Six experiments were conducted to examine the factors modulating the size of age differences in recollection. The research presented in the current thesis was guided by the notions of self-initiated processing and environmental support. Older and younger adults’ performance in recollection was measured by Jacoby’s (1990) process dissociation procedure (PDP); the age differences as a function of self-initiated processing demands of the task and the amount of support provided to the participants were assessed by manipulating the encoding (Experiments 2.1, 2.2, and 2.3) and retrieval (Experiments 3.1, 3.2, and 3.3) contexts.
Experiments 2.1, 2.2, and 2.3 examined interactions of aging and encoding contexts. Recollection under baseline conditions (i.e. visually presented words) was contrasted with recollection of items encoded under contexts that are assumed to enhance memory. The results showed differential age-related patterns of benefits from encoding conditions: Presenting pictures with words benefited older adults more than younger adults; word generation benefited both groups equally; and presenting sound effects with visual words benefited younger more than older adults.
Experiments 3.1, 3.2, and 3.3 investigated age-related changes in retrieval processes and their interactions with retrieval contexts. In each of the three experiments, some of the test lists were constructed so that participants had to recollect specific aspects of the encoding event to differentiate between the to-be-included and to-be-excluded items, whereas other test lists were constructed so that they only had to recollect general aspects. Older adults showed reduced levels of recollection than younger adults for the high-specificity test lists only (Experiment 3.1). Encoding manipulations improved (Experiment 3.2) or reduced (Experiment 3.3) recollection performance but the effects did not interact with test, whereas DA at retrieval (Experiment 3.3) in younger adults partly mimicked aging.
In summary, the six experiments showed that older adults have greater difficulties in spontaneously carrying out distinctive and integrative processes at encoding, and in accessing specific information at retrieval compared to their younger counterparts. These age-related changes further interact with the processing demanded or afforded by the encoding and retrieval conditions.
| Identifer | oai:union.ndltd.org:TORONTO/oai:tspace.library.utoronto.ca:1807/11229 |
| Date | 31 July 2008 |
| Creators | Luo, Lin |
| Contributors | Craik, Fergus I. M. |
| Source Sets | University of Toronto |
| Language | en_ca |
| Detected Language | English |
| Type | Thesis |
| Format | 566531 bytes, application/pdf |
Page generated in 0.002 seconds