More Going On in the Brain Than We Realize
The news story about a girl who can see in both eyes with half a brain has stunned neurophysiologists (see New Scientist and Live Science). Somehow, the remaining parts of her brain underwent a massive reorganization of the circuits involved in vision. “It was quite a surprise to see that something like this is possible,” one of the neuroscientists who imaged the girl’s brain remarked. Even more surprising is that the girl appears to be able to lead a normal life. This story illustrates that much about the workings of the brain remains to be understood.
How aware is an unborn baby in the womb? Live Science reported that experiments seem to show short-term memory in fetuses 30 weeks of age. Tests with vibroacoustic stimulation on 100 pregnant women in the Netherlands apparently showed habituation to stimuli by the growing infants. This does not necessarily correspond to consciousness, but was unexpected; Dr. Jan Nijhuis, a co-author of the study and an obstetrician at Maastricht University Medical Center in The Netherlands, said that until a few decades ago, “people would say that the human fetus is a sort of black box.” Tests on infants below 30 weeks were negative, but that could be due to using the wrong kind of stimulus.
Apes have brains but something is missing: the ability to innovate. Experiments show they can imitate one another, and even pass on lessons learned. But New Scientist said, “For all their cognitive prowess, chimpanzees will never build four-stroke engines, stone pyramids, or even a simple wheel.” Why? When watching another chimp, they focus on the outcome, but not on the process that produced the outcome. Andrew Whiten (St. Andrews U, UK) thinks that dichotomy, however, is too simplistic. His observations acknowledged the monkey-see-monkey-do ability, but said, “They didn’t show any kind of cumulative cultural evolution.” What in the brain of a chimp limits them? It’s not just size, as the first story indicated.
New Scientist also debunked the myth that we only use 10% of our brains by discussing the vital role of glial cells that has been coming to light in recent years. Long thought as mere scaffolding, these cells that constitute 90% of brain tissue may underlie dreams and imagination. They have also been implicated in cell regeneration and cell death. For those reasons, they may hold keys to understanding Alzheimer’s disease and other neural disorders. Helen Thomson wrote about this in her review of a book, The Root of Thought by Andrew Kolb, that surveyed the history of speculation about the brain. Thomson ended, “No matter what scientists uncover, though, it is clear that the brain is a far more subtle structure than the neural lightning storm it was once thought to be.”
Bacteria don’t have brains at all but they display some uncanny abilities that seem downright brainy. New Scientist described bacteria that can communicate, make decisions, cooperate, form communities, navigate, learn, remember, and adapt. “Remarkable though these behaviours are, we have probably only scratched the surface of what single-celled organisms can do,” reporter Michael Marshall wrote. “With so many still entirely unknown to science, there must be plenty more surprises in store.”
Another story on New Scientist warned that doctors may be misdiagnosing patients in comas. New testing methods found that 41% judged in a vegetative state were actually minimally conscious. The thought of a partly conscious human being denied food and allowed to die should bring shudders to family members who are typically more concerned about their loved one than the medical staff. “We may have become much too comfortable about our ability to detect consciousness,” said Joseph Giacino, the doctor in Belgium whose team re-diagnosed 44 patients and reclassified them as minimally conscious. “I think it’s appropriate for there to be some level of alarm about this.” Most diagnoses are made with subjective techniques that are subject to examiner bias. The new method devised in 2004, called revised coma recovery scale, uses a series of behavioural tests based on criteria that can be used to distinguish between the two states. It considers patients who may pop in and out of consciousness, and distinguishes reflex responses more objectively.
Judging the mental state of someone seemingly unconscious is important. It can be a matter of life or death. Some jurisdictions allow withdrawal of food depending on the diagnosis of vegetative state. The other investigator said, “It’s very important to be sure of the diagnosis.”
Between birth and death, that 3-pound jelly-like mass in your skull is your physical key to rationality, decision-making, and emotion in ways we do not fully understand. It may half as large as others – that’s not the important thing. Take what you have and use it wisely. And be careful how you treat the brains of others.