The researchers also showed Roger pictures of himself, of people he knew and of strangers. He almost always recognized himself and never mistook another person for himself. He did sometimes have difficulty recognizing a photo of his face when it appeared by itself on a black background, without any hair or clothing.
Roger also distinguished the sensation of tickling himself from the feeling of someone else tickling him and consistently found the latter more stimulating. When one researcher asked for permission to tickle Roger's armpits, he replied, “Got a towel?” As Philippi and Rudrauf note, Roger's quick wit indicates that in addition to maintaining a sense of self, he adopts the perspective of others—a talent known as theory of mind. He anticipated that the researcher would notice his sweaty armpits and used humor to preempt any awkwardness.
In another task, Roger had to use a computer mouse to drag a blue box from the center of a computer screen toward a green box in one of the corners of the screen. In some cases, the program gave him complete control over the blue box; in other cases, the program restricted his control. Roger easily discriminated between sessions in which he had full control and times when some other force was at work. In other words, he understood when he was and was not responsible for certain actions.
Given the evidence of Roger's largely intact self-awareness, Philippi, Rudrauf and their colleagues argue that the insular cortex, anterior cingulate cortex and medial prefrontal cortex cannot by themselves account for conscious recognition of oneself as a thinking being. Instead they propose that self-awareness is a far more diffuse cognitive process, relying on many parts of the brain, including regions not located in the cerebral cortex.
Laughing without a Brain
In the new study, Philippi, Rudrauf and their co-authors point to a fascinating 1999 review of children with hydranencephaly, a rare disorder in which fluid-filled sacs replace the brain's cerebral hemispheres. Children with hydranencephaly are essentially missing every part of their brain except for the brain stem and cerebellum and a few other structures. Holding a light near such a child's head illuminates the skull like a jack-o'-lantern.
Although many children with hydranencephaly appear relatively normal at birth, they often quickly develop growth problems, seizures and impaired vision. Most die within a year; some live for years or even decades. Such children lack a cerebral cortex, but at least a few give every appearance of genuine consciousness. They respond to people and things in their environment. They smile, laugh and cry. They know the difference between familiar people and strangers. And they prefer some kinds of music to others. If some children with hydranencephaly are conscious, then the brain does not require an intact cerebral cortex to produce consciousness.
Whether such children are truly self-aware is more difficult to answer, especially as they cannot communicate with language. In the 1999 review one child showed intense fascination with his reflection in a mirror, but it is not clear whether he recognized his reflection as his own. Still, research on hydranencephaly and Roger's case study indicate that self-awareness—this ostensibly sophisticated and unique cognitive process layered on consciousness—might be more universal than we realized.
This article was originally published with the title Self-Awareness with a Simple Brain.