Friday, January 31, 2014

Descartes in 25 minutes

John Cottingham



Pinky, are you pondering what I’m pondering?

False Memory implantation! 

In Mice. 


From a student in my philosophy class: A very interesting report on neurological research using lab mice. Some key bits:

The first step in the mouse experiment took place last year when Ramirez and his colleagues isolated an individual memory in a mouse’s brain by tagging the brain cells associated with it and inducing recall of the memory at will by forcing those neurons to fire with light. In this new study, they artificially stimulated neurons to make associations between events and environments that had no ties in reality and, in essence, implanted a new, false memory.

They used a technique called optogenetics, which uses light to turn on and off activity of individual brain cells in a living animal. An optical fiber feeds light into the mouse’s hippocampus, the area of the brain that plays a prominent role in forming new memories…

…Say a mouse gets put in a chamber with red walls. It is sniffing around, when suddenly it feels a mild shock zap its feet. When the mouse is dropped into the same red room the next day, even if there’s no shock, it recalls the unpleasant experience and freezes in fear.

…Next, Tonegawa and his colleagues wanted to find out if they could induce recollection of a memory at will by forcing the neurons associated with that memory to fire. They put the mouse in a different, benign blue room, where it boldly moved about and probed the new surroundings as usual. But once the scientists forced those neurons to activate, the mouse immediately remembered the bad experience and froze.

…Putting a new mouse in the red chamber, they let it recognize the room as harmless. The following day, they had it explore a blue-walled chamber, and then gave it a mild jolt while simultaneously inducing recall of the red room. This was meant to artificially associate the memory of the shock-free red room with the fear of being shocked.

Brain…I’m not following…Narf.

It’s very simple Pinky.

No. Zoink! Blue, Red, Pink…. So many colors.

Really Pinky.  Just read on.

On the third day, Tonegawa and his colleagues wanted to see whether this false association had successfully been implanted. They placed the mouse in the red room, where it froze even though nothing bad had ever happened to it there. A false memory had been formed and recalled.

So, essentially, you turn on some portion of the lab mouse’s blue room memories as it is exploring the innocuous red room and it acts, in the red room, as if it is in the blue room, and certainly does not act as if it is in the pink. This leads naturally to the following question:

Q1: Subjectively, what is the mouse experiencing when he is so reacting?
Is he experiencing an “I am in the blue room right now and it’s shocking me” experience, or is he experiencing an “I’m in the red room, and it is shocking me” experience?

After all, the way the story describes it, what could be going on in Pinky’s experiential world is that Pinky is blithely exploring away in the red room, when suddenly he finds himself in the blue room getting that crap shocked out of him. If that were the case, then the negative association would be set up between the pain and blue room experiences.

On the other hand what could be going on in Pinky’s experiential world is that he is exploring away in the red room, and suddenly he finds it shocking the droppings out of him.

Way to find out:  Give it some time, next day, stick that mouse in the red room, and see how he reacts (this time, he is not hooked up to the diabolical machine, so you know he sees and experiences the red room).

What happens? Mouse reacts. So, it appears he reacts because he believes the red room is dangerous, and is about to shock the droppings out of him even though it isn’t and never had done so. 

It is pretty amazing that the experimenters can pinpoint the optical stimulation to such a degree of precision that they can activate the pain experience, while not affecting the visual experiences.

And you thought Pinky and the Brain was just a kid’s show, premised on a far-fetched idea.  Too bad the series isn’t still around. An obvious Pinky and the Brain parody suggests itself:

Mouse-ception. Or perhaps Inmouseception?

Pinky and the Brain get revenge on their researchers by using the Inception technology to implant the thought “OBEY BRAIN” in all of us.

It’s only a matter of time.