Head over: Will ultrasound help treat depression and anxiety
Despite all the scientific progress, the workings of consciousness remain a mystery to scientists. For decades, neuroscientists have only been able to observe the work of the brain, without being able to directly influence the underlying processes. A development recently presented by MIT researchers, transcranial focused ultrasound (tFUS), can change the situation. The technology allows for non-invasive penetration through the skull and targeted effects on deep areas of the brain previously inaccessible to direct stimulation. Izvestia investigated what this might mean for ordinary people and scientists of different fields, and whether it is even possible to explore the subconscious mind.
What is the essence of the new development
For a long time, scientists have been trying to understand how thoughts, emotions, and sensations are formed in the brain. The main obstacle in these studies was the lack of tools that can directly track changes in brain activity during these processes.
Transcranial focused ultrasound (tFUS), which is being researched by scientists at the Massachusetts Institute of Technology (MIT), opens up new perspectives not only for science, but also for the average person. As Lev Yakovlev, a senior researcher at the Skoltech Center for Bio and Medical Technologies, notes, the technology allows noninvasively and with high accuracy to affect small areas of the brain, including deep structures that were previously practically inaccessible.
"Unlike the already used TMS and tDCS (transcranial magnetic stimulation and direct current stimulation — ed.), ultrasound can focus on subcortical areas that were previously practically inaccessible without surgery," the expert explained to Izvestia.
It is the nodes of neural networks in the subcortical zone that are responsible for the regulation of emotions, motivation and motor functions. That is, for everything that defines our personality in many ways.
Rinat Gimranov, professor, neurophysiologist and scientific director of the Clinic of Restorative Neurology, reminds Izvestia that the thalamus and elements of the limbic system are located here, including areas that are traditionally associated with emotions, sensations and unconscious processes. The very fact of the possibility of noninvasive effects on such structures, in his opinion, looks like a serious technological step forward.
The new technology may help neuroscientists and other scientists in establishing cause-and-effect relationships in the study of processes in the brain. They have a tool that allows them to purposefully change the work of specific neural circuits and observe how this affects sensations, perception and thinking. This is a fundamentally new level of consciousness study.
What does this mean for us?
The emergence of new technology opens up new perspectives for all people. First, it can provide a deeper understanding of the nature of pain, emotions, anxiety, depression, and other conditions. If it is possible to accurately identify the neural mechanisms underlying subjective experiences (such as anger, sadness, anxiety, or apathy), it will be possible to create more targeted and gentle therapies for mental disorders.
Secondly, it opens up the possibility of investigating a fundamental question: does consciousness arise solely as a result of complex cognitive processing, or can it be formed at the level of local neural patterns, including subcortical structures, that is, in fact, it is a physiological process? The answer to it can change the very understanding of human nature.
Finally, the technology creates conditions for ethically acceptable experiments with healthy volunteers, which was previously extremely limited due to the need for surgical intervention. In the future, such research may affect not only medicine, but also philosophy, psychology, education, and even the development of human-machine interaction technologies.
What technologies are already being used when working with the brain
Modern methods of neuroscience mainly allow us to record correlations between brain activity and human behavior. Electroencephalography (EEG) and functional MRI, which are well-known to many, show which areas are activated at a given moment and link these data to specific reactions or experiences. However, the presence of such a correlation has not yet meant an understanding of the cause-and-effect mechanisms.
This is where active neuromodulation techniques come into play, from transcranial magnetic stimulation (TMS) to ultrasound. They make it possible not just to observe, but to experimentally change the activity of specific areas of the brain. If this changes a person's behavior or subjective experience, there is reason to talk about the causal role of the stimulated zone.
— A similar approach has long been used to study relatively simple functions. For example, the motor and sensory cortex have a strict topical organization. That is why mapping the motor cortex using TMS has become a classic tool: stimulation of a specific area leads to movement of a certain part of the body. These principles are well studied and reproducible, which is clearly demonstrated by the well—known neural "homunculi", explains Olga Martynova, Associate Professor of the Basic Department of the Institute of Bioorganic Chemistry of the Russian Academy of Sciences, PhD.
However, as we move on to more complex cognitive functions, this clarity begins to fade. The higher the level, the more the localization becomes blurred. The frontal lobes and prefrontal cortex are involved in almost everything: emotions, behavior, cognitive and inhibitory control. Here it is no longer possible to say: "this point is responsible for a specific function."
