Tuesday, February 19, 2008

Human Flocking Behavior with a Shaky Segue into Mirror Neurons

On occasion, I will be in a public place like an airport, sports stadium, or bar/club, and I’ll pause to look at the sea of people that I’m part of. I then usually start to feel being human is a little less significant than we are inclined to think it is, as I get caught up making zoologically comparative observations. In the case of the airport or large event, I often consider how we resemble herds of cattle, moving in one direction or another with the urging of signs or velvet ropes instead of sheepdogs (or sometimes even with security guards barking at us much like a sheepdog would). When at a bar or club, I’m prone to make comparisons to the courtship displays of various animals, like the ostentatious demonstration of the male peacock, or the male fruit fly’s persistent pursuit of a mate.

A group of scientists at the University of Leeds recently published a study that inevitably leads one to similar comparisons. It focuses on flock-like behavior in humans. The researchers conducted their experiments in a large hall with groups of people that varied in size. A number of people in the group were given specific directions about which walking route to follow, the rest were left uninformed, to amble about on their own. They also weren't told that directions were given out to anyone. The participants in the group weren’t allowed to communicate with one another, by speech or gesture.

The study found that the uninformed individuals tended to follow those who had been given directions, even though they were a comparative few to the many. In fact, the researchers observed that as the number of people in the group was increased, the less informed participants were needed to create a following. The largest groups of 200 or more only needed about 10 people walking in a specific direction to cause the rest of the group to fall in behind them. The followers, when interviewed afterward, often didn’t seem to be aware they were being led.

You might be wondering what this all has to do with neuroscience and the answer is: no one knows. This was a behavioral study, and the authors didn’t speculate on the brain regions that might be involved. Although suggesting their involvement in this type of flocking behavior is purely speculative, it seems like as good a time as any to bring up the subject of mirror neurons.

Mirror neurons were first discovered in experiments with macaque monkeys. A group of researchers led by Giacomo Rizzolatti were using electrodes to measure brain activity while the monkeys engaged in motor tasks, like picking up pieces of food. They unexpectedly found that some of the neurons were activated not only when the monkeys picked up the food, but also when they saw someone else (experimenter or another monkey) pick it up. After this finding, areas were identified in the human brain that may play a similar role. They include regions of the inferior frontal cortex and parietal lobe.

Since this discovery much excitement has surrounded the concept of mirror neurons. As these neurons seem to be specifically activated when watching another person perform a goal-directed action, some have suggested they may underlie our ability to understand that other people have intentions. This could mean they are the foundation for empathy, imitation, and communication. Some studies have even indicated malfunctioning mirror neurons may contribute to autism.

The truth is (as is usually the case with the brain), mirror neurons aren’t going to be that easy to figure out. Nor will they be a magic bullet that will conveniently explain a panoply of human behavior. They are part of a complex system that we have a very vague understanding of at this point. We can only speculate about their involvement in much larger reactions like empathy and language. They do seem to play a role in perceiving intention, however, and thus have an intriguing potential when it comes to understanding human behavior, as so much of it is based on knowing that we are surrounded by other intentional agents.

So, to get back to the flocking study, it doesn’t have a specific connection to neuroscience—yet. Just remember, however, if you are standing in line among hundreds to get to your gate at the airport, or being herded through the turnstile at the sports stadium, or observing the human courtship rituals at a club with a sense of detachment, and these sights seem surreal or slightly dehumanizing to the comparative biologist in you, and you begin thinking how similar we are to cattle, or sheep, you may not be far off base—and you’re not alone.

1 comment :

Jacqueline said...

cool stuff. also liked your post on gsw's and thirst.