The effect of encoding and retrieval manipulation on the retention of 'subject-performed tasks' in normal aging and Alzheimer's Disease : a thesis presented in partial fulfilment of the requirements for the degree of Master of Arts in Psychology at Massey University
This research examined a technique termed ihe 'Subject-Performed Task' (SPT) in which subjects physically enact a verbal instruction and are subsequently administered recall tests to determine what information is retained. SPT is consistently found to produce superior recall to verbal instruction alone in several populations which experience memory difficulties with standard memory tasks, such as older adults and those with Alzheimer's Disease (DAT). The present study examined three issues, the first of which concerned what type(s) of information encoded in SPTs might be responsible for this effect. The second concerned the manner in which SPT was thought to instigate automatic activation of semantic category information. Finally, a comparison was made between DAT and older adult subjects to examine the ability of both groups to retain SPT information in memory. A total of 112 subjects (56 DAT subjects and 56 older adults) were presented with a series of 25 SPTs. The SPTs were presented visually and auditorally and were also demonstrated by an actor. Following presentation, subjects either performed the SPTs (motoric encoding condition) or verbally rehearsed (multisensory encoding condition) the randomly presented SPTs. Examination of automatic activation of semantic category information was assessed by comparing a relational recall condition which required categorisation of the SPTs into five semantic categories, with a free recall condition. DAT group subjects showed very low levels of recall and no significant effects of encoding or recall manipulations were found. The older adults showed higher levels of recall and both motoric encoding and relational recall enhanced performance. Reasons for the failure of DAT subjects to benefit from SPT are discussed, and the results obtained by the DAT group and the older adults are evaluated in the context of three predominant theories of SPT and memory.