Inhibition and behavioral contrast

In one experiment, pigeons’ pecks were reinforced during successive presentations of one stimulus (RFT) and not during successive presentations of a second stimulus (EXT). The highest rate of pecking occurred during the presentation of RFT stimuli that immediately followed EXT stimuli. In a second experiment, pecks were reinforced during the presentation of any of the top 8 of a column of 16 stimuli (RFT) and not during the presentation of any of the bottom 8 of these stimuli (EXT). The highest rate of pecking occurred during the presentation of the RFT stimulus that was closest to the EXT stimuli.