Vision begins in the brain – not the eye
We often think that sight starts in the eye. But new research shows that the brain takes the lead, reshaping signals from the eye to guide our reactions. This could provide insights into disorders where sensory processing fails, such as ADHD.
Imagine spotting a shadow out of the corner of your eye. Before you even realise it, your body is already on alert. A tiny midbrain structure called the superior colliculus translates what you see into action: a glance, fleeing, or even chasing.
Not a straight line
“For a long time, we thought visual signals travelled in a simple, straight line from the eye to the brain,” says Keisuke Yonehara, last author of the study. “Our research shows the brain doesn’t just pass on information—it breaks it down and reorganises it to make vision more flexible.”
The retina acts as a sensor, turning light into electrical signals. Normally, responses to light and motion are closely linked. But in the superior colliculus, this connection is split, allowing the brain to recombine light and motion in new ways.
Breaking up the signals
The result? Faster, more precise reactions in complex situations: spotting movement, focusing on what matters, and guiding eye movements with accuracy.
“This shows that the brain is not a passive receiver,” Keisuke explains. “It actively processes what we see to help us act quickly and effectively.”
New insight into sensory-based disorders
The discovery has implications beyond understanding vision. It could shed light on disorders in which the brain struggles to process sensory information. In ADHD, attention difficulties and problems filtering stimuli may be linked to how the brain reorganises signals from the eye.
In schizophrenia, disrupted visual integration could contribute to misinterpretations of the environment.
“Mapping this mechanism gives researchers a new starting point to investigate where the process goes wrong—and, in the long term, to develop better strategies for diagnosis and treatment,” explains Keisuke.
About the research:
- Name and contact information of the researcher(s)
Keisuke Yonehara, Professor at the National Institute of Genetics, Mishima Japan, keisuke.yonehara@nig.ac.jp
- Study method
This is basic research using the methods of mouse, in vivo two-photon imaging, and data analysis based on machine learning
- Funding
DANDRITE grant from Lundbeck Foundation, Ascending Investigator grant from Lundbeck Foundation, and ERC starting grant to Keisuke Yonehara
- Information on any impartiality issues
None
- Direct link to the abstract or the scientific article: www.cell.com/current-biology/abstract/S0960-9822(25)01554-4