1. A method of identifying regions within the brain, the method comprising the steps of: a. providing a collection of N-dimensional data points, each data point being representative of a location in the brain and containing N>1 different types of data therefrom; b. sampling N different types of data from a location in the brain, thereby defining a sampled N-dimensional data point; c. automatically defining within a processor M discrete data point clusters (M>1) from the collected data points and from the sampled data point, wherein: i. each data point cluster contains data points which are proximate in N-dimensional space, and ii. the M data point clusters correspond to M discrete regions within the grey matter of the brain; and d. indicating whether the sampled data point is within a particular data point cluster, and therefore within a particular one of the M regions of the brain.