Page - 52 - in Cyborg Mind - What Brain–Computer and Mind–Cyberspace Interfaces Mean for Cyberneuroethics

52 • Cyborg Mind locked-in patients, who retain cognitive functions but cannot move or com- municate verbally due to complete paralysis of nearly all voluntary muscles in the body. As a result of developments in the medical field, other applications are now being considered, such as in the gaming industry. Examples of games that use noninvasive neuronal interfaces include those where participants wear headsets while trying to control, through their thinking, the motion of a small ball on a screen. The headset measures brain activity by way of multiple electrodes placed on the outside of a person’s skull, while using brain sensors linked to wireless technology to control the ball.26 Neuroimaging The term ‘neuroimaging’ refers to a group of noninvasive technologies that acquire measurements of the brain’s structure, biochemistry or function without having to physically investigate the brain. They generally mea- sure the architecture and activity of large populations of neurons and usu- ally interpret signals from many locations throughout the entire brain simultaneously. The procedures presented below differ in terms of their: (1) spatial resolu- tion (how well they can distinguish between two close points in the brain); and (2) temporal resolution (how well they can distinguish between two close moments in time). Unfortunately, there is often a trade-off between these two forms of resolution, though this can often be addressed by using a com- bination of procedures.27 Neuroimaging techniques can also be classified into two broad categories, namely ‘structural’ (or anatomical) neuroimaging, which observes the brain’s architecture, and ‘functional’ neuroimaging, which examines images that reflect the brain’s activity.28 X-Rays One way to look inside the skull of a human being is through X-ray photog- raphy. This originated with German physicist Wilhelm Roentgen’s (1845– 1923) discovery of high-energy particles in 1895 and his realisation that they could pass through solid objects leaving a shadow-like image on a fluorescent screen. Indeed, his observation that the beam of particles only reflected the bones of his wife’s hand launched a whole industry.29 The images are useful in determining the shape and structure of hard materials in the human body, such as bones and kidney stones. But when the rays pass through soft materials, such as the brain, only a small effect is noticed. Thus, on their own, X-rays have little to offer the brain scientist or neurologist. This open access edition has been made available under a CC-BY-NC-ND 4.0 license thanks to the support of Knowledge Unlatched. Not for resale.