Prosopagnosia has been reported as a visual agnosia with a high or full selectivity for faces as opposed to other objects. In other words, prosopagnosic patients display severe problems with recognising familiar faces (i.e. famous persons or family members) but show little or no difficulty in recognising everyday objects (i.e. chairs, appliances). This essay will first explain the two opposing arguments concerning of whether prosopagnosia is indeed a result of a damage to a face recognition module. Thereafter it will give details to the theoretical background of face recognition and prosopagnosia. Lastly it will focus on a specific case study suggestive of "pure" prosopagnosia. This case study will illustrate the findings supporting the existence of a face-module. In order to adequately evaluate such finding other analogous or undermining studies will be considered. .
Findings from a vast research have highlighted two opposing arguments concerning prosopagnosia. Firstly, that there is a specific "face-module" dedicated to face recognition. This has been called the holistic hypothesis, that suggests that some areas of the brain are better at processing objects into parts (i.e. doors and windows of a house) and some are better at taking objects as wholes (Gauthier, Behrmann & Tarr 1999). Faces are thought to be discriminated on the configural basis (i.e. as wholes) therefore prosopagnosia would be the result of damage to such a brain system that was superior at processing stimuli as wholes. On the other hand, it has been argued that prosopagnosia is a deficit resulting from damage to a more general recognition system. The line of this argument follows the logic that objects and faces share the same recognition system but prosopagnosia affects mostly faces since faces are the most demanding stimuli to discriminate. This has been called the individual hypothesis (Gauthier et al. 1999). Most objects can be recognised at different levels of categorisation, some at the "basic" level (bird, car, table) some at more subordinate levels (duck vs.