False Recognition in Alzheimer Disease: Evidence from Categorized Pictures

Objectives: To better understand memory distortions and false recognition in patients with Alzheimer disease (AD), using a paradigm of categorized color photographs. Background: Previous research has found that patients with AD and older adults showed similar levels of uncorrected false recognition of semantic associates and of perceptually related novel objects. In contrast to these results, using a paradigm in which semantically related words were accompanied by black and white line drawings, it was found that patients with AD showed a trend toward higher levels of uncorrected false recognition compared with older adults. Methods: To explore this trend, 24 patients with AD and 24 older adults matched for age, education, and gender were examined using a false recognition paradigm consisting of categorized color photographs (e. g., flowers, motorcycles, cats). Results: Compared with older adults, patients with AD showed higher levels of uncorrected false recognition, but lower levels of corrected false recognition and lower levels of item-specific recollection. Conclusions: The authors suggest that these results may be attributable to the poor ability of patients with AD to acquire both gist and item-specific information as well as these patients' inherent frontal lobe dysfunction leading to difficulty inhibiting responses on the basis of familiarity alone.