title: Fusiform Gyrus Dysfunction is Associated with Perceptual Processing Efficiency to Emotional Faces in Adolescent Depression: A Model-Based Approach.
abstract: While the extant literature has focused on major depressive disorder (MDD) as being characterized by abnormalities in processing affective stimuli (e.g., facial expressions), little is known regarding which specific aspects of cognition influence the evaluation of affective stimuli, and what are the underlying neural correlates. To investigate these issues, we assessed 26 adolescents diagnosed with MDD and 37 well-matched healthy controls (HCL) who completed an emotion identification task of dynamically morphing faces during functional magnetic resonance imaging (fMRI). We analyzed the behavioral data using a sequential sampling model of response time (RT) commonly used to elucidate aspects of cognition in binary perceptual decision making tasks: the Linear Ballistic Accumulator (LBA) model. Using a hierarchical Bayesian estimation method, we obtained group-level and individual-level estimates of LBA parameters on the facial emotion identification task. While the MDD and HCL groups did not differ in mean RT, accuracy, or group-level estimates of perceptual processing efficiency (i.e., drift rate parameter of the LBA), the MDD group showed significantly reduced responses in left fusiform gyrus compared to the HCL group during the facial emotion identification task. Furthermore, within the MDD group, fMRI signal in the left fusiform gyrus during affective face processing was significantly associated with greater individual-level estimates of perceptual processing efficiency. Our results therefore suggest that affective processing biases in adolescents with MDD are characterized by greater perceptual processing efficiency of affective visual information in sensory brain regions responsible for the early processing of visual information. The theoretical, methodological, and clinical implications of our results are discussed.
authors: Department of Psychiatry, University of California, San Francisco, San Francisco CA, USA.
authors: Tiffany C
authors: TC
authors: Ho
authors: Cognitive Science, University of California, San Diego, La Jolla CA, USA.
authors: Shunan
authors: S
authors: Zhang
authors: Neuroscience Graduate Program and Department of Psychology, Stanford University, Palo Alto CA, USA.
authors: Matthew D
authors: MD
authors: Sacchet
authors: The Osher Center for Integrative Medicine, University of California, San Francisco, San Francisco CA, USA.
authors: Helen
authors: H
authors: Weng
authors: Department of Psychiatry, University of California, San Francisco, San Francisco CA, USA.
authors: Colm G
authors: CG
authors: Connolly
authors: Department of Psychiatry, University of California, San Francisco, San FranciscoCA, USA; Clinical Neuroscience, Karolinska InstitutetStockhold, Sweden.
authors: Eva
authors: E
authors: Henje Blom
authors: Department of Psychiatry, University of California, San Francisco, San Francisco CA, USA.
authors: Laura K M
authors: LK
authors: Han
authors: Department of Psychiatry, University of California, San Francisco, San Francisco CA, USA.
authors: Nisreen O
authors: NO
authors: Mobayed
authors: Department of Psychiatry, University of California, San Francisco, San Francisco CA, USA.
authors: Tony T
authors: TT
authors: Yang
keywords: adolescent; depression; fMRI BOLD; face processing; fusiform gyrus; mood disorders; response time modeling