Have you ever tried to keep your eyes still while looking out the window of a moving train? It does not work: our eyes move involuntarily without a break. Munich researchers are now unraveling the basis of this so-called optokinetic reflex: there are certain brain cells encoding both the speed of the landscape and the eye movement.
Enjoying the landscape when traveling by train—while this activity sounds like pure relaxation, in reality, it requires maximum performance of our eyes’ motor system. To prevent blurring of the passing image, our eyes need to follow the environmental pace with many repetitive brief movements.
Brain cells encoding both the speed of the landscape and the eye movement ensure that we can clearly recognize a passing scenery instead of seeing it blurred.
Mareike Kardinal/Bernstein Koordinationsstelle (BCOS)
Scientists led by Professor Stefan Glasauer at the Bernstein Center and LMU Munich have now found in collaboration with colleagues from the Washington National Primate Research Center at the University of Washington in Seattle that neurons in the posterior parietal lobe play an important role in the conversion of the landscape stimuli into a control signal for the eye muscles.
"By means of electrophysiological recordings, we could show that nerve cells of the so-called MSTd area combine information about the motion of the visual stimulus on the retina with the eye movement speed," Lukas Brostek—first author of the study—explains.
The way how this is done clearly differs from cell to cell—hereby enabling the generation of completely new signals. Using computer models, the researchers demonstrated that the observed distribution of signal combinations corresponds exactly to the one required to calculate the velocity of the ambient scene. This is the information the brain ultimately requires to control eye movements.
Several areas of the brain are involved in the control of the optokinetic reflex. The necessary information processing includes essentially three steps: In a first step, the speed of a visual stimulus on the retina is calculated. In a second step, the proper eye motion is combined with this information to obtain the environmental velocity.
This is the process, the researchers were now able to localize in the brain. "The neurons we have recorded from provide the basis for the final step—the unconscious control of eye muscles. Hereby they ensure that our eye movements match the environmental motion and that we can recognize a passing scenery instead of seeing it blurred," Glasauer says.
The Bernstein Center Munich is part of the National Bernstein Network Computational Neuroscience in Germany. With this funding initiative, the German Federal Ministry of Education and Research (BMBF) has supported the new discipline of Computational Neuroscience since 2004 with over 180 million Euros. The network is named after the German physiologist Julius Bernstein (1835-1917).
Prof. Dr. Stefan Glasauer
Department of Neurology
81377 Munich (Germany)
Tel: +49 (0)89 7095-4839
L. Brostek, U. Büttner, M. J. Mustari & S. Glasauer (2014): Eye velocity gain fields in MSTd during optokinetic stimulation. Cerebral Cortex, advanced online publication
http://www.bccn-munich.de/people/scientists-2/stefan-glasauer Stefan Glasauer
http://www.bccn-munich.de Bernstein Center München
http://www.uni-muenchen.de LMU Munich
http://www.nncn.de National Bernstein Network Computational Neuroscience
Mareike Kardinal | idw - Informationsdienst Wissenschaft
First images of dolphin brain circuitry hint at how they sense sound
07.07.2015 | Emory Health Sciences
Two are better than one – another checkpoint enzyme for flawless cell division
07.07.2015 | Universität Basel
Researchers explore ultrafast control of magnetism across interfaces: A new study discovers how the sudden excitation of lattice vibrations in a crystal can trigger a change of the magnetic properties of an atomically-thin layer that lies on its surface.
A research team, led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter at CFEL in Hamburg, the University of Oxford, and the...
Wind turbines could be installed under some of the biggest bridges on the road network to produce electricity. So it is confirmed by calculations carried out by a European researchers team, that have taken a viaduct in the Canary Islands as a reference. This concept could be applied in heavily built-up territories or natural areas with new constructions limitations.
The Juncal Viaduct, in Gran Canaria, has served as a reference for Spanish and British researchers to verify that the wind blowing between the pillars on this...
New technique combines electron microscopy and synchrotron X-rays to track chemical reactions under real operating conditions
A new technique pioneered at the U.S. Department of Energy's Brookhaven National Laboratory reveals atomic-scale changes during catalytic reactions in real...
Think of an object made of iron: An I-beam, a car frame, a nail. Now imagine that half of the iron in that object owes its existence to bacteria living two and a half billion years ago.
Think of an object made of iron: An I-beam, a car frame, a nail. Now imagine that half of the iron in that object owes its existence to bacteria living two and...
A team of scientists including PhD student Friedrich Schuler from the Laboratory of MEMS Applications at the Department of Microsystems Engineering (IMTEK) of...
25.06.2015 | Event News
16.06.2015 | Event News
11.06.2015 | Event News
07.07.2015 | Health and Medicine
07.07.2015 | Health and Medicine
07.07.2015 | Materials Sciences