Andrew Huberman· PhD
as audience of this podcast will know that because I've said it too much but I'll say it again that the eyes are the only two pieces of your brain that are outside the cranial Vault I mean they're literally two pieces of brain lining the back of your eyes and the Dynamics of the pupils those changes of course reflect how bright or dim it is in the room but they also reflect levels of arousal that are on the millisecond time scale so as one expresses you know words of um of Glee right the pupils constrict a little bit believe it or not or excuse me dilate a little bit I got it backwards there for a moment um and vice versa you know as one feels uh less less excited um sort of moments of Despair expressions of Despair the pupils should get a little bit smaller because arousal is going down