Abnormalities in how the brain reorganizes prior experiences
Neuroscientists have, for the first time, identified abnormalities in the way memories are 'replayed' in the brains of people with schizophrenia; researchers say the pathbreaking study provides an entirely new basis for explaining many of the condition's core symptoms.

In the study, published in the journal Cell, researchers used state-of-the-art brain imaging, known as magnetoencephalography (MEG), along with machine learning tools, to measure and assess neural activity corresponding to inner states of mind during rest periods when the brain is consolidating its prior experiences.

For the study, 55 participants, 28 with schizophrenia (13 unmedicated) and 27 healthy volunteers, were given an abstract rule e.g [A ? B ? C ? D], and then asked to arrange in their minds a series of presented pairs of images into two distinct groups and sequences, by applying an abstract rule they had learned.

Once participants had completed the tasks they then relaxed for five minutes, enabling the brain to enter a 'rest period'; this is the time when the brain subconsciously replays its prior experiences using neural replay, and this is thought to be an important mechanism for memory consolidation as well as inference and belief formation.

Researchers found participants with schizophrenia were far less able to 'build a structure of the task. This behavioral impairment was directly linked to an impoverished expression of neural replay measured during a post-task 'rest-period'.

By contrast, healthy volunteers demonstrated a pattern of replay that was consistent with their brains inferring a correct task structure.

"These findings raise the tantalizing possibility that subtle impairments in memory replay might result in alterations in memory consolidation and belief formation, and thus explain previously mysterious aspects of schizophrenia."

Source: https://doi.org/10.1016/j.cell.2021.06.012