Monday 18th April 12:00-1:00 PM in the Keats Reading Room, Psychology Building Callaghan Campus & Science Office Meeting Room Ourimbah Campus.
What can a first-impression bias in auditory processing tell us about prediction modelling and perceptual inference.
Kaitlin Fitzgerald, PhD Candidate
Supervisors: A/Prof Juanita Todd & Prof Andrew Heathcote.
Functional Neuroimaging Laboratory
School of Psychology
University of Newcastle, Callaghan. NSW 2308 AUSTRALIA
Abstract: Adaptive auditory processing is characterised by the ability to prioritise limited neural resources towards the aspects of the current environment which are most informative for behaviour (Winkler, Karmos & Näätänen, 1996). The neural substrate thought to be responsible for this process is a component of the auditory event-related potential (ERP) known as the mismatch negativity (MMN). MMN is produced in response to any rare and unexpected deviation from an established pattern, and triggers an attention switch towards a stimulus when sufficiently salient (Escera, Yago, Corral, Corbera & Nunez, 2003; Naatanen, Gaillard & Mantysalo, 1978). Whilst many claim MMN amplitude is governed solely by local probability statistics, our lab has revealed that the initial context in which a sound is encountered has a lasting effect on the perception of that sound in future contexts – a “primacy bias” (Todd, Provost & Cooper, 2011; Todd et al., 2013, Todd et al., 2014). Whilst this result is well replicated, much remains unknown about the mechanisms driving the bias and what it can tell us about perceptual inference processes. Research conducted within this thesis will build on existing primacy bias research to further our understanding of these processes. To date, this has involved confirming the presence of primacy bias in spatial deviance. Planned research will now utilise spatial manipulation to conduct a more powerful examination of its relationship to the information value of sounds, whilst a further study will investigate bias patterns in individuals with schizophrenia, a population with known deficits in MMN production (see Michie, 2001 for a review).