In cutting-edge experiments, scientists have injected human brain cells into monkey fetuses to study the effects. Critics warn that these experiments may accidently produce monkeys with brains more human than animal, posing a new set of ethical issues.
An excellent coverage of some of the ethical and social implications of research into brain-machine interfaces. The author takes a look at its potential for mind-control or intelligence augmentation, i.e. making humans into cyborgs.