Project 1:The influence of reward sensitivity on learning and cognitive control
While significant advances have been made in understanding the neurobiological basis of reward processing, including how individual differences in reward sensitivity are represented in the brain, it is not well understood how these differences influence key behaviours such as learning and cognitive control. The aim of this project is to investigate the relationship between the neural mechanisms underlying reward sensitivity, feedback processing, learning and cognitive control. We use a range of cognitive-behavioural tests in conjunction with event related fMRI designs to manipulate and observe reward, learning and control processes in the healthy brain. Results from this research form the basis of our research into the neural mechanisms of cognitive control dysfunction in various clinical groups, in particular, individuals with substance use problems.
For a representative publication, see: O’Connor et al (2012), Neuroimage.
Project 2: The contribution of increased reward sensitivity (and punishment insensitivity) to cognitive control dysfunction in opiate users
Cognitive control dysfunction and increased reward sensitivity are hallmark features of addiction, yet little is known about the influence of reward and punishment sensitivity on the implementation of cognitive control, or the interactions between the neural mechanisms underlying these processes in affected individuals. The aim of this project is to demonstrate how alterations to the neural mechanisms underlying the processing of reward and punishment influence an opiate addicted individual’s ability to exert cognitive control. We have developed a number of cognitive tasks that examine how cognitive control dysfunction and hypersensitivity to reward (and insensitivity to punishment) influence control over a rewarding response. These tasks are currently being used in an event related fMRI design to measure activation patterns in key brain areas such as the ACC, striatum and dorsolateral prefrontal cortex in opiate users and matched controls. The results of this research will assist in the evaluation (and development of) programs and policies concerned with the prevention and treatment of opiate addiction.
For a representative publication, see: Rossiter et al (2012), Drug and Alcohol Dependence.
Project 3: Error awareness and learning in healthy ageing
Normal ageing has been associated with a progressive deterioration in the ability to adjust behaviour following an error. For older adults, a failure of error monitoring is particularly troublesome as it necessitates the intervention of others and compromises their ability to live independently. While many studies have examined the neural mechanisms involved in error processing, it remains relatively unclear how error-related neural activity influences post-error processes such as awareness and learning. This is particularly relevant to older adults, as there is growing evidence of a diminished neural response to errors in normal ageing, which declines further in conditions such as Parkinson’s disease. The aim of this project is to use cognitive-behavioural testing and an event related fMRI design to investigate the influence of healthy ageing on the relationships between neural networks underlying error processing and post-error processes. In particular, we are currently examining whether the previously reported decline in error-related activation in older adults influences conscious awareness of, and ongoing learning from, errors. Results from this research will provide a clearer understanding of the neural mechanisms underlying the decline in error monitoring and adjustments as part of the normal ageing process, and also the accelerated decline of such abilities in neurological conditions such as Parkinson’s disease and various dementias.
For a representative publication, see: Hester et al (2009), Journal of Neuroscience