ABSTRACT
A common assumption in cognitive neuropsychology is that a single dissociation will trump any accounts suggesting totally shared mechanisms, and this no matter how many observations of associations can be mustered. A methodological issue not considered in great detail by J. Geskin and M. , however, is how a dissociation is defined. S. G. Crawford et al. have even developed computer programmes which can be used to assess whether a particular performance pattern qualifies as a dissociation when both criteria are taken into account. From a clinical point of view it may not matter much whether an individual with a face recognition deficit has a subtle impairment in visual object recognition or not. Differences in perceptual differentiation and visual similarity are known to yield different patterns of category effects in visual object recognition. Geskin and Behrmann have identified several limitations in the current literature on developmental prosopagnosia.
