When attacked, a skunk's natural inclination is to turn around, lick its tail and spray a noxious scent. That works when a skunk faces a natural predator in the wild, but it's not as helpful when faced with, let's say, an oncoming car.
"They didn't evolve to deal with that circumstance," says neuroscientist Dean Buonomano. "And humans suffer some of the same consequences of living in a time and place we didn't evolve to live in. ... And by peering into the brain, we can learn a lot about why we are good at some things and why we are not very good at others."
In Brain Bugs: How the Brain's Flaws Shape Our Lives, Buonomano explains how and why our brains sometimes fail us when we try to do things like remember long lists of information, add large numbers in our heads or make long-term decisions. He tells Fresh Air's Dave Davies that the brain's weaknesses and strengths have evolved over thousands of years, based on what our ancestors needed — and didn't need — to survive.
For example, we don't have a sense of what numbers mean intuitively in the same way that we can look at a friend and recognize that person through analyzing their various facial features. "When we recognize a pattern and I look at your face, part of the task is to grasp the whole from the sum of the parts," Buonomano says. "And because neurons are very social and communicating with our neurons, that allows them to communicate with each other and provide a picture of the whole and provide a context."
Priming The Brain
The brain is made up of billions of neurons, which connect to other neurons through connections called synapses. When we think of a concept — let's say, ice cream — our brain's neurons quickly fire and connect our thoughts with memories related to ice cream and other associations throughout the brain.
"If you hear that chocolate and pretzels make a good ice cream and you share that with your friends, those neurons are being activated at more or less the same time, and somehow the neurons representing each one of those concepts come to be connected with one another," Buonomano explains.
Those patterns can also be used by others to affect our behavior in noticeable ways. In one example, researchers at New York University asked subjects in a study to do word puzzles. Some of the subjects were given puzzles with words associated with kind behavior, while another group received word searches filled with words associated with impolite behavior. After they finished the task, subjects were instructed to talk to an assistant in the lab, who was pretending to be on the phone.
"The people who did word puzzles that were more heavily populated with rude words actually waited less to interrupt the ongoing conversation than those who were doing word puzzles with polite words," Buonomano says. "So this is an example of behavioral priming in which the words have the ability to influence our thoughts."
Though the effects are subtle, priming the brain and other associative tricks have been used by advertisers and marketers for years.
"This is one of those things where I think marketers understood the brain before neuroscientists," Buonomano says.
"Much of marketing has always been tapping into the associative structure or the associative architecture of the brain toward leading us toward positive opinions or negative opinions by leading us to the appropriate words," he adds.
On our ability to do math
"The brain is very good at pattern recognition. The fact that we currently use numbers in order to quantify anything from baseball scores or our salaries — there [weren't] many situations in which that was required. People weren't negotiating, they weren't making transactions. They were judging whether something [was] that dangerous or not — there wasn't a need or the ability to manipulate symbols. So in the case of numerical calculations, there [weren't] that many circumstances in which animals will benefit from manipulating numbers — from doing long division and so forth."
On memory errors
"One type of memory error that we make — a memory bug — is really a product of the fact that in human memory, there's no distinction between storage and retrieval. So when a computer writes something down, it has one laser that's used to store the memory and another laser to retrieve the memory, and those are very distinct processes. In human memory, the distinction between storage and retrieval is not very clear, and this can have very dramatic consequences. ... The act of retrieving a memory can affect the storage."
"Unlike the clocks on our wrists that can be used to tell a few milliseconds or months and years, the brain has very fundamentally different mechanisms for telling very short periods of time and very long periods of time — and that's a consequence of the evolutionary process. ... We don't seem to have a very precise clock. Time is very much distorted when we are anticipating what's about to happen, when we're nervous, when we're stressed and when we have high-adrenaline moments."