Evidence Animals Consciously Monitor Their Own Behavior Revealed
Science is closer than ever to proving that animals are capable of consciously monitoring their behavior in a manner similar to humans, according to researchers from the RIKEN-MIT Center for Neural Circuit Genetics.
"Some believe animals may be behaving without thinking about it, and that only humans have acquired the ability to be conscious of it," Susumu Tonegawa, who directed the study published in the journal Cell, told Nature World News. "Others disagree."
Key to the debate is working memory.
Back in the days of the Yellow Pages, a person would have to hunt through the book that could double as a booster seat to find a number and quickly dial it before it evaporated from memory.
"That," Tonegawa explained, "is working memory." And exactly how it works - what drags something into the spotlight of consciousness and back out again - is the "holy grail of neuroscience," according to the Nobel Laureate.
In order to test working memory in mice, Tonegawa and colleagues began putting them in T-shaped mazes. The first time a mouse would run down the path to the fork in the maze, the scientists randomly blocked one of the two paths. The mouse was then forced to go the opposite direction, which was invariably stashed with a sweet morsel. Twenty to 30 seconds later, the researchers would then return the mouse to the maze, this time allowing it to run whichever direction it pleased. However, to earn a reward, the mouse would have to head in the opposite direction than it had in the past. This was repeated 20 times a day.
About 15 to 20 percent of the mice failed the task, but of the 80 percent who were successful, not all were triumphant on their first try. Between 3 to 4 percent initially chose the wrong path before screeching to a halt and, realizing their mistake, ran in the other direction. According to Tonegawa, these "oops events," as the researchers called them, may hold the answer to just how self-aware the mice are of their own decision-making process.
Each time a mouse made the correct decision to run in the opposite direction and toward the food, the researchers detected very specific electrical activity known as high frequency gamma waves in the areas of the brain known as the hippocampus and entorhinal cortex. When the mouse ran the wrong way, the waves were absent - with one exception. Right before a mouse experienced an "oops event," the gamma waves were again released.
While the study doesn't prove the waves are behind consciousness, it comes "really close," according to Tonegawa.
"Personally, I believe it. But I cannot convince everyone," he said.
Skeptics include Harvard University psychologist Güven Güzeldere.
"Every brain as a chemico-electrical organ generates a voltage difference, and every voltage-differential based electrical activity can in principle generate gamma waves - but, so what?" Güzeldere said in an email.
While he agreed the study contains "an interesting implication" that "deserves attention," he noted that, overall, "consciousness has no single and simple silver-bullet neural signature, and self-awareness takes a lot more sophisticated cognitive processing, which cannot occur in the absence of an equally complex underlying nervous system."
Tonegawa says the next step is to run a similar experiment in humans. But doing so has its ethical challenges, namely the implantation of electrodes into the brain as was done in the case of the mice. Tonegawa is currently playing with the idea of collaborating with physicians working with epileptic patients headed for surgery. In some cases, before surgeons operate on epileptic patients they must first put electrodes on different areas of the brain in order to determine the trouble regions. Tonegawa is hopeful physicians could safely administer tasks to volunteers prior to surgery that could prove, once and for all, that "high frequency gamma waves are crucial to conscious awareness."