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Computational Neuroscientist; Francis Crick Professor, the Salk Institute; Coauthor, The Computational Brain

What is the impact of spending hours each day in front of a monitor, surfing the Internet and playing games?  Brains are highly adaptable and experiences have long-term effects on the brain's structure and function. You are aware of some of the changes and call it your memory, but this is just the tip of the iceberg. We are not aware of more subtle changes, which nonetheless can affect your perception and behavior. These changes occur at all levels of your brain, from the earliest perceptual levels to the highest cognitive levels. 

Priming is a dramatic example of unconscious learning, in which a brief exposure to an image or a word can affect how you respond to the same image or word, even in degraded forms, many months later. In one experiment, the outlines of animals and other familiar objects were viewed briefly and 17 years later the subjects could still identify the animals and objects above chance levels from versions in which half the outlines were erased. Some of the subjects did not remember participating in the original experiment. With conceptual priming, an object like a table can prime the response to a chair. Interestingly, priming decreases reaction times and is accompanied by a decrease in brain activity — it becomes faster and more efficient.

Brains, especially youthful ones, have an omnivorous appetite for information, novelty and social interaction, but it is less obvious why we are so good at unconscious learning. One advantage is that it allows the brain to build up an internal representation of the statistical structure of the world, whether it is the frequency of neighboring letters in words or the textures, forms and colors that make up images. Brains are also adept at adapting to sensorimotor interfaces. We first adapted to clunky keyboards, then to virtual pointers to virtual files, and now to texting with fingers and thumbs. As you become an expert at using it, the Internet, as with other tools, becomes an extension of your brain. 

Are the changes occurring in your brain as you interact with the Internet good or bad for you?  Adapting to the touch and feel of the Internet makes it easier to extract information, but a better question is whether the changes in your brain will improve your fitness. There was a time, no long ago, when the heads of corporations did not use the Internet because they never learned to type, but they are going extinct and have been replaced with more Internet savvy managers.

Gaining knowledge and skills should benefit survival, but not if you spend all of your time immersed in the Internet. The intermittent rewards can become addictive, hijacking your dopamine neurons that predict future rewards. The Internet, however, has not been around long enough, and is changing too rapidly, to know what the long-term effects will be on brain function. What is the ultimate price for omniscience?