Fig. 1.
Comparison of performance on the fixed-interval peak procedure (FIPP) 30-s and the variable-interval (VI) 75-s schedule. Ordinate: response rate (responses minute−1); abscissa: time from trial onset (s). Points are group mean data from successive 2-s time-bins in the last ten sessions of the experiment: open circles, rats trained under VI 75-s; filled circles, rats trained under FIPP 30-s. The continuous curve is the best-fit modified Gaussian function for the rats trained under FIPP 30-s.