oscillatory dynamics of the MEG signal.

The action has resulted in 3 publications (Journal of Cognition, eNeuro, Attention, Perception & Psychophysics), a textbook chapter, 6 conference presentations, 8 invited talks, and 4 newspaper articles/media interviews.
The outcomes have expanded the hypothesis space regarding the neurophysiological architecture that underpins visual prioritisation, and the computational underpinnings the brain may utilise to implement the influence of expectations. The fellow has also contributed to the wider community by serving as an early career representative on the Executive Committee for the Organisation for Human Brain Mapping. Here she contributed to the development of a webinar series on best practices and cutting edge techniques in neuroimaging, attended by ~330 members of the Australian neuroscience community. She also helped facilitate the access of the Asia-Pacific community to the mentorship of the international neuroimaging community by managing the Australia-Pacific Hub of the OHBM Brainhack, 2020; a hackathon event that trains mentees in the production of reproducible neuroimaging pipelines, and brings together collaborators internationally to work on projects of benefit to the neuroimaging community. The impact of these efforts for creating inclusive, diverse, neuroscientific communities have been documented in two collaborative publications (Gau et al, (2021) DOI: 10.1016/j.neuron.2021.04.001 and Levetis et al, (2021) DOI: 10.1093/gigascience/giab051). Thus the action has contributed to the promotion of diversity and inclusivity in neuroscience and the wider scientific community.
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