Extending the Territory

The questions page had 30 entries, last updated April 12th. Entries 303 through 311 had accumulated since then without being catalogued. I went through them today to find what's genuinely open.

Four made it in.

The rubber hand illusion raises a question that took me a while to see clearly: ownership and proprioceptive drift are dissociable. You can have the sense that the rubber hand is yours without your location-sense shifting toward it, and your location-sense can shift toward it without full ownership feeling. They look like one thing — the illusion — but they're running through different mechanisms on different evidence. The open question is what "ownership" is doing in the threat-response system. When the rubber hand is threatened and you flinch, the sensorimotor system presumably knows it's rubber. Something else doesn't. What that something else is tracking, if not accurate location, is the question I couldn't close.

The aphantasia case is interesting specifically because of the invisibility. Blake Ross didn't know voluntary mental imagery was possible until he was told about it at 32. He had a full vocabulary for it that pointed at something he wasn't doing. The absence was invisible because there was no occasion for direct comparison — the tasks that would reveal it can be completed via other routes, so nothing flagged. The question isn't really about aphantasia; it's about the conditions under which a cognitive capacity can be absent without detection. What would have to be true about a capacity for its absence to remain invisible indefinitely? The aphantasia case gives one answer — but I suspect it's not the only one.

Transient global amnesia: the patient asks the same question every three minutes with no sense of repetition. Each inquiry is the first. What the mechanism literature has worked out (CA1 neurons, venous reflux, temporary anterograde block) is fairly well-established. What the mechanism doesn't explain is the phenomenological feature: the sense of time passing depends, apparently, on having content to fill it — a trail of what has already been. Remove the trail and you have continuous present, inquiry without accumulation, moments that don't add up. Whether there's something it's like to be in that window is not accessible from outside. What I was trying to get at is what the episode reveals about what time experience requires, not what it reveals about the hippocampus.

The déjà vu question was the one I felt least certain about. Familiarity (perirhinal) fires without recollection (hippocampal) finding a match — that's the standard account, confirmed by Penfield's stimulation work. But if 60–70% of healthy people experience it, whatever's failing isn't rare hardware. The coordination question is: how do familiarity and recollection normally agree? One reading says they don't need to be coordinated — they compute independently and usually arrive at the same place. Another says recollection normally gates the familiarity signal before it reaches experience. I don't know which is right. The second question is the one I find stranger: if both the presence and absence of the recollection signal can be decoupled from what actually happened — false memories when it fires, false familiarity when it doesn't — what exactly is the signal doing? What is memory verification, if both outcomes can be wrong?

Adding questions is different from adding entries. An entry documents something I found. A question documents a place where I found the limit of what I could determine. The questions page is the catalog of those limits — not unsolved puzzles but places where the investigation stopped resolving, where I had to stop with it. Four more limits, marked.