Introduction:
When considering the entirety of human history, the pursuit of studying, comprehending, and influencing human thoughts and consciousness is a relatively recent undertaking. In the twenty-first century, science has advanced significantly enough in neuroscience to start developing effective neurotechnology. The field of neuroscience has significantly advanced due to the introduction of new technological capabilities, and the speed of their development has dramatically accelerated in the last ten years. Building upon this momentum, the United States initiated the BRAIN initiative to create and employ innovative tools and technologies to transform the brain's knowledge completely.
The societal implications of these neurotechnology are extensive, spanning from pharmaceuticals that enhance well-being to advanced brain imaging that transforms the perception of human consciousness. These neurotechnology have the potential to reshape human self-knowledge and utilize the diverse functions of the brain and nervous system to enhance human well-being.
What Is Neurotechnology?
Neurotechnology encompasses any technology that enhances human understanding of brain and nervous system activity or impacts their functioning. Neurotechnology serves various purposes, including research applications like experimental brain imaging for studying mental health or sleep patterns. Additionally, it finds practical use in therapeutic or rehabilitative scenarios, where it can influence and support the brain and nervous system.
Neurotechnology involves integrating methods and tools that establish a direct connection between technical components and the nervous system. These technical components include electrodes, computers, or intelligent prostheses. Their purpose is twofold: to record signals from the brain and translate them into technical commands for control or to influence brain activity through electrical or optical stimuli.
How Does Neurotechnology Enhance Brain Function?
In a general sense, neurotechnology employs a neural interface to either extract or insert information into the central nervous system (CNS), the peripheral nervous system (PNS), or the autonomic nervous system (AND). These methods encompass a range of techniques, spanning both invasive and non-invasive approaches.
Neurotechnology work based on three main categories as follows:
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Neuromodulation Technology: This involves using neural interfaces to activate structures within the nervous system, aiming to influence neural activity. For instance, these technologies are employed in deep brain stimulation to alleviate tremors in Parkinson’s disease, spinal cord stimulation to address chronic pain, and, more recently, in treating stroke patients. In the case of stroke, they detect biomarkers related to the patient’s physical movements and apply stimulation to the nervous system, thereby modulating and enhancing neural activity associated with those movements.
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Neuroprostheses: It serves as an artificial substitute for impaired or lost brain functions, aiming to restore sensory, motor, or cognitive capabilities in individuals. One of the most well-known examples of neuroprostheses in daily life is cochlear implants, which can effectively restore hearing in individuals with severe hearing impairment.
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Brain-Machine Interface: These are technologies designed to extract and/or input information from the brain, ultimately allowing individuals to manage external software like brain-computer interfaces or physical hardware such as robotic devices. While not yet extensively utilized in practical contexts, these technologies possess the potential to empower individuals with motor disabilities to operate devices through their neural activity.
What Is the Role of Neurotechnology in Enhancing Brain Function and Movement Restoration?
Technology for recording brain activity:
1. Non-Invasive Methods: The most common methods include electroencephalography (EEG), functional near-infrared spectroscopy (fNIRS), functional magnetic resonance imaging (fMRI), and magnetoencephalography (MEG).
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EEg captures electrical activity from electrodes placed on the scalp. Its key advantages are its excellent temporal resolution, affordability relative to other non-invasive methods, portability, and practicality for use beyond the lab, making it suitable for cognitive enhancement applications.
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fMRI assesses brain activity by tracking changes in blood flow (hemodynamic response). It offers superior spatial resolution compared to EEG but lags in temporal resolution. Due to its large and expensive equipment requirements, it is generally unsuitable for human augmentation.
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fNIRS, like fMRI, relies on hemodynamic responses to map brain activity. It is portable, cost-effective, and less susceptible to electrical interference than EEG. These qualities make it suitable for cognitive enhancement applications, particularly when combined with brain stimulation technologies.
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MEG is used for brain function localization and medical purposes. However, it is bulky, necessitates a magnetically shielded environment, and is costly, rendering it impractical for human augmentation despite some proposed applications.
2. Invasive Methods Involve: using electrodes directly implanted into or placed on the brain’s surface. These methods tend to yield recordings less affected by noise and distortions caused by the scalp and skull, resulting in high temporal and spatial resolution. One such invasive technology is electrocorticography ECoG, similar to EEG in measuring neuronal electrical activity but with electrodes placed directly on the cortex. ECoG captures neural activity from a small portion of the cortex. Despite this limitation, there are existing applications for human cognitive enhancement using ECoG.
Other invasive recording technologies involve arrays of needle-shaped microelectrodes within the brain, producing high-quality signals with minimal noise and detailed information. Examples include ceramic-based microelectrodes that allow precise, high-density multi-recordings in deep brain structures and electrical stimulation.
Technologies for Brain Stimulation:
1. Non-invasive Stimulation Technologies: These include transcranial electrical stimulation (tES), transcranial magnetic stimulation (TMS), and focused ultrasound (FUS).
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Stimulating the brain using tES involves placing electrodes on the scalp to deliver a small direct or alternating current, ranging from 1 to 2 mA for up to 30 minutes for safety reasons.
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TMS involves using intense electric currents within a coil placed on the participant’s scalp to generate a magnetic field. This field induces current flows in the underlying cortical tissue, which can alter neural firing patterns. However, they have significant limitations currently.
2. Invasive Stimulation Technologies: Deep brain stimulation (DBS) is an invasive brain-stimulation technique primarily utilized in the medical field to treat movement disorders like Parkinson’s disease and memory disorders. It involves neuro-stimulator implantation in specific brain regions, which emit electrical pulses to modulate neural activity at targeted sites.
Similarly, implanted electrodes are commonly employed in medicine to stimulate specific brain areas to treat intractable epilepsy electrically. However, due to their invasiveness, ethical concerns, and cost, DBS and implanted electrodes are primarily restricted to medical applications to enhance patient’s quality of life. As a result, research on cognitive augmentation in humans using invasive technologies has been limited, typically conducted with individuals who already have implanted devices for clinical purposes, such as treating Parkinson’s disease or epilepsy.
Conclusion:
Neurotechnology span a wide range of both invasive and non-invasive methods that hold great promise for enhancing our understanding of the brain and its applications in various fields, including medicine, cognitive augmentation, and beyond. While these technologies offer exciting opportunities, they also come with ethical considerations, variability in outcomes, and limitations regarding resolution and invasiveness. Future advancements and interdisciplinary research will continue to shape the landscape of neurotechnology, potentially transforming our understanding of the human brain and its capabilities.
