It is obvious that the information that reaches us through the eyes is a fundamental way to navigate the world, but what is less clear is exactly how this visual data is processed in the brain to prevent us from entering the walls and edges of the cliffs.
A new study on the behavior of fruit flies (Drosophila melanogaster) in a “virtual reality” environment offers some clues, and it seems that conventional scientific wisdom about how vision and movement intertwine may be wrong.
The new experiments show that the vision was used to prevent the flies from leaving their intended course before it happened, instead of returning them to the track after they had already deviated from a route, and that is a difference. substantial.
“The long-standing view is that of reactive compensatory rotations, either through head-to-body coordination or directly in body rotations,” says neuroscientist Eugenia Chiappe of the Champalimaud Center for the Unknown Research Facility. Portugal.
“What we have found is that this is not the case. What the vision does to maintain the stability of the gaze is to influence body movements by adjusting postural adjustments as a preventative measure.”
The researchers were not able to attach a pair of VR glasses to the flies, but they did put them through a bespoke environment with static walls, a static ceiling, and a floor that could be manipulated. to change what the flies were flying. saw.
The walls were heated to direct the movement of the flies and to test intentional versus random movements.
Even when we don’t see anything, we still adjust our movements and posture based on feedback sent from various parts of the body, such as tilting our feet to keep us upright on a slope, whether visible or not.
What the team saw on the flies was visual information that nullified the rest of the body’s comments to achieve goals like walking in a straight line.
By treating the postural signals from other places as less important when they could see where they were going, the flies seemed to use their vision to preventively keep their course. This suggests a very close link between sight and motor control.
“The effect of vision must occur much closer to the control of the limbs than previously thought, in the equivalent of the spinal cord of the fly,” says neuroscientist Tomás Cruz.
The researchers suggest that their findings are also related to larger-brained animals, including humans. They say we are likely to have the same kind of two-way interactions between the spinal cord and the visual circuits of the brain, making sure the information in our eyes takes precedence and is used quickly.
Future research could go far beyond simply exploring how animals are able to walk in a straight line. According to the team, these links between brain and body may be relevant to our sense of self and to the way we perceive ourselves in relation to everything else.
Researchers want to investigate how vision and locomotion are affected in different types of behaviors and in different scenarios, such as patients with psychiatric conditions that affect the relationship between how we see what surrounds us and their relationship to our movement.
“The next steps would be to identify the exact circuits in which these sources of information converge and investigate how they interact to guide the animal’s behavior,” Cruz says.
The research has been published in Current biology.