A powerful combination of engineering, artificial intelligence and brain research may lead to a new era in medicine
When we interact with the environment, the sensory system in our body receives and processes signals from different senses. "For example," says Prof. Ilana Nisky from Ben-Gurion University of the Negev, "when we knock on a door, we feel the muscles of the raised arm stretch, we see the fingers collide with the door, hear the click, feel the force received in the finger joints and the stretching of the skin at the time of contact. Although all the signals originate from a single event - the click - 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 the various delays."
In her studies, which won a research grant from the National Science Foundation, and which were carried out in her laboratory in the Department of Biomedical Engineering, together with her students and research partners, Prof. Nisky examines how exactly the brain manages to attribute all these signals to that single event. Does it, for example, use an internal clock that allows it to represent the delay as a time difference between the current and the delayed information? Or does he estimate it only based on the information available to him at that moment, without reference to the time differences? Beyond the understanding of how the brain performs integration between the senses, the findings may be important in the understanding of neural phenomena related to problems in the timing of sensory information, for example in side neglect (which may appear following a stroke), as well as in the rehabilitation of patients who suffer from these diseases or phenomena. The scientists, led by Prof. Nisky, hope that these findings will lead to the development of cutting-edge technologies in which there is an inevitable delay in the transfer of information, such as surgeries using robotic systems from a great distance.
In one of the experiments carried out as part of the research, which won a research grant from the National Science Foundation, subjects made straight movements towards a target. At one point in the experiment, the researchers interfered with the movements 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 of the subjects in the study, and was activated with a delay of several tens of milliseconds. The subjects were indeed able to cope with the delayed force and returned to performing straight movements despite the disturbance. However, the researchers found that the brain fails to represent the force as a factor that depends only on the delayed speed, but only as a combination of the current and delayed speeds.
In another study, the researchers looked at how the brain deals with delayed visual feedback. Subjects played a virtual ping 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 subjects' brains failed 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. What is the question? What happens when the sensory feedback that our body transmits to the brain is delayed? And how can you compensate for the delay and reduce its consequences?
Dealing with a delay in performing motor actions is not necessarily done through internal clocks
Dr. Guy Avraham, whose studies were carried out in part as part of his doctoral thesis and who is currently conducting post-doctoral research at the University of Berkeley in California, says that the findings of the studies indicate that dealing with a delay in the performance of motor actions is not necessarily carried out through internal clocks, but through a representation based on information in real time. However, the picture is even more complex. In a series of studies in Nisky's laboratory led by Dr. Raz Leib, who is currently doing postdoctoral research in Munich, Germany, the scientists found seven tactile "virtual" springs (which are actually activated by robotic arms), something that simulates the movement of a doctor checking whether a tissue he is touching is health, or as we all examine the degree of ripeness of fruits; The effect of delay is different on perception and action. While the delay makes us think that the springs we are touching are softer, we are applying gripping forces to the object that match the object's true stiffness and are timed as if our brain is able to accurately represent the difference in times.
Prof. Nisky says that in addition to her basic research, as the head of the biomedical robotics laboratory, she feels obligated to try and contribute to applied research as well. Together with her clinical partners from Soroka Hospital, she aims to improve the training of surgeons, using methods of remote surgery and virtual reality. With her partners from the physiotherapy department, she develops sensory interfaces that will help in the rehabilitation and daily life of patients with neurological diseases. To this end, she recently joined the rehabilitation laboratory at "Adi-Negev Nachalat Eran" as the main researcher for rehabilitation with sensory interfaces.
Prof. Amir Karniel Ali HaShalom, and Dr. Lior Shmuelof from the Department of Brain Research also participated in these studies, as well as Prof. Ofer Donhin, Dr. Assaf Pressman from Ben-Gurion University of the Negev; Dr. Firas Mavasi who recently established a lab at the Technion, and Prof. Sandro Moussa-Ibaldi from the Rehabilitation Institute in Chicago. Nisky's clinical partners are Prof. Yael Rafali, Dr. Uri Netz, Dr. Yair Binimini, and Prof. Alex Geftler, all from the Soroka University Center, and Dr. Simona Bar-Chaim from the Department of Physiotherapy at Ben-Gurion University of the Negev and the Rehabilitation Laboratory at Adi-Negev Nachelat Eran" in Ofakim.
Life itself:
Prof. Nisky ran long distances, enjoys running in the field, and especially in the desert, in the Sde Boker area, south of Be'er Sheva. She participates in marathons to enjoy running, not for competitive motivation. In her training runs she is joined by the dogs she raises. In addition, she also enjoys climbing, at this point on an artificial climbing wall, but soon she hopes to try her hand in this field, in the field. She is married to Dr. Uzi Hadad from Ben Gurion University, and they both have a daughter, Dror. These days she plans to go on a sabbatical in Cambridge, England, and after her return she and her family will move to Kibbutz Talalim in the Negev.
