Robert Barry

Biography

Robert (Bob) Barry initially studied Physics (BSc, U.N.S.W.), trained as a teacher (DipEd, U. Sydney), and taught high school for some 7 years.  During this period, he diversified and completed a BA (Honours I) in Psychology (U. Sydney) and began an MSc in Physics (Macquarie U.).  He followed this with a PhD in Psychology (U. Sydney) and became a Lecturer in Education at U.N.S.W.  Over the following 18 years he was awarded a higher doctorate in Psychophysiology (DSc, U.N.S.W.) and moved through the ranks to full Professor in Education, before taking up the Chair of Psychology at U. Wollongong in 1993, where he remains as Professor.

Bob has published more than 330 full papers in Psychophysiology, and has a Scopus H-index of 63.  He has graduated some 45 research students (MSc or PhD).  He serves as Associate Editor for International J. Psychophysiology and Clinical Neurophysiology.  Bob was the founding President of the Australasian Society for Psychophysiology and is currently President of the International Organization of Psychophysiology.

His research has four interacting themes: the Orienting Reflex as a model of stimulus-response processes in perception and cognition; electrophysiology of sex differences and typical/atypical development, particularly in AD/HD; arousal and activation as the substrates of phasic responding; and the brain dynamics linking EEG at stimulus presentation to ERP outcomes and behaviour.

Description of the general focus of the symposium "Inhibitory control: Responses, errors, and their neural and psychophysiological correlates"

Response inhibition is one of the most important cognitive processes in daily life. It reflects the ability to stop actions that are not suitable in a given situation, like speeding up a car when approaching people crossing the road (reactive inhibition). It also corresponds to the ability to control impulses, which can lead to premature responses, such as starting a car when the green traffic light is not yet displayed (proactive inhibition). People are prone to making inhibitory errors; even if attentive and self-possessed, they are not always able to develop a proper assessment of situations or manage their impulsive reactions. In cognitive neuroscience and psychology, these phenomena can be studied with the well-established paradigms such as the go/no-go task, stop signal task, flanker task, and others. Each of these paradigms emphasizes different aspects of inhibitory control. Therefore, the general focus of this symposium is to present and discuss recent advances in research on inhibitory control and error processing during inhibitory tasks. When addressing this issue, researchers usually concentrate on different neural fingerprints of cognitive subprocesses that lead to specific behavioural patterns. It might be achieved through various methods of analysing magneto-/electroencephalography signals, temporally coherent with behavioural or peripheral (e.g., electromyographic) measures, as well as comparing brain activity under different conditions using functional magnetic resonance imaging. Thus, presentations submitted for this symposium should be based on research of human brain activity or peripheral measures, and experimental paradigms involving response inhibition. A better understanding of how the brain works in such situations can be useful for designing engineering, organizational and psychological solutions to make our lives safer. 

Talk: "Inhibition in the equiprobable Go/NoGo task – an EEG-ERP study"

Our brain dynamics studies have focused on the auditory equiprobable Go/NoGo task. This is an easy cognitive/behavioural task that can be used readily with a wide range of participants. Using ERP components, we have developed a processing schema that maps some of the cognitive stages involved, and have used this as a tool to explore developmental and sex differences, as well as some of the EEG/ERP brain-dynamics involved. Today I explore some of the correlates of inhibitory processing in this task, using a data-driven approach to the electrophysiology of cognitive processing.

We begin our data collection with an eye-calibration task to establish EEG-EOG regression coefficients for subsequent removal of EOG from the continuous task-related EEG data. We then filter, interpolate bad channels, extract 1 s epochs (-500 to +500 ms relative to stimulus onset) for correctly-responded trials, baseline these across the 100 ms period immediately-prestimulus, and reject trials with artefacts. For the ERP quantification, we form average Go and NoGo ERPs for each participant, then submit the -100 to 500 ms data to separate Go and NoGo temporal PCAs to extract the underlying ERP components. For EEG, we take the immediately-prestimulus 500 ms epochs (-500 to 0 ms), DC-correct these, zero-pad each to 1 s, decompose these with a Discrete Fourier Transform, then the Pink and White noise is computed and removed from each participant’s mean Go and NoGo spectra, after which the Go and NoGo noise-free spectra are submitted to separate frequency PCAs. We then relate the prestimulus EEG frequency components, and Pink and White noise amplitudes, to the ERP components and behavioural outcomes.