Fig. 2.

a) Approach and avoidance motivation elicit divergent behavioral responses, with the former associated with actions to approach the rewarding outcome and the latter associated with actions to avoid or escape from the aversive outcome. b) According to Reinforcement Sensitivity Theory (RST), three core systems underlie human emotion: 1) fight-flight-freeze system (FFFS), 2) behavioral approach system (BAS), and 3) behavioral inhibition system (BIS). Adapted from Gray, 1982 & Gray and McNaughton, 2000. Relevant to the current proposal, the BIS system mediates the resolution of goal conflict (e.g., approach-avoidance motivational conflict). The intensity of this conflict is associated with increased subjective anxiety. c) Recent extensions of RST have suggested defensive distance and defensive direction as two important dimensions that may help organize defensive responses to aversive motivation. Defensive distance describes the perceived distance from a threat (proximal to distal) that influences the intensity of a defensive response. Defensive direction describes the range of responses between actively avoiding or escaping a threat (defensive avoidance) to cautiously approaching a threat (defensive approach). Relevant to the current review, this delineation between defensive avoidance and defensive approach reveals how the critical distinction between negative reinforcement and punishment may underlie distinct fear-mediated and anxiety-mediated defensive responses to aversive motivation. Simplified adaptation from McNaughton and Corr, 2004.