Laboratoire de psychologie (EA 4139), Université de Bordeaux, France
The study investigated the aging of object categorization manipulating the spatial frequency (SF) content in photographs of object and the object category. Thirty young (m = 22 years old) and 24 mature adults (m = 57 years old) categorized 120 items (animals/tools) presented for 200 ms each, in one of three versions: a normal version (no filter), a band-pass filtered version (medium to high SF) and a low-pass filtered version (low SF). Results showed that this categorization task relied mainly on the medium to high SF band and that the mature group had a large impairment on that band. This impairment resulted for this group in a category-specific deficit toward the tools, for which the weak intra-category similarity in the items requires that SF range to be processed. An impairment of performance with increasing age was also found for the low SF band, specifically for animals. This interaction between the SF-specific deficit with age and the category is discussed according to the relevance of SF band for the task and to the characteristics of the two categories.