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How the striatum contributes to visual-selection

Periodic Reporting for period 1 - STRIAVISE (How the striatum contributes to visual-selection)

Reporting period: 2018-10-01 to 2020-09-30

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 overall objectives are threefold:
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.
2) To ascertain whether a causal role can be established for subcortical brain regions when such predictions guide visual-selection
3) To understand the scope of striatal influence on the cortical dynamics (i.e. ongoing neural communication) that underpin visual attention operations
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 resulting paper has now been published (Garner et al., 2020, DOI:10.1523/ENEURO.0139-20.2020) and has received an Altmetric score of 124, ranking it in the top 5% of all research outputs scored by Altmetric. The fellow has also 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 (Garner et al., 2021, DOI: 10.3758/s13414-020-02124-w). The fellow is currently completing data collection for a high-resolution imaging study that will assess the extent to which information pertaining to visual expectations is present in the striatum (OSF:https://osf.io/svjy4/). To ascertain the feasibility of this study, the fellow has completed a development study, comparing sequences using the 7T MRI scanner at the Centre for Advanced Imaging (CAI), UQ. The data for this study have been collected and the results are currently being written up for publication.

2) To ascertain whether a causal role can be established for subcortical brain regions when such predictions guide visual-selection
The initial focus of this objective was to work with patients receiving deep brain stimulation treatment for patients with Parkinson's Disease. However, the Covid-19 pandemic and the ensuing lock downs have resulted in an inability to access this patient group. The fellow has instead 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 OSF (https://osf.io/8btx9/) and data collection is currently underway.

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 protocols can be found online (https://github.com/kel-github/value-in-the-visual-system). 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. The analysis is currently being finalised, as are the additional protocols for a subsequent investigation using MEG/MRI.
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 . In recognition of her work, the fellow has been invited as a speaker to the Centre for Integrative Brain Function Workshop in Adelaide, December 2019, and as a Symposium speaker at the 46th joint annual meeting Psychology and the Brain (PuG) (2021). Despite the setbacks of the Covid-19 pandemic, Dr. Garner has spoken at two international and three national conferences about the outcomes of the action; Neuromatch [online], November, 2020, Organisation for Human Brain Mapping (Online, June, 2021), the Annual Meeting of the Australian Chapter for the Organisation of Human Brain Imaging (Newcastle, Oct 2019), the Annual Meeting of the Australasian Cognitive Neuroscience Society (Launceston, Nov 2019) and the Experimental Psychology Conference (Brisbane, April 2021). The fellow has also been invited to serve as an early career representative on the Executive Committee for the Organisation for Human Brain Mapping. She 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, (under review) DOI: 10.31234/osf.io/vj5tu).

The fellowship has been fundamental to the fellow's progress with her career stage as she has been mentored further in grant writing (attaining two further grants to supplement the research funds of the current action, thereby enabling more extensive and thorough development work). The fellow has improved her mentoring skills having mentored three honours students (UQ), one of whom achieved the highest grade of her year group in 2019, two research placement students (UQ), and a masters student at the University of Birmingham (UK, 2021). She has also gained experience in communicating science to a general audience. She has presented the outcomes of the action to the general public at Pint of Science, Brisbane 2019 and 2021; the largest public science festival of its kind in Brisbane. She was also invited to speak at the Mansfield State High School Meet a Scientist series, where she spoke to high school students about what it is like to study the human brain. She has also completed multiple press interviews about the outcomes of the action, including with The Daily Mail (UK), The ABC (Aus), and COSMOS (US).
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