title: Facial emotion recognition in agenesis of the corpus callosum.
abstract: BACKGROUND
  Impaired social functioning is a common symptom of individuals with developmental disruptions in callosal connectivity. Among these developmental conditions, agenesis of the corpus callosum provides the most extreme and clearly identifiable example of callosal disconnection. To date, deficits in nonliteral language comprehension, humor, theory of mind, and social reasoning have been documented in agenesis of the corpus callosum. Here, we examined a basic social ability as yet not investigated in this population: recognition of facial emotion and its association with social gaze.
  
  
  METHODS
  Nine individuals with callosal agenesis and nine matched controls completed four tasks involving emotional faces: emotion recognition from upright and inverted faces, gender recognition, and passive viewing. Eye-tracking data were collected concurrently on all four tasks and analyzed according to designated facial regions of interest.
  
  
  RESULTS
  Individuals with callosal agenesis exhibited impairments in recognizing emotions from upright faces, in particular lower accuracy for fear and anger, and these impairments were directly associated with diminished attention to the eye region. The callosal agenesis group exhibited greater consistency in emotion recognition across conditions (upright vs. inverted), with poorest performance for fear identification in both conditions. The callosal agenesis group also had atypical facial scanning (lower fractional dwell time in the eye region) during gender naming and passive viewing of faces, but they did not differ from controls on gender naming performance. The pattern of results did not differ when taking into account full-scale intelligence quotient or presence of autism spectrum symptoms.
  
  
  CONCLUSIONS
  Agenesis of the corpus callosum results in a pattern of atypical facial scanning characterized by diminished attention to the eyes. This pattern suggests that reduced callosal connectivity may contribute to the development and maintenance of emotion processing deficits involving reduced attention to others' eyes.
authors.affiliation: DuBois Regional Medical Center, 15801 DuBois, PA, USA.
authors.forename: Matthew W
authors.initials: MW
authors.lastname: Bridgman
authors.affiliation: Travis Research Institute, Fuller Theological Seminary, 91101 Pasadena, CA, USA.
authors.forename: Warren S
authors.initials: WS
authors.lastname: Brown
authors.affiliation: Division of Humanities and Social Sciences, Caltech, 91125 Pasadena, CA, USA ; Scripps College, 91711 Pomona, CA, USA.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Spezio
authors.affiliation: Neurological Surgery, University of California, 94117-1080 San Francisco, CA, USA.
authors.forename: Matthew K
authors.initials: MK
authors.lastname: Leonard
authors.affiliation: Division of Humanities and Social Sciences, Caltech, 91125 Pasadena, CA, USA ; Division of Biology, Caltech, 91125 Pasadena, CA, USA.
authors.forename: Ralph
authors.initials: R
authors.lastname: Adolphs
authors.affiliation: Division of Humanities and Social Sciences, Caltech, 91125 Pasadena, CA, USA.
authors.forename: Lynn K
authors.initials: LK
authors.lastname: Paul
keywords: Corpus callosum; Corpus callosum agenesis; Facial emotion