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RESEARCH

SERENA ZHAO, Harvard College '24

Discovering ourselves with EEG

THURJ Volume 13 | Issue 2

In recent decades, the field of neuroscience has been advancing at extraordinary rates. From treatments for neurodegenerative diseases, to neuron formation and restoration, to relationships between behavior and brain chemistry, many important discoveries have been made in humanity's pursuit to understand its most complex organ: the brain. What was once elusive is becoming more clear to us, but while this clarity brings great scientific and medical potential for human health, it also requires us to re-examine our ethical boundaries in science.
One of the most crucial and advanced organs in the human body, the human brain is the command center for the human nervous system, making up about 2 percent of a human's body weight. Though it has the same basic structure as other mammal brains, the human brain is larger in relation to body size compared to other brains. This larger size is a defining feature of human anatomy and allows the human brain to specialize to a more detailed extent than other mammal brains. Functional specialization is a common property of biological systems, so it comes as no surprise that the brain may exhibit this same type of specialization.” While the true extent of functional special n (versus a more general- purpose model of function for the brain) is still being studied today, hemispheric specialization is a prominent characteristic of the organization of the human brain.
Also known as cerebral dominance or lateralization of function, hemispheric specialization is the relative specialization between the two hemispheres of the human brain: the right hemisphere is better suited for more holistic and coarse information processing, while the left hemisphere is better suited for more analytic and fine- grained processing. When demand for task processing is, high, the brain's processing capacity can be increased by interaction between these two processors. Specialization of the brain accounts for our dexterity, capability for higher-level reasoning, ability to feel nuanced emotions, and other unique cognitive and emotional capability that humans possess. In addition, this type of structural and functional organization is significantly capitalized
upon in scientific studies and experiments related to the brain, a point that will be explored throughout this article.

Since the earliest civilizations, humans have been intrigued by the brain - and rightly so, for the brain is the root of a whole host of medical conditions, from. mild headaches to life-threatening glioblastomas. Unfortunately, out of all the organs in the human body, the brain may be the most difficult one to study, with and without modern technologies. The brain is an incredibly delicate organ, and little disturbances on an individual's brain have the ability to damage major cognitive, emotional, and motor functions. This means that, in order to study the brain while it is alive, we must either employ completely non-invasive technologies or have a very good understanding of what can and cannot be touched, both of which are high requirements. Because of this, ancient civilizations studied human cadavers, which lacked living brain cells and thus could not show the living processes of the brain. In recent years, however, this has changed.
Diving into our Brains
In order to study the brain, we must first understand
how the brain functions. The brain contains 80-100 billion nerve cells, or neurons, each of which is connected to more than 1,000 other neurons. In total, there are around 60 trillion connections, or synapses. These synapses become important when we examine exactly how neurons transmit information. Neurons communicate with each other using electrochemical signals - which is simply an electrical signal produced by chemical changes - by changing ionic concentrations across a cell membrane to affect the electrical charge of the neuron. This mechanism is best explained by an example: suppose you stubbed your toe on a wall. This stimulus - the painful action of stubbing your toe - causes neurons in your body to respond by taking in more positive ions, which makes the cell more positively charged. Once the cell reaches a certain charge threshold (approximately -55 mV), the neuron fires an action potential, which is an event that occurs when a cell membrane rapidly gains positive charge (depolarization) and then loses it (repolarization). The action potential
travels through the length of the neuron, but once it reaches the end of the neuron, the electrical signal triggers the release of neurotransmitters into the synapse between the next neuron, These neurotransmitters are able to cross the synapse and attach to receptors on the next neuron, acting as a stimulus to activate that neuron and continue the signal, restarting the process above. This effectively sets off a chain reaction that is complete when the signal finally reaches the brain, where it is processed (at which point you will consciously register the pain coming from your stubbed toe). This whole process is also extremely efficient: even though neurons range from less than a millimeter to more than a meter in length, the speed of a signal ranges from 1 mile per hour to upwards of 268 miles per hour, depending on the type of neuron,” At the heart of neural activity is electrochemical
signals that trigger such activity, so it only makes sense that we study brains and brain functions through the lenses of electricity. This has several advantages, among them considerations for both scientific accuracy and convenience. Firstly, there are methods of studying electrical activity - with electrodes and signal measuring devices - that do not require direct contact with the source of electrical activity. This means that we do not have to cut open a person's head to study their brain, eliminating the necessity of using human cadavers. Secondly, since electrical activity can be studied without opening brains, living people may be used to study brain activity: this opens the realm of discovery beyond just physical brain structure and allows scientists to examine how living brains function and react to different stimuli. Finally, electrical activity is simple to measure and yields relatively accurate results, allowing us to obtain scientifically accurate and objective data.

Indeed, recent neuroimaging techniques reveal that scientists are studying brains through a variety of biomarkers and indicators, including electrical activity. Electroencephalography (EEG) is a method that records the brain's electrical waves to detect abnormal activity, such as in seizures and sleep disorders. ("Scanning the Brain’) EEG tests are conducted in a variety of settings, from medical diagnoses to clinical trials. During an. EEG test, electrodes made of small discs with thin wires attached are pasted onto the subject’s scalp. The electrodes detect electrical charges originating from neuron activity and amplify these charges, and a computer connected to the electrodes records the amplified charges. The recorded electrical signals then appear as a graph on a computer screen or as a printed recording on paper. Trained professionals are then able to analyze the results based on EEG wave shape, amplitude, frequency and; any unusual behavior. ("Electroencephalogram (EEG)")

