Link to the University of Pittsburgh Homepage
Link to the University Library System Homepage Link to the Contact Us Form

Top-down modulation and memory deficits: Neural enhancement in the context of aging

Miller, Destiny Lynn (2014) Top-down modulation and memory deficits: Neural enhancement in the context of aging. Doctoral Dissertation, University of Pittsburgh. (Unpublished)

Primary Text

Download (1MB) | Preview


Top-down modulation from a broader perspective suggests that some effortful control over posterior brain regions occurs. This study examined the extent to which age-related differences in top-down modulation could explain age-related memory decline. The theory of top-down modulation suggests that neural transmission during encoding requires the enhancement of relevant information and suppression of irrelevant information for efficacious neural function. Enhancement of attention to stimuli should be greater under higher task demands. In this study, we compared cortical modulation in a less effortful facial encoding task to cortical modulation in a more effortful facial encoding task. One-hundred-thirty older adults (mean age = 66.43 yrs) and 30 younger adults (mean age = 24.13 yrs) completed 2 tasks of facial encoding using functional magnetic resonance imaging (fMRI), a structural magnetic resonance imaging (MRI) scan, and a computer administered test of facial recognition outside the scanning environment. Activity in the fusiform face area was extracted when participants were told to view faces in the first encoding task and remember faces in the second encoding task. An enhancement index reflected the change in neural activity in the fusiform face area moving from the view faces task to the remember faces task. As predicted, levels of neural enhancement in the fusiform face area significantly predicted older and younger adult participants’ ability to correctly discriminate between faces they had and had not previously seen. Against predictions, the level of fusiform face area enhancement did not differ between younger and older adults. Thus, differences in enhancement levels are not driving age-related differences in facial recognition discrimination ability. In functional connectivity analysis, the idea that connections between the “top” and “bottom” components of the memory encoding network were examined. Consistent with predictions, the functional connection between right ventrolateral prefrontal cortex and the fusiform face area related with recognition. Taken together these data suggest that sensory enhancement is a critical component of efficacious memory encoding processes, but top-down enhancement of sensory activity does not adequately explain age-related decrement in memory performance.


Social Networking:
Share |


Item Type: University of Pittsburgh ETD
Status: Unpublished
CreatorsEmailPitt UsernameORCID
Miller, Destiny Lynndld22@pitt.eduDLD22
ETD Committee:
TitleMemberEmail AddressPitt UsernameORCID
Committee ChairErickson, Kirk Ikiericks@pitt.eduKIERICKS
Committee MemberKamarck, Thomastkam@pitt.eduTKAM
Committee MemberWheeler, Markmew8@pitt.eduMEW8
Committee MemberPeter, Gianarosgianaros@pitt.eduGIANAROS
Committee MemberCaterina, RosanoRosanoC@edc.pitt.eduCAR2350
Date: 4 February 2014
Date Type: Publication
Defense Date: 26 August 2013
Approval Date: 4 February 2014
Submission Date: 2 December 2013
Access Restriction: No restriction; Release the ETD for access worldwide immediately.
Number of Pages: 96
Institution: University of Pittsburgh
Schools and Programs: Dietrich School of Arts and Sciences > Psychology
Degree: PhD - Doctor of Philosophy
Thesis Type: Doctoral Dissertation
Refereed: Yes
Uncontrolled Keywords: aging, cognitive decline, fMRI, neuroimaging, top-down modulation, memory
Date Deposited: 04 Feb 2014 16:18
Last Modified: 15 Nov 2016 14:16


Monthly Views for the past 3 years

Plum Analytics

Actions (login required)

View Item View Item