Occasion setting in humans: Norm or exception?

In this commentary, we propose that occasion setting in humans may be even more widespread than Leising and colleagues assume. In contrast to animal work, our research using the feature negative procedure (A+ AX-) reveals substantial individual differences in what people learn about the feature (X). We discuss findings showing that the majority of participants in our experiments learn something akin to occasion setting, and present reasons for why this may be the case. We conclude that occasion-setting may be the norm in humans because it allows existing learning to be preserved, and for the possibility that the effect of a cue is unique to its accompanying target.