Neurotechnologies

Live Imaging

Magnetoencephalography is a functional neuroimaging technique for mapping brain activity by recording magnetic fields produced by electrical currents occurring naturally in the brain using sensitive magnetometers. Arrays of SQUIDs (superconducting quantum interference devices) are the most common magnetometers. Applications of MEG include basic research into perceptual and cognitive brain processes, localizing regions affected by pathology before surgical removal, determining the function of various parts of the brain, and neurofeedback. This can be applied in a clinical setting to find locations of abnormalities and in an experimental setting to measure brain activity.

 

Magnetic resonance imaging (MRI) is used to scan the brain for topological and landmark structures, but it can also be used for imaging activation in the brain. At the same time, details about how MRI works are reserved for the actual MRI article; the uses of MRI are far-reaching in the study of neuroscience. It is a cornerstone technology in studying the mind, especially with the advent of functional MRI (fMRI). Functional MRI measures the oxygen levels in the brain upon activation (higher oxygen content = neural activation) and allows researchers to understand what areas are responsible for activation under a given stimulus. This technology is a large improvement to single cell or area activation using exposing the brain and contact stimulation. Functional MRI allows researchers to draw associative relationships between different areas and regions of the brain and provides a large amount of knowledge in establishing new landmarks and areas in the brain.

 

Computed Tomography (CT) is another technology used for scanning the brain. It has been used since the 1970s and is another tool neuroscientists use to track brain structure and activation. While many of the functions of CT scans are now done using MRI, CT can still be used as the mode by which brain activation and injury are detected. Using an X-ray, researchers can detect radioactive markers in the brain that indicate brain activation to establish relationships and detect many injuries/diseases that can cause lasting damage to the brain, such as aneurysms, degeneration, and cancer.

 

Positron Emission Tomography (PET) is another imaging technology that aids researchers. Instead of using magnetic resonance or X-rays, PET scans rely on positron-emitting markers bound to a biologically relevant marker such as glucose. The more activation in the brain, the more that region requires nutrients, so higher activation appears brighter in an image of the brain. PET scans are becoming more frequently used by researchers because PET scans are activated due to metabolism. In contrast, MRI is activated on a more physiological basis (sugar activation versus oxygen activation).

 

Transcranial Stimulation

 

Transcranial Magnetic Stimulation (TMS) is direct magnetic stimulation to the brain. Because electric currents and magnetic fields are intrinsically related, by stimulating the brain with magnetic pulses, it is possible to interfere with specific areas in the brain to produce a predictable effect. This field of study is currently receiving a large amount of attention due to the potential benefits that could come out of a better understanding of this technology. Transcranial magnetic movement of particles in the brain shows promise for drug targeting and delivery as studies have demonstrated this to be noninvasive on brain physiology.

 

Cranial Electrotherapy Stimulation (CES)  is a non-invasive, transcranial pulsed-current stimulation class that applies a particular amplitude, frequency, and waveform to patients. CES devices have two parts: a box to control settings and a set of electrodes the patient attaches to the earlobes or scalp. The U.S. Food and Drug Administration (FDA) approved in 1979 for CES for the treatment of insomnia, depression, and anxiety, and it is commercially available for personal use. Controlled studies provide evidence that CES is effective for anxiety, headaches, fibromyalgia, smoking cessation, drug withdrawal symptoms, and (in some but not all studies) pain.

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Transcranial Direct Current Stimulation (tDCS) is a form of neurostimulation that uses constant, low current delivered via electrodes placed on the scalp. The mechanisms underlying tDCS effects are still incompletely understood. Still, recent advances in neurotechnology allowing for live assessment of brain electric activity during tDCS promise to advance understanding of these mechanisms. Research into using tDCS on healthy adults have demonstrated that tDCS can increase cognitive performance on a variety of tasks, depending on the area of the brain being stimulated. tDCS has been used to enhance language and mathematical ability (though one form of tDCS was also found to inhibit math learning), attention span, problem-solving, memory, and coordination. Some modalities of tDCS can help with depression, anxiety, stress, and sleeping problems.

 

Low-field magnetic Stimulation, which provides stimulation with low-intensity magnetic fields, is currently under study for depression at Harvard Medical School and has previously been explored by Bell. It has FDA approval for the treatment of depression. It is also being researched for other applications, such as autism. One issue is that no two brains are alike, and stimulation can cause either polarization or depolarization.

 

Cranial Surface Measurements

 

Electroencephalography (EEG) is a method of measuring brainwave activity non-invasively. Several electrodes are placed around the head and scalp, and electrical signals are measured. Typically, EEGs are used when dealing with sleep, as characteristic wave patterns are associated with different sleep stages. Clinically, EEGs are used to study epilepsy as well as stroke and tumor presence in the brain. EEGs are a different method to understand the electrical signaling in the brain during activation.

 

Magnetoencephalography (MEG) is another method of measuring brain activity by measuring the magnetic fields that arise from electrical currents in the brain. The benefit of using MEG instead of EEG is that these fields are highly localized and give rise to a better understanding of how specific areas react to stimulation or if these regions over-activate (as in epileptic seizures).

 

Implant Technologies

Neurodevices are any devices used to monitor or regulate brain activity. Currently, a few are available for clinical use as a treatment for Parkinson's disease. The most common neurodevices are deep brain stimulators (DBS) that give electrical stimulation to areas stricken by inactivity. Parkinson's disease is known to be caused by the inactivation of the basal ganglia (nuclei), and recently, DBS has become the preferred form of treatment for Parkinson's disease, although current research questions the efficiency of DBS for movement disorders.

Neuromodulation is a relatively new field that combines neuro devices and neurochemistry. The basis of this field is that the brain can be regulated using several different factors (metabolic, electrical stimulation, physiological) and that all these can be modulated by devices implanted in the neural network. While this field is still in the research phase, it represents a new type of technological integration in neurotechnology. The brain is a very sensitive organ, so besides researching the amazing things that neuromodulation and implanted neural devices can produce, it is important to research ways to create devices that elicit as few negative responses from the body as possible. This can be done by modifying the material surface chemistry of neural implants.

 

Cell Therapy

 

Stem cells in the brain are being researched to find uses for the brain, and these have recently been found in a few areas. Many studies are being done to determine if this therapy could be used on a large scale. Experiments have successfully used stem cells in the brains of children who suffered from injuries in gestation and older adults with degenerative diseases to induce the brain to produce new cells and to make more connections between neurons.

Pharmaceuticals

 

Pharmaceuticals are vital in maintaining stable brain chemistry and are the most commonly used neurotechnology by the general public and medicine. Drugs like sertraline, methylphenidate, and zolpidem act as chemical modulators in the brain, and they allow for normal activity in many people whose brains cannot act normally under physiological conditions. While pharmaceuticals are usually not mentioned in neurotechnologies and have their field, the role of pharmaceuticals is perhaps the most far-reaching and commonplace in modern society. The movement of magnetic particles to targeted brain regions for drug delivery is an emerging field of study and causes no detectable circuit damage