title: Affective Flattening in Patients with Schizophrenia: Differential Association with Amygdala Response to Threat-Related Facial Expression under Automatic and Controlled Processing Conditions.
abstract: OBJECTIVE
  Early neuroimaging studies have demonstrated amygdala hypoactivation in schizophrenia but more recent research based on paradigms with minimal cognitive loads or examining automatic processing has observed amygdala hyperactivation. Hyperactivation was found to be related to affective flattening. In this study, amygdala responsivity to threat-related facial expression was investigated in patients as a function of automatic versus controlled processing and patients' flat affect.
  
  
  METHODS
  Functional magnetic resonance imaging was used to measure amygdala activation in 36 patients with schizophrenia and 42 healthy controls. During scanning, a viewing task with masked and unmasked fearful and neutral faces was presented.
  
  
  RESULTS
  Patients exhibited increased amygdala response to unmasked fearful faces. With respect to masked fearful faces, no between-group differences emerged for the sample as a whole but a subsample of patients with flat affect showed heightened amygdala activation. The amygdala response to masked fearful faces was positively correlated with the degree of flat affect. Conversely, amygdala response to unmasked fearful faces was negatively correlated to the severity of affective flattening. In patients, amygdala responses to masked and unmasked fearful faces showed an inverse correlation.
  
  
  CONCLUSIONS
  Our findings suggest that amygdala hyperresponsivity to unmasked fearful faces might be a functional characteristic of schizophrenia. Amygdala hyperresponsivity to masked fearful faces might be a specific characteristic of patients with affective flattening. A model of flat affect as a response mechanism to emotional overload is proposed.
authors.affiliation: Department of Psychosomatic Medicine, University of Leipzig, Leipzig, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Lindner
authors.affiliation: Department of Psychiatry, University of Münster, Münster, Germany.; Department of Psychiatry, University of Marburg, Marburg, Germany.
authors.forename: Udo
authors.initials: U
authors.lastname: Dannlowski
authors.affiliation: Department of Psychiatry, University of Münster, Münster, Germany.
authors.forename: Jochen
authors.initials: J
authors.lastname: Bauer
authors.affiliation: Department of Psychiatry, University of Münster, Münster, Germany.
authors.forename: Patricia
authors.initials: P
authors.lastname: Ohrmann
authors.affiliation: Department of Psychiatry, University of Münster, Münster, Germany.
authors.forename: Rebekka
authors.initials: R
authors.lastname: Lencer
authors.affiliation: Institute of Psychology, University of Münster, Münster, Germany.
authors.forename: Pienie
authors.initials: P
authors.lastname: Zwitserlood
authors.affiliation: Department of Clinical Radiology, University of Münster, Münster, Germany.
authors.forename: Harald
authors.initials: H
authors.lastname: Kugel
authors.affiliation: Department of Psychosomatic Medicine, University of Leipzig, Leipzig, Germany.; Department of Psychiatry, University of Münster, Münster, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Suslow
keywords: Affective flattening; Amygdala; Facial affect processing; Fear; Schizophrenia; fMRI