WHY are you reading this article when you could be watching paint dry instead? It’s all because of our innate hunger for information. Humans, it turns out, are infovores.
The term was introduced into the scientific lexicon recently by neuroscientists trying to work out why we get a kick out of learning something new – why we have an appetite for knowledge. Irving Biederman of the University of Southern California in University Park and Edward Vessel of New York University, who coined the term, now think they have identified the brain mechanism responsible. They claim that the neural pathways through which we learn about the world tap into the same pleasure networks in the brain as are activated by drugs like heroin. They say that, for humans, only the basic urges of hunger, harm avoidance and the need to find a mate can distract us from this info-craving (American Scientist, vol 94, p 247).
How does information give people a high? The key is a type of chemical receptor known as a mu-opioid receptor, which is found on the surface of some brain cells. Like other opioid receptors, it is activated by heroin, morphine or naturally produced substances called endorphins, and is found in areas of the brain that mediate pain and pleasure. Mu-opioid receptors are also found in areas that process sensory information and memories. They occur in increasing numbers along the neural pathways in these areas, from the early stages where the brain processes basic things like colour to the later stages of conscious recognition.
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These are the areas that become active when the brain is trying to interpret the information it is receiving, whether that is an image of an object, or words on a page, or the song of a bird. Biederman and Vessel suggest that when this happens, the endorphins that stimulate mu-opioid receptors are released, causing a feeling of pleasure. What’s more, because the number of mu-opioid receptors increases further along the neural processing pathway, information that triggers the most memories and conveys the most meaning to a person causes the greatest pleasure response. It is this bonus that compels people to browse for new information.
“Information that triggers the most memories causes the greatest pleasure”
Does the effect ever wear thin? Yes, with repetition. Reading a book for the second time is less stimulating than reading it for the first time. That is, unless you didn’t understand it first time round. Biederman and Vessel say that endorphins are released at the “click” of comprehension, and that until the penny drops people are happy to return to a subject. Children take longer to “click” than adults – which explains their enthusiasm for hearing the same bedtime story night after night.
