When I read about this brain-in-a-dish project I was tickled by the implications and thought of it as a science-fiction-in-real-life item. The story, told in that light, is that scientists have made a mini brain of 40-60 neurons and given it a 12 second memory. That's close enough to have fun imagining the possibilities. As Jeff Toney blogged the other day:
This is amazing. I wonder what the "memory" could be - could be a good subject for a science fiction story.
But as I've been slowly composing (procrastinating) this post, it's taken on a different meaning for me. The experiment isn't so much a mini-brain as a model of brain activity. The idea is that the brain is so complex and its processes are so fast, that researchers have a hard time studying what it's doing. So they took brain cells from a rat embryo from the part of the brain that deals with memory (well, they were cultured cells, so I guess technically "descended" from a rat embryo). Those cells, rather that grow into functioning brain cells inside a rat's head, did so on a little dish, forming the loop networks they're programmed to join.
The researchers then gave them a jolt, and the cells lit up with a "burst of network activity." Because the cells' natural inhibitory response was disabled, the split second activity lasted 12 seconds. To me that sounds more like a seizure than a memory, but the question of how to characterize it is sort of the point. At what point, definitionally, do signals become memories or thoughts? One of the ways to get to that answer is to build a model like the one in this experiment to study the signal itself. And after last week's segment on the politicization of personhood, what makes this even more amazing to me is not just whether that signal is a memory, but whether a memory requires a "who" to have it.
Even the briefest of searches on cognition and personhood reveals a can of worms that I'm probably better off not opening here, but really, can you imagine breaking down the brain's functions into isolated signal networks and then trying to figure out which and how many of those are necessary to make "you"?
I send signals through networked loops of cultured hippocampus cells, therefore I am?