Our visual cerebral cortex is where we collect and process the visual impressions that enable us to navigate in our surroundings. Research from Aarhus University now shows that we record visual movements somewhere else in the brain than previously thought. This knowledge can be used to understand how the brain monitors its environments.

2021.08.24 | Helle Horskjær Hansen

The ability of humans and animals to sense visual movement is crucial for what we do in our daily lives. For example, when we orientate ourselves in traffic, when animals hunt, and when we walk down the street with our eyes on our smartphone. Our visual system must be able to deal with two fundamental forms of movement: when objects in our field of vision are in motion, and when we ourselves are in motion.

New research from Aarhus University now contributes to a better understanding of where motion is initially sensed in the visual system. And this happens somewhere else than where researchers had previously thought.

"We discovered that the direction of image direction of motion is already being calculated in the so-called axon terminals in a special type of cell in the eye's retina called bipolar cells," explains Keisuke Yonehara from Aarhus University, who is behind the study.

The results have been published in the scientific journal Neuron and, according to the researcher, they will come to change our understanding of how nerve cells and the brain calculate sensory traits.

The researchers have not previously been able to identify the signal for visual motion in the bipolar cells found in the eye's retina – this is only possible now thanks to new techniques such as two photon imaging of the neurotransmitter release and advanced computer models.

"We should investigate whether similar signalling mechanisms can be observed in other parts of the brain, such as the cerebral cortex or the brain stem. This may help us learn about how other senses in the brain such as hearing and taste work," says the researcher.

The research results are particularly interesting for neuroscientists who wish to understand the mechanisms of neural calculations, as well as for ophthalmologists who need to restore normal sight in blind patients and engineers who are building machine vision for robots.

Background for the results

• The study is basic research.
• A team put together by Professor Shai Sabbah at the Hebrew University of Jerusalem, Israel.
• The study is financed by the Lundbeck Foundation, the Velux Foundation, the Novo Nordisk Foundation, the Carlsberg Foundation, and the European Research Council.
• The scientific article can be read in Neuron

Contact

Group Leader & Associate Professor Keisuke Yonehara
Aarhus University, Department of Biomedicine and DANDRITE
Tel.: (+45) 9350 8084
Email: Keisuke.yonehara@dandrite.au.dk