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
Molecular evolution: How the building blocks of life may form in space
26.04.2018 | American Institute of Physics
Multifunctional bacterial microswimmer able to deliver cargo and destroy itself
26.04.2018 | Max-Planck-Institut für Intelligente Systeme
Magnetic resonance imaging, or MRI, is a widely used medical tool for taking pictures of the insides of our body. One way to make MRI scans easier to read is...
At the Hannover Messe 2018, the Bundesanstalt für Materialforschung und-prüfung (BAM) will show how, in the future, astronauts could produce their own tools or spare parts in zero gravity using 3D printing. This will reduce, weight and transport costs for space missions. Visitors can experience the innovative additive manufacturing process live at the fair.
Powder-based additive manufacturing in zero gravity is the name of the project in which a component is produced by applying metallic powder layers and then...
Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.
Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...
University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.
Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.
Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.
Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...
13.04.2018 | Event News
12.04.2018 | Event News
09.04.2018 | Event News
26.04.2018 | Power and Electrical Engineering
26.04.2018 | Life Sciences
26.04.2018 | Power and Electrical Engineering