Brain Activity in Imagination Overlaps with Perception in High-Level Areas

Researchers reported that brain activity during imagination of sights and sounds overlaps with perception in high-level brain areas that handle multiple types of sensory inputs. The study involved eight participants who imagined scenes, faces, speech, internal monologues, and sounds while undergoing MRI scans. Researchers collected extensive data to create individualized brain maps.

received open-ended prompts, such as imagining a castle on a hill or a rock song on the radio. After each prompt, they rated the vividness of their visual and auditory experiences. Follow-up questions outside the scanner explored details contributing to vividness, including envisioning locations of objects, people, or places.

participants imagined locations or events, they reported high visual vividness and showed increased activity in the brain's default network A, associated with spatial processing. For speech or language imagination, high auditory vividness was reported, engaging the language network, which processes reading or listening to speech.

Both networks are transmodal, responding to information regardless of the originating sense.

studies where participants imagined recently seen objects, activating basic visual areas, this study's holistic prompts did not engage those sensory-specific regions. Basic visual areas respond to details like edges, colors, and orientations, but participants may not imagine such fine details in broader scenes. The findings were published March 31 in the journal Neuron.