Role of the medial temporal lobe memory system in regulating behaviour

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The long-range goal of this research is to elucidate mechanisms by which memory and cognitive control systems interact to regulate behaviour. It is widely recognized that the "memory system" associated with the hippocampal/medial temporal lobe brain regions does much more than just store and retrieve memories. It is part of a large-scale network known as the "default mode network" (DMN) or autobiographical memory network. It is crucial for contextualizing behaviour, modulating emotion, stress, and other responses, imagining the future and planning actions based on past experience and expected future rewards (episodic future thinking). Our recent work, using computational modelling, rodent studies, human neuroimaging and virtual reality studies, has further characterized the role of the hippocampus and DMN in the formation of contextually detailed memories and in spatial cognition. Our next step will be to conduct a study using two different neuroimaging modalities simultaneously: functional magnetic resonance imaging, which has excellent spatial resolution and can identify exactly which brain areas are active, and electroencephalograpy (EEG), which has excellent temporal resolution and can identify rapidly changing dynamic features such as cross-frequency synchronization of neural activity across different regions of the brain. We will apply sophisticated signal processing and machine learning methods to identify EEG features that characterize the main intrinsic brain networks. Next, we will conduct a series of studies in different populations, to examine how lifestyle factors modulate the intrinsic brain networks. In varsity athletes who compete in high impact sports such as rugby, we will investigate the impact of repeated sub-concussive head trauma on brain networks and cognition. In sedentary university students, we will compare the impact of aerobic exercise, EEG-based Mindfulness practice and a combination of the two on brain networks, mood and cognition. In undergraduates who are heavy drinkers, we will evaluate the impact of an "episodic future thinking" intervention on drinking behaviours and on the interplay between the DMN intrinsic network and reward-related regions of the brain. Finally, having delineated EEG features of intrinsic brain networks and verified them in these intervention studies, we will develop EEG neurofeedback and brain-computer-interfacing applications that train a person to control their brain networks and use them to control external devices. This research will lead to novel methods for studying intrinsic brain networks using EEG, opening up wide-ranging opportunities for developing clinical and commercial applications of portable EEG devices in treating disorders of the brain.