Big Bang Theory Quote
Leonard: She doesn't want to talk.
Sheldon: Penny's emotional response is originated in the primitive portion of the brain, known as the amygdala. While speech is centered in the much more recently developed neo-cortex. The former can easily overpower the latter, giving scientific credence to the notion of being "rendered speechless."
Sheldon: Or maybe she just doesn't want to talk.
Quote from S01E17 - The Tangerine Factor