Patrick Lynch summarizes Normans thinking here.
“Why attractive things work better
In psychology, emotional reactions to stimuli are called affective responses. Affective responses happen very fast, and are governed in an automatic, unconscious way by the lower centers of the brain that also govern basic instincts (food, fear, sex, breathing, blinking, etc.). Think of affective responses as the brain’s bottom-up reaction to what you see and feel. Cognitive responses are your brain’s slower, top-down, more considered responses. They’re governed by your personal cultural views, learning, experiences, and personal preferences that you are aware of and can easily articulate. Affective reactions assign value to your experiences; cognitive reactions assign meaning to what you see and use.
Affective and cognitive responses to visual stimuli are governed by a three-stage process in the brain, at visceral, behavioral, and reflective processing levels:”