J Psychiatry Neurosci 2010;35(3):185-194
Janina Seubert, PhD; James Loughead, PhD; Thilo Kellermann, PhD; Frank Boers, Dipl.-Ing; Colleen M. Brensinger, MS; Ute Habel, PhD
Seubert, Kellermann, Habel — Department of Psychiatry and Psychotherapy, Rheinisch-Westfälische Technische Hochschule, Aachen University; Seubert, Kellermann, Habel — Jülich Aachen Research Alliance, Translational Brain Medicine; Boers — Brain Imaging Physics, Institute for Neuroscience and Medicine INM-4, Research Center Jülich, Germany; Seubert, Loughead — Department of Psychiatry, University of Pennsylvania; Brensinger — Center for Clinical Epidemiology and Biostatistics, School of Medicine, University of Pennsylvania, Philadelphia, Pa.
Background: Patients with schizophrenia frequently have deficits in social cognition, and difficulties in the discrimination of emotional facial expressions have been discussed as an important contributing factor. We investigated whether this impairment is aggravated by difficulties relating the observed facial expression to contextual information, as is often provided by emotionally valenced crossmodal stimulation.
Methods: We investigated the effects of odorant primes on the accuracy and speed of emotional face recognition. Healthy controls and patients with schizophrenia were exposed to 2-second odorant stimuli: vanillin (pleasant), ambient air (neutral) and hydrogen sulfide (unpleasant). The odours were followed by an emotional face recognition task, in which participants determined if a face showed happiness, disgust or neutral affect.
Results: Controls showed improved performance in the categorization of disgusted faces after all types of odour stimulation irrespective of the emotional valence. However, in controls, the response time for happy faces was slower after presentation of any odour. Schizophrenia patients showed an attenuated effect of olfactory priming on disgust recognition, which resulted in the increased performance differences between the groups. This effect was particularly strong for the unpleasant odour.
Limitations: The study design did not allow us to fully differentiate between the effects of perceived odour intensity and valence. A possible contribution of cognitive deficits on the observed effects should be investigated in future studies.
Conclusion: Our results provide novel evidence for a special connection between the presentation of odorant cues and the accuracy of recognition of disgusted faces in healthy controls. This recognition advantage is disturbed in patients with schizophrenia and appears to contribute to the observed deficit in emotional face recognition.
Submitted Aug. 4, 2009; Revised Nov. 25, 2009, Jan. 17, 2010; Accepted Jan. 19, 2010.
Competing interests: Dr. Seubert has received a scholarship from IRTG 1328 Schizophrenia and Autism and travel assistance from GlaxoSmithKline. None declared for Drs. Loughead, Kellermann, Boers and Habel and Ms. Brensinger.
Contributors: Drs. Seubert, Loughead, Boers and Habel designed the study. Dr. Seubert acquired the data, which all authors analyzed. Dr.Seubert wrote the article, which all other authors reviewed. All authors approved the final version submitted for publication.
Correspondence to: Dr. J. Seubert, Brain Behavior Laboratory, Department of Psychiatry, Neuropsychiatry Section, University of Pennsylvania, 3400 Spruce St., 10 Gates Pavilion, Philadelphia, PA 19104; firstname.lastname@example.org