Preference for Signal-Shock vs Shock-Signal

Sixteen rats were run in a tilt box for 11 hr. on each of three successive days, and then three more days with conditions reversed. On one side, Ss received 3 sec. light followed immediately by .5 sec. shock. On the other side, they received the same stimuli in reverse order. Six shocks were presented each half hour regardless of Ss' behavior. A reliable preference for signal-shock was acquired during pre-reversal training. There was some tendency for Ss to shift their preference to the new signal-shock side during reversal, but this did not differ reliably from chance at the end of the reversal training. The results are interpreted as supporting a preparatory response interpretation of classical conditioning and of the acquisition of observing responses in the absence of differential external reinforcement.