Examining Age Differences in the Influence of Schematic Information on Retrieval Success

Open Access
Author:
Webb, Christina Eileen
Graduate Program:
Psychology
Degree:
Master of Science
Document Type:
Master Thesis
Date of Defense:
November 10, 2015
Committee Members:
  • Nancy Anne Coulter Dennis, Thesis Advisor
Keywords:
  • schema; recollection; fmri; aging
Abstract:
Schemas act as memory mechanisms that allow one to build frameworks in order to support memory through the use of gist information. This gist information can be especially beneficial to older adults in supporting successful memory. The current study sought to use naturalistic scenes in order to investigate age-related changes in the neural basis of true memories for information that was inherently tied to the scene’s schema compared to that which was not related to the schema. During encoding, participants viewed schematic scenes (e.g., Christmas, bathroom, camping) and were tested on their memory for the content of the scene, including targets that were related (e.g., toilet) and unrelated (e.g., vase) to its theme. Analyses focused on both similarities and differences in neural recruitment supporting memory for items related and unrelated to the schema. Correct responses to both schematically-related items and to items that were not related to the schema (non-schematic) were associated with increases in neural activity in the typical retrieval success network in younger adults, but a very limited network in older adults. A direct comparison between retrieval of schematic vs. non-schematic items found greater activity in bilateral visual and occipito-temporal regions, including the medial temporal lobe, indicating automatic recapitulation of items in the scene along with their surrounding schematic contexts. Additionally, results revealed greater activation in prefrontal and parietal regions associated with decision-making, evaluation and attention, when comparing non-schematic retrieval with schematic retrieval. Older adults showed evidence of a reliance on the schema when comparing schematic and non-schematic retrieval, with greater activation in middle and superior temporal gyri. However, the reverse contrast revealed very limited activation, limiting the age comparison analysis. Thus, the discussion focuses on interpretation of the younger adult results, as well as additional functional connectivity analyses.