During high-stress situations such as making a goal in soccer, some athletes experience a rapid decline in performance under pressure, known as "choking." Now, Salk Institute researchers have uncovered what might be behind the phenomenon: one-way signals from the brain's emotion circuit to the movement circuit.

This study could contribute to novel approaches in dealing with disorders with disrupted movement, such as obsessive-compulsive disorder, anxiety and depression, along with aiding in recovery from spinal cord injuries or physical performance under pressure.

"This finding is very exciting as it is the first time that a comprehensive circuit mechanism has been found showing how emotional states can influence movement through connections in an area of the brain called the basal ganglia, a region involved in guiding behavior," says Associate Professor Xin Jin, senior author on the paper. "We did not previously know much about this pathway, so it brings about a whole new paradigm for examining psychiatric disorders as well as spinal cord injury."

Previously, it was thought that the brain’s emotion and movement loops were independent of each other. However, researchers believed that there could be more to this. Looking at neuropsychiatric conditions like depression, increased inactivity is known to be a symptom that could be the result of disrupted emotional processing and reduced motivation. Still, scientists did not have much to go on about the connections within each circuit or how the circuits might interact.

"We wanted to explore how emotion information reaches the movement circuitry in the brain by using a combination of cutting-edge viral and optogenetic techniques," says Sho Aoki, co-first author and postdoctoral fellow in the Jin lab.

Using various genetic and viral tracing tools, the scientists studied areas of the brain involving emotion and movement. Their goal was to trace these circuits in mouse models to get a better idea of each step of neuronal communication, as well as to observe how each loop was organized in the brain.

Astonishingly, they located a one-way communication pathway from the emotion loop to the movement loop through an area located deep in the brain called the basal ganglia. This area is associated with several functions such as control of voluntary motor movements, procedural learning, habit learning, eye movements, cognition, and emotion. It acts as a junction for the emotion circuit to directly access the movement circuit, thus controlling action.

"Psychiatric diseases such as depression and anxiety can alter actions in a dramatic way by either decreasing or increasing movement. This mechanism represents a likely way that emotional states are related to changes in action control in psychiatric diseases," says Jin.

Findings from this study may prove useful for spinal cord injury recovery. Before this, researchers focused on movement centers in the brain. It made sense because spinal cord injury is a movement issue. However, since these results suggest that emotions can influence brain movement centers, experiencing positive emotions such as motivation may aid patients in the recovery process. Activating emotion centers could likewise stimulate movement centers and facilitate recovery, according to the Salk co-first authors Jared Smith, a postdoctoral fellow, and Hao Li, a senior research associate.

Furthermore, these results suggest that emotional states could directly influence sports performance. So, Jin advices, maybe the next time you feel anxious during a game, just calm down and let the action take care of itself.