Summary: The anterior lateral motor cortex, an area of the brain associated with action planning, plays a major role in premature actions such as when a person “jumps the gun”, or starts to run before a race starts.
Source: Florey Institute of Neuroscience and Mental Health
In a study published in Nature Neuroscience, a team led by The Florey’s Associate Professor Lucy Palmer found that the anterior lateral motor cortex—a part of the brain that plans physical movement—plays a major role in premature actions, or “jumping the gun.”
When cell activity in this part of the brain was suppressed in the animal model, the success rate of the anticipated behavior drastically increased.
Associate Professor Palmer says this is an early milestone for research into addictive behaviors and conditions such as schizophrenia and obsessive compulsive disorder.
“The anterior lateral motor cortex, the ‘ALM,’ is well-known for its role in planning actions, but until now we have never understood its role in premature actions—when we anticipate an action but get it wrong,” said Associate Professor Palmer.
“We have all seen athletes have false starts—this is a great example of anticipating a cue and acting impulsively. Our study shows that too much brain cell activity in the ALM increases the chance of these ‘false starts.’
“This is interesting information for everyone—we all control impulses every day. But it gives important insights into conditions where we see impulsive behavior that we struggle to control—such as gambling, use of drugs and alcohol and a plethora of mental health conditions.
“This study gives us important knowledge to build future research on. This part of the brain could be a key target for treatment of a wide range of neurophysiological diseases in the future.”
Neural basis of anticipation and premature impulsive action in the frontal cortex
Planning motor actions can improve behavioral performance; however, it can also lead to premature actions.
Although the anterior lateral motor cortex (ALM) is known to be important for correct motor planning, it is currently unknown how it contributes to premature impulsive motor output. This was addressed using whole-cell voltage recordings from layer 2/3 pyramidal neurons within the ALM while mice performed a cued sensory association task.
Here, a robust voltage response was evoked during the auditory cue, which was greater during incorrect premature behavior than during correct performance in the task.
Optogenetically suppressing ALM during the cued sensory association task led to enhanced behavior, with fewer, and more delayed, premature responses and faster correct responses.
Taken together, our findings extend the current known roles of the ALM, illustrating that ALM plays an important role in impulsive behavior by encoding and influencing premature motor output.