Subjective rating of working memory is associated with frontal lobe volume in schizophrenia
Received 5 October 2009; accepted 24 February 2010. published online 22 March 2010.
Abstract
Background
Patients with schizophrenia commonly show deficits in working memory on objective neuropsychological measures, and brain imaging studies have documented neural abnormalities during performance of working memory tasks. It remains unclear to what extent such patients are able to accurately gauge the integrity of their working memory in their daily lives.
Aims
We evaluated the relationship between subjective rating of working memory integrity in daily life and volumes of the frontal, temporal, and parietal lobes in patients with schizophrenia.
Methods
Participants included 29 patients with schizophrenia and 26 healthy comparison subjects. Participants completed a structural magnetic resonance imaging (MRI) scan, the Self Report form of the Behavioral Rating Inventory of Executive Function — Adult version (BRIEF-A), and Digit Span Backwards as an objective measure of working memory. Lobar volumes were obtained using an automated processing package and adjusted for total intracranial volume.
Results
The patient group reported worse working memory in daily life, and performed worse on Digit Span Backwards, than the comparison group. Within the patient group, poorer working memory in daily life was associated with smaller left and right frontal lobe volumes. Shorter backwards digit span was associated with smaller left frontal and left and right temporal lobe volumes.
Conclusions
The significant relationship between frontal lobe volumes and subjective working memory in daily life provides some support for the validity of self report measures of cognitive functioning in patients with schizophrenia, and provides further evidence for a contribution of frontal lobe abnormality to executive dysfunction in the illness.
aNeuropsychology Service & Brain Imaging Laboratory, Department of Psychiatry, Dartmouth Medical School/DHMC, One Medical Center Drive, Lebanon, NH 03756-0001, USA
bNew Hampshire Hospital, 36 Clinton Street, Concord, NH 03301, USA
cDepartment of Radiology, Indiana University School of Medicine, 950 W Walnut Street R2, E124, Indianapolis, IN 46202, USA
Corresponding author. Neuropsychology Service & Brain Imaging Laboratory, Department of Psychiatry, Dartmouth Medical School, One Medical Center Drive, Lebanon, NH, 03756-0001, USA. Tel.: +1 603 650 5824; fax: +1 603 650 5842.
ABSTRACT