Examining Differences In Face Specialization In Subjects With Alzheimer’S Disease Using Functional Magnetic Resonance Imaging

Alzheimer’s disease (AD), a devastating neurodegenerative disease, profoundly affects an individual’s ability to socialize, stay motivated, and recognize faces. Grasping an understanding of the neural basis of this disease may lead to future behavioral or pharmacological interventions. The overall goal of the study was to identify group differences in neural activation of AD subjects and healthy controls (HC) while viewing face and non-face stimuli. The main hypothesis of this study is that AD subjects would show decreased activation in the fusiform face area (FFA) and increased primary visual cortex activation. To test this hypothesis, 5 AD and 55 HC subjects underwent a functional magnetic resonance imaging (fMRI) session, in which they viewed blocks of faces, objects, and textures. The fMRI images were preprocessed to correct for any head motion or geometric distortions using FSL (the interface for looking at brain images), FEAT (for skull-stripping and creating a model), and FEATQUERY (to extract the signals) software programs. Once the signals were extracted, ANOVAs were conducted for each region of interest. The results did not reveal significant group differences in face specialization in the FFA and the primary visual areas, but additional exploratory analyses revealed group differences in the face specialization of the amygdala, an area linked to emotional processing and detecting salience. Unlike the healthy control group, the amygdala activation in AD subjects was not face specific. This activation pattern may reflect diminishing salience of faces vs. objects in Alzheimer’s disease