A while back someone shared an article about using #ML to recognize the object a person was visualizing by training the system on their brain patterns while seeing the object.
I wondered at the time if that would work with people with #aphantasia, and suspected it would not.
Well, the verdict is in, and it's even weirder than that.
- The near visual cortex does activate with patterns when people with aphantasia try to recall an image.
- But the activation bears no apparent resemblance to what happens when they actually see the object. ML can't decode it.
- It's on the wrong side of the brain.
The first ones don't surprise me, but the last one is particularly curious. It's one of those things you probably learned in high school. "The left visual cortex receives information from the right eye and visual field. The right visual cortex receives information from the left eye and visual field." Nope. Not for people with aphantasia. For them the processing is on the same side as the eye.
At this point nobody knows what this means. The researcher in the video suggests that maybe the activity in the near visual cortex isn't strong enough to trigger vision. But they also say it's warped in some way that isn't understood.
For me at least, it feels like I'm simply picking out what appear to be salient attributes from the image, rather than an image.* Which makes me wonder whether there's anyone with aphantasia who also doesn't have an internal speaking voice, because I have no idea how I would recall an image if I couldn't talk out a description.
* The other month I was was introduced to and invited to a meetup by a man I talked to. And a month later I was at the meetup and ran into the party organizer and the person who invited me, and thought the first was the second. The person I mistook for who invited me was a tall thin grey haired white man with a beard. The person who did invite me was a middle-aged heavy set black man. Looking back, I realized I'd only registered his outgoing boisterous personality, and that's the thing they both had in common. I'm not face blind, but it takes multiple exposures to someone before I can come up with a reliable recognition algorithm.
https://www.youtube.com/watch?v=b38qWjlMAvs