Comment by observationist
19 days ago
Also, with regards to faces, that's kind of what I'm getting at - we don't have grid cells for faces, there seem to be discrete, functional, evolutionary structures and capabilities that combine in ways we're not consciously aware of to provide abilities. We're reflexively able to memorize faces, but to bring that to consciousness isn't automatic. There've been amnesia and lesion and other injury studies where people with face blindness get stress or anxiety, or relief, when recognizing a face, but they aren't consciously aware. A doctor, or person they didn't like, showing up caused stress spikes, but they couldn't tell you who they were or their name, and the same with family members- they get a physiological, hormonal response as if they recognized a friend or foe, but it never rises to the level of conscious recognition.
There do seem to be complex cells that allow association with a recognizable face, person, icon, object, or distinctive thing. Face cells apply equally to abstractions like logos or UI elements in an app as they do to people, famous animals, unique audio stings, etc. Split brain patients also demonstrate amazing strangeness with memory and subconscious responses.
There are all sorts of layers to human memory, beyond just short term, long term, REM, memory palaces, and so forth, and so there's no simple singular function of "memory" in biological brains, but a suite of different strategies and a pipeline that roughly slots into the fuzzy bucket words we use for them today.
It's not just faces. When recognizing objects in the environment, we normally filter out a great number of details going through the visual cortex - by the time information from our eyes hits the level of conscious awareness, it's more of a scene graph.
Table; chair behind and little to the left of the chair; plant on table
Most people won't really have conscious access to all the details that we use in recognizing objects - but that is a skill that can be consciously developed, as artists and painters do. A non-artist would be able to identify most of the details, but not all (I would be really bad compared to an actual artist with colors and spatial relationships), and I wouldn't be able to enumerate the important details in a way that makes any kind of sense for forming a recognizable scene.
So it follows from that that our ability to recognize faces is not purely - or even primarily - an attribute of what we would normally call "memory", certainly in the sense of conscious memory where we can recall details on demand. Like you alluded to re: mammals and spaces, we're really good at identifying, categorizing, and recognizing new forms of structure.