When we look at a photograph, we effortlessly identify people and objects—re-creating a three-dimensional scene in our mind from the two-dimensional image. As easy as that task seems, scientists have long puzzled over exactly how our brain does it; even the most powerful computers still struggle to pick 3-D objects out of 2-D images. Until now, most research has focused on the simpler neural representation of 2-D patterns, but a new study shows for the first time that some neurons are also tuned to 3-D details.
The sheer number of possible 3-D shapes has made it hard to study how the brain processes them. A team headed by Charles Connor and Yukako Yamane, neuroscientists at Johns Hopkins University, sidestepped this problem by using a computer program that generated a series of shapes that evolved according to which items provoked the greatest response from certain neurons. They eventually pinpointed several neurons that each responded to specific 3-D configurations.
Object fragments such as projecting points or ridges elicited the greatest response. “Neurons carry very clear information for 3-D parts and for where those parts are relative to each other,” Connor says. The findings support a classical theory that the brain can comprehend objects as spatial combinations of 3-D parts rather than only learning to recognize objects from different 2-D per-spectives. Connor notes, however, that the brain may still rely heavily on faster 2-D processing in situations that require rapid recognition.
Note: This article was originally printed with the title, "Seeing In Three Dimensions".
This article was originally published with the title Seeing in Three Dimensions.
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3 Comments
Add CommentOkay, I admit it, when I first read the title, I thought "Duh...two eyes"
Reply | Report Abuse | Link to thisThe thing that puzzles me is how the brain creates the impression that what we see is 'outside' us using an internal support. I once heard a biology teacher say that the neurones terminations which actually 'recreate' this visual impression are actually situated in the eyes! Anyone have any more information on this?
Reply | Report Abuse | Link to thisI'm not sure which is more amazing: how the brain works, or how we don't know this stuff instinctively even though we are using the very instrument we're studying to draw our conclusions!
Reply | Report Abuse | Link to thisI'm personally curious about the brains ability to adapt to new inputs. It would be very interesting to study how the brain would adapt to something like true 3D input (as opposed to two meshed 2D inputs with inferred depth), or even 4D input! That is the next logical step after we exhaust the possible ways to saturate our sensors with things like moving pictures and music.