Baddeley's (1990) Working Memory model was used as a theoretical basis to examine the acquisition and retention of visual patterns in older adults with senile dementia of the Alzheimer type (SDAT) and in age-matched controls. To assist with diagnosis the CERAD screening and Neuropsychological Battery was administered to the 8 patients (CDR = 0.5 to 1.0) and 8 controls (CDR = 0). Various distractor ("interference") conditions were used during the delay period prior to recall. In addition to a zero second delay condition, no distractor, a visual distractor, an auditory distractor and a central executive system (CES) distractor was used during either a 3 second or 12 second delay interval. The forced choice delayed matching-to-sample computer task revealed lengthening response latencies across distractor conditions for SDAT subjects, but not controls. SDAT subjects correctly recognised fewer patterns than controls, especially as the delay interval increased. These findings concur with Baddeley and Morris's (Morris & Baddeley, 1988; Morris, 1994) claims that the CES is differentially impaired in early SDAT, as any subsidiary task concurrent with maintenance rehearsal caused a decrement in performance in the patient group.