Show simple item record

dc.contributor.advisorSchnyer, David M.en
dc.creatorPacheco, Jennifer Lynnen
dc.date.accessioned2011-06-09T17:13:01Zen
dc.date.accessioned2011-06-09T17:13:56Zen
dc.date.available2011-06-09T17:13:01Zen
dc.date.available2011-06-09T17:13:56Zen
dc.date.issued2011-05en
dc.date.submittedMay 2011en
dc.identifier.urihttp://hdl.handle.net/2152/ETD-UT-2011-05-3106en
dc.descriptiontexten
dc.description.abstractMemory monitoring, or the ability to accurately assess one’s memory retrieval success, is known to be declined for older adults. The behavioral decline has been well explored, and is specific to tasks of source monitoring; tasks involving item memory monitoring do not show age-related deficits. This study attempts to further characterize the decline by exploring neuroanatomical contributions to the decline, and genetic influences that may explain performance variability in older adults. Older adults were genotyped for the serotonin transporter (5-HTTLPR) gene, and those that are carriers of the low-expressing allele demonstrate the expected age-related decline of source monitoring performance when compared to younger adults. Interestingly, older adults who lack this allele did not display any decline in performance when compared to younger adults. Neuroanatomical correlates of task performance indicate that prefrontal regions in the inferior and lateral cortices support accurate source memory monitoring, likely through their role in the proper selection of memory cues and inhibition of irrelevant information. This relationship suggests that age-related atrophy occurring in these structures could be responsible for the performance deficits on source memory monitoring tasks. There was no direct relationship seen between genotype for the 5-HTTLPR gene and cortical volumes, however diffusion tensor imaging shows that older adults who carry this allele have altered connections between the medial temporal lobe, responsible for memory retrieval, and prefrontal cortex, which monitors the retrieval process. Through stronger connections of critical networks, older adults who lack the 5-HTTLPR short allele may be able to compensate for the age-related atrophy seen in the prefrontal cortex. Functional results further indicate that the older adult non-carriers recruit inferior and lateral frontal regions to a greater extent than the older adult carriers during accurate memory monitoring. These results begin to suggest a neuroprotective mechanism for the 5-HTTLPR genotype, wherein some older adults may be able to postpone the expected decline of memory monitoring by retaining the ability to recruit essential inferior frontal structures through more organized white matter pathways.en
dc.format.mimetypeapplication/pdfen
dc.language.isoengen
dc.subject5-HTTLPRen
dc.subjectAgingen
dc.subjectfMRIen
dc.subjectMemory monitoringen
dc.subjectMemory (psychology)en
dc.subjectMemory lossen
dc.subjectGeriatric psychologyen
dc.subjectSerotonin transporter geneen
dc.subjectMemory--Age factorsen
dc.subjectMemory--Testingen
dc.titleCharacterizing the age-related decline of memory monitoring : neuroimaging and genetic approachesen
dc.date.updated2011-06-09T17:13:56Zen
dc.contributor.committeeMemberMaddox, W T.en
dc.contributor.committeeMemberBeevers, Christopher G.en
dc.contributor.committeeMemberHaley, Andreanaen
dc.contributor.committeeMemberHolahan, Caroleen
dc.description.departmentPsychologyen
dc.type.genrethesisen
thesis.degree.departmentPsychologyen
thesis.degree.disciplinePsychologyen
thesis.degree.grantorUniversity of Texas at Austinen
thesis.degree.levelDoctoralen
thesis.degree.nameDoctor of Philosophyen


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record