Never thought about this found some research on it:I got up to nerdy spergery in the Hartley thread and cant help but wonder: do the anencephalic things have sleep-wake cycles?
I'm guessing kinda? The last part is in the forebrain very close to the thalamus but all prior parts they should have. It's like its cycling through the system but never ending the loop because the end simply isnt there. But what does that qualitatively look like?!
Also haha, even the most simple vertebrates have a forebrain. Your fetus is evolutionarily below a lampray.
"It is important to delineate some similarities and differences between patients in a persistent vegetative state and infants with anencephaly. Both have in common (1) a state of permanent unconsciousness (a loss or absence of all cerebral cortical function); (2) a reflexive response to pain, presumably without the ability to experience suffering; and (3) cycles of sleep and waking (although these are not observed in most infants with anencephaly). "
Another article stated:
"No circadian rhythm was found in the anencephalic fetus despite day-night rhythm in the maternal heart rate. The lack of circadian rhythmicity in the anencephalic fetus despite the presence of this rhythm both in the mother as well as in the intact twin fetus, supports the notion that the fetal brain (most probably the fetal biological clock) is necessary for appearance of this endogenous rhythm."