Figure 4.

A lever CS associated with sign-tracking is preferred over a tone CS associated with goal-tracking in a choice test following within-subject 2-CS PCA training. (A) Mean (±SEM) of sign- and goal-tracking response rates to a lever CS and tone CS during the 14th session from the 2-CS PCA training period prior to choice training. (B) Mean (±SEM) percent (%) choice of the lever CS when the probability of reinforcement was equivalent (1.0) across both alternatives. (C) Mean (±SEM)% choice for the lever CS as a function of increasing odds against [(1 − p)/p] food delivery following the lever CS. Solid lines are choice functions defined by s/(1 + k(odds against)), (s) sensitivity to lever CS value; (k) discounting rate of lever CS value.