Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Surprisingly complex behaviors appear to be ’hard-wired’ in the primate brain

16.03.2005


When you grab a piece of food and put it in your mouth, when you smile in response to the smile of a passerby or squint and grimace in anger, the complex pattern of movements that you make may be hard-wired into your brain.

Scientists have long known that many of the behaviors of lower organisms are innate. In the insect world, for example, instinctive behaviors predominate. Birds have a larger repertoire of fixed behaviors than dogs. In primates, voluntary or learned behavior predominates, so neuroscientists have assumed that the hard-wiring in primate brains is limited to simple movements and complex behaviors are all learned. Now, however, studies are finding that a number of surprisingly complex behaviors appear to be built into the brains of primates as well.

These are "biologically significant" behaviors that appear likely to improve the primate’s ability to survive and reproduce. They include aggressive facial patterns, defensive forelimb movements, and hand-to-mouth and reaching-and-grasping movements.



Vanderbilt researchers, writing this week in the Proceedings of the National Academy of Sciences Online Early Edition, report that they can elicit these complex behaviors by stimulating specific areas in the brain of a small nocturnal primate called the Galago or bush baby (Otolemur garnetti). Their results provide significant new support for the proposition that all primate brains, including our own, contain such a repertoire of innate complex behaviors.

"We have now seen this feature in the brain of an Old World monkey and New World prosimian. The fact that it appears in the brains of two such divergent primates suggests that this form of organization evolved very early in the development of primates. That, in turn, suggests that it is characteristic of all primate brains, including the human brain," says Jon Kaas, the head of the research group, Distinguished Professor of Psychology at Vanderbilt University and investigator at the Vanderbilt Kennedy Center for Research on Human Development.

"These results explain why certain behaviors – such as defensive and aggressive movements, smiling and grasping food – are so similar around the world. It is because the instructions for these movements are built-in and not learned," he adds.

Over the last 20 years, neuroscientists have identified an area called the primary motor cortex, which, when stimulated, triggers simple muscle movements. The fact that they were able to produce only motions by single muscles and other simple movements reinforced the idea that only simple movements were hard-wired into primate brain circuitry.

Then, last year Michael Graziano at Princeton University pointed out that previous stimulation experiments in the motor cortex – the area that controls bodily motions – had been done using very short electrical pulses that last less than a half-second. He further suggested that longer pulses might stimulate more complicated motions. Working with alert macaques, he and his colleagues found that applying such long-duration signals did in fact elicit several of these complex behaviors, much as they had predicted.

Kaas and his colleagues, research assistant professor Iwona Stepniewska and doctoral student Pei-Chun Fang, decided to follow the Princeton researchers’ lead and try long-duration stimuli in the simpler brain of the Galago. When they did, they also found that this type of stimuli triggered complex behaviors. In fact, they were able to stimulate a larger number of complex movements than the Princeton group had reported, including aggressive facial patterns, defensive forelimb movements, and hand-to-mouth and reaching-and-grasping movements.

The Princeton researchers stimulated areas in the motor cortex. The Vanderbilt researchers found that they could also elicit these behaviors by stimulating a nearby area of the brain called the posterior parietal cortex. This area is heavily interconnected with the motor cortex and had previously been associated with transforming data from the eyes and other senses into a spatial map of the surrounding environment. The new findings reveal that this brain area also plays an important role in complex, innate behaviors.

David F. Salisbury | EurekAlert!
Further information:
http://exploration.vanderbilt.edu/news/news_hard_wired.htm
http://www.vanderbilt.edu

More articles from Life Sciences:

nachricht No gene is an island
25.07.2017 | Institute of Science and Technology Austria

nachricht Topologische Quantenchemie
21.07.2017 | Max-Planck-Institut für Chemische Physik fester Stoffe

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Flexible proximity sensor creates smart surfaces

Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.

At first glance, the proximity sensor appears to be nothing special: a thin, elastic layer of silicone onto which black square surfaces are printed, but these...

Im Focus: 3-D scanning with water

3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects

A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

No gene is an island

25.07.2017 | Life Sciences

Flexible proximity sensor creates smart surfaces

25.07.2017 | Materials Sciences

Ultrathin device harvests electricity from human motion

24.07.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>