Scientists at Brown University have uncovered how the human brain optimizes working memory through learning, potentially revolutionizing treatments for dopamine-related disorders like Parkinson’s and ADHD.
Scientists at Brown University’s Carney Institute for Brain Science have made significant strides in understanding how humans optimize working memory, a cognitive function crucial for daily tasks such as remembering phone numbers or making grocery lists. Their research sheds light on the mechanisms underlying working memory limitations and offers new insights into treating dopamine-related disorders like Parkinson’s disease, ADHD and schizophrenia.
Michael Frank, a professor of cognitive and psychological sciences, along with graduate student Aneri Soni, developed a computer model representing the basal ganglia and the thalamus — critical brain regions for working memory. According to their study published in eLife, the key to understanding working memory limitations lies in the process of learning.
“The simulations we ran show that if we did hold more than just a few items at a time, it becomes too difficult to learn how to manage so many pieces of information at once, such that the brain gets confused and can’t use the information it does store,” Soni said in a news release. “At the same time, our research demonstrates that when faced with these limitations, the brain responds by learning to strategically tap into a mechanism to help conserve space.”
The researchers pinpointed dopamine’s pivotal role in how learning is connected to working memory. This neurotransmitter is known for its influence in disorders such as Parkinson’s disease, ADHD and schizophrenia.
By mimicking the brain’s dopamine delivery system within their computer model, Soni and Frank were able to delve deeper into how these disorders impact cognitive functions.
The team tested this model against a prior human experiment from 2018 conducted by researchers in Frank’s lab and researchers in the lab of Matt Nassar, an assistant professor of neuroscience and cognitive and psychological sciences at the Carney Institute. This earlier study found that humans can “chunk” related information together to better manage working memory.
Soni validated her brain-like computer model by challenging it with a task similar to the 2018 experiment. The model was shown screens with colored blocks in different orientations and then asked to recall the direction of each color. Over time, the model learned to compress related colors, such as blue and light blue, into chunks to save mental space.
By running simulations with and without the chunking mechanism, the researchers discovered that learning, not storage capacity, drives working memory efficiency. The model with a chunking ability used its storage space more effectively, reflecting how strategic information storage is essential to cognitive performance.
Frank emphasized the broader implications of these findings.
“Take Parkinson’s disease as an example. Most people think of it as a movement disorder because changes in movement are so obvious. But it turns out that Parkinson’s patients also have changes in working memory,” he said in the news release. “They are generally treated with drugs that target the prefrontal cortex, but our findings suggest that we should be testing whether drugs that target the basal ganglia and thalamus help to improve symptoms.”
The team’s research could prompt new treatment options for patients with dopamine-related disorders by enhancing understanding of how the basal ganglia and thalamus function.