Dr Nigel Rogasch

Brain stimulation, imaging and cognition group

The brain is a remarkably dynamic organ that is continually reorganising and adapting its structure and function. These rapid and long term changes give rise to our thoughts, govern how we perceive our environment and allow us to either retain information in our mind for brief periods or to store information over many years. Even subtle disruptions in the mechanisms governing brain dynamics can have devastating effects on social and cognitive functioning and possibly underlie mental illnesses such as schizophrenia. As such, understanding the functional importance of the mechanisms responsible for dynamic brain organisation is a key focus of neuroscience research.

One method particularly suited to studying the dynamic brain is transcranial magnetic stimulation (TMS), a non-invasive method of stimulating cortical brain regions in living humans. TMS is a versatile technique which can be used to probe specific excitatory and inhibitory cortical circuits, to map connectivity between brain regions and to temporarily alter brain function by inducing neuroplasticity (i.e. transiently reorganising brain circuits). The ability of TMS to alter brain activity makes it a powerful tool to causally investigate the role of specific brain mechanisms, regions and networks in function and behaviour.

My research concentrates on combining TMS with neuroimaging techniques (EEG, MRI) to understand the role of excitatory/inhibitory mechanisms, brain organisation (oscillations, connectivity) and plasticity in healthy and unhealthy brain function. My specific interests include: understanding the brain mechanisms responsible for short and long term memory; developing concurrent TMS-EEG methods to non-invasively study cortical network properties; investigating whether abnormal excitation/inhibition, connectivity and plasticity contribute to cognitive deficits in mental illnesses such as schizophrenia; understanding how dynamic changes in brain organisation (i.e. oscillations, connectivity) give rise to improved or reduced behavioural performance (i.e. learning).

Research Project 1

Title: How inhibition shapes brain oscillations and memory

Project description:

The ability to retain information in short-term ‘working’ memory is crucial for cognition, influencing our personality and intelligence. Converging evidence from animal/computational research indicates that brain oscillations, which depend on neural inhibition, are critical for working memory. However, the brain mechanisms underlying this fundamental process in humans remain unclear.

The project will use a novel combination of genetics, neuroimaging, brain stimulation and cognitive testing to map a pathway from molecules, to brain function, to behavior. Such a map will detail how neural mechanisms shape human behavioural performance and guide efforts to enhance memory and cognitive function.

This project is particularly well-suited to students with training in human neurophysiology, cognitive neuroscience, and/or physics/mathematics/engineering. Students will receiving training in human brain stimulation (TMS), and neuroimaging methods (EEG, fMRI, DTI), as well as advanced analytical methods.

Projects available for: Honours and HDR

Location: SAHMRI; AHMS (Adelaide Health & Medical Sciences Building, North Tce)

Research project start: Semester 1 and 2

Special requirements: None

Research Project 2

Title: Driving plasticity in humans with non-invasive brain stimulation

Project description:

The brain is a remarkably dynamic organ which is continually changing its structure and function via neural plasticity, a fundamental mechanism which underlies all development, learning and memory. In humans, neural plasticity can be driven using non-invasive brain stimulation methods, offering unprecedented insight into how different brain regions and networks contribute to behaviour. Furthermore, brain stimulation has enormous potential as a new treatment for serious mental and neurological disorders.

This project will conduct innovative research into how brain stimulation alters brain function in humans, from the excitability of local cortical areas to large scale brain networks. Methods developed in this project will be used to uncover the neural mechanisms underlying memory in healthy brain function, and in disorders such as schizophrenia. A key outcome of this project will be the development of a biophysical model, which explains how brain stimulation interacts with cortical circuits.

This project is particularly well-suited to students with training in human neurophysiology, cognitive neuroscience, and/or physics/mathematics/engineering. Students will receiving training in human brain stimulation (TMS), and neuroimaging methods (EEG, fMRI, DTI), as well as advanced analytical methods.

Projects available for: Honours and HDR

Location: SAHMRI; AHMS (Adelaide Health & Medical Sciences Building, North Tce)

Research project start: Semester 1 and 2

Special requirements: None