title: Single-unit responses selective for whole faces in the human amygdala.
abstract: The human amygdala is critical for social cognition from faces, as borne out by impairments in recognizing facial emotion following amygdala lesions [1] and differential activation of the amygdala by faces [2-5]. Single-unit recordings in the primate amygdala have documented responses selective for faces, their identity, or emotional expression [6, 7], yet how the amygdala represents face information remains unknown. Does it encode specific features of faces that are particularly critical for recognizing emotions (such as the eyes), or does it encode the whole face, a level of representation that might be the proximal substrate for subsequent social cognition? We investigated this question by recording from over 200 single neurons in the amygdalae of seven neurosurgical patients with implanted depth electrodes [8]. We found that approximately half of all neurons responded to faces or parts of faces. Approximately 20% of all neurons responded selectively only to the whole face. Although responding most to whole faces, these neurons paradoxically responded more when only a small part of the face was shown compared to when almost the entire face was shown. We suggest that the human amygdala plays a predominant role in representing global information about faces, possibly achieved through inhibition between individual facial features.
authors.affiliation: Department of Neural Systems, Max Planck Institute for Brain Research, 60528 Frankfurt am Main, Germany. urut@caltech.edu
authors.forename: Ueli
authors.initials: U
authors.lastname: Rutishauser
authors.forename: Oana
authors.initials: O
authors.lastname: Tudusciuc
authors.forename: Dirk
authors.initials: D
authors.lastname: Neumann
authors.forename: Adam N
authors.initials: AN
authors.lastname: Mamelak
authors.forename: A Christopher
authors.initials: AC
authors.lastname: Heller
authors.forename: Ian B
authors.initials: IB
authors.lastname: Ross
authors.forename: Linda
authors.initials: L
authors.lastname: Philpott
authors.forename: William W
authors.initials: WW
authors.lastname: Sutherling
authors.forename: Ralph
authors.initials: R
authors.lastname: Adolphs
mesh_terms: D000293:Adolescent; D000328:Adult; D000679:Amygdala / Q000502:physiology*; D004567:Electrodes, Implanted; D004827:Epilepsy; D005149:Facial Expression; D005260:Female; D006801:Humans; D008297:Male; D009474:Neurons / Q000502:physiology*; D010364:Pattern Recognition, Visual; D055815:Young Adult