Neuroscience and Biobehavioral Reviews 37 (2013) 1774–1785 Contents lists available at ScienceDirect Neuroscience and Biobehavioral Reviews journal h om epa ge: www.elsevier.com/locate/neubiorev Review Neural correlates of alexithymia: A meta-analysis of emotion processing studies Jorien van der Velde a,∗ , Michelle N. Servaas a , Katharina S. Goerlich b , Richard Bruggeman c , Paul Horton d , Sergi G. Costafreda d , André Aleman a,e a Neuroimaging Center, University Medical Center Groningen, Antonius Deusinglaan 2, 9713 AW Groningen, The Netherlands b Department of Psychiatry, Psychotherapy, and Psychosomatics, Medical School, RWTH Aachen University, Pauwelstrasse 30, 52074 Aachen, Germany c Department of Neuroscience and Psychiatry, University Medical Center Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands d Department of Old Age Psychiatry, Institute of Psychiatry, King’s College London, PO Box 070, De Crespigny Park, SE5 8AF London, United Kingdom e Department of Experimental Psychopathology, University of Groningen, Grote Kruisstraat 2/1, 9712 TS Groningen, The Netherlands a r t i c l e i n f o Article history: Received 26 January 2013 Received in revised form 8 July 2013 Accepted 12 July 2013 Keywords: Alexithymia Amygdala Brain Cingulate Emotion Fusiform gyrus Insula Meta-analysis Mirror neuron system Neuroimaging Precuneus a b s t r a c t Alexithymia is a personality trait characterized by difficulties in the experience and cognitive processing of emotions. It is considered a risk factor for a range of psychiatric and neurological disorders. Func- tional neuroimaging studies investigating the neural correlates of alexithymia have reported inconsistent results. To integrate previous findings, we conducted a parametric coordinate-based meta-analysis including fifteen neuroimaging studies on emotion processing in alexithymia. During the processing of negative emotional stimuli, alexithymia was associated with a diminished response of the amygdala, sug- gesting decreased attention to such stimuli. Negative stimuli additionally elicited decreased activation in supplementary motor and premotor brain areas and in the dorsomedial prefrontal cortex, possibly underlying poor empathic abilities and difficulties in emotion regulation associated with alexithymia. Positive stimuli elicited decreased activation in the right insula and precuneus, suggesting reduced emo- tional awareness in alexithymia regarding positive affect. Independent of valence, higher (presumably compensatory) activation was found in the dorsal anterior cingulate possibly indicating increased cogni- tive demand. These results suggest valence-specific as well as valence-independent effects of alexithymia on the neural processing of emotions. © 2013 Elsevier Ltd. All rights reserved. Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1775 2. Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1776 2.1. Systematic literature search . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1776 2.2. Data extraction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1776 2.3. Data-analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1776 3. Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1777 3.1. Negative stimuli . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1777 3.2. Positive stimuli . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1779 4. Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1779 4.1. Valence-independent emotional processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1779 4.2. Valence-specific emotional processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1780 4.2.1. Negative emotional stimuli . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1780 4.2.2. Positive emotional stimuli . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1782 ∗ Corresponding author at: Department of Neuroscience, Neuroimaging Center, UMCG-O&O, P.O. Box 196, 9700 AD Groningen, The Netherlands. Tel.: +31 50 363 87 92; fax: +31 50 363 88 75. E-mail addresses: jorien.van.der.velde@umcg.nl (J. van der Velde), m.n.servaas@umcg.nl (M.N. Servaas), k-goerlich@ukaachen.de (K.S. Goerlich), r.bruggeman@umcg.nl (R. Bruggeman), horton paul@hotmail.com (P. Horton), sergi.1.costafreda@kcl.ac.uk (S.G. Costafreda), a.aleman@umcg.nl (A. Aleman). 0149-7634/$ – see front matter © 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.neubiorev.2013.07.008