A team of researchers at the Neuropsychology Service and Brain Imaging Laboratory led by researcher Matthew Garlinghouse have recently discovered some support for the validity of self report methods and the relationship between frontal lobe abnormality and dysfunction in patients diagnosed with schizophrenia. The findings were published in the Schizophrenia Research journal in April.
While past research has indicated that patients with schizophrenia show deficits in working memory on objective tests, Matthew Garlinghouse found that fMRI scans showed abnormal signs in patients with schizophrenia while the patients were performing working memory tasks.
“We hypothesized that there should be a relationship between self-reported problems with working memory and volume of brain regions implicated in working memory and in schizophrenia,” said Garlinghouse in an email to DUJS.
Participants in the study included 29 patients diagnosed with schizophrenia, and 26 control group comparison subjects without the illness. The diagnosis of the sample population was based on the Diagnostic and Statistical Manual of Mental Disorders, which uses the Structured Clinical Interview.
To conduct their study, all of the participants were asked to complete the self-report form of the Behavior Reporting Rating Inventory of Executive Function-Adult version (BRIEF-A). This measure is a 75-item questionnaire designed to evaluate executive functioning in daily life over the past month. It yields nine scales (Inhibit, Shift, Emotional Control, Self Monitor, Initiate, Working Memory, Plan/Organize, Task Monitor, and Organization of Materials).
The participants were also asked to fill out the Beck Depression Inventory-II (BD-II), which was used to evaluate mood, and the Digit Span subtest of the Wechsler Adult Intelligence Scale-III.
Analysis of the data found that poorer subjective working memory was reported in more of the participants who had been diagnosed with schizophrenia in comparison to those who had not. The research team also found that poorer subjective working memory was associated with smaller adjusted left and right frontal lobe volumes in patients. Although these findings were consistent with prior research which has led to the conclusion that the frontal lobe and its relationship to the working memory, the relationship between lobe size and subjective working memory in this study was not significant.
The research team also found that schizophrenic patients were also worse at the objective test of working memory, which suggests that the left frontal lobe might play an instrumental role in controlling working memory in daily life.
This research suggests that subjective rating of working memory in patients with schizophrenia might be valid and potentially useful.
Given the need for the appropriate treatment of mental illnesses such as schizophrenia, research in the field of schizophrenic patient understanding is crucial.
The research team, according to Garlinghouse, plans to “investigate whether specific cortical subregions of the frontal lobes are more related than others to the cognitive problems discussed in our study.” In addition, the team wishes to “further explore the validity issue we have been examining whether self-reported working memory is associated with activation on fMRI scans in patients with schizophrenia during performance of a working memory task.”