Vivian on 12/2/2007 at 16:29
Sounds like 21st century phrenology to me. Bah. How come everyone is an expert in NMR tech all of a sudden? All I know is that they're huge and from experience that they don't quite fit an adolescent elephant leg in them.
Gingerbread Man on 12/2/2007 at 16:41
Quote Posted by Briareos H
Saying that we can extract conscious and even unconscious representations from brain activity alone is not a decade old GBM.
Who said anything about extracting conscious and even unconscious representations of brain activity? For that matter, what the fuck does that even mean?
What this article, and this brou-ha-ha, revolves around is the not-exactly-cutting-edge approach of looking at activation patterns that signal imminent behaviour manifestations. You think it's a new discover that specific parts of the brain prime themselves in anticipation of further activation? Did you imagine that everything you've been able to read about the pre-frontal cortex in textbooks for the past 15 years was just kinda speculation and hastily slapped together using crayons and a photocopy machine?
Cerebral topography is very well understood and mapped. Has been for a very long time. So if you see Wee Bit 335 in the planning / staging areas light up just before Wee Bits 87389, 3667, 38670, and 3878 in the motor cortex on a regular and predictable basis just before someone makes a sound like OOOOO, then it's really not a phenomenal leap of logic to start to assume that if Wee Bit 335 flashes on then the guy in the MRI is either about to say OOOO or is seriously thinking about it.
And anyway, if you'd been paying the slightest bit of attention to me over the years you'd realise that I don't believe it's yet possible for us to operationally define conscious and unconsious cognition. There are a couple of ways to determine the relative contirbutions of conscious and unconscious processes to behavioural responses -- one of which was developed by me of all people -- but as of yet no way to operationally define the processes. And therefore no way to know if you're even LOOKING at one.
Or something.
Bottom line: Getting all BRLarmist on this is like getting all freaked out because omg did u know they can shine radiation on you and SEE YOUR BONES???!?!??!!!!
Briareos H on 12/2/2007 at 16:49
I was talking about the
scientific (
http://www.nature.com/nrn/journal/v7/n7/abs/nrn1931.html) paper from which this one has most probably been extrapolated by journalists.
And extracting sensory representation from brain activity means being able to tell that someone is looking at an apple just by analyzing how the neurons react to it. Obviously they are not able to tell it is an apple, but they seem to pretend they can extract a "mental state", whatever it means.
EDIT : oh shi the pdf is available on the website. Their research is not that advanced, actually what they are proposing is to extract the "deception" state of mind of someone who's lying.
EDIT again : re. unconscious. We are not talking about FREUD OLOL, we are talking about representations of some attribute we do not consciously extract from the percepts, such as the exact detail, etc...
fett on 12/2/2007 at 16:53
The big question that everyone is missing here is: How the hell are all three triplets going to fit in that thing?
Rogue Keeper on 12/2/2007 at 16:59
Er... It's not my fault somebody took my foggy PreCrime hint way too seriously. *whistle* But hey, I'm good in marketing and as you can read in the article, those scientistcs are getting similar ideas.
Vivian on 12/2/2007 at 17:03
Hey GBM, how do MRIs or NMRs or whatever actually read neuron activation? Do they track certain ions or what?
Gingerbread Man on 12/2/2007 at 17:11
Technically, it's fMRI that's used for neural imaging. Basically, it's got to do with detecting increased blood flow. Less basically: (
http://www.fmrib.ox.ac.uk/fmri_intro/physiology.html)
Quote:
The local T2* critical in fMRI contrast is thus determined by the balance of deoxygenated to oxygenated haemoglobin in blood within a voxel, which in turn is a function of local arterial autoregulation or vasodilation. By increasing the flow of oxygenated blood or reducing oxygen extraction to a region in the brain an increase in local, intravoxel T2* occurs which in turn leads to an increase in image intensity. An increase in oxygenated arterially delivered blood in response to local activation will result in more oxygenated iron in the capillary and venous vascular beds, thereby creating a relatively longer regional T2* and an image intensity increase. It also reflects a decrease in deoxyhaemoglobin content, i.e. an increase in venous blood oxygenation and a longer effective T2*.
The image intensity for a given voxel in the brain can therefore significantly increase if more oxygenated blood enters this region and fills the venous bed. This assumes, however, that cortical activation causes local vasodilation which is not accompanied by a significant increase in oxidative metabolism. It should be remembered that local image intensity increases will also be dependent on differences in haemodynamic (blood volume, flow and oxygenation) and vessel architecture (radii, orientation, vascular openness).
lol scientists
Vivian on 12/2/2007 at 18:37
Wow, is is that simple (well, not exactly simple but you know what I mean)? I thought you actually saw neurotransmitters being moved or Ca+ or something along those lines.
The_Raven on 12/2/2007 at 19:13
Burnt toast? or new weapon in the war on terror?
Turtle on 12/2/2007 at 20:05
Wait, so if we install an MRI machine in BR40928495842935924490282509's ass we'll be able to predict when he's going to post an ill advised, alarmist thread?
