Barry, Robert J. Professor

My research program is focused on four interacting themes:

• Orienting Reflex

This is my first and major scientific interest, using the Orienting Reflex (OR) as a model of stimulus-response processes in perception and cognition.  After my early work indicated that the OR was not a unitary phenomenon, I have been developing Preliminary Process Theory, a sequential processing theory of the psychophysiology of the OR.  This has been published in a number of developmental versions, including most recently in a special-issue paper on habituation (Barry, 2009b).  Recent activities in this area have been focussed on extending the theory to accommodate event-related potentials and understanding the sequential processing reflected in ERPs relevant to the OR, such as the Novelty P3 (see Barry et al., in press).  A series of papers developing a schema for sequential processing in the equiprobable Go/NoGo task has helped to strengthen my authority in the ERP context.

• Electrophysiology of AD/HD

This is my applied area, concentrating on using electrophysiology to obtain a better understanding of AD/HD.  Some years ago I extended my activities into a private clinic focused on objective electrophysiological assessment in AD/HD, and subsequently started a number of PhD students in this area, including Johnstone (working on ERPs), and Clarke (working on EEG).  These are now both Associate Professors in this School, and much of my work in this area is in collaboration with them and their students (e.g., Robbie et al., 2016).  Together we have made major contributions to the global understanding of this disorder in both children and adults.

• Arousal and Activation

This work aims at the clarification of the energetic aspects of behaviour.  Leading theories of the OR see the current arousal state as providing an “amplifier” for physiological responses.  From early work (Barry & Sokolov, 1993), I have developed electrodermal skin conductance level as the “gold standard” measure of arousal, and linked this to EEG alpha activity.  This has been useful in exploring models of AD/HD (e.g., Barry et al., 2009), and has been funded by ARC.  Our arousal/activation perspective is illustrated in VaezMousavi et al. (2009).  Current work on EEG changes from eyes-closed to eyes-open resting conditions from childhood to older adults is expanding notions of reactivity and compensatory brain function in healthy older adults and may provide benchmarks to explore early aspects of loss in Alzheimer’s dementia.

• Brain Dynamics

My interest in brain dynamics developed with access to digital signal processing systems in Wollongong.  It spans a number of aspects relating prestimulus EEG activity to ERP outcomes, exploring mechanisms of ERP genesis (e.g., Barry, 2009a).  In particular, my main focus has been on adaptive phase changes, with demonstrations that, in studies with repetitive stimuli, the brain organises its ongoing activity to generate preferred phase states at stimulus onset, which optimise stimulus processing and its ERP outcomes (see Barry et al., 2014).  I am currently working with variable ISIs to avoid this phenomenon and explore EEG phase effects in isolation.