Many of the advances made in neuroscience have come about due to advances in technology. Non-invasive methods of examining brain activity include EEG and MRI. It was soon realized that there are levels of consciousness ranging from fully awake, to daydreaming, trances, and sleep, to being under anesthetic or in a vegetative state, and there is much electrical activity in each.
Research into consciousness was spearheaded by Francis Crick, whose work in 1995 revealed that more activity occurs in the prefrontal cortex of people experiencing awareness compared to those without any such experience. Others, however, dispute this ‘localization of consciousness’. Memory, though, does not occur in one specific portion of the brain. In fact, much of what we remember happens outside the brain entirely. And yet, in a theory by Guilio Tononi, consciousness appears to come from the interconnection of various areas within the brain that handle sensory input, memories, and thinking. Thus, consciousness emerges from the interaction between different regions of the brain.
