RECOGNITION IMPAIRMENTS AND FACE IMAGERY

We investigated face imagery for H.J.A. and P.H., who experience profo und difficulties in recognising familiar faces. H.J.A.'s problems invo lve a perceptual impairment that compromises the integration of featur es into a coherent representation, and he does not show covert recogni tion of faces in indirect tests. In contrast, P.H. has shown extensive covert recognition effects, leading to the suggestion that his defici t occurs at a higher level of visual processing than H.J.A.'s. H.J.A. and P.H. were given tasks intended to explore their ability to answer questions that depended on imaging single faces, and on configuration- based or feature-based comparisons of imaged sets of three faces. For all of these face imagery tasks, P.H.'s overall performance was severe ly impaired. H.J.A., though, showed preserved face imagery when imagin g single faces and when making feature-based comparisons between image d faces. However, when configuration-based comparisons were demanded H .J.A. also showed a severe and stable impairment of face imagery. Thes e observations are inconsistent with the idea that face recognition im pairments have a unitary underlying cause and vary only in severity. I nstead, they imply multi-stage causation, with the nature of consequen t impairments of face imagery being determined by the level at which t he recognition deficit arises.