Understanding the neural processes involved in integrated perceptual decisions

Virtually every aspect of human behavior is underpinned by our capacity to make adaptive and reliable decisions, from choosing a meal to deciding when it is safe to cross a busy road. Significant progress has been made in understanding how neural circuits accumulate sensory evidence in support of simple visual decisions, such as judging the direction of motion of a passing car. In the real world, however, even simple perceptual decisions typically require prioritization of behaviorally relevant sensory inputs over irrelevant distractors, as well as flexible integration and weighting of information over time and space. Here I will describe a novel approach for investigating how observers combine task-relevant signals from two or more sources into a single, integrated decision. In a typical version of the task, observers are required to reproduce the average motion direction of two consecutively presented target-motion patches, while we record brain activity using EEG or fMRI. Across a series of experiments, we have investigated the influence of salient distractors on such integrated decisions, and have quantified the effects of variations in the strength of component motion signals. Using forward encoding modelling, we have also determined how neural signatures of the featural information carried by target stimuli contribute to observers’ final, integrated decisions. We are currently using a modified version of our task to investigate deficits in decision-making in stroke patients with unilateral cortical lesions.

Presenter Biography: 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 work is directed toward understanding the behavioural and neural processes associated with three key cognitive functions – selective attention, prediction and decision making – with a particular focus on how these processes influence learning, multisensory integration, motor behaviour, neural plasticity and consciousness. Professor Mattingley has received Early Career Awards from the Academy of Social Sciences in Australia and the Australian Psychological Society. In 2007 he was elected a Fellow of the Academy of Social Sciences in Australia, and in 2012 he was awarded the Australian Psychological Society’s Distinguished Contribution to Psychological Science Award. He is currently Associate Director of the Australian Research Council Centre of Excellence for Integrative Brain Function.