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
Multi-institutional collaboration uncovers how molecular machines assemble
02.12.2016 | Salk Institute
Fertilized egg cells trigger and monitor loss of sperm’s epigenetic memory
02.12.2016 | IMBA - Institut für Molekulare Biotechnologie der Österreichischen Akademie der Wissenschaften GmbH
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.
Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
02.12.2016 | Medical Engineering
02.12.2016 | Agricultural and Forestry Science
02.12.2016 | Physics and Astronomy