3-D brain centers pinpointed

August 1, 2007

In studies with monkeys, researchers have identified in detail the brain regions responsible for the unique ability of primates, including humans, to process visual 3D shapes to guide their sophisticated manipulation of objects.

Specifically, the researchers delineated regions of the parietal cortex responsible for extracting 3D information by integrating disparities in information from the two eyes. Such integration is critical to perceiving three dimensions, because each eye receives only a two-dimensional projection of an image on the retina.

Led by Guy Orban of Katholieke Universiteit Leuven, the researchers published their findings in the August 2, 2007, issue of the journal Neuron, published by Cell Press.

The researchers performed experiments in which they required monkeys to fixate on computer images of objects projected on a screen. As the animals watched the objects, the researchers scanned their brains using magnetic resonance imaging. This widely used technique involves using harmless magnetic fields and radio waves to measure blood flow in brain regions, which reveals brain activity in those regions.

In one set of experiments, the researchers presented images of connected lines, like partially unfolded paper clips, that could be perceived as three-dimensional structures. The researchers studied the influence of motion on 3D perception by presenting the connected-line images only to one eye and “moving” the objects.

The researchers’ analysis of activity in regions of the parietal cortex during these experiment revealed that two areas—called the anterior intraparietal cortex and the lateral intraparietal cortex—were specifically sensitive only to depth structure.

In a second experiment, the researchers presented to the monkeys computer images that simulated small, complex objects. Perception of the three-dimensionality of small objects is central to primates’ ability to grasp and manipulate with their hands. The researchers’ analysis of the animals’ brain activity revealed that the same intraparietal regions are also uniquely sensitive to the depth structure and two-dimensional shape of such objects.

“This study goes beyond previous imaging studies by demonstrating not only that different parietal areas process distinct aspects of visual 3D space in line with their involvement in distinct sensorimotor functions, but also that 3D shape features are specifically represented in anterior intraparietal regions, where such information is required for the efficient control of hand manipulation tasks,” concluded the researchers.

Source: Cell Press

Explore further: On the crest of the wave: Electronics on a time scale shorter than a cycle of light

Related Stories

Rejuvenating the comparative approach in modern neuroscience

July 20, 2015

65 years ago, the famed behavioral endocrinologist Frank Beach wrote an article in The American Psychologist entitled 'The Snark was a Boojum'. The title refers to Lewis Carroll's poem 'The Hunting of the Snark', in which ...

Imaging glucose uptake activity inside single cells

July 17, 2015

Researchers at Columbia University have reported a new approach to visualize glucose uptake activity in single living cells by light microscopy with minimum disturbance. In a recent study published in Angewandte Chemie International ...

Is your fear of radiation irrational?

July 14, 2015

Bad Gastein in the Austrian Alps. It's 10am on a Wednesday in early March, cold and snowy – but not in the entrance to the main gallery of what was once a gold mine. Togged out in swimming trunks, flip-flops and a bath ...

Recommended for you

Machine Translates Thoughts into Speech in Real Time

December 21, 2009

(PhysOrg.com) -- By implanting an electrode into the brain of a person with locked-in syndrome, scientists have demonstrated how to wirelessly transmit neural signals to a speech synthesizer. The "thought-to-speech" process ...

Quantum Theory May Explain Wishful Thinking

April 14, 2009

(PhysOrg.com) -- Humans don’t always make the most rational decisions. As studies have shown, even when logic and reasoning point in one direction, sometimes we chose the opposite route, motivated by personal bias or simply ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.