science
Study Shows Imagining Objects Reactivates Neurons Used in Visual Perception
Researchers recorded brain activity in epilepsy patients and found that imagining viewed objects reactivates about 40 percent of the same neurons active during perception. The study, published April 9 in Science, examined activity in the ventral temporal cortex. Findings provide evidence on neural mechanisms of mental imagery.
Bagley J, LaRocca G, Jimenez DA, Urban NN. / Wikimedia (CC BY 2.0)Audio version
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Researchers at Cedars-Sinai Medical Center in Los Angeles conducted a study on neural activity during visual perception and mental imagery. The work involved 16 adults with epilepsy who had electrodes implanted in their brains to locate seizure origins. Participants viewed hundreds of images from five categories: faces, text, plants, animals, and everyday objects.
Activity was recorded from over 700 neurons in the ventral temporal cortex, a brain region associated with visual object representation. Approximately 450 of these neurons responded selectively to the image categories. Machine learning analysis indicated that 80 percent of the category-responsive neurons were selective to specific visual features within the images.
During Imagination Six participants then imagined some of the previously viewed objects.
About 40 percent of the neurons active during perception showed similar responses during these mental imagery tasks. To verify the results, researchers used neural data to reconstruct the imagined pictures. The study was published on April 9 in the journal Science.
Ueli Rutishauser, a neuroscientist at Cedars-Sinai and lead researcher, noted that prior research using functional MRI had shown overlapping brain regions for perception and imagination but had not confirmed involvement of the same individual neurons.
“This was a study that the field was waiting for.”
The findings support the concept of a generative model in the brain, where reactivating neural patterns from perception enables mental image formation. Study coauthor Varun Wadia, a neuroscientist at Cedars-Sinai, stated that disruptions in mental imagery may relate to conditions such as schizophrenia and PTSD, potentially informing future therapies.
