Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

How the brain sends eyeballs bouncing

08.11.2007
All vision, including reading this sentence, depends on a constant series of infinitesimal jumps by the eyeball that centers the retina on target objects—words or phrases in the case of reading. Such jumps, or saccades, are critical to vision because only the small central region of the retina, called the fovea, produces the clear image necessary for perception. Such saccades take place several times a second and are generated within a brain region known as the frontal eye field (FEF).

In studies with monkeys, Robert Schafer and Tirin Moore have taken an important step in understanding how circuitry of the FEF generates saccades—with the FEF’s attentional circuitry governing the motor circuitry that produces saccades. The researchers published their findings in the November 8, 2007, issue of the journal Neuron, published by Cell Press.

In a preview of the paper in the same issue of Neuron, Stefan Everling wrote that the researchers’ findings “are exciting, because they demonstrate that attention and action interact more closely in the FEF than previously thought, and they suggest a mechanism by which attention can modulate saccade motor commands.” Everling is at the University of Western Ontario in Canada.

In their experiments, Schafer and Moore took advantage of a well-known optical phenomenon involving the influence of the motion of a drifting grating on saccades that target the grating. The moving grating causes a motion-induced bias of saccades; for example, if the eye makes a saccade to a grating that is drifting upward, that saccade to the grating is biased to land higher than it would if the grating were stationary.

... more about:
»FEF »saccade

The researchers trained monkeys to shift their gaze to such moving gratings upon command, in return for a juice reward. During the experiments, the researchers used eyetracking to precisely measure the direction of the animals’ gaze. After measuring how the saccades were influenced by the grating motion, the researchers then electrically “microstimulated” the FEF. They then analyzed how such microstimulation affected the saccades to moving gratings.

The researchers said their analyses “indicate that the attentional effects of microstimulation determine the metrics of concurrently planned saccades, causing them to be more strongly influenced by the visual target features.” They wrote that even though the two roles of FEF circuitry—attention and motor—can be experimentally teased apart, “our results suggest that the saccadic role depends on the attentional role to select the features of the visual target and the best movement to foveate it.”

Cathleen Genova | EurekAlert!
Further information:
http://www.cell.com

Further reports about: FEF saccade

More articles from Life Sciences:

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

nachricht Topological Quantum Chemistry
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: 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....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

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

NASA looks to solar eclipse to help understand Earth's energy system

21.07.2017 | Earth Sciences

Stanford researchers develop a new type of soft, growing robot

21.07.2017 | Power and Electrical Engineering

Vortex photons from electrons in circular motion

21.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>