We know that the brain can direct thoughts, but how this is achieved is difficult to determine. Researchers at the Sainsbury Wellcome Center have devised a brain-machine interface (BMI) that allows mice to learn to guide the cursor using only their brain activity. By tracking this mouse by controlling the mouse by moving it to a target location to get a reward, the researchers were able to study how the brain represents intentional control.
The study, published today in Neuron, illuminates how the brain represents cause-controlled objects. The researchers found that when mice controlled the cursor, brain activity in the higher visual cortex was directed toward the target and contained information about the animal’s intent. This research could one day help improve BMI design.
“Brain machine interfaces are devices that allow a person or animal to control a computer with their mind. In humans, it can be controlling a robotic arm to pick up a cup of water or moving the cursor on a computer to type a message using In animals we use these devices as models to understand how improve BMI “, said the first author of the paper, dr. Kelly Clancy, who completed her studies at the Sainsbury Wellcome Center, University College London, after previous work at the Biozentrum, University of Basel.
“Currently, BMI is difficult for people to use and takes a long time to learn how to operate a robotic arm, for example. Once we understand the neural circuits that support how to learn intentional control, which this work begins to shed light on, we hope to make it easier for people to use BMI. and, ”said the co-author of the paper, Professor Tom Mrsic-Flogel, director of the Sainsbury Wellcome Center, University College London.
Traditionally, it has been difficult to study how causally controlled objects are represented in the brain. Imagine trying to determine how the brain represents the cursor it controls relative to the cursor it is passively observing. In the first case there are motor signals, and in the second not, so it is difficult to compare the two. In BMI, the subject does not move physically, so a clearer comparison can be made.
In this study, the researchers used a technique called wide-field imaging of the brain, which allowed them to look at the entire dorsal surface of the cortex while the animal used BMI. This technique allowed an unbiased cortex screen to locate areas that were involved in learning with intentional cursor control.
Visual cortical areas in mice were found to be involved during the task. These areas included the parietal cortex, an area of the brain involved in intent in humans.
Researchers have long studied the parietal cortex in humans. However, we did not necessarily expect this area to pop up on our unbiased mouse brain screen. There appears to be something special in the parietal cortex that is located between the sensory and motor areas in the brain and can act as a passing cell between them. “
Dr. Kelly Clancy, first author of the study, Sainsbury Wellcome Center
By delving deeper into the way this cell functions, researchers hope to understand more about how the brain controls. In this study, mice learned to map their brain activity into sensory feedback.
This is analogous to the way we learn to communicate with the world – for example, we adapt the way we use a computer mouse depending on the gain setting. Our brains build notions about the behavior of objects and perform actions accordingly. By understanding more about how such rules are generated and updated in the brain, researchers hope to be able to improve BMI.
Sainsbury Wellness Center
Clancy, KB, and others. (2020) Sensory display of causally controlled objects. Neuron. doi.