Large detached section from the main face. It is just before you get to the As de Pique sector.
What a good name for this secteur. It has the shape of a brain and the texture also reminds you of a brain.
You have never been so pumped climbing a 5.9 (La diagonale du fou).
Not beacause of a lack of holds but because of an abondance of sloppey holds interspaced with just a few good enough holds to keep it in the 5.9 range.

There is a short connection from the lower part of sector Hommage à Radoth to sector Le cerveau. You can also access from the top trail but it involves some scrambling down.