Neurotechnologies: Applications in Medicine and Society
As technologies that interface with the brain become more common, they offer new paths for healing while prompting vital conversations about privacy and autonomy.
Neurotechnologies are methods and devices that establish a direct connection with the nervous system to monitor, analyze, or influence the activity of neurons. The field is advancing by merging insights from neuroscience, engineering, and computer science. This progress is expanding the presence of these technologies in medicine and other areas of daily life.
Understanding Key Neurotechnologies
Electroencephalography (EEG) is a non-invasive technique that records the brain’s electrical activity. It functions by placing electrodes on the scalp to detect the electrical impulses from large groups of brain cells communicating. The resulting patterns, known as brain waves, are visualized as wavy lines and provide information about a person’s neurological state.
Functional Magnetic Resonance Imaging (fMRI) provides an indirect measure of brain activity by tracking changes in blood flow. When a brain area becomes more active, it requires more oxygen delivered by the blood. An fMRI machine uses magnets to detect changes in blood oxygenation levels, a process known as the blood-oxygen-level-dependent (BOLD) effect, to create maps showing which parts of the brain are engaged during specific tasks.
Transcranial Magnetic Stimulation (TMS) uses magnetic fields to modulate nerve cell activity in the brain. The procedure involves placing an electromagnetic coil against the scalp, which generates focused magnetic pulses. These pulses pass through the skull and induce small electrical currents in a targeted region, which can either stimulate or suppress nerve cell activity without surgery.
Deep Brain Stimulation (DBS) is an invasive procedure that involves surgically implanting electrodes into specific areas deep within the brain. These electrodes are connected by wires to a small, battery-operated device called a pulse generator, implanted in the chest. This device sends continuous electrical impulses to the brain electrodes to regulate abnormal signals that cause neurological symptoms.
Brain-Computer Interfaces (BCIs) create a direct communication pathway between the brain’s electrical activity and an external device, such as a computer or prosthetic limb. These systems acquire brain signals, decode the user’s intent, and translate that intent into commands. After a period of training, a user can learn to control the device using signals recorded non-invasively with scalp EEG or invasively with electrodes on the brain.
Impact on Medicine and Healthcare
EEG is a tool for diagnosing epilepsy, as it can detect the abnormal electrical discharges associated with seizures. It can also identify patterns that indicate a tendency toward seizures even when they are not occurring. EEG is also used to diagnose sleep disorders by monitoring brain wave activity to find irregularities that define conditions like insomnia or sleep apnea.
In surgical planning, fMRI is used to map eloquent cortex—the areas of the brain responsible for functions like language and movement. Before a surgeon removes a brain tumor, an fMRI scan can identify these regions. This pre-surgical mapping allows the surgeon to plan the procedure to maximize tumor removal while minimizing damage to functional areas, leading to better patient outcomes.
Deep Brain Stimulation (DBS) is an established surgical treatment for movement disorders like Parkinson’s disease. By delivering electrical impulses to targeted brain areas, DBS can interrupt the faulty nerve signals that cause motor symptoms such as tremor, rigidity, and slowed movement. This treatment can often allow for a reduction in medication.
Transcranial Magnetic Stimulation (TMS) is approved for treating major depressive disorder, especially for individuals who have not responded to other treatments. Repeated magnetic pulses stimulate nerve cells in underactive brain regions, like the prefrontal cortex. This stimulation can help regulate mood and alleviate depressive symptoms over a course of sessions.
Brain-Computer Interfaces assist individuals with severe paralysis from conditions like amyotrophic lateral sclerosis (ALS) or spinal cord injuries. BCIs can translate attempted speech or movement signals from the brain into text on a screen or commands to move a robotic arm. This provides a new way to communicate or control assistive devices.
Expanding Horizons Beyond Medicine
Beyond the clinic, neurotechnologies are tools in basic neuroscience and cognitive science research. Technologies like EEG and fMRI allow scientists to observe the brain in action. This provides insights into the neural underpinnings of perception, memory, learning, and decision-making, which expands our knowledge of how the brain works.
The applications for Brain-Computer Interfaces are extending into non-medical fields, including gaming, entertainment, and general device control. In gaming, BCIs could offer a more immersive experience where a player’s thoughts influence the game’s environment. The technology is also being explored for controlling smart home devices, offering a hands-free way to interact with the digital world.
A market has emerged for consumer neurotechnology devices, often in the form of headbands or earbuds that use simplified EEG sensors to monitor brain activity. They are marketed with claims of improving focus, aiding meditation, or tracking sleep quality. The effectiveness of many of these consumer-grade devices is still a subject of scientific inquiry, as they are not held to the same standards as medical devices.
Navigating Ethical and Societal Landscapes
The advancement of neurotechnologies brings complex ethical and societal considerations, with a primary concern being the privacy and security of neural data. This information can reveal sensitive details about an individual’s health, emotions, and cognitive processes. Questions about who owns this data and how to protect it from misuse are central to ongoing discussions.
These privacy concerns are linked to cognitive liberty, which is the right to self-determination over one’s own brain and mental experiences. As technologies gain the ability to influence brain activity, discussions have emerged about protecting an individual’s freedom of thought from potential coercion or manipulation. This includes the right to decide whether to use neurotechnologies to alter one’s own mental processes.
The issue of equity and access is another societal challenge. There is a risk that the benefits of advanced neurotechnologies, from medical treatments to cognitive enhancements, could be available only to the wealthy. This could create new forms of inequality or worsen existing social divides, making it important to ensure fair access.
The potential for bias in the algorithms that interpret neural data is a consideration. If these systems are trained on non-diverse datasets, they could lead to discriminatory outcomes. There are also dual-use concerns, where technologies developed for therapeutic purposes could be adapted for military, surveillance, or other non-benevolent applications.