Affiliations: [a] Département de psychologie, Université de Montréal, Montréal, Canada | [b] Centre de recherche Institut universitaire de gériatrie de Montréal (CRIUGM), Montréal, Canada | [c] Département de psychologie, Université du Québec à Montréal, Montréal, Canada | [d] Centre de recherche du Centre hospitalier universitaire de Montréal (CHUM), Montréal, Canada | [e] Département de médecine, Université de Montréal, Montréal, Canada | [f] Clinique de cognition, Institut universitaire de gériatrie de Montréal, Montréal, Canada | [g] CHU Purpan, Toulouse, France | [h] Institut de Recherche en Sciences Psychologique et institut de Neuroscience, Université Catholique de Louvain, Louvain-la-Neuve, Belgium
Correspondence:
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Correspondence to: Dr. Sven Joubert, CRIUGM, 4565 Queen-Mary road, Montréal, Quebec, H3W 1W5, Canada. Tel.: +1 514 340 3540/Ext. 3551; E-mail: sven.joubert@umontreal.ca.
Abstract: Prevalent face recognition difficulties in Alzheimer’s disease (AD) have typically been attributed to the underlying episodic and semantic memory impairment. The aim of the current study was to determine if AD patients are also impaired at the perceptual level for faces, more specifically at extracting a visual representation of an individual face. To address this question, we investigated the matching of simultaneously presented individual faces and of other nonface familiar shapes (cars), at both upright and inverted orientation, in a group of mild AD patients and in a group of healthy older controls matched for age and education. AD patients showed a reduced inversion effect (i.e., larger performance for upright than inverted stimuli) for faces, but not for cars, both in terms of error rates and response times. While healthy participants showed a much larger decrease in performance for faces than for cars with inversion, the inversion effect did not differ significantly for faces and cars in AD. This abnormal inversion effect for faces was observed in a large subset of individual patients with AD. These results suggest that AD patients have deficits in higher-level visual processes, more specifically at perceiving individual faces, a function that relies on holistic representations specific to upright face stimuli. These deficits, combined with their memory impairment, may contribute to the difficulties in recognizing familiar people that are often reported in patients suffering from the disease and by their caregivers.
Keywords: Alzheimer’s disease, face inversion effect, face recognition, vision, visuoperceptual processing
