They had to lie down to bring the intracranial pressure — that inside their skulls — closer to what it would be like in space.
In one experiment, 10 volunteers who already had medical devices implanted to measure intracranial pressure sealed their lower bodies inside an LBNP chamber.
Participants had to lie down for the experiment to bring their intracranial pressure closer to what it would be like in space.
M.H.M. Vlak, et al. “Trigger Factors and Their Attributable Risk for Rupture of Intracranial Aneurysms.”
Coffee-drinking increases the risk of intracranial aneurysm by 10.6 percent.
This act of intracranial-moviemaking renders us territorial.
(ii) If there be symptoms of inflammation of the mastoid process, or of internal-ear or of intracranial suppuration.
This will permit of free drainage and diminish the risk of future intracranial complications.
(viii) As a preliminary step in intracranial suppurative lesions of otitic origin.
In addition, much information may thus be gained in a doubtful case with regard to the situation of the intracranial lesion.
(iii) Symptoms may occur pointing to some intracranial complication, and further operation may become necessary.