Figure 1
From: The birth, death and resurrection of avoidance: a reconceptualization of a troubled paradigm
Active avoidance: the shuttlebox learning paradigm. Top panel: initially, subjects undergo Pavlovian threat conditioning, in which a conditioned stimulus (CS; tone) is paired with an aversive unconditioned stimulus (US; shock). Middle panel: once the CS–US association is acquired, subjects learn that the US can be inactivated by shuttling—this is an escape response. On subsequent trials, subjects learn that shuttling during the CS causes the inactivation of the CS and the omission of the US—this is an avoidance response. Bottom panel: once behavior becomes well-trained, the behavior is preformed in the presence of the CS, even though the US does not result. With continued training the behavior persists habitually in spite of the fact that US is no longer predicted by the CS.
