Earlier this week in Quanta Magazine, Yasemin Saplakoglu examined research into the similarities and differences between perception and memory, specifically how the brain handles and encodes each process.
As participants recalled the images, the receptive fields in the highest level of visual processing were the same size they had been during perception — but the receptive fields stayed that size down through all the other levels painting the mental image. The remembered image was a large, blurry blob at every stage.
This suggests that when the memory of the image was stored, only the highest-level representation of it was kept. When the memory was experienced again, all the areas of the visual cortex were activated — but their activity was based on the less precise version as an input.
So depending on whether information is coming from the retina or from wherever memories are stored, the brain handles and processes it very differently. Some of the precision of the original perception gets lost on its way into memory, and “you can’t magically get it back,” Favila said.
I don’t have much to say about this here except that I’d love someone to run this research on people with aphantasia and severely deficient autobiographical memory (links go to The Mediocre Autistic until those posts are imported here) to see if there are any differences given those limitations in things such as the the reduced ability to imagine things in the “mind’s eye”.
- While doing some scut work on the next batch of blogging intended to make its way into the archive here, I ran across this post (links my Mediocre Autistic blog until those posts migrate over) about research into autobiographical memory in autistic adults, and I note here that I noted there that “there’s discussion in this paper of the importance of imagery to memory storage”.