Fear Acquisition. (A) For groups with a Keypad, participants displayed significant discrimination between the reinforced CS+'s and the CS–. CS HAB = CS habituation phase. For each trial, participant responses were coded as “+1” if they expected the airblast on the trial, coded “0” if they were uncertain, and coded “–1” if they did not expect an airblast. (B) Participants with and without a Keypad showed robust fear-potentiated startle to the CS+a and CS+b with an enhanced degree of fear-potentiated startle to both the CS+a, and CS+b in those who used a Keypad. (C) Fear-potentiated startle calculated as a Difference Score between the CS+'s and NA examined during the last block of Acquisition was significantly higher for the CS+a compared to the CS–, with no interaction effects with either Retrieval group or Keypad group. **** p < 0.0001, *** p < 0.001, p < 0.05; Difference Score = [startle magnitude in the presence of a CS] – [startle magnitude in response to noise alone (NA)].