Page - 36 - in Cyborg Mind - What Brain–Computer and Mind–Cyberspace Interfaces Mean for Cyberneuroethics

36 • Cyborg Mind brain regions cannot be ascribed to a unique function. Instead, a particular brain structure may be associated with a number of mental processes, while particular mental processes may involve several brain areas.10 For instance, a number of human experiences, such as the perception of pain, involve a spa- tial and temporal pattern of activity in multiple brain regions.11 Biological Development of the Brain The brain continues to develop in a human person until about the age of twenty, during which time the wiring of the brain undergoes major changes that are dependent on environmental influences. When a person is born, the great majority of his or her neurons already exist and are in their final position in the brain, though many are still disconnected from one another. New connections are formed only after birth and continue until adulthood. These are then preserved or reduced depending on neuronal activity and any external factors that affect this activity. This means that every interac- tion with, for example, physical and societal environments as well as lifelong learning processes will influence the arrangement and structure of neuronal connections in the brain. It is believed that this happens as a result of existing connections being strengthened or weakened in relation to how much they are used. This implies that the neurological structure of a mature brain may be influenced by: – genetic predisposition that determines the general structure of the brain; – the cellular and physiological shaping of connections that modify the brain in relation to its environment during development; – lifelong adjustments in response to different experiences.12 Many neurobiologists believe that all functions of the brain can be reduced to its structure and the connections between neurons, though it should be emphasised that every function is the result of widely distributed neuronal networks. Thus, for these scientists, the most complex functions of the brain can only be the result of what goes on in the brain. This includes basic functions such as the ability to perceive, remember and act, but also higher functions such as the ability to decide, control attention and generate emotions. Even the ability to understand and generate speech, to consciously deliberate and be self-aware as an independent, autonomous and intentional agent is believed to only be the result of brain structure, the connections between neurons and the signals that pass between these neurons.13 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.