title: Testing the connections within face processing circuitry in Capgras delusion with diffusion imaging tractography.
abstract: Although Capgras delusion (CD) patients are capable of recognizing familiar faces, they present a delusional belief that some relatives have been replaced by impostors. CD has been explained as a selective disruption of a pathway processing affective values of familiar faces. To test the integrity of connections within face processing circuitry, diffusion tensor imaging was performed in a CD patient and 10 age-matched controls. Voxel-based morphometry indicated gray matter damage in right frontal areas. Tractography was used to examine two important tracts of the face processing circuitry: the inferior fronto-occipital fasciculus (IFOF) and the inferior longitudinal (ILF). The superior longitudinal fasciculus (SLF) and commissural tracts were also assessed. CD patient did not differ from controls in the commissural fibers, or the SLF. Right and left ILF, and right IFOF were also equivalent to those of controls. However, the left IFOF was significantly reduced respect to controls, also showing a significant dissociation with the ILF, which represents a selective impairment in the fiber-tract connecting occipital and frontal areas. This suggests a possible involvement of the IFOF in affective processing of faces in typical observers and in covert recognition in some cases with prosopagnosia.
authors.affiliation: Cuban Center for Neuroscience, Havana, Cuba. Electronic address: antonieta@cneuro.edu.cu.
authors.forename: Maria A
authors.initials: MA
authors.lastname: Bobes
authors.affiliation: Cuban Center for Neuroscience, Havana, Cuba.
authors.forename: Daylin
authors.initials: D
authors.lastname: Góngora
authors.affiliation: CENSAM, Havana, Cuba.
authors.forename: Annette
authors.initials: A
authors.lastname: Valdes
authors.affiliation: Cuban Center for Neuroscience, Havana, Cuba.
authors.forename: Yusniel
authors.initials: Y
authors.lastname: Santos
authors.affiliation: Cuban Center for Neuroscience, Havana, Cuba.
authors.forename: Yanely
authors.initials: Y
authors.lastname: Acosta
authors.affiliation: Basque Center on Cognition, Brain and Language (BCBL).
authors.forename: Yuriem
authors.initials: Y
authors.lastname: Fernandez Garcia
authors.affiliation: Cuban Center for Neuroscience, Havana, Cuba.
authors.forename: Agustin
authors.initials: A
authors.lastname: Lage
authors.affiliation: Cuban Center for Neuroscience, Havana, Cuba.
authors.forename: Mitchell
authors.initials: M
authors.lastname: Valdés-Sosa
mesh_terms: D000368:Aged; D001931:Brain Mapping / Q000379:methods; D003702:Delusions / Q000473:pathology / Q000503:physiopathology*; D056324:Diffusion Tensor Imaging / Q000379:methods; D005145:Face; D006801:Humans; D008297:Male; D009415:Nerve Net / Q000473:pathology / Q000503:physiopathology*; D009434:Neural Pathways / Q000473:pathology* / Q000502:physiology / Q000503:physiopathology; D021641:Recognition, Psychology / Q000502:physiology