Structural and functional correlates of olfactory reward processing in behavioral variant frontotemporal dementia

Area of Science:

• Neuroscience
• Neurology
• Psychology

Background:

• Behavioral variant of frontotemporal dementia (bvFTD) is characterized by altered reward pursuit.
• The neural underpinnings of these reward changes, particularly concerning structural and functional brain alterations, remain unclear.

Purpose of the Study:

• To investigate the structural and functional brain correlates of olfactory reward valence perception in bvFTD patients.
• To explore the relationship between brain atrophy, functional connectivity, and the subjective experience of pleasantness in bvFTD.

Main Methods:

• Studied 24 patients with bvFTD.
• Utilized resting-state functional connectivity and structural MRI to analyze reward-related brain regions.
• Performed regression analyses to link brain measures with olfactory reward valence ratings.

Main Results:

• Positive olfactory reward perception correlated with ventral pallidum connectivity to reward circuit regions, notably the anterior cingulate cortex (ACC) and ventromedial prefrontal cortex (vmPFC).
• ACC atrophy was associated with perceiving stimuli as more rewarding.
• An interaction effect showed ventral pallidum connectivity influenced pleasantness perception more strongly when ACC volume was reduced.

Conclusions:

• Structural atrophy and functional connectivity in reward circuits independently and interactively affect pleasantness perception in bvFTD.
• These findings suggest alterations in hedonic 'liking' signals may underlie reward perception changes in bvFTD.