Ferris Jabr writes: The computer, smartphone or other electronic device on which you are reading this article has a rudimentary brain—kind of. It has highly organized electrical circuits that store information and behave in specific, predictable ways, just like the interconnected cells in your brain. On the most fundamental level, electrical circuits and neurons are made of the same stuff—atoms and their constituent elementary particles—but whereas the human brain is conscious, manmade gadgets do not know they exist. Consciousness, most scientists argue, is not a universal property of all matter in the universe. Rather, consciousness is restricted to a subset of animals with relatively complex brains. The more scientists study animal behavior and brain anatomy, however, the more universal consciousness seems to be. A brain as complex as the human brain is definitely not necessary for consciousness. On July 7 this year, a group of neuroscientists convening at Cambridge University signed a document officially declaring that non-human animals, “including all mammals and birds, and many other creatures, including octopuses” are conscious.

Humans are more than just conscious—they are also self-aware. Scientists differ on the difference between consciousness and self-awareness, but here is one common explanation: Consciousness is awareness of one’s body and one’s environment; self-awareness is recognition of that consciousness—not only understanding that one exists, but further understanding that one is aware of one’s existence. Another way of thinking about it: To be conscious is to think; to be self-aware is to realize that you are a thinking being and to think about your thoughts. Presumably, human infants are conscious—they perceive and respond to people and things around them—but they are not yet self-aware. In their first years of life, infants develop a sense of self, learn to recognize themselves in the mirror and to distinguish their own point of view from other people’s perspectives.

Numerous neuroimaging studies have suggested that thinking about ourselves, recognizing images of ourselves and reflecting on our thoughts and feelings—that is, different forms self-awareness—all involve the cerebral cortex, the outermost, intricately wrinkled part of the brain. The fact that humans have a particularly large and wrinkly cerebral cortex relative to body size supposedly explains why we seem to be more self-aware than most other animals.

One would expect, then, that a man missing huge portions of his cerebral cortex would lose at least some of his self-awareness. Patient R, also known as Roger, defies that expectation. Roger is a 57-year-old man who suffered extensive brain damage in 1980 after a severe bout of herpes simplex encephalitis—inflammation of the brain caused by the herpes virus. The disease destroyed most of Roger’s insular cortex, anterior cingulate cortex (ACC), and medial prefrontal cortex (mPFC), all brain regions thought to be essential for self-awareness. About 10 percent of his insula remains and only one percent of his ACC.

Roger cannot remember much of what happened to him between 1970 and 1980 and he has great difficulty forming new memories. He cannot taste or smell either. But he still knows who he is—he has a sense of self. [Continue reading…]