A Step Closer to 'Remote Mind Control'
Stimulation of deep brain structures through technological means is currently achieved in a several ways, invasive and non-invasive. The most widespread methods have some advantages and applications, but also downsides. Deep brain stimulation—already in use for three decades—involves the surgical insertion of electrodes into the brain to send electrical pulses to the targeted areas. Despite its usefulness in the treatment of Parkinson's, dystonia or obsessive-compulsive disorder, it is an inherently dangerous procedure owing to the risk of hemorrhage or infection.
Transcranial magnetic stimulation (TMS), on the other hand, stimulates brain tissues non-invasively through electromagnetic induction. It merely involves the placement of an electric coil near the patient's head, directly above the brain region of interest. This technique helps diagnose numerous conditions and may help manage major-depressive disorder and neuropathic pain. The downside is the lack of precision - TMS cannot be used to excite a very small region of the brain.
To circumvent these obstacles, researchers took advantage of a strategy that involves inducing a low-frequency electric field region inside the brain by intersecting two high-frequency electrical currents generated by electrodes placed on the patient's scalp. The intersection creates a phenomenon known as temporal interference, which excites the brain cells. Changing the frequency, power and direction of these electric fields allows researchers to precisely control where and how large the low-frequency stimulation is. The high-frequency currents don't affect neurons, so this technique is free from side effects. The same cannot be said of deep brain stimulation and TMS.
Experimenting with mice, scientists were able to 'exercise' the hippocampus and different parts of the motor cortex. The amazing control granted by the technique is reminiscent of science fiction tales as scientists were able to induce behavioral responses from mice, prompting them to move their ears, paws and whiskers. Although the spatial resolution still lags behind deep brain stimulation, the new method shows great promise as an alternative treatment for Parkinson's, depression and many other brain-related conditions. The head of the Picower Institute for Learning and Memory, Li-Huei Tsai, highlights how this technique is versatile enough to control behavioral responses in addition to inducing neural activity.
Tsai is not new to 'remote brain control'. Using nothing but light, she had already managed to induce anti-amyloid plaque brain waves in mice, the results she hopes to replicate with the new temporal interference-based transcranial electrical brain stimulation technique given the serious implications for Alzheimer's treatment. The study documenting the new method has been published in the journal Cell.
The breakthrough results from a collaboration between the Massachusetts Institute of Technology (MIT), the IT'IS Foundation and the Beth Israel Deaconess Medical Center. While transcranial electrical stimulation is not necessarily a new development, this technique is one of the most promising. Transcranial electrical stimulation has the potential to be harmless and significantly more affordable than alternative methods such as transcranial magnetic or transcranial ultrasound stimulation.