Memory for faces dissociates from memory for location following anterior temporal lobectomy

Area of Science:

• Neuroscience
• Cognitive Psychology
• Neuroimaging

Background:

• The mesial temporal lobes (MTL) are implicated in long-term memory (LTM).
• The left MTL's role in verbal memory is established, but the right MTL's function in non-verbal memory is debated.
• Specialized cortical pathways exist for visuospatial information processing.

Purpose of the Study:

• To investigate the differential localization of memory processing for visuospatial information within the MTL.
• To examine the contribution of right and left MTL structures to LTM for facial and spatial information.
• To test if memory for faces and spatial locations relies on distinct MTL pathways.

Main Methods:

• Compared memory performance for unfamiliar faces and spatial locations in 86 patients undergoing unilateral anterior temporal lobectomy (ATL).
• Assessed patients (35 left ATL, 51 right ATL) pre- and post-surgery.
• Analyzed memory recall related to the side of ATL and testing time.

Main Results:

• Memory for spatial locations was independent of the side of ATL or testing time.
• Right ATL patients exhibited pre-existing facial memory impairments, which worsened post-surgery compared to left ATL patients.
• These findings suggest a dissociation in LTM systems for facial and spatial information.

Conclusions:

• The right MTL is specifically involved in the memory encoding of new faces, not spatial locations.
• This supports a dissociation in LTM systems mirroring visuospatial processing pathways.
• Right MTL lesions adjacent to facial recognition areas impair facial memory encoding.