Our unconscious gaze is controlled by an automatic selection process computed by a neural network in the brain. Details of this computation have now been studied by an international team collaborating with the Technical University of Munich (TUM). This finding could soon become relevant for robotic implementations.
We are almost constantly surrounded by a variety of visual objects, all of which could, theoretically, be important for us. But only a very small area on our retinas, the fovea in the macula lutea, has high visual acuity; a large portion of our field of vision has only a low resolution. Therefore, our gaze must be directed toward a specific target in order to precisely identify the object.
Unconsciously deciding what we look at
But what functionality decides where we direct our vision when we are not looking for anything in particular and do not know where look at in the first place? Researchers from the Department of Zoology at the Weihenstephan School of Life Sciences of the Technical University of Munich, working in cooperation with Chilean and American colleagues, asked themselves this very question.
"The decision where to look is made unconsciously; the objective of our study was to investigate this selection process in detail," reports Prof. Harald Luksch from the Department of Zoology at the TUM, who also heads the Bionics Center at the TUM. Gaze control involves an evaluation of the field of vision from which a selection is made as to where the fovea will be directed next.
"A neural network called the isthmic system performs the selection process," explains zoologist Luksch. Because this network is well characterized anatomically in birds, the study was carried out on chickens and, in part, on isolated brain tissue (in vitro).
Some stimuli are suppressed, others reinforced
"We were able to demonstrate that individual nerve cells of the visual midbrain establish parallel connections to three areas of the brain," states Prof. Luksch, summarizing the findings, "which each create their own feedback loops with the visual midbrain."
This feedback reinforces the most salient visual stimuli while suppressing others at the same time. In this manner, an unconscious selection is made. "What surprised us was that the various feedback loops, reinforcing and inhibitory, are triggered by one and the same cell," remarks Luksch. "In the past, scientists assumed that this was performed by various cells." Therefore, a single cell controls entirely different processes, although with different time courses.
Automatic attention control
The importance of this study is not limited to basic research: "The very same mechanisms that work in birds also affect humans in the same way," says Harald Luksch. This allows us to better understand how our perception and bottom-up attention are controlled, which is, in turn, closely related to our consciousness — one of the most exciting fields of neuroscience.
Because the selection process which has now been researched can be represented as a technical circuit diagram, these intelligently evolved mechanisms in the animal world could also be implemented in robots. It is necessary for robots to react in a manner similar to that of organisms, particularly for interactivity with humans. Therefore, Harald Luksch expects these findings to be important for bionic transfers to technical systems in the future.
Prof. Dr. Harald Luksch
Technical University of Munich
Chair of Zoology
Phone: 0049/8161/71 2801
Garrido-Charad, F.; Vega-Zuniga, T.; Gutiérrez-Ibáñez, C.; Fernandez, P.; Lopez-Jury, L.; González-Cabrera, C.; J. Karten, H.; Luksch, H. and J. Marín, G.: “Shepherd´s crook" neurons drive and synchronize the enhancing and suppressive mechanisms of the midbrain stimulus selection network, Proceedings of the National Academy of Sciences, 07/2018. DOI: https://doi.org/10.1073/pnas.1804517115
Dr. Ulrich Marsch | Technische Universität München
Blocking the iron transport could stop tuberculosis
02.04.2020 | University of Zurich
Discovery of life in solid rock deep beneath sea may inspire new search for life on Mars
02.04.2020 | University of Tokyo
90 million-year-old forest soil provides unexpected evidence for exceptionally warm climate near the South Pole in the Cretaceous
An international team of researchers led by geoscientists from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) have now...
The bacteria that cause tuberculosis need iron to survive. Researchers at the University of Zurich have now solved the first detailed structure of the transport protein responsible for the iron supply. When the iron transport into the bacteria is inhibited, the pathogen can no longer grow. This opens novel ways to develop targeted tuberculosis drugs.
One of the most devastating pathogens that lives inside human cells is Mycobacterium tuberculosis, the bacillus that causes tuberculosis. According to the...
An international team with the participation of Prof. Dr. Michael Kues from the Cluster of Excellence PhoenixD at Leibniz University Hannover has developed a new method for generating quantum-entangled photons in a spectral range of light that was previously inaccessible. The discovery can make the encryption of satellite-based communications much more secure in the future.
A 15-member research team from the UK, Germany and Japan has developed a new method for generating and detecting quantum-entangled photons at a wavelength of...
Together with their colleagues from the University of Würzburg, physicists from the group of Professor Alexander Szameit at the University of Rostock have devised a “funnel” for photons. Their discovery was recently published in the renowned journal Science and holds great promise for novel ultra-sensitive detectors as well as innovative applications in telecommunications and information processing.
The quantum-optical properties of light and its interaction with matter has fascinated the Rostock professor Alexander Szameit since College.
Researchers at the University of Zurich show that different stem cell populations are innervated in distinct ways. Innervation may therefore be crucial for proper tissue regeneration. They also demonstrate that cancer stem cells likewise establish contacts with nerves. Targeting tumour innervation could thus lead to new cancer therapies.
Stem cells can generate a variety of specific tissues and are increasingly used for clinical applications such as the replacement of bone or cartilage....
02.04.2020 | Event News
26.03.2020 | Event News
23.03.2020 | Event News
02.04.2020 | Physics and Astronomy
02.04.2020 | Information Technology
02.04.2020 | Health and Medicine