delanceyplace.com 11/12/13 - our brain's favorite activity

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In today's selection -- from Social: Why Our Brains Are Wired to Connect by Matthew D. Lieberman. For almost all human beings, the brain's favorite activity -- the activity that almost every brain defaults to when not overtly engaged in some other activity -- is to think about others and our relationship to them. Scientists call this state the "default network," and by using scanning technology they can observe discrete areas of the brain associated with the default network, which activates whenever task-oriented activity abates. We are almost all "wired" to think about social relationships when our brain is otherwise idle, and we are social because we are wired that way:

"It turns out our brains have a passion of their own; we know this because the brain seems to devote nearly all of its spare time to one thing. Unlike the different choices you and I might have made about how to divide up our free time, our brains, when given a chance, almost all seem to practice the same thing. Yes, our brains respond adaptively to whatever tasks they are given throughout the day. If you are an accountant completing a report on a deadline, the brain regions involved with math are recruited to support your calculations. If you are an art historian working as a curator at a museum, other brain regions might be brought online. But when the brain is not focused on a specific task, when there are no tax spreadsheets or art inventories to be updated, the brain turns to its lifelong passion.

"What is it that the human brain likes to practice? Clearly, it must be extremely important to our success and well-being in life. The brain did not evolve over millions of years to spend its free time practicing something irrelevant to our lives. Indeed, the discovery that the brain is constantly practicing something suggests that evolution has, in a sense, made a bet about the value of that particular thing. ...

"Close your eyes for thirty seconds and try [to rest]. If you did, your mind probably darted around from one thought, feeling, or image to another. Instead of being at rest, [scientists have determined through PET (positron emission tomography) scanning that most people's minds are] highly active. If you are like most people, you thought about other people, yourself, or both. In other words, you engaged in what psychologists call social cognition, which is simply another way of describing thinking about other people, oneself, and the relation of oneself to other people. A college sophomore asked to do boring repetitive tasks in a psychology experiment in order to earn money to take someone on a date will start thinking, as soon as there is a break in the task, about the girl, the date, and whether or not she really likes him. ...

"Initially, I thought, 'We turn on the default network during our free time because we are interested in the social world.' While that is true, the reverse is also true and far more interesting: I now believe 'we are interested in the social world because we are built to turn on the default network during our free time.' In other words, if this network comes on like a reflex, it may nudge our attention toward the social world. And not just to other people as objects in our environment. Rather, the default network directs us to think about other people's minds -- their thoughts, feelings, and goals. ...

"But is there any reason to believe this claim that default network activity can be a cause, rather than a consequence, of our interest in the social world? ...

"One key finding comes from newborns. Babies show default network activity almost from the moment of birth. One study looked at which brain regions were engaged in highly coordinated activity in two-week-old babies and found that the default network was chugging away just as it does in adults. Another group found evidence of a functional default network in two-day-old infants. ... Why does the presence of default network activity in infants matter? Because infants clearly haven't cultivated an interest in the social world yet, or in model trains, or in anything. Two-day-old infants cannot even focus their eyes yet. In other words, the default network activity precedes any conscious interest in the social world, suggesting it might be instrumental in creating those interests. ...

"There is a second reason to think default network activity is often a cause, rather than a consequence, of our focus on the social world. Typically, the default network is studied by giving people extended periods of rest, ranging from thirty seconds to several minutes. It is easy to imagine that with all that time, people intentionally turn their minds to whatever matters to them in their daily lives. But what if people had only a few seconds of downtime? Imagine solving a math problem; afterward, you know you have just two seconds before the next math problem. It's unlikely that people would decide to try to think about anything other than getting ready for the next math problem. Nevertheless, when Robert Spunt, Meghan Meyer, and I gave people only a few seconds of pause between math problems, they showed almost the same default network activity as when they had much longer breaks. In fact, the default network activity was present the instant the math problems were finished. This suggests that the default network really does come on like a reflex. It is the brain's preferred state of being, one that it returns to literally the second it has a chance. ...

"The default network quiets down when we perform a specific task, such as calculating a math problem in math class or studying ancient Greek pottery in history class. But when the mind's chores are done, it returns to Old Faithful -- the default mode. In other words, the brain's free time is devoted to thinking socially. ... This neural habit is at work in two-day-old infants and in our adult brains the moment we stop whatever else we are doing. In essence, our brains are built to practice thinking about the social world and our place in it.