The associative conditioning phenomenon of blocking has recently been demon
strated in nonhuman place-learning paradigms, including the Morris water ta
sk (MWT). We demonstrate blocking in humans learning to place navigate in a
computerized version of the MWT. Participants trained to locate an invisib
le goal with an initial set of distal cues were deficient in learning to lo
cate the goal with a set of cues inserted later during training. This outco
me is inconsistent with the spontaneous integration of novel environmental
features into a unified spatial representation proposed by cognitive mappin
g theory (O'Keefe & Nadel, 1978) and suggests that error-correcting associa
tive learning principles operate in the human spatial mapping system.