The main experimental technique used in our laboratory is functional magnetic resonance imaging (fMRI) which allows us to measure blood oxygenation changes, an indirect measure of neural activity while human volunteers make simple decisions in real-time.
A cornerstone of our approach is the adoption of a new method in fMRI research known as “model-based fMRI”, in which one takes a precise quantitative computational model for a particular cognitive process and applies this model to fMRI data in order to identify brain regions with response profiles consistent with a specific computational signal. This method allows one to begin to characterize how a particular cognitive function is implemented in the brain, as opposed to merely identifying where in the brain such functions are located, as is done in more traditional fMRI studies.
We are now also involved in using other techniques alongside and in combination with fMRI, such as studying the effects of discrete lesions in specific brain regions on decision making behaviour, as well as using transcranial magnetic stimulation (TMS) to induce temporary lesions in healthy subjects. These other approaches allow one to address the causal role that specific brain regions play in implementing particular behaviours, thereby complementing the results of the fMRI experiments, which can provide insight into correlations between neural activity and behaviour but are agnostic as to causal relationships.
