Summary: New research has revealed that switching between actions is more complex than just stopping and starting again, but rather a distinct brain mechanism that blocks the earlier action to prompt a new one. Using mathematical designs, behavioral duties, and scientific data from Parkinson’s patients, researchers found that stopping and switching are different mental machine processes.
This understanding could lead to more effective treatments for neurological conditions like Parkinson’s and provide inspiration for autonomous systems ‘ biologically motivated models. The findings show the richness and accuracy of how the human brain quickly adapts to change.
Important Information:
- Switching vs. Switching actions are distinct from stopping, constantly suppressing previous movements.
- Parkinson’s Insight: Studying Parkinson’s people during deep brain stimulation reveals crucial mental activity related to switching.
- Potential Applications: Recognizing activity regulation could lead to new automation technologies and improve treatments.
Origin: USC
New USC study offers an unknown understanding into how the brain shifts gears. The researchers discovered that a special head process is responsible for our innate ability to quickly alter motor function.
We watch in awe as our favorite person easily switches movements in the NBA’s high-stakes world in the blink of an eye. A great touchdown is instantly defended. The shooter reverses direction in midair and heads to an empty partner for a part three.
When life throws us a ball, people have a remarkable ability to quickly move between various motor activities. You try to open a doorway, but you suddenly realize you have to go outside. In visitors, you must think hard to alter from accelerating to avoiding or braking to prevent an obstacle.
The important question is whether the brain’s function is the same as the one used to prevent our movement. The mind function that helps us change program has been the subject of extensive scientific debate.
A new research from USC’s Alfred E. Mann Department of Biomedical Engineering has uncovered that this change is a unique actions that constantly suppresses the preceding one, allowing a smooth transition to the new destination.
The research group has also been observing Parkinson’s patients playing basic video game tasks in order to analyze the system in action.
The study, which was published in the journal PLOS Computational Biology, sheds new light on how our brains choose, cease, and switch between steps.
The difficulty of how this is triggered in the mind has long been a secret, according to lead author Vasileios Christopoulos, an associate professor of biological architecture.
” Typically, psychologists believe that switching is an extension of stopping. It’s what we refer to as “go, quit, go.” You leave. You quit and you switch to the new motion”, Christopoulos said.
” However, we think that your head doesn’t do that, especially when you have to do something really quickly. Instead, the new behavior halts your previous action without employing another system to halt it. Stopping and switching are two distinct mental machine techniques”.
Given that people constantly change and manage their actions throughout the day, Christopoulos claimed that understanding the function was essential.
We can develop healthier medical treatments for patients if, from a clinical standpoint, we can better understand how the brain regulates activities and how Parkinson’s affects these mechanisms, said Christopoulos.
” There’s also the executive view. If we can build a design of the brain that generates activities, we can build biologically inspired robotic techniques that mimic autonomous cars in accordance with how the brain basically regulates these actions.
The study team used a three-pronged method to test their hypothesis about how mental switches activities work.
First, they built a mathematical model of the brain, which aimed to model how the brain decides which action to do, how it inhibits an continued action, and how it initiates a fresh action when the context changes.
Then, they used human participants to perform tasks like switching, stopping, and reaching movements.
The team compared the motor behaviors of the participants to the model-generated motor patterns.
Finally, the team has been working with Parkinson’s patients at Cedars Sinai and the University of Texas Southwestern Medical Center to see the mechanism in action through patients ‘ recorded brain activity.
Nader Pouratian, the chair of the neurosurgery department at UT Southwestern Medical Center, is Christopoulos ‘ co-author on the paper. In addition to creating and analyzing the behavioral data for the study, Shan Zhong, a postdoctoral researcher in the Alfred E. Mann Department, created the computational models.
This new insight into one of the foundational aspects of human motor control could be an essential development for the 90, 000 Americans diagnosed with Parkinson’s disease each year.
When they want to move, Parkinson’s patients experience longer reaction times and delays as compared to those of us who don’t have complex neurological conditions.
The USC Viterbi research team was interested in this patient group because their treatment involves intense brain stimulation of the subcortical regions that regulate motor function, which is a prime opportunity to track brain activity in order to understand the intricate mechanisms underpinning motor regulation in this region.
Christopoulos said that when the patients in the test groups undergo the deep brain stimulation procedure, the surgeon accesses this region via a burr hole, inserting a long electrode that simultaneously allows brain activity to be monitored while they are awake during treatment. The method aims to treat Parkinson ‘s-related tremors by stimulating the subthalamic nucleus or STN region, which Christopoulos described as the brain’s natural braking system, a crucial component of the switching-gears mechanism.
” This is how our brains stop our actions. For instance, we’ve all experienced that sensation when you freeze because you’re scared or surprised”, Christopoulos said.
This area of the brain that causes you to become scared is what happens when it sends a signal to the brain to stop what you’re doing right away. This area is hyperactive and causes a tremor and bradykinesia ( slowed movement ) in Parkinson’s patients.
” The patients are awake and given a joystick. We show them tasks that involve reaching for targets, stopping an action, and switching an action from one target to the other, Christopoulos said.
” So, the next step is to extract this information from the neurosurgeons and analyze it. We’re going to see how similar the predictions of our simulated model are to what actually happens in the brain”.
Christopoulos claimed that the research had added clinical value. Monitoring how Parkinson’s patients perform while receiving deep brain stimulation and how the treatment affects the brain could aid in preventing unnecessary side effects and enhancing patient care.
By harnessing their computational model supported by carefully designed experiments, Christopoulos and his team are continuing to unravel the intricate neural mechanisms that underpin our most essential cognitive functions, paving the way for new discoveries and applications.
Funding: An NIH U01 award titled” Modeling and Mapping Human Action Regulation Networks” provided funding for the study.
About this news about neuroscience research
Author: Amy Blumenthal
Source: USC
Contact: Amy Blumenthal – USC
Image: The image is credited to Neuroscience News
Open access to original research
Vasileios Christopoulos et al.,” switching of motor actions is a computational mechanism..” PLOS Computational Biology
Abstract
switching of motor actions is a computational mechanism.
Survival of species in an ever-changing environment calls for a flexibility that goes beyond just picking the most appropriate actions. It also involves readiness to stop or switch actions in response to environmental changes.
Although a lot of research has been done to understand how the brain switches actions, it is still difficult to understand how the switching process works and how it relates to the selecting and stopping processes.
A standard theory suggests that switching is merely an extension of the stopping process, in which a current action is first blocked by an independent pause mechanism before a new action is created.
This theory was challenged by the affordance competition hypothesis, according to which the switching process is implemented through a competition between the current and new actions, without engaging an independent pause mechanism.
We used a neurocomputational theory to model the selection, stopping, and switching of reaching movements in order to define the computations that underlie these action regulation functions.
We tested the model predictions on healthy people who performed reaches in dynamic and uncertain environments that frequently necessitated stopping and switching actions.
Our findings suggest that unlike the stopping process, switching does not necessitate a proactive pause mechanism to delay movement initiation.
In response, different mechanisms appear to be used during the planning stage of the reaching movement to implement the switching and stopping processes.
However, once the reaching movement has been initiated, the switching process appears to involve an independent pause mechanism if the new target location is unknown prior to movement initiation.
These findings offer a new understanding of the computations underlying action switching, contribute valuable insights into the fundamental neuroscientific mechanisms of action regulation, and open new avenues for future neurophysiological investigations.
