Both Uses of

convoluted

in

The Magic Mountain

"A convoluted process," the Italian said with a laugh.
Chpt 5.5 *

convoluted = complex

…assistance to the medium's subjectivity so that it might find a mirror in reality, but rather—at least partially, at least tentatively—certain "selves" from outside, from beyond, got mixed up in things; what they were dealing with—possibly, though never expressly admitted—were nonvital elements, entities that used the convoluted, furtive opportunity of the moment to return to matter and manifest themselves to whoever called them—in short, the spiritualistic conjuring of the dead.
Chpt 7.8

Definitions:

(1) (convoluted as in: convoluted thinking)
complex -- often more complex than necessary
(2) (convoluted as in: convoluted folds of the brain)
having complex coils, folds, twists, or irregularities