An ethological analysis suggests that effort and protection actions, which are expressions of distress, are comparable with pain expressions. Distress occurs with uncontrollable pain, and the expressions are ritualized pain responses with exaggerated features and lower thresholds. Pain is a sensory-motor feeling state with aversive motivational (hedonic) value. Distress is an emotional state of failure of pain responses to control the pain.
The “reward” systems described by Rolls are systems for drive-reinforced associations of contact and distant stimuli and not for emotional behaviours. The neural systems delineated may be associated with distinct categories of “affect,” namely “hedonic feelings,” “moods,” and “emotions.” Awareness of these affects requires external perceptual as well as internal feedback. Levels of feedback in evolution and development suggest sensory qualia may not require language.