New research reveals how the brain deals with information that is not synchronized in time. The findings of the studies are of great importance in understanding neurological phenomena related to problems in the timing of sensory information, such as in multiple sclerosis and side neglect, and in the rehabilitation of patients who suffer from them. In addition, the findings will lead to the development of cutting-edge technologies for surgeries using robotic systems from a great distance.
Two new studies show how the brain represents delayed sensory feedback, that is, sensory information that returns to the brain for processing at a later time than the moment when the event that led to it occurred. Beyond the understanding of how the brain performs integration between the senses, these findings are important in the understanding of neural phenomena related to problems in the timing of sensory information, for example multiple sclerosis and lateral neglect (which may appear following a stroke), and in the rehabilitation of patients who suffer from them. Moreover, these findings will lead to the development of modern technologies for surgeries using robotic systems from a great distance.
The research was done as part of Dr. Guy Avraham's doctoral thesis, under the guidance of Dr. Ilana Nisky and the late Prof. Amir Karniel from the Department of Biomedical Engineering, and Dr. Lior Shmuelof from the Department of Brain and Cognition and the Zalotovsky Center for Nerve Research at Ben-Gurion University of the Negev. They were made in collaboration with Dr. Firas Mavasi (Johns Hopkins University), Dr. Raz Leib, Prof. Ofer Donhin, Dr. Assaf Pressman (Ben-Gurion University) and Prof. Sandro Moussa-Ibaldi (Rehabilitation Institute of Chicago) . The studies were carried out under the funding of the Israel-USA Binational Science Foundation (BSF), the National Science Foundation (ISF) and the agricultural, biological and cognitive robotics initiative of Ben-Gurion University of the Negev.
Dr. Ilana Nisky: "When interacting with the environment, such as knocking on the door, the sensory system in our body receives and processes signals from different senses: we feel the muscles of the raised arm stretch, we see the fingers collide with the door, hear the click, and feel the force which is obtained in the joints of the fingers. Although all the signals originate from a single event - the tapping - each of them reaches the brain and is processed at a different speed, so that the delays between the signals originating from different senses are obtained. This phenomenon is natural, and the fact that we perceive the clicking event as a single event indicates that the brain manages to cope with these delays. However, it is not clear how it does this: does it use an internal clock that allows it to represent the delay as a time difference between the current and the delayed information? Or is he estimating it only based on the current information available to him at that moment?"
In one of the studies, the researchers looked at how the brain deals with feedback Force suspended. The photo of Danny Machlis, the university's photographer, was chosen to represent the study on the cover of the Journal of Neurophysiology. As part of the study, subjects made straight movements towards a target, and at one point the researchers interfered with their movement by applying a force in a direction perpendicular to the direction of movement using a robotic arm. The strength of this force depended on the speed of the hand movement a few tens of milliseconds back (delayed speed). The subjects were indeed able to cope with the delayed force and returned to perform straight movements despite the presence of the force. However, the researchers found that the brain fails to represent the force as depending only on the delayed speed, but only as a combination of the current and delayed speeds.
In the second study, accepted for publication in the journal eNeuro, the researchers looked at how the brain deals with feedback I saw suspended. Subjects played a virtual pong game: by moving their hand, they controlled the movement of a racket on the screen and were asked to hit a ball moving on a plane. During the experiment, the researchers paused the movement of the racket in relation to the movement of the hand (similar to what happens when working with slow computers). After the subjects played for a certain amount of time in the delayed environment, it was found that they performed longer movements than those they performed before. That is, the brain of the subjects was not able to interpret the delay between the movement of the hand and the movement of the racket as a time difference, but as a spatial distortion of the relationship between them.
Dr. Guy Avraham explained that these studies indicate that dealing with delay during the performance of motor actions is not necessarily done through the use of internal clocks that measure time, but through a representation based on current information. As mentioned, this conclusion has great value in understanding neurological phenomena and developing relevant medical technologies for treatment and rehabilitation.
One response
Hello, I'm recovering from Corona. (It's been about a month and a half since the symptoms appeared).
And I was left with breathing difficulties and a sharp decrease in brain functions.
After a neurological examination I was told that there is indeed delayed brain damage.
I couldn't really understand what it is???
I would appreciate it if you could get back to me by email and explain a little. And also does it pass to corona patients? If so when? And can the situation deteriorate further? And is there a possibility to do exercises or something else that will help solve the problem.
Thank you very much, Orly.
Please do not display this email on the website.