Wow, just checked back here after over a month away, lots of interesting discussion here!
The comparison of text-seeking with face-seeking makes a lot of sense, they're definitely linked phenomena.. but I'd think face-seeking has a biological evolutionary basis, where visual language is a culturally learned skill. Something worth following up.
I recently tried DMT for the first time (and kept my eyes open throughout) - before I'd breathed out, neon purple alien hieroglyphics melted out of the walls... recognisable as language but not readable.
Really wish I could remember what phrase I saw when I last had a clear 'graffiti' flash. The whole situation I was in was emotionally and socially loaded (still don't really know what to make of it) and would love to know what my subconscious was writing about at the time - like a built-in I-Ching! Dictaphone required methinks...
Some of my favourite early lexical hallucinations were the rest of sleep deprivation, MDMA and smoking lots of dope. Eyes closed, with a black background, the ASCII character set suddenly started printing itself backwards, one character at a time; I remember distinctly being aware that I was actually reading them off my eyelids faster than I could think of what should come next. This character-dump then morphed into a 5-line poem of some kind, like a limerick or haiku in a predefined structure. I was able to read the poem, but when I got to the last word, the first word would change, making the whole thing invalid, and I'd start reading it again, and the same thing would happen. So I started skim-reading it very fast and all the words started changing very fast.