Is real science catching up to Topher ?
New Scientist reports that a Laser has been used to create false memories in fly brains.
"A flash of laser light can alter the brains of fruit flies so that they learn to fear pain that they never actually felt".
OK so Topher probably doesn't have too much to worry about just yet, except maybe a guest appearance by Jeff Goldblum, but does anyone else find it amazing that even such a tiny amount of brain alteration is actually possible ?
October 15 2009
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Salocin | October 15, 23:47 CET
Mercenary | October 15, 23:49 CET
"It would be unethical to engineer transgenic humans and tell them what memories to have"
True but the conversations between you and your engineered person would make great tv.
My sweater is itchy.
Sunfire | October 16, 00:08 CET
The One True b!X | October 16, 00:10 CET
DaddyCatALSO | October 16, 01:27 CET
Pointy | October 16, 01:55 CET
Like how I hate morons in stadiums or other 360 degree venues that bring laser pointers.
orangewaxlion | October 16, 04:17 CET
QuanticoMVP | October 16, 06:08 CET
The passage of time works pretty well for that, too.
jcs | October 16, 06:18 CET
Nice experiment that, i'm not totally convinced the conclusion's justified quite yet (i'm with the guy who says they didn't show what was happening to those particular neurons in the "genuine learning" situation with real electric shocks) but it seems fairly safe to assume that, since memories are at some level biochemical then if you can alter the biochemistry with sufficient precision you can create memories.
The problem with the dollhouse tech in real-life was never that we can't create artificial memories it was always (to me) more about reading (and then writing) an entire brain state.
Saje | October 16, 07:08 CET
Extrapolating the future, it’s not inconceivable to me that it’ll be possible to alter and meter most parts of the brain. But to do it in the time and with the ease with which it’s done in the series seems pretty damn far off. I’ve never thought about the altering process as physically changing the target brain into a perfect copy of the source brain. That would approach impossibility. Instead, what seems more reasonable is transforming the source unto the underlying ‘hardware’ of the target brain, so to speak. How to calculate that transform is possibly a harder problem to solve than the biochemistry bit.
hence | October 16, 08:28 CET
CZGoldEdition | October 16, 08:54 CET
Not really sure what you mean by "transform" hence. Do you mean altering the copy of the personality so that when you "play it back" on the active's brain it behaves as if it's the original copy (despite the different brain structure and chemistry) ? So where the original would have stimulus A -> brain state X, the copy might have stimulus A -> black box transformation -> brain state X (because the copy's actual brain state due to stimulus A would, without the transform, have been Z) ?
Interesting idea that (if that's what you mean). As you say though, the transform would be very hard in practice and maybe even impossible in principle since it would seem to require knowledge of ALL possible brain states (and their accompanying stimuli) and how to get from one to another. It also depends on stimulus A always yielding brain state X (or at least on the resulting brain state being reachable from X in a consistent, deterministic manner) which might hold true in drosophila but may well not in a species that's aware (to some extent) of its own brain states and how they might relate to stimuli.
As to whether the brain state is read/writeable at all, I think it comes down to the level of detail required. To me, for a complete consciousness copy which is exact in every way (as with e.g. the copy of Margaret) you'd need to record the brain state (position of neurons, concentration of neurotransmitters, blood flow etc.) right down to the quantum level which Heisenberg's uncertainty principle tells us just isn't doable.
(and the laser stuff's cool but presumably it's not going to work on us because only a very small proportion of our neurons are exposed to light ?)
Saje | October 16, 10:04 CET
Yes, precisely. In the spirit of wild speculation it at least sounds more plausible to me :) It would still require modifying the response function of individual neurons, but compared to the scenario of making a perfect ‘molecular’ copy, where you’d have to grow new dendrites and whatnot, it’s not quite as far-fetched. It may also solve the problem of measuring and modifying with the precision you were talking about. As long as a group of neurons behave sufficiently close to how the corresponding group behaves in the source brain, things might work out and the individual neurons wouldn’t have to be exact copies. A neural net computes, or approximates, functions. So the problem is reduced to modifying an existing net to compute the same function as another net that is topologically different.
A neat side effect of looking at it like that is that it fits the metaphor of acting a bit better, maybe.
(and the laser stuff's cool but presumably it's not going to work on us because only a very small proportion of our neurons are exposed to light ?)
Would have to be awfully strong light to penetrate our thick brainpans.
hence | October 16, 11:05 CET
Shey | October 16, 11:26 CET
Or awfully long light ;), thinking about Salocin's EM pulses (probably too imprecise though).
Yeah hence, I like the fit with the acting metaphor, different actors could be said to have some segments of their neural net in closer approximation to the "original" performance than others for instance.
Re: approximations though, to me that's unlikely to lead to a good copy (in the sense of being accurate enough to seem to be the same person to outsiders, let alone to the person themselves). Just seems like the less precise the copy the more quickly it'll diverge from the original. Guess it depends on how resistant to perturbations our brains normally are though (if they're normally kind of "close-ish is good enough" when it comes to results then a close-ish copy might do).
(but I definitely agree it's more plausible since, as I say, i'm not convinced an exact copy is possible even in principle)
Saje | October 16, 12:06 CET