Consciousness in the Raw

http://www.sciencenews.org/articles/20070915/bob9.asp

Dr. Bjorn Merker, a neuroscientist originally from Sweden, recently proposed an intriguing idea after visiting with five families in Disney World in Florida. Each of these families had a child with a rare condition called hydranencephaly. This condition, usually experienced before birth or shortly thereafter as a result of a stroke or other serious medical issues, causes about 80% of the child's brain to be destroyed, including the cortex. Hydranencephaly is when the cerebrospinal fluid floods the hole in a child's head and these children typically die within a year due to other ailments brought on by the crippling damage to their brain. The cortex is the outer layer of the brain, and until recently, scientists believe it to be the center for all awareness. Merker, however, proposes an alternative.
While most families with children who have hydranencephaly are told their children will be "vegetables" for the duration of their short lives, Merker observed that these same children exhibited a number of emotions and remained alert. During his visits to each family's home, Merker noticed that the children recognized adults, toys, sounds, and settings. Many of the children, even with restricted mobility, were able to perform normal behavioral functions. Merker also noted a curious fact about all the children: they had relatively good hearing, but had poor eyesight. This was unusual, as most children who suffered from their condition retained parts of their visual cortex, but none of their auditory cortex.
Merker proposes in Behavioral and Brain Sciences that the fundamental awareness of the world, inside and out, is not dependant on the cortex, but on the brain stem. According to Merker, the brain stem not only provides children who have hydranencephaly with a basic form of conscious thought, but also with auditory structures that would be previously destroyed along with the cortex. He also states that the condition damages the optic nerves, completely independently of the brain stem. While more complex thought patterns may rely on the cortex, Merker believes that "primary consciousness", or the ability to integrate stimulus and feelings, comes from the tissue located between the spinal cord and the cortex, otherwise known as the brain stem. If this proposal is true, not only would all vertebrates be primarily conscious, but doctors and scientists would be forced to administer pain medication and anesthesia to patients with hydranencephaly.
Merker drew his ideas from the earlier work of Doctors Wilder Penfield and Herbert Jasper. Neurosurgeons from more than fifty years earlier, Jasper and Penfield removed massive parts of their patients cortex as a treatment for epilepsy. However, their patients would remain conscious and awake during the surgery and used only small amounts of anesthesia. Although the patients would lose parts of their mental abilities, they would retain a conscious stream of thought. Jasper and Penfield electrically stimulated parts of the brain during the operations in order to find functional areas, and were duly surprised when they found all types of seizure could be reproduced - except what is known as "absence epilepsy", when a patient loses consciousness for several seconds. Based on this observation, Jasper and Penfield believed that absence epilepsy was triggered by the brain stem, and direct corroboration with the cortex provided conscious thought and independent actions.
With these observations added to his own, Merker states that three adjacent parts of the brain stem are responsible for basic consciousness. The top part of the brain interprets the surrounding, below that is the area responsible for emotion-related actions, and the furthest region accounts for eye gaze and decision making. Merker proposed that even with little cortex, the brain stem simulates a two-dimensional map of moving shapes. Based on experiments over the last forty years performed on cats and lab rats, the animals with no cortex were still able to participate in normal activities, such as grooming and and climbing. Merker also records a phenomenon called the Sprague effect: when the removal of the visual cortex on one half of the brain causes total blindness in the opposite side. However, subjects are able to distinguish moving objects when a small incision is made in the midbrain. Merker proposes that the Sprague effect interrupts the visual stimulus from the brain stem and by cutting the midbrain, the activity from the Sprague effect is halted.
Merker's research challenges the assumption that newborns and fetuses cannot feel pain. According to Dr. K.J.S. Anand, the brain stem is responsible for the feelings of pain before and after birth. The cortex, which expands greatly during growth, takes over the pain perception. Although Merker's research and observations are fascinating, many scientist disagree with his work. They insist that the cortex is at least partly responsible for consciousness, and they suggest that the consciousness seen in the children with hydranencephaly is due to the remnants of their cortex, however small.
Further research into children with hydranencephaly shows that, while physicians usually give the children fewer than two years to live, many exert consciousness and emotions when raised in a comfortable, loving environment. These children often exhibit happy feelings when presented with happy songs, and sad feelings when presented with sad songs. Merker believes that since the children often experience absence epilepsy, this only furthers his proposal of a basic consciousness. Even more importantly, the observations made based on children with hydranencephaly provide intriguing evidence that the brain stem is not merely a remnant of more reptilian days. While the mystery of consciousness is still at large, scientist can all agree that children with no cortex provide infallible clues to aid in solving the mystery.

I found this article both fascinating and horrifying. The new research explained in this article gave me hope for the advancement of medicine, and the ability to provide answers to those who are most in need. But I was equally horrified that patients, especially children, were often operated on with very little aid from pain medication. I believe that the research done by Dr. Merker was not only breakthrough, but extremely informative. This article shows how far scientists have come in understanding the human body, and with the new information they find daily, people everywhere will be able to receive the help they need. I found the complexity of the brain, as explained in the article, intriguing and fascinating. I enjoyed reading about how the brain interprets signals, and which parts of the brain do what. I think it was extremely interesting that an animal's brain is able to perform many of the same functions as human brains. But I found the part about the brain stem not being a relic of a reptilian ancestry (aka evolution) extremely interesting.