Neuronal Learning Observed

Gregg Favalora writes "According to this week's EE Times, R. Colin Johnson reports that researchers at UC San Diego have directly observed the physical changes that neurons undergo during learning. His article explains that neurons were cultured on a smooth, photoconductive silion substrate. Using optical techniques, they were able to trigger individual neurons into firing -- and were actually able to observe some of the physical changes that underly short- and long-term learning. According to the article, "[The team] tested out the theory that learning results from a physical change that strengthens the connections between selected neurons. [They showed] how short- and long-term memories result from different physical effects in the brain. Short-term memories, it turns out, result from the instant assembly of more filaments to strengthen the skin of the cell temporarily, whereas long-term memories result from the growing of a new synapse to strengthen the connection permanently." Besides the interesting cellular observations they're making, I am also intrigued by the process the article describes which uses properties of the silicon substrate to aid in firing individual neurons. "

Comments

Not quite what it is claimed (skepticism)

[sam_handelman]

[The team] tested out the theory that learning results from a physical change that strengthens the connections between selected neurons. [They showed] how short- and long-term memories result from different physical effects in the brain

They showed physical effects that MAY be responsible for the phenomenon that we call memory. This is very good work, and it shows that these physical effects occur in the brain (there is some possibility that it's an artifact of their method but it's pretty slim.) They also occur on about the right timescale to explain memory. HOWEVER that is NOT sufficient to show that these physical effects are responsible for the phenomenon we call memory, just that they very well could be.

The point at which you call something "proven" can be fairly subjective but in this case we haven't eliminated other potential physical effects that might play some role, possibly a crucial or pivotal one, in actual memory.

As a scientist, I am convinced (just short of certain) that the effects that they've observed play some role in real memory. That doesn't mean that they play the definitive role.

I suspect that the scientists responsible for the research couched there statements in a number of caveats that the reporter simply ignored.