Figure 4
The average entropy of hole-poking, per 100 events (hole-poke, dipper approach, and reinforcement) as a function of the number of reinforcers received during the first 6 sessions of FI 1 s. The acquisition curves are drawn by Equation 1 acting on entropy (U = -Σplog 2 (p)), the sum of the logarithms of the probabilities of visiting each hole weighted by that probability.