3-D brain centers pinpointed

Aug 01, 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: 3-D human skin maps aid study of relationships between molecules, microbes and environment

Related Stories

Lightbulb using graphene is to go on sale this year

15 hours ago

The BBC reported on Saturday that a graphene bulb is set for shops, to go on sale this year. UK developers said their graphene bulb will be the first commercially viable consumer product using the super- ...

Big toe's big bone holds evolutionary key

Mar 13, 2015

Our skeletons hold tell-tale signs that show that human bipedalism – walking upright and on two feet – are unique to humans especially when compared to our closest living relatives, apes. Exactly when ...

Recommended for you

'Google Maps' for the body: A biomedical revolution

20 hours ago

A world-first UNSW collaboration that uses previously top-secret technology to zoom through the human body down to the level of a single cell could be a game-changer for medicine, an international research ...

New compounds could offer therapy for multitude of diseases

22 hours ago

An international team of more than 18 research groups has demonstrated that the compounds they developed can safely prevent harmful protein aggregation in preliminary tests using animals. The findings raise hope that a new ...

User comments : 0

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.