EEG is used to diagnose a variety of conditions.
Historically, EEG has been used to observe and diagnose epilepsy, brain lesions resulting from tumors or stroke, brain trauma, drug intoxication, and narcolepsy, or any other medical condition that involves a change in brain activity or related abnormalities. (“Electroencephalogram (EEG)") More recently, the boundaries of EEG use are being pushed and refined, as new medical uses are discovered and the actual technology is improved. In particular, EEG use in the realm of psychiatric practice is being studied and developed, with studies supporting the use of EEG in diagnosis and treatment of autism spectrum disorder (ASD) and schizophrenia.
as a method to diagnose ASD for refractory cases or for individuals who are on anti-seizure medication but still it aggressive behaviors. Similarly, EEG could be incorporated into a precision medicine approach to treat cognitive impairment in schizophrenia with tailored treatments to each individual, overall treatment efficacy may rise.9 In addition, the accuracy of EEG methods is sometimes compromised due to reliance on a trained professional to visually examine the produced wave graph, so researchers are developing new machine learning methods to complete EEG classification tasks. Theoretically, these deep learning methods can increase the accuracy and efficiency of EEG methods, thereby increasing their practicality in the real world?
Personalizing Brain Discovery
While most might think of EEG as a purely medical device, this has proven untrue in recent years. The convenience of EEG has led it to become a device used outside of laboratories and medical centers for a whole host of purposes, most of them far from medical. EEG is uniquely beneficial for medical, commercial, and personal use. Among all of the different methods - MRIs, fMRIs, PET scans, CT scans, and more - used to study the brain, EEG is the most cost-efficient. It does not require expensive equipment, nor is significant training necessary to understand how to operate an EEG device. In addition, EEG is an extremely non-invasive method and powerful due to its ability to directly measure brain activity, making it a very useful device for diagnostics. For these reasons, scientists and engineers are continuously looking for new and improved ways to utilize EEG in medical and commercial settings. Most notably, EEG devices are being used to study the effects of meditation on a meditator’s mind state as well as the process of meditation itself, with the goal of expanding the accessibility of this practice and its benefits to all. Researchers are analyzing EEG data to detect meditation brain states, using various data analytics techniques and measurements. In particular, characteristic features of brain wave data are being isolated and inputted into machine learning algorithms to classify the “meditation state” from other brain states. Researchers are also optimizing this classification process for greater accuracy and applicability: their hope is that, by generating a machine learning algorithm that can classify meditative states from other states, people can use a device built on this algorithm to more efficiently practice meditation!"
Another interesting application of EEG technology is measuring - and improving - focus and attention. This is particularly applicable to present-day: many people spend all day staring at a computer, trying to be as efficient as possible in work, but most find themselves daydreaming or mentally wandering after some period of time, which detracts from their productivity. Researchers are interested in two fronts: firstly, the application of EEG in detecting and recognizing human attention and secondly, the potential for EEG technology to train human attention and focus. One study developed EEG detection tools, connected to mobile sensors, that are able to classify the attentiveness of students in class with an accuracy rate of 76.82%. This demonstrates the potential for EEG to recognize human focus with relative accuracy, which could decrease the burden on humans themselves to analyze each other's focus (case in point: teachers forced to read students’ expressions to determine if they are focused)?2 Furthermore, a second study demonstrated the ability for a wearable EEG-based game to improve the focus of individuals with Attention Deficit Hyperactivity Disorder (ADHD) and Attention Deficit Disorders (ADD), two disorders characterized by the lack of attention and focus. The wearable EEG technology is able to measure brain focus, and these results are used to produce a virtual reality game that the wearer can play to improve focusing ability. The study found such a device to produce an average improvement of 10% in engagement and 8% in focus for people who utilized the EEG-controlled device compared to the same game but keyboard-controlled.3
In order to truly publicize the benefits of EEG technology, devices must be geared towards use by th general population - that is, by people who might not have a background in neuroscience, meditation, or electroencephalography. On this front of personalized brain discovery, entrepreneurs and researchers alike are diving into how to make EEG products wearable and accessible to the general public, and studies are being. conducted to examine the applicability of EEG technology to personal use. Studies have found that this is a viable use of EEG, and current avenues pursued in this research area involve optimizing the EEG headsets for convenient usage and developing EEG protocols that are simple without headset with dry electrodes as
opposed to conventional wet electrodes, since home users will likely not want to purchase and apply gel to their scalp each time they use an EEG headset. The study found that EEG signals, collected in such a way, is a viable method of detecting meditation and other attention-based activities.4 Another study developed self-calibrating protocols for wearable EEG headsets, allowing each headset to become “personalized” to the user by enabling the headset to recognize mind states and brain waves unique to that person.5 Studies like these are becoming increasingly important to ensure the accessibility of EEG technology.
Commercialization for the Future
While the affordability of EEG suits it for a variety of commercial and personal purposes, the commercialization of this type of neurotechnology does not come without its costs and dangers. Currently, wearable EEG headsets are already available from companies like Muse, EMOTIV, and NeuroSky, but what is glaringly lacking are neuroethics protocols that guide how personal neuro-data is to be stored, used, and treated. In addition, there are cybersecurity concerns surrounding brain-computer interface BCI) systems which leverage brainwave information acquired by a brain monitoring device - such as an EEG device - to interact with a computerized system. Such systems are prone to attacks and must be secured and controlled to ensure that personal data is not leaked, much like protecting our email and bank account passwords.6
As EEG and BCI technology advances, we must address these neuroethics and cybersecurity concerns before valuable, private information is carelessly lost or immorally used. However, the benefits of EEG are undeniable, and it is the responsibility of the scientific community to ensure that these benefits are available to all: perhaps in 20 years, all of us will be able to improve our attention span with custom EEG headsets, safely guarded by established security and ethics protocols

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