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'The role of prediction in sensory encoding'

Abstract: The brain receives more sensory information than it can use to guide adaptive behaviour, creating the need for mechanisms that promote efficient processing of incoming sensory signals. One way in which the brain can reduce its sensory processing load is to use stored knowledge to predict likely future states of the world and update this information only when new stimuli violate expectations. In this talk I will present findings from experiments in humans and animal models in which we asked whether the encoding of elementary visual features, such as edge orientation, is modulated when otherwise identical stimuli are expected or unexpected based on the history of stimulus presentation. In human participants we used brain imaging to measure neural activity evoked by grating stimuli of different orientations, and used multivariate forward modelling to determine how orientation selectivity is affected for expected versus unexpected stimuli. In rodents and non-human primates, we used two-photon calcium imaging and micro-electrode array recordings to quantify the effects of expectation on orientation tuning in single neurons and multi-unit activity patterns. Across species and imaging modalities, we consistently find that visual selectivity is modulated by stimulus expectancy, even when predictions are generated within the auditory modality. I will discuss the implications of these findings for predictive coding theories of sensory processing.

Bio: Professor Jason Mattingley is Foundation Chair in Cognitive Neuroscience at The University of Queensland, where he holds joint appointments in the Queensland Brain Institute and School of Psychology. His research is directed toward understanding the brain processes that support a range of cognitive functions, including attention, predictive coding and decision-making, in health and disease. Professor Mattingley is a Fellow of the Academy of Social Sciences in Australia, a Fellow of the Association for Psychological Science, and a Fellow of the Canadian Institute for Advanced Research. In 2012 he was awarded the Australian Psychological Society’s Distinguished Contribution to Psychological Science Award, and in 2020 he received the Lifetime Contribution Award from the Australasian Cognitive Neuroscience Society. He is currently President of the Australasian Neuroscience Society.