A single brain signal may help explain a range of seemingly unrelated schizophrenia symptoms, a new study has found.
Schizophrenia is often described as a list of separate problems. People may perceive the world differently, act on their surroundings differently, or speak in ways that are hard to follow.
Published in Science Advances, the study identified a common mechanism underlying all three symptoms. The findings emerged from a collaboration among researchers at McGill University, the McConnell Brain Imaging Centre, the University of Montreal, the Research Centre of the University of Montreal Health Centre and the Douglas Research Centre.
Researchers measured beta-band brain activity in 25 people with schizophrenia and 25 members of a healthy control group while they completed a task involving the timing of sights and sounds. Their speech was also analyzed for signs of disorganization.
Compared with members of the control group, schizophrenia patients showed weaker and slower beta-band activity. Notably, patients with the greatest differences in this brain signal tended to have more difficulty processing the timing of sights and sounds, more disorganized speech and more severe clinical symptoms, three features of schizophrenia that are normally studied separately.
"This gives us early but compelling evidence that measuring the brain's operations, especially how it builds and revises its own model of the world, may help us appreciate that there is a common thread behind the confusing array of symptoms we see in disorders like schizophrenia," said Dr. Lena Palaniyappan, senior author of the study, Professor of Psychiatry at McGill and director of the Centre of Excellence in Youth Mental Health at the Douglas Hospital.
"The very first sign of schizophrenia begins in our adolescence, but this often gets missed for a long time. If this finding is confirmed in larger samples, we may have a potentially useful method to identify who, among youth seeking help for mental health, needs extra support to prevent psychosis," he said.
The study relied on high-resolution MEG imaging carried out at the McConnell Brain Imaging Centre at the Montreal Neurological Institute-Hospital (The Neuro).
"What struck us was that the same weakened brain signal kept showing up wherever we looked, whether patients were processing a sound, a sight or completing a movement," said Hsi (Tiana) Wei, lead author of the study and postdoctoral scholar in McGill's Department of Psychiatry and the Douglas Research Centre. "Seeing the same pattern across these different domains suggested there may be a common underlying process linking the symptoms."
"This is a first, modest-size study, and the associations with speech and clinical severity will need to be tested in larger independent samples before we can be confident in them," she said.
Beyond its potential to help identify people at risk of psychosis, she added, the brain signal may also be worth exploring as a future treatment target.
Photos and b-roll available upon request
About the study
"Neurophysiological dynamics related to perception, action, and language in schizophrenia" by Hsi T. Wei, Dominic Boutet, Rukun Dou, Jessica Ahrens, Nadia Zeramdini, Alban Voppel, Fernando Gonzales-Aste, Fatme Abboud, Sylvain Baillet and Lena Palaniyappan was published in Science Advances.
The study was supported in part by McConnell Brain Imaging Centre pilot funding awarded to Lena Palaniyappan and Sylvain Baillet, a Mitacs Accelerate Fellowship to Hsi T. Wei, the Quebec Bioimaging Network and the Canada Foundation for Innovation's John R. Evans Leaders Fund, matched by the Government of Quebec.
