That's... a rather strange notion to contemplate. Humanity has never had credible reports of such aspects of the mind affecting anything beyond one's own body at the most, unless one counts mere mundane self-expression as "external". Certainly the laws of physics don't include mood-dependent provisions. [And for that matter, he sounds disdainful of the very idea.] I'm left to wonder how it is that such matters could possibly differ to such an extreme.