Senior Research Fellow
Translational Research Institute, University of Queensland
Dr Marcus Gray is a senior research fellow at the Translational Research Institute, University of Queensland. An overall theme in his research is the integration of the mind with the ongoing regulation of the body. The mind is fundamentally embodied.
An intimate integration of mind and body supports flexible and adaptive behaviour in a dynamic environment, via the interaction of cognitive, emotional and executive processing with the autonomic control of the body.
Dr Gray’s research explores these associations in a wide range of contexts, spanning low level homeostatic mechanisms through to subtle interactions between attention, emotion and physiology. In particular, clinical and autonomic populations provide valuable areas for investigation using advanced techniques including magnetic resonance imaging.
One area of research examined by Dr Gray is the influence of inflammation in the body on cognition and emotion. Inflammation can induce changes in mood and thinking which are very similar to the symptoms of depression, and many are now suggesting that depression may be linked immune responses.
Crohn’s disease is relevant here, as gastrointestinal inflammation is a cardinal feature and psychiatric symptoms including depression are common. We examined the influence of anti-inflammatory treatment (anti-TNF-a) on gastrointestinal symptoms, and implicit biases in cognition. Following anti-inflammatory treatment, gastrointestinal symptoms (unpleasant fullness) were reduced, and implicit biases reflecting positive health attributions were increased. Improvements in implicit wellbeing were associated with treatment induced changes in the amygdala.
A simple example of the way the body influences the mind is provided by hunger. Understanding how hunger motivates eating behavior may allow us to confront the global epidemic of obesity apparent in many western countries. In this study, healthy adults who had fasted overnight were shown pictures of appetizing food during brain scanning. While many studies have demonstrated neural representations of appetitive stimuli, our results were the first to reveal that concentrations of the orexigenic hormone ghrelin in saliva mediated the subjective desire to eat via increasing responsivity in the parrahippocampal gyrus when participants saw food cues.