How the brain sees people in motion

March 15, 2006

A swaying tree and a moving person activate distinctive areas of the brain's visual cortex, since recognizing people is essential for social interaction. So, an important question in exploring the visual system is how the visual cortex manages such specific recognition of "biological motion."

In an article in the March 16, 2006, issue of Neuron, Marius Peelen and colleagues at the University of Wales, Bangor have used detailed functional magnetic resonance (fMRI) imaging of human volunteers to shed new light on this process. The widely used analytical technique of fMRI employs harmless magnetic fields and radio waves to measure blood flow in brain regions, which reflects brain activity in their region.

In their experiments, the researchers found that in detecting biological motion the visual cortex not only uses a specific region known to detect motion of other people, but engages areas that respond to the static human form as well.

The researchers designed their experiments to give subjects information only on biological motion and not on a human form. Specifically, they scanned the subjects' brains while showing them only "point-light" animation of human movement such as jumping or throwing. These animations consist only of a small number of white dots on a black background, not portraying skin, clothes, or other specific features of a human in action.

As a control, to separate effects of viewing motion in general, the researchers also showed the subject scrambled dots making the same motion, but not organized to create an illusion of a human in motion. The researchers also established the "body-selective" regions involved in recognizing the human form by showing subjects images of human faces and human bodies. And they mapped the region responsible for detecting motion in general by showing the subjects abstract oscillating patterns of rings.

Detailed analyses of the brain regions activated by the patterns revealed that the animations did activate the brain region responsible for detecting biological motion.

But importantly, the researchers also reported that "Our results show that visual areas involved in analyzing the form of the human body . . . are selectively activated by sparse movement patterns that induce the percept of a person performing an action." They also found that overlapping regions could nevertheless be responsible for distinctive components of the process.

"This work significantly clarifies our emerging picture of how the human brain makes sense of the appearance and actions of other individuals," concluded the researchers.

"We believe this approach will prove useful both in further studies on the neural basis of 'social vision' and more generally in studies of other regions where multiple functional areas occupy overlapping cortical territory," they wrote.
-end-
The researchers include Marius V. Peelen, Alison J. Wiggett, and Paul E. Downing of the University of Wales in Bangor, United Kingdom. This research was supported by BBSRC grant BB/C502530/1.

Peelen et al.: "Patterns of fMRI Activity Dissociate Overlapping Functional Brain Areas that Respond to Biological Motion." Publishing in Neuron 49, 815-822, March 16, 2006. DOI 10.1016/j.neuron.2006.02.004 www.neuron.org

Cell Press

Related Brain Articles from Brightsurf:

Glioblastoma nanomedicine crosses into brain in mice, eradicates recurring brain cancer
A new synthetic protein nanoparticle capable of slipping past the nearly impermeable blood-brain barrier in mice could deliver cancer-killing drugs directly to malignant brain tumors, new research from the University of Michigan shows.

Children with asymptomatic brain bleeds as newborns show normal brain development at age 2
A study by UNC researchers finds that neurodevelopmental scores and gray matter volumes at age two years did not differ between children who had MRI-confirmed asymptomatic subdural hemorrhages when they were neonates, compared to children with no history of subdural hemorrhage.

New model of human brain 'conversations' could inform research on brain disease, cognition
A team of Indiana University neuroscientists has built a new model of human brain networks that sheds light on how the brain functions.

Human brain size gene triggers bigger brain in monkeys
Dresden and Japanese researchers show that a human-specific gene causes a larger neocortex in the common marmoset, a non-human primate.

Unique insight into development of the human brain: Model of the early embryonic brain
Stem cell researchers from the University of Copenhagen have designed a model of an early embryonic brain.

An optical brain-to-brain interface supports information exchange for locomotion control
Chinese researchers established an optical BtBI that supports rapid information transmission for precise locomotion control, thus providing a proof-of-principle demonstration of fast BtBI for real-time behavioral control.

Transplanting human nerve cells into a mouse brain reveals how they wire into brain circuits
A team of researchers led by Pierre Vanderhaeghen and Vincent Bonin (VIB-KU Leuven, Université libre de Bruxelles and NERF) showed how human nerve cells can develop at their own pace, and form highly precise connections with the surrounding mouse brain cells.

Brain scans reveal how the human brain compensates when one hemisphere is removed
Researchers studying six adults who had one of their brain hemispheres removed during childhood to reduce epileptic seizures found that the remaining half of the brain formed unusually strong connections between different functional brain networks, which potentially help the body to function as if the brain were intact.

Alcohol byproduct contributes to brain chemistry changes in specific brain regions
Study of mouse models provides clear implications for new targets to treat alcohol use disorder and fetal alcohol syndrome.

Scientists predict the areas of the brain to stimulate transitions between different brain states
Using a computer model of the brain, Gustavo Deco, director of the Center for Brain and Cognition, and Josephine Cruzat, a member of his team, together with a group of international collaborators, have developed an innovative method published in Proceedings of the National Academy of Sciences on Sept.

Read More: Brain News and Brain Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.