J Psychiatry Neurosci 2013; 39(2):97-109
Philippe-Olivier Harvey, PhD; Martin Lepage, PhD
Department of Psychiatry, McGill University, Montréal, Que., and the Douglas Mental Health University Institute, Montréal, Que., Canada
Background: Social dysfunction is a hallmark characteristic of schizophrenia. Part of it may stem from an inability to efficiently encode social information into memory and retrieve it later. This study focused on whether patients with schizophrenia show a memory boost for socially relevant information and engage the same neural network as controls when processing social stimuli that were previously encoded into memory.
Methods: Patients with schizophrenia and healthy controls performed a social and nonsocial picture recognition memory task while being scanned. We calculated memory performance using d’. Our main analysis focused on brain activity associated with recognition memory of social and nonsocial pictures.
Results: Our study included 28 patients with schizophrenia and 26 controls. Healthy controls demonstrated a memory boost for socially relevant information. In contrast, patients with schizophrenia failed to show enhanced recognition sensitivity for social pictures. At the neural level, patients did not engage the dorsomedial prefrontal cortex (DMPFC) as much as controls while recognizing social pictures.
Limitations: Our study did not include direct measures of self-referential processing. All but 3 patients were taking antipsychotic medications, which may have altered both the behavioural performance during the picture recognition memory task and brain activity.
Conclusion: Impaired social memory in patients with schizophrenia may be associated with altered DMPFC activity. A reduction of DMPFC activity may reflect less involvement of self-referential processes during memory retrieval. Our functional MRI results contribute to a better mapping of the neural disturbances associated with social memory impairment in patients with schizophrenia and may facilitate the development of innovative treatments, such as transcranial magnetic stimulation.
Submitted Jan. 11, 2013; Revised Apr. 5, May 6, 2013; Accepted May 7, 2013.
Acknowledgments: This study was supported by an operating grant from the Canadian Institutes of Health Research (CIHR) (#53280). The CIHR had no further role in study design; in the collection, analysis and interpretation of data; in the writing of the report; or in the decision to submit the paper for publication. Both authors are supported by a salary award from the Fonds de la Recherche en Santé du Québec (FRSQ). We thank Dr. M. Brodeur and M. Pelletier for assistance with clinical assessments.
Competing interests: None declared.
Contributors: Both authors designed the study, analyzed the data, reviewed the article and approved it for publication. P.-O. Harvey acquired the data and wrote the article.
Correspondence to: P.-O. Harvey, Department of Psychiatry, McGill University, Douglas Mental Health University Institute, 6875 LaSalle Blvd, Montréal QC H4H 1R3; firstname.lastname@example.org