As maps go, I'm not sure this one gives me much direction, but I really like the experiment and the researchers have done a great, generous job with sharing the results - the first interactive map of the brain's "semantic space."
As explained more thoroughly by the nice fellow below, Alex Huth, first author of the paper, what they did was show labeled images and actions to people while scanning their brains with an MRI machine. The subjects watched hours of video, with their brains observed processing and organizing the images and information.
What they show is that the brain does indeed make relational groupings of what it sees, but what it doesn't do is order those groups in discrete areas of the brain.
If, like me, you've absorbed the urban legend about only using a small portion of your brain (and the rest is untapped secret psychic power from our alien ancestors!) then you might have the sense that the brain works like a series of compartments. While it is the case that different regions of the brain serve different functions, what we see in this semantic map is that there's no single spot for, say, "cowboy."
There's more to the story and it's all presented in this amazing interactive "map" that shows the relationship between the categories and the bloodflow in the brain.
Other than the overall lesson of how distributed the activity is, I'm still puzzling through how to use the map, so if this is something you know about, I appreciate your insights.
Alex Huth, first author of our new paper, talks about how visual information about thousands of objects and actions are represented across human visual cortex. For more information, please visit our web site (gallantlab.org) or get the paper: Huth, A.G., S. Nishimoto, A.T. Vu & J.L. Gallant (2012). A continuous semantic space describes representation of thousands of object and action categories across the human brain. Neuron, December 20 2012.
For more information about this paper or our other work please visit our lab web page:
http://gallantlab.org
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It would be interesting to see if these statistical correlations have any validity across a larger sample size than 5 subjects from Western European culture. For example, let's go to even more primitive semantic constructs- identification of orientation and distance. Brains trained in rectilinear "carpentered" environments are vulnerable to optical illusions having to do with inferences about distance drawn from converging lines. For individuals whose experience is devoid of rectilinear spaces (homes are circular- yurts, huts), it is not surprising their perception do not draw the same incorrect inferences. (Consider this brief MIT paper for example)
There is great survival pressure placed on advantages with more accurate modeling of intentionality of perceived entities in the world. We do not think of apples as having intentionality, but Kasper Hauser does (video clip). So it would not be surprising if the "animal category" of this study lit up when Hauser's brain was observing a moving apple.
There is good cause to be skeptical about the method of deduction of these maps. Linear regression analysis used in this study is particularly susceptible to false correlations as has been amply demonstrated in the Econometric space by Granger. Correlations do not imply causality.
There is a yawning gulf between what we know at the micro level of neuron activity and the macro level of thought. As we descend from thought into non rational consciousness, or attempt to ascend from biofunction of neurons, we rapidly move into a black box of mystery.
The dramatic re visioning and expansion of what we understood the cosmos to be was synchronous with radical improvements in the resolving power of telescopes. Our primitive hypotheses which transfixed our imaginations at the time were not very important at all. Similarly, our knowledge of these black box relationships will become more clear as our ability to gather data on brain function becomes more accurate. It is not just fMri instruments that are revolutionizing our knowledge. For example- there is wide varation in neuron types- Using gene mircroarray analysis, the Paul Allen center in Seattle has identified 900 different neuron cell types with unique gene expression. Within each "Voxel" which neuron types are being activated? We don't know, because the resolution of the "Voxel" is too crude. The study is making an assumption that the physical proximity of a few milimeters in the brain has some meaningful modular correlation. But maybe it doesn't. Maybe what is important is which neurons of which of 900 types are lighting up within that 2mm X 2mm X 4mm space.
The study suggests some further randomized control experiments to validate their hypothesis. For example, if multiple different types of representations of the same"animal" displays a largely similar statistical "animal category" fMRI signature across test samples from subjects from widely diverse cultures, then perhaps these researchers are onto something.
I would not at all be surprised if such tests fail miserably.
Nonetheless we should be massively increasing funding for such research. Understanding consciousness is key to many of our social and political challenges.
That's hard to top. At least it isn't a condemnation from another neuroscientist dismissing the as-yet unquantifiable. I cannot condemn enough the "psychic" cottage industries, or the rest of the hocus pocus. 100 years ago, much of what we know about the universe was at best "crackpot' theories. I've made many jokes about aliens, but when you look at the vastness of the universe(s), it starts to look feasible to theorize that there's a chance of sentient beings around somewhere. There are some very credible former-USSR pilots that still claim on the record that they engaged w/some type of unidentifiable objects in the early 60s from a secret base in Siberia that still exists. If you view the satellite photos, it looks like some of the aerial shots of other ancient "designs" around the world. As far as neuroscience & devices go, a Canadian doctor built a magnetic halo that when placed on the subject & activated induces not only an instant belief of any incoming suggestions, it also induces visions of "ghosts", or "angels"- similar to a deep, religious experience. Sony holds a patent for a microwave emitter that swells the brain slightly, producing an audible "click" in the subject when triggered. This has vast military potential, as you might imagine. I think a "spot" targeted MRI device would also work, though I've yet to hear of one. Personally, I tread very lightly in the area of psychic phenomenon, as it rarely tends to elicit any favorable responses from anyone I'd want to tell it to. Hysterics, or mysticism, are not my idea of a good time. I don't have all the answers, I just keep an open mind. I have to.