Advances in human neuroscience
Dr A Ellison
Durham University
2008 – 2011 Postdoctoral Fellowship
The orientation of attention in space, an interaction study using dual-site transcranial magnetic stimulation (TMS).
Dr Amanda Ellison is a Lecturer in the Department of Psychology and a member of the Cognitive Neuroscience Research Unit at Durham University.
Much human cognitive neuroscience remains at an early stage of development, and has a long way to go to explain the complexities of human behaviour. Understanding the neural basis of attentional control is at the core of many neuroscientific questions ranging from the basis of consciousness to the neural mechanisms of action selection. In addition, the attentional system is easily impaired by various forms of brain damage and this is a feature of many brain disorders (e.g. schizophrenia).
In many cases we know the principal brain areas involved in the control of a particular cognitive process, but we know little about how they interact. For example, functional imaging studies have identified a rich and complex network of cortical and sub-cortical structures which are active during attention demanding tasks. However, the specific role of each brain structure and the way they work together is very poorly understood. Such questions have traditionally been explored in animal experiments, typically awake non-human primates, either with brain lesions or implanted electrodes.
The Dr Hadwen Trust funded early work by Dr Amanda Ellison (then at Oxford University), which demonstrated that transcranial magnetic stimulation (TMS) could be used to temporarily disrupt areas of the brain in healthy human volunteers. TMS is proving to be a valuable neuroscience research tool that is being used in place of brain damaging experiments on non-human primates. (Read more at Dr Hadwen Trust’s Science Room: TMS and brain function)
Dr Ellison recently demonstrated that a new manipulation of TMS over two sites (dual-site TMS) can be used to investigate the interaction of different brain regions [1]. With a further grant from the Dr Hadwen Trust, she is now applying dual-site TMS in human volunteers to investigate the relationship between two brain areas know to be involved in attentional control, in place of invasive animal studies. Her research will seek to investigate what exactly these two different brain regions (the frontal eye field and the posterior parietal cortex) contribute to attention and how they interact in time the normal functioning human brain.
Reference
1. Ellison A, Lane AR & Schenk T (2007). The interactions of brain regions during visual search processing as revealed by transcranial magnetic stimulation. Cereb Cortex 17:2579-2584.