NPR: In the Brain, Objects Seen and Imagined Follow the Same Neural Path
NPR recently interviewed Ueli Rutishauser, PhD, director of the Center for Neural Science and Medicine at Cedars-Sinai, and postdoctoral scientist Varun Wadia, PhD, about how the brain creates mental images, and how closely that process mirrors actually seeing them.
Rutishauser and Wadia led a research team that found imagining and viewing images activate many of the same brain neurons, pointing to a shared neural mechanism. Their work was published in the journal Science.
“I can look at an object in the world around me, but I can also close my eyes and imagine the object,” Wadia told NPR correspondent Jon Hamilton.
The researchers studied patients with epilepsy who already had electrodes implanted in their brain to locate seizure activity, which allowed the team to track individual brain cells as participants viewed images and later imagined them. Many of the same neurons were active in both cases, suggesting the brain uses similar mechanisms for perception and imagination.
“About 40% of those neurons reactivated when you were imagining the object,” Wadia told Hamilton. “And they reactivated with roughly equal strength, which is also very surprising.”
Rutishauser, a professor of Neurosurgery, Neurology and Biomedical Sciences, told Hamilton the overlap was so strong that researchers could identify when a patient was imagining a specific object—along with details such as size, angle and setting.
He noted that not everyone experiences mental imagery. Some people rely on words or concepts instead.
Rutishauser told Hamilton that after a recent talk, a scientist said to him, “I don’t know what you’re talking about. I don’t see anything when I close my eyes.”
Listen to the complete segment from NPR.