A hallmark symptom of schizophrenia is difficulty in distinguishing external reality from internal experiences. Whether or not this impairment is irreversible has long been debated. Now, a pilot study at the University of California, San Francisco, led by NARSAD Independent Investigator Grantee Sophia Vinogradov, M.D., has shown that targeted computer “brain training” can improve reality monitoring in people with schizophrenia. NARSAD Young Investigator Grantee Karuna Subramaniam, Ph.D., was the lead author of the research paper, published Feb. 23, 2012 in the journal Neuron.
The symptoms of schizophrenia, beyond delusions and hallucinations, include a range of cognitive and social deficits, such as impaired memory and decision-making, as well as limited ability to read social clues. These problems are not helped by current antipsychotic drugs, and psychotherapeutic measures are of limited benefit. Dr. Vinogradov hypothesized that in order to improve a higher order cognitive function, such as the ability to distinguish experiences created internally from actual external events, training should be designed to target impairments in a range of component processes, including lower-level perceptual processing, attention, working memory, and social cognition.
In the 16-week trial, 31 schizophrenia patients were randomly assigned to one of two groups: one group to receive 80 hours of active cognitive training, the other to serve as controls and spend the 80 hours of the trial period playing various commercial computer games. All the participants were assessed before and after the trial by means of behavioral performance tests and functional magnetic resonance imaging (fMRI) of brain activation patterns. Sixteen healthy comparison subjects were also studied for their brain activation patterns, but did not undergo training.
Before the training, the schizophrenia patients all made errors in reality monitoring tasks. Even when they performed accurately, they showed abnormally low activation of the medial prefrontal cortex (mPFC), a region of the brain associated with self-referential thinking. One of the questions the researchers wanted to answer was whether improved reality monitoring correlated with increased mPFC activity. The cognitive training included auditory verbal processing exercises for ten weeks, visual processing exercises for six weeks and emotion identification exercises throughout the 16 weeks. All of the exercises became progressively more difficult as the patients showed improved performance.
In contrast to the control patients who showed no behavioral or neural improvements, the patients who received the training program demonstrated that they could perform a complex reality monitoring task, one that had not been part of their training exercises, and this improved ability correlated with increased mPFC activity. Equally significant, tests showed that increased mPFC activity was associated with later improved social functioning. Another striking aspect of the research, the authors point out, is that the mean length of illness of the patients was 19 years, showing that even the chronically ill could benefit from this type of training. “These findings,” they state, “demonstrate that a serious behavioral deficit in schizophrenia, and its underlying neural dysfunction, can be improved by well-designed computer cognitive training, resulting in a better quality of life.”