Live Imaging

Magnetoencephalography is a functional neuroimaging technique for mapping brain activity by recording magnetic fields generated by naturally occurring electrical currents 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 brain regions, and neurofeedback. This can be applied in a clinical setting to identify abnormal locations and in an experimental setting to measure brain activity.

 

Magnetic resonance imaging (MRI) is used to scan the brain for topographical and landmark structures, but it can also be used to image brain activation. At the same time, details of how MRI works are reserved for the actual MRI article; MRI's uses 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 oxygen levels in the brain during activation (higher oxygen levels = neural activation) and allows researchers to identify which areas are responsible for activation in response to a given stimulus. This technology is a significant improvement over single-cell or area activation, as it avoids exposing the brain to contact stimulation. Functional MRI allows researchers to draw associative relationships between different brain regions and provides substantial knowledge for establishing new landmarks and locations in the brain.

 

Computed Tomography (CT) is another imaging modality used to scan the brain. It has been used since the 1970s and is another tool neuroscientists use to track brain structure and activation. While many CT functions are now performed with MRI, CT can still be used to detect brain activation and injury. 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, 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. Researchers increasingly use PET scans because they are activated by 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, stimulating the brain with magnetic pulses can interfere with specific areas to produce a predictable effect. This field of study is currently attracting significant attention due to the potential benefits that could result from a better understanding of this technology. Transcranial magnetic stimulation of particles in the brain shows promise for drug targeting and delivery, as studies have demonstrated that it is noninvasive to brain physiology.

 

Cranial Electrotherapy Stimulation (CES) is a non-invasive, transcranial pulsed-current stimulation class that applies specific amplitude, frequency, and waveform parameters to patients. CES devices have two parts: a box to control settings and a set of electrodes that the patient attaches to the earlobes or scalp. The U.S. Food and Drug Administration (FDA) approved CES in 1979 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, enabling live assessment of brain electrical activity during tDCS, promise to advance understanding of these mechanisms. Research on healthy adults has demonstrated that tDCS can improve cognitive performance across a range of tasks, depending on the targeted brain area. tDCS has been used to enhance language and mathematical ability, attention span, problem-solving, memory, and coordination. Some modalities of tDCS can help with depression, anxiety, stress, and sleeping problems.

 

Low-field magnetic stimulation uses low-intensity magnetic fields and is currently under study for depression at Harvard Medical School; Bell has previously explored it. 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 non-invasive method for measuring brainwave activity. Several electrodes are placed on the scalp, and electrical signals are measured. Typically, EEGs are used in sleep research, 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 distinct method for understanding electrical signaling in the brain during activation.

 

Magnetoencephalography (MEG) is another method for measuring brain activity by detecting the magnetic fields generated by electrical currents in the brain. The benefit of using MEG instead of EEG is that these fields are highly localized and provide a better understanding of how specific areas respond to stimulation or when 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), which deliver electrical stimulation to areas affected 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 by several factors (metabolic, electrical stimulation, and physiological) and that all of 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.

 

Cell Therapy

 

Stem cells in the brain are being researched for potential uses, and these have recently been identified 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 injuries in utero and in older adults with degenerative diseases to induce the brain to produce new cells and form more connections between neurons.

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Pharmaceuticals

 

Pharmaceuticals are vital in maintaining stable brain chemistry and are the most commonly used neurotechnology by the general public and the medical community. 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. While pharmaceuticals are usually not mentioned in neurotechnologies and have their own field, their role is perhaps the most far-reaching and commonplace in modern society.