In a new study published in Nature Neuroscience from HWNI member Hillel Adesnik’s lab and collaborators at the Allen Institute, researchers have discovered a specialized type of neuron that plays a key role in the perception of certain optical illusions, such as the Kanizsa triangle, that appear to show edges, or contours, that do not actually exist.
The scientists found that these “illusory contour (IC)-encoder” neurons respond when mice view this type of illusion. When they activated IC-encoders in the absence of visual stimuli, the mice had brain activity patterns similar to when they were actually viewing the illusions. The IC-encoders are in a lower level of the brain’s visual system — the primary visual cortex — and the study suggests that higher brain areas send signals back down to this lower level to create the perception of these illusions, as part of a process called recurrent pattern completion.
This research, which was supported in part by the Weill Neurohub, provides insight into how visual perception works, and could potentially aid in the study of diseases like schizophrenia that involve visual hallucinations.
