Research Suggests an Expanded Role of the Brain’s Thalamus

Research that is taking a closer look at activity in the thalamus — a region long considered a relay station for the brain and involved in consciousness and motor activity — reveals the thalamus may play a decisive role in abstract thinking and executive control. The collaborative work by researchers at the University of Wisconsin-Madison and Stony Brook University and their findings are detailed in a paper published in the journal Neuron.
By investigating the electrical properties of the cells and tissues (electrophysiology) of the thalamus in a primate model, in combination with computer modeling, the research team showed that higher-order thalamic nuclei can select behavioral rules and dynamically shape activity in the prefrontal cortex, the region responsible for cognitive flexibility.
They used precision simultaneous electrophysiology, which revealed that the thalamus does not just passively transmit information, as might be expected of a relay station in the brain, but instead actively guides the brain’s most complex decisions — a unique finding in current neuroscience work.
“This discovery offers a breakthrough in understanding how higher-level brain functions work and could lead to new treatments for conditions like schizophrenia, ADHD, and brain injury using targeted brain stimulation,” said study co-author Sima Mofakham, assistant professor and director of research in the Department of Neurosurgery in the Renaissance School of Medicine (RSOM), and assistant professor in the Department of Electrical and Computer Engineering at Stony Brook University.

She adds that the findings frame a new role for the thalamus in the prefrontal cortex, essentially acting as a guide and shaping cortical dynamics, a process which would likely be the same in humans.
Traditionally, scientists have thought that the cortex, especially the prefrontal cortex, does all the heavy lifting for the brain in abstract thinking and cognitive control. But this research changes that perception and may provide a new basis for neuroscience investigation on specific roles of brain regions, namely the thalamus.
A research team from the University of Wisconsin-Madison, led by Jessica Phillips (first author) and Yuri Saalmann (senior author), conducted MRI-guided electrophysiological recordings as primates completed various tasks. Mofakham and Charlies Mikell, along with PhD student Xi Cheng, at Stony Brook Medicine completed the computational modeling that was crucial to confirming the results.
According to Mofakham, continued research is necessary to further understand what the electrophysiological activity in the thalamus related to prefrontal cortex executive functioning fully means.
However, she and colleagues believe the findings also have implications for designing next-generation brain-computer interfaces and artificial intelligence systems capable of making real-time adaptive decisions. For example, brain-computer interfaces could one day leverage thalamic signals to better interpret intention, context and abstract goals within brain decision-making processes, and deep brain stimulation could target thalamic hubs to help restore goal-oriented behavior or awareness in pathological cases.
This research was supported, in part, by several National Institutes of Health grants: R01MH110311, R01NS117901 and P51OD011106.
For more about the broader neuroscience research conducted on consciousness at the RSOM, see this link to the Mofakham Mikell Laboratory.