Lower Activation in Frontal Cortex and Posterior Cingulate Cortex Observed during Sex Determination Test in Early-Stage Dementia of the Alzheimer Type

Authors

Ravi Rajmohan, Department of Pharmacology and Neuroscience, Texas Tech University Health Sciences CenterLubbock, TX, United States.
Ronald C. Anderson, Department of Electrical and Computer Engineering, Texas Tech UniversityLubbock, TX, United States.
Dan Fang, Department of Human Development and Family Studies, Texas Tech UniversityLubbock, TX, United States.
Austin G. Meyer, School of Medicine, Texas Tech University Health Sciences CenterLubbock, TX, United States.
Pavis Laengvejkal, Department of Neurology, Texas Tech University Health Sciences CenterLubbock, TX, United States.
Parunyou Julayanont, Department of Neurology, Texas Tech University Health Sciences CenterLubbock, TX, United States.
Greg Hannabas, Department of Public Health, Texas Tech University Health Sciences CenterLubbock, TX, United States.
Kitten Linton, Department of Family Medicine, Texas Tech University Health Sciences CenterLubbock, TX, United States.
John Culberson, Department of Family Medicine, Texas Tech University Health Sciences CenterLubbock, TX, United States.
Hafiz Khan, Department of Public Health, Texas Tech University Health Sciences CenterLubbock, TX, United States.
John De Toledo, Department of Neurology, Texas Tech University Health Sciences CenterLubbock, TX, United States.
P Hemachandra Reddy, Department of Pharmacology and Neuroscience, Texas Tech University Health Sciences CenterLubbock, TX, United States.
Michael W. O'Boyle, Department of Human Development and Family Studies, Texas Tech UniversityLubbock, TX, United States.

Document Type

Article

Abstract

Face-labeling refers to the ability to classify faces into social categories. This plays a critical role in human interaction as it serves to define concepts of socially acceptable interpersonal behavior. The purpose of the current study was to characterize, what, if any, impairments in face-labeling are detectable in participants with early-stage clinically diagnosed dementia of the Alzheimer type (CDDAT) through the use of the sex determination test (SDT). In the current study, four (1 female, 3 males) CDDAT and nine (4 females, 5 males) age-matched neurotypicals (NT) completed the SDT using chimeric faces while undergoing BOLD fMRI. It was expected that CDDAT participants would have poor verbal fluency, which would correspond to poor performance on the SDT. This could be explained by decreased activation and connectivity patterns within the fusiform face area (FFA) and anterior cingulate cortex (ACC). DTI was also performed to test the association of pathological deterioration of connectivity in the uncinate fasciculus (UF) and verbally-mediated performance. CDDAT showed lower verbal fluency test (VFT) performance, but VFT was not significantly correlated to SDT and no significant difference was seen between CDDAT and NT for SDT performance as half of the CDDAT performed substantially worse than NT while the other half performed similarly. BOLD fMRI of SDT displayed differences in the left superior frontal gyrus and posterior cingulate cortex (PCC), but not the FFA or ACC. Furthermore, although DTI showed deterioration of the right inferior and superior longitudinal fasciculi, as well as the PCC, it did not demonstrate significant deterioration of UF tracts. Taken together, early-stage CDDAT may represent a common emerging point for the loss of face labeling ability.

Publication Date

1-1-2017

Publication Title

Frontiers in aging neuroscience

ISSN

1663-4365

Volume

9

First Page

156

PubMed ID

28588478

Digital Object Identifier (DOI)

10.3389/fnagi.2017.00156

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