1. A method for MRI signal analysis of an area of a biological tissue comprising: a) providing a biological tissue, wherein physiological activity is taking place in an area thereof; b) acquiring sequential magnetic resonance images, at least during a portion of time in which said physiological activity is taking place, of said area and of at least a portion of the tissue in a vicinity of the area; c) constructing, responsive to at least one pixel-related parameter value of said images, a pixel parameter space; and d) separating the pixel parameter space into at least two subspaces.