Patrik Lindenfors blogg

Det finns hopp för oss med dåligt minne. Från New York Times:

In a series of experiments, scientists at Wake Forest led by Sam A. Deadwyler trained rats to remember which of two identical levers to press to receive water; the animals first saw one of the two levers appear and then (after being distracted) had to remember to press the other lever to be rewarded. Repeated training on this task teaches rats the general rule, but in each trial the animal has to remember which lever appeared first, to inform the later choice.The rats were implanted with a tiny array of electrodes, which threaded from the top of the head down into two neighboring pieces of the hippocampus, a structure that is crucial for forming these new memories, in rats as in humans. The two slivers of tissue, called CA1 and CA3, communicate with each other as the brain learns and stores new information. The device transmits these exchanges to a computer.

To test the effect of the implant, the researchers used a drug to shut down the activity of CA1. Without CA1 online, the rats could not remember which lever to push to get water. They remembered the rule — push the opposite lever of the one that first appeared — but not which they had seen first.

The researchers, having recorded the appropriate signal from CA1, simply replayed it, like a melody on a player piano — and the animals remembered. The implant acted as if it were CA1, at least for this one task.

“Turn the switch on, the animal has the memory; turn it off and they don’t: that’s exactly how it worked,” said Theodore W. Berger, a professor of engineering at U.S.C. and the lead author of the study, being published in The Journal of Neural Engineering. His co-authors were Robert E. Hampson and Anushka Goonawardena, along with Dr. Deadwyler, of Wake Forest, and Dong Song and Vasilis Z. Marmarelis of U.S.C.