EVENT: Psychology Colloquium: Jason Mattingley: What can evoked neural oscillations reveal about visual perception and selective attention?

Presenter: Prof Jason Mattingley

Professor Jason Mattingley is Foundation Chair in Cognitive Neuroscience at The University of Queensland, and an Austalian Research Council Laureate Fellow. His work is directed towards understanding the mechanisms of selective attention, in health and disease, with a particular focus on how attentional processes influence learning and neural plasticity. His research has appeared in many of the worlds top scientific journals, including Nature, Science, Neuron, Current Biology and Nature Neuroscience. Professor Mattingley is a Fellow of the Academy of Social Sciences in Australia, and in 2012 was awarded the Australian Psychological Society's Distinguished Contribution to Psychological Science Award.

Title: What can evoked neural oscillations reveal about visual perception and selective attention?

Abstract:

Perceptual, cognitive and motor processes often unfold over extended time periods, yet many studies in cognitive neuroscience are designed to measure brain activity in response to discrete and rather brief psychological events. Here I discuss various applications of an approach that uses electroencephalography (EEG) to measure steady-state evoked potentials (SSEPs) over prolonged timescales, from seconds to minutes. In a typical SSEP paradigm, several competing stimuli are flickered continuously, and their unique neural signatures are recovered from the EEG trace using frequency-based analyses. We have used such "frequency tagging" methods to assess various aspects of visual perception and selective attention, in health and disease. At the level of early visual perception, we have used frequency tagging to reveal the neural correlates of amodal completion of visual surfaces hidden behind occluding objects. We have used analogous approaches to show that feature-based attention spreads to ignored locations during conjunction search, but not during unique feature search, and that this spread of attention reflects active enhancement of target-coloured items at irrelevant locations. Finally, we have adapted these paradigms to investigate anomalous visual processing in macular degeneration patients suffering from visual hallucinations.