I know what you’re attending to!
Neuron : Dynamics of Parietal Neural Activity during Spatial Cognitive Processing
Here’s John Lisman’s review of this paper (from Georgopoulos’s group)… I don’t think I can say it better than him:
If ever there was a paper that would bring tears to one’s eyes, this is it: a previously hidden mental process has now become subject to experimental study. The mental process is the covert movement of attention, the selective focussing of attention to subregions of the visual field, but without eye movement. The movements of covert attention were hypothesized based on psychophysics, but the authors can now follow it using a vector field derived from a population of neurons in the parietal cortex. The monkey has been trained to use covert attentional shifts to solve a maze task. The major finding is that the vector derived from the population of parietal cells follows in time the path through the maze, as the monkey solves the maze.
From the abstract:
We found that the direction of the followed path could be recovered from neuronal population activity.
Yet another scary but cool result…
May 11th, 2006 at 3:45 pm
There’s an actual PDF on Averbeck’s site. For those of us without site licenses.
May 11th, 2006 at 9:23 pm
Where is the review by Lisman published?
Thanks!
May 12th, 2006 at 12:47 am
The review can be found on Faculty of 1000 Biology at this link. It’s a short review… I essentially put most of it in the post…
BTW, since Bayle and I are at institutions with site licenses, we often post articles that others without institutions willing to pay $$$ may not be able to access. I apologize for that and encourage readers who find accessible copies of the articles (eg. where the author has retained rights to put the article on his/her own website for free download) to post links in the comments section, so that others can benefit from their legwork!
May 16th, 2006 at 9:30 pm
That IS scary. This sort of thing always gives me the creeps, no matter how intellectually cool it is.
May 19th, 2006 at 5:31 pm
I disagree: what would be “scary” is if this could not be done.
May 30th, 2006 at 6:30 pm
Surprisingly nice paper, though I don’t know about tears to my eyes, but figure 3 is pretty nice. However, it might be just my lack of understanding, but it seems to be a bit circular in it’s argument. i.e. Cells that fire during a maze with a 45 degree exit, are 45 degree prefering cells, and look, wow, when you present a maze with a 45 degree exit, the 45 degree prefering cells fire. And then things fall a part a bit. In figure 4, the population vector, when looking a “1 turn mazes” should (at least in my mind) first be tuned to the path of the first segment of the maze, and then to the second. But they show data wherein the path is 0 degrees, then 90 degrees. However the population vector peaks for 0 degrees, then 45… but there is no power in the 90 degrees vector.
Now I know they’re trying to say that the neurons they’re recording are infact coding for the vector from the origin to the exit; but how can you know that? I mean, it just gets very complicated when you start ascribing purposes to behavioral-neural corelations (or cognitive-neural in this case).
I suppose the idea is like, if you recorded from some neurons and they spiked violently when you showed them a banana, that doesn’t tell you if the cells are recognizing the yellow of the banana, the edge of the banana or responding to a hunger cue, however if you lesion the area you’re in, and the monkeys still see bananas, and still eat them but can no longer tell yellow from blue, then you’ve got your answer.
So someone needs to design a very clever cognitive/behavioral test to see what this cognition-neural correlation is actually coding for.