The magnocellular visual pathway and facial emotion misattribution errors in schizophrenia Jeffrey S. Bedwell a, ⁎, Chi C. Chan a , Ovad Cohen b , Yinnon Karbi b , Eyal Shamir c , Yuri Rassovsky d, e, f a Department of Psychology, 4000 Central Florida Blvd., University of Central Florida, Orlando, FL 32816-1390, USA b Academic College of Tel Aviv-Yafo, 2 Rabenu Yeruham St., Tel-Aviv Yaffo, 61083, Israel c Abarbanel Mental Health Center, 15 Keren-Kayement St., Bat Yam, 59100, Israel d Department of Psychology, Bar-Ilan University, Ramat-Gan, 52900, Israel e Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan, 52900, Israel f UCLA Semel Institute for Neuroscience and Human Behavior, 760 Westwood Plaza, Los Angeles, CA 90095, USA abstract article info Article history: Received 12 December 2012 Received in revised form 15 January 2013 Accepted 20 January 2013 Available online 28 January 2013 Keywords: Anger Emotion Fear Schizophrenia Social cognition Visual processing Many individuals with schizophrenia show impairment in labeling the emotion depicted by faces, and tend to ascribe anger or fear to neutral expressions. Preliminary research has linked some of these difficulties to dysfunc- tion in the magnocellular (M) visual pathway, which has direct projections to subcortical emotion processing re- gions. The current study attempted to clarify these relationships using a novel paradigm that included a red background. Diffuse red light is known to suppress the M-pathway in nonpsychiatric adults, and there is prelim- inary evidence that it may have the opposite (stimulating) effect in schizophrenia-spectrum disorders (SSDs). Twenty-five individuals with SSDs were compared with 31 nonpsychiatric controls using a facial emotion iden- tification task depicting happy, angry, fearful, and sad emotions on red, green, and gray backgrounds. There was a robust interaction of group by change in errors to the red (vs. green) background for misattributing fear expres- sions as depicting anger (p = .001, ή 2 =.18). Specifically, controls showed a significant decrease in this type of error with the red background (p = .003, d =0.77), while the SSD group tended to increase this type of error (p =.07, d =0.54). These findings suggest that the well-established M-pathway abnormalities in SSDs may con- tribute to the heightened misperception of other emotions such as anger, which in turn may cause social misper- ceptions in the environment and elicit symptoms such as paranoia and social withdrawal. As the ventral striatum plays a primary role in identifying anger and receives efferent input from the M-pathway, it may serve as the neuroanatomical substrate in the perception of anger. © 2013 Elsevier Inc. All rights reserved. 1. Introduction Among the diverse cognitive deficits described in schizophrenia (Irani et al., 2011; Schmidt et al., 2011), impairment in social cogni- tion may be particularly important, as it has been shown to be related to poorer quality of life, social support, and work outcome in these indi- viduals (Maat et al., 2012; Schmidt et al., 2011). Many individuals with schizophrenia have difficulty accurately identifying emotions depicted by photographs of faces, particularly for fear expressions (Chan et al., 2010; Kohler et al., 2010). This difficulty appears to be relatively stable over time and independent of general cognitive ability (Chan et al., 2010; Kohler et al., 2010). Research has also shown that individuals with schizophrenia are more likely to mislabel a neutral facial expres- sion as depicting fear or anger (Habel et al., 2010; Pinkham et al., 2011; Premkumar et al., 2008). Two studies have suggested that re- duced performance on facial emotion identification tasks in individuals with schizophrenia is related to poorer magnocellular visual pathway (M-pathway) functioning (Butler et al., 2009; Norton et al., 2009). The M-pathway has relatively direct projections from the thalamus to sub- cortical regions such as the amygdala and ventral striatum (see Fig. 1), which are thought to quickly process the low spatial frequencies of fa- cial emotional expressions (Vuilleumier et al., 2003). It also appears that these connections may prime the perception of threat-based emo- tions such as fear and anger to allow for a fast response (West et al., 2010; Williams et al., 2011). The precise abnormality within the M-pathway in individuals with schizophrenia remains unclear, as one study has suggested that the dysfunction begins at the level of the rod photoreceptors in the retina (Hebert et al., 2010), while other research has suggested that the dysfunction begins at later stages in M-pathway processing (Chen et al., 2004; Guthrie et al., 2006). One way of manipulating M-pathway activity involves the use of diffuse red light, which suppresses the M-pathway (Bedwell et al., Progress in Neuro-Psychopharmacology & Biological Psychiatry 44 (2013) 88–93 Abbreviations: M-pathway, magnocellular pathway; SSD, schizophrenia-spectrum disorder; SCID-I, Structured Clinical Interview for DSM-IV Axis I Disorders; SCID-II, Structured Clinical Interview for DSM-IV Axis II Disorders; fMRI, functional magnetic resonance imaging. ⁎ Corresponding author. Tel.: +1 407 823 5858; fax: +1 407 823 5862. E-mail addresses: Jeffrey.bedwell@ucf.edu (J.S. Bedwell), chichan@knights.ucf.edu (C.C. Chan), ocohen@zahav.net.il (O. Cohen), yinnonkarbi@yahoo.com (Y. Karbi), dreyalshamir@gmail.com (E. Shamir), yurir@ucla.edu (Y. Rassovsky). 0278-5846/$ – see front matter © 2013 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.pnpbp.2013.01.015 Contents lists available at SciVerse ScienceDirect Progress in Neuro-Psychopharmacology & Biological Psychiatry journal homepage: www.elsevier.com/locate/pnp