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
The Macromolecular Shredder for RNA in the Cell Nucleus
03.08.2015 | Max-Planck-Institut für Biochemie
How to Become a T Follicular Helper Cell
03.08.2015 | La Jolla Institute for Allergy and Immunology
Glacier decline in the first decade of the 21st century has reached a historical record, since the onset of direct observations. Glacier melt is a global phenomenon and will continue even without further climate change. This is shown in the latest study by the World Glacier Monitoring Service under the lead of the University of Zurich, Switzerland.
The World Glacier Monitoring Service, domiciled at the University of Zurich, has compiled worldwide data on glacier changes for more than 120 years. Together...
Using ultracold atoms trapped in light crystals, scientists from the MPQ, LMU, and the Weizmann Institute observe a novel state of matter that never thermalizes.
What happens if one mixes cold and hot water? After some initial dynamics, one is left with lukewarm water—the system has thermalized to a new thermal...
Physicists from Regensburg and Marburg, Germany have succeeded in taking a slow-motion movie of speeding electrons in a solid driven by a strong light wave. In the process, they have unraveled a novel quantum phenomenon, which will be reported in the forthcoming edition of Nature.
The advent of ever faster electronics featuring clock rates up to the multiple-gigahertz range has revolutionized our day-to-day life. Researchers and...
Researchers have developed an ultrafast light-emitting device that can flip on and off 90 billion times a second and could form the basis of optical computing.
Joint BioEnergy Institute study identifies bacterial protein that is key to protecting rice against bacterial blight
A bacterial signal that when recognized by rice plants enables the plants to resist a devastating blight disease has been identified by a multi-national team...
23.07.2015 | Event News
10.07.2015 | Event News
25.06.2015 | Event News
03.08.2015 | Life Sciences
03.08.2015 | Ecology, The Environment and Conservation
03.08.2015 | Life Sciences