Scientists have identified weakened brain signals that may help explain why schizophrenia can affect perception, movement, language and other aspects of behavior at the same time. In a study of 25 people diagnosed with schizophrenia and 25 healthy participants, abnormalities in beta-band brain activity were associated with difficulties judging the timing of sights and sounds, disorganized speech and more severe clinical symptoms.
Schizophrenia is a complex mental illness that can change how people experience the world, interact with their surroundings and communicate. These features are often studied separately, but the new findings suggest that they may be linked by disruptions in a shared process for handling information.
The research was conducted by scientists at McGill University, the McConnell Brain Imaging Center, the Université de Montréal, the Université de Montréal Health Center Research Center and the Douglas Research Center.
Weakened brain signals linked to several symptoms
The researchers examined beta-band brain activity, rhythmic electrical activity involved in information processing, perception and motor coordination. Participants completed a task designed to measure how accurately they could judge the timing of visual and auditory information. The researchers also analyzed their speech for signs of disorganized thinking or communication.
People with schizophrenia showed weaker and slower beta-band activity than the healthy control group. Participants with the most pronounced abnormalities in these signals also tended to have greater difficulty processing the timing of sights and sounds, more disorganized speech and more severe clinical symptoms.
These three features of schizophrenia are usually investigated independently. Their association with changes in the same brain signals suggests that common underlying processes may contribute to the disorder’s diverse effects.
A possible common mechanism
“This is a first showing that measuring how the brain works, and in particular how it builds and modifies its own models of the world, may help us understand the commonalities behind the confusing array of symptoms seen in diseases like schizophrenia. We present preliminary but compelling evidence,” said the study’s lead author, Dr. Lena Palaniyappan, professor of psychiatry at McGill University and director of the Center of Excellence in Adolescent Mental Health at Douglas Hospital.
The brain constantly uses incoming sensory information to develop and update its understanding of the surrounding environment. This process helps people interpret what they see and hear, predict events and adjust their actions. The findings suggest that disruptions in this process could help explain why schizophrenia affects multiple aspects of perception and behavior.
Researchers measured brain activity with high-resolution magnetoencephalography (MEG), an imaging technique that detects the tiny magnetic fields produced by electrical activity in the brain. MEG can track changes in neural signals with high precision. The scans were performed at the McConnell Brain Imaging Center at the Montreal Neurological Institute Hospital (The Neuro).
“What struck us was that the same weakened brain signals continued to appear everywhere we looked, whether the patients were processing sound, processing vision, or completing movements,” said Shi (Tiana) Wei, lead author of the study and a postdoctoral fellow in the McGill Department of Psychiatry and the Douglas Research Center. “Seeing the same pattern in these different areas suggests that there may be a common underlying process linking the symptoms.”
Potential implications for early detection
The findings could eventually help researchers identify young people at high risk of developing psychosis. Psychosis involves disruptions in how a person perceives or interprets reality and may include hallucinations and delusions.
Early identification is important because the first signs of schizophrenia often emerge during adolescence but may go unrecognized for a long time.
“The first signs of schizophrenia begin in adolescence, but this is often overlooked for a long time. If confirmed in a larger sample, this finding could help identify among young people seeking mental health help who may need extra support to prevent psychosis,” Palaniyappan said.
The researchers emphasized that the results are preliminary. The study included only 50 participants, and larger studies involving independent groups will be needed to determine how reliably the brain signals are associated with language impairment and overall symptom severity.
“This is the first moderately sized study, and we need to test it in a larger, independent sample to be confident of the association between speech and clinical severity,” Wei said.
If future research confirms the results, beta-band activity could become a useful tool for identifying people who may benefit from early support. Wei also suggested that these brain signals could be investigated as potential targets for future schizophrenia treatments.
Source: www.sciencedaily.com
