The three panels show conditioned responses (CRs) to the tone conditioned stimulus (CS) during six days of CS-unconditioned stimulus (US) pairings (Acquisition), during one (top), three (middle), or six (bottom) subsequent days of unpaired CS/US presentations (Unpaired Extinction) with either a 1-psi (circle), 4-psi (square), or 8-psi (triangle) US, and then a further seven (top), five (middle), or two (bottom) days of unpaired CS/“US” presentations with the 1-, 4, or 8-psi US air puff tubing moved to the front of the chamber and away from the eye (CS Extinction).