Page - 50 - in Cyborg Mind - What Brain–Computer and Mind–Cyberspace Interfaces Mean for Cyberneuroethics

50 • Cyborg Mind In actual fact, in order to determine what is happening inside a brain, it was necessary to measure the electrical signals that are present in a neuron or group of neurons. Historical research in this area dates back to the 1950s, with the examination of squid neurons, which are exceptionally large and easy to manipulate. The final aim was to obtain a complete read-out of the state of a brain by measuring every single electrical signal in every brain neuron.14 At present, neuronal output interfaces that can be used to analyse brain functions are very much anticipated by scientists. The aim is for electrical sig- nals from the brain to be interpreted in order to predict cognitive intentions, such as performing a movement, meaning that they could eventually replace any lost connections that a person’s brain has with his or her body or any other machine. Nonetheless, neuronal interfaces could eventually become the preferred way for human beings to interact with computers instead of using keyboards, touchscreens, mice and voice command devices.15 Interfacing out of the brain with output neuronal interface systems can take place, first of all, though the means of electrodes that can either be situ- ated on the surface of the skin of the head (noninvasive) or inside the skull (invasive). The different types of electrodes used result in significant differ- ences in success rates in terms of making contact with the desired area or cell type in the brain. Safety concerns also vary depending on which kinds of electrodes are used or where they are located. For example, surgery is required with implanted and invasive electrodes, which is associated with a number of risks. Another more general and indirect read-out of brain activity can be obtained through different kinds of scanning procedures. These do not directly measure the electrical activity of neurons, either individually or in groups, but rely on the fact that thinking necessitates small amounts of energy that can be measured in terms of the variation of brain metabolism. But this still has many limitations and can only be used for some of the most basic brain activities.16 Invasive Output Neuronal Interface Systems The first experiments using invasive neuronal interfaces with electrodes placed inside the brain were undertaken on nonhuman primates, such as Rhesus monkeys, in the 1970s in the United States.17 From these experi- ments, a relationship was discovered between the electrical responses in the brains of these monkeys and the direction in which they moved their arms.18 More recently, experiments using electrode implants in the brains of the same species of monkeys have been undertaken to associate brain signals with their use of a mechanical robotic arm. 19 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.