Stand der Ursachen - Mitteldeutsche Psychiatrietage 2011

Poster | Gerontopsychiatrie
P36
The neural networks underlying personal familiarity in aging and early cognitive
decline
M. Donix, L. Jurjanz, S. Meyer, D. Baeumler, E. Amanatidis, K. Poettrisch, U. Herold, K. Petrowski, T.
Huebner, M. Smolka, V. Holthoff, Dresden
Background: Accessing information that defines personally familiar context in real-world situations is
essential for the social interactions and the independent functioning of an individual. Personal familiarity is
associated with the availability of semantic and episodic information as well as the emotional
meaningfulness surrounding a stimulus. These features are known to be associated with neural activity in
distinct brain regions. Our aim was to investigate whether aging and early cognitive decline would
modulate brain activity in the neural networks underlying personal familiarity.
Methods: We used functional magnetic resonance imaging (fMRI) to investigate the neural network
associated with personal familiarity during the perception of personally familiar faces (e.g., spouse,
childres) and places (from the subjects’ own home). A total of 48 subjects participated. We studied 12
healthy young subjects (mean age: 30.4±6.1 years, 6 female, 6 male), and 12 healthy middle aged and
elderly participants (mean age: 62.1±5.4 years, 6 female, 6 male). We additionally investigated 12 patients
with mild cognitive impairment (MCI, mean age: 66.6±8.7 years, 6 female, 6 male), and 12 Alzheimer’s
disease (AD) patients (mean age: 69.6±6.1 years, 5 female, 7 male).
Results: The healthy young and elderly control subjects showed a similar activation pattern associated with
personal familiarity, predominantly in anterior cingulate and posterior cingulate cortices, irrespective of the
stimulus type (face/place). The young subjects, but not the elderly subjects demonstrated an anterior
cingulate deactivation when perceiving unfamiliar stimuli. MCI patients compared with elderly control
subjects showed reduced activity in right prefrontal brain regions when perceiving personally familiar
stimuli. Using the same contrast, AD patients relative to elderly controls, failed to activate frontal cortical
areas known to be important for retrieving context information and episodes surrounding a familiar
stimulus. The direct group comparison between MCI patients and elderly controls, as well as between AD
patients and elderly subjects, showed that the subjects did not differ in posterior cingulate and precuneus
neural activity, brain areas important fo r perceptual familiarity recognition. Contrasting MCI and AD
patients did not result in significant brain activity differences for all contrasts investigated.
Discussion: Although we found evidence for an age-dependent reduction in frontal cortical deactivation,
our data show that there is a stimulus-independent neural network associated with personal familiarity of
faces and places, which is less susceptible to aging-related changes. Our data also highlight changes in a
frontal cortical network associated with knowledge-based personal familiarity among patients with MCI and
AD. This suggests a frontal cortical network dysfunction that contributes to the patients’ impairment in
accessing knowledge details and episodes surrounding a familiar stimulus. These changes could
contribute to deficits in social cognition and may reduce the patients’ ability to transition from basic to
complex situations and tasks.
8. Mitteldeutsche Psychiatrietage | 100