— As a result, the study of consciousness and subconscious processes faces a fundamental limitation. The brain is a system with a huge number of neurons and degrees of freedom, where connections are constantly being rebuilt. Some of them are stable, others are temporary, arising only in a specific context. At the moment, it is almost impossible to accurately establish all the cause-and—effect relationships in the human brain," emphasizes Martynova. — There are too many variables.
However, even partial interference in the work of neural networks is already used in clinical work today. For example, depression is treated with TMS in cases where medication and psychotherapy are ineffective. Theoretically, similar approaches can be implemented using ultrasound, with higher accuracy and access to deep structures.
Functional MRI, in turn, provides a spatial picture — it shows which areas and networks are involved in emotions, memory, or intuitive decisions. But this is a slow method that captures metabolic changes rather than the electrical activity itself. Combining EEG and fMRI allows you to see exactly where the network is working and in what rhythm it functions. The addition of TMS takes the study to the next level — there is the possibility of intervention. The advent of tFUS extends this logic even further.
— If earlier we could mainly modulate the cortical nodes of networks, now it becomes possible to influence deep relays-thalamic and limbic structures. Namely, they largely determine the emotional coloring, motivation and intuitive assessment of stimuli," notes Gimranov.
According to the metaphor of the expert, EEG shows the "music" of the brain, fMRI shows the "map of the orchestra", TMS allows you to change the playing of individual instruments, and ultrasound for the first time gives a chance to reach the "conductor". Combined with behavioral tests, evoked potentials, and functional connectivity analysis, this creates a toolkit capable of linking objective neurophysiology with subjective experience.
A whole field is already being formed in psychiatry and psychotherapy, which can be conditionally called instrumental psychotherapy, says psychiatrist and psychotherapist Nadezhda Solovyova.
— Modern technological solutions are used in combination with classical therapeutic work. This is not about replacing psychotherapy, but about strengthening it. Transcranial stimulation (magnetic, electromagnetic and, in the future, ultrasound) is considered as an additional tool that expands the capabilities of a specialist and allows for a more targeted effect on certain areas of the brain, the expert notes.
Among the technological tools already used, she highlights VR therapy, which makes it possible to safely simulate frightening situations and conduct modern exposure therapy. Ultrasound stimulation in this context can become another way of accurate and personalized help, especially in cases where it is difficult for a person to cope with the condition only through volitional efforts or psychological techniques. However, it is important to use technology in conjunction with the work of a psychologist or psychotherapist, the specialist emphasizes.
What can ultrasound tell you about the brain?
However, experts emphasize that tFUS cannot yet be considered a completely "transparent" tool. Unlike transcranial magnetic stimulation, the mechanisms of action of which are relatively well studied, the effect of ultrasound on neurons has not been fully deciphered. Simply put, researchers can see the effect of their exposure, but they are not yet able to determine what exactly caused it.
— This may be a mechanical effect on the membranes of neurons, an effect on ion channels, changes in microcirculation, or a combination of several factors. We've learned how to reach deep, but we still don't fully understand what exactly we're doing there," explains Rinat Gimranov.
According to experts, it is precisely this uncertainty that marks the main boundary of technology today. On the one hand, tFUS already demonstrates high accuracy and relative safety, on the other hand, it requires a deeper understanding of biophysical mechanisms before it can be used for systematic research of consciousness and subconsciousness.
Is it necessary to limit the use of ultrasound
Obviously, there are certain limitations when using such a powerful tool. The first of them is financial in nature — so far the equipment looks too expensive for mass use, for example, in medical centers or clinics. But the development of technologies usually leads to their cheapening and standardization, recalls Nadezhda Solovyova. Therefore, in her opinion, we can count on the gradual integration of new technologies into clinical practice.
Lev Yakovlev, in turn, emphasizes the need for strict regulation. As technology evolves and commercial applications may appear, the issue of control, in his opinion, will become more acute. Even today, medical protocols require strict safety standards, and as the range of indications expands, this system should only be strengthened.
Experts agree that here, first of all, we are talking about the "technology of personality transformation." Therefore, any intervention is possible only within the framework of the patient's voluntary, conscious work and professionally structured medical care. In this sense, the future of transcranial focused ultrasound and other stimulation methods is not to replace therapy, but to expand the capabilities of modern medicine, where technology becomes part of an integrated, ethically regulated approach to treatment.
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