Full Idea
The nuts and bolts of thinking - holding ideas in mind and manipulating them - takes place on the upper side of the prefrontal cortex.
Clarification
The 'prefrontal cortex' is at the top of the head, near the front
Gist of Idea
Thinking takes place on the upper side of the prefrontal cortex
Source
Rita Carter (Mapping the Mind [1998], p.312)
Book Reference
Carter,Rita: 'Mapping the Mind' [Phoenix 2000], p.312
A Reaction
Keep this firmly in view! Imagine that the skull is transparent, and brain activity moves in waves of colour. Dualism would, in those circumstances, never have even occurred to anyone.