Friday, February 13, 2009

Value Proxy

Read Montague described a simple but revealing experiment on monkeys conducted by Wolfram Schultz in his fascinating book “How We Make Decisions.” In the experiment, lights precede the arrival of juice squirts a short time later. When the light is initially presented, there is no change in the dopamine activity in the monkey’s brain, that is, the light is initially considered “things are just as expected.” However, the arrival of the juice a short time later causes a burst of activity in the dopamine neurons; that is, “things are better than expected.”

If the light-juice sequence is repeatedly delivered to the monkey, two remarkable things happen. The juice no longer triggers a burst of activity. Instead, the light triggers a burst of activity. That is, the monkey’s brain responds to the light in the same fashion that it reacted initially to the juice. The light has become a “value proxy” for the future juice delivery.

The light has become a form of money - which stands for future value in the world of human beings. Money enables us to buy the things that give us satisfaction: food, entertainment, leisure, enjoyment, ...

This phenomenon is a part of neural reinforcement learning. It gives the system (brain) more time to prepare its actions, hence more time to avoid costly, energy-wasting decisions. It makes us more efficient.

Unfortunately, we human beings often mistake the value proxy for the real value. We laugh at the monkey that jumps at the light but ignores the juice. But we ourselves think money is value, and we hoard money. Why don’t we laugh at ourselves?

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