Face Processing in Developmental Prosopagnosia: Altered Neural Representations in the Fusiform Face Area.

Area of Science:

• Neuroscience
• Cognitive Psychology
• Human Neuroimaging

Background:

• Developmental prosopagnosia (DP) affects face recognition, impacting social interaction.
• The Fusiform Face Area (FFA) is crucial for face identity processing and is implicated in DP.
• Representational Similarity Analysis (RSA) is a method to study neural representations in brain regions like the FFA.

Purpose of the Study:

• To investigate alterations in FFA activation patterns during face encoding and maintenance in individuals with DP using RSA.
• To compare neural representations in the FFA between individuals with DP and healthy controls under varying memory loads.

Main Methods:

• Functional MRI (fMRI) and morphological MRI were used in 13 individuals with DP and 12 healthy controls.
• A modified Sternberg paradigm assessed face memory encoding and maintenance under low, medium, and high memory loads.
• RSA was applied to voxel-level correlation matrices of FFA activity, with group comparisons using Donsker's random walk analysis.

Main Results:

• Increased memory load enhanced FFA activation and voxel correlation in controls, but this was deficient in individuals with DP.
• Individuals with DP exhibited significantly lower and less sustained correlation levels between FFA voxels.
• Poorer behavioral performance and longer reaction times in DP correlated negatively with FFA voxel correlation, especially under high memory load.

Conclusions:

• Individuals with DP fail to generate robust and sustained neural representations in the FFA during face memory tasks.
• Altered neural coding in the FFA may underlie working memory deficits and impaired long-term memory and mental imagery in DP.
• These findings highlight the critical role of FFA neural representations in face recognition and memory.