Spatial deficits in a virtual water maze in amnesic participants with hippocampal damage.

The Morris water maze is a standard paradigm for the testing of hippocampal function in laboratory animals. Virtual versions of the Morris water maze are now available and can be used to assess spatial learning and memory ability in both healthy and brain injured participants. To evaluate the importance of the hippocampus in spatial learning and memory, we tested five amnesic participants with selective hippocampal damage using a virtual water maze called the Arena Maze. The amnesic participants with hippocampal damage were impaired on the invisible platform (place) task that required them to use distal cues, but were able to navigate almost as well as comparison participants when the invisible platform was marked by a single proximal cue. These results not only confirm that the hippocampus plays a necessary role in human navigation in large-scale environments but also provides a new link between the mnemonic and navigational roles of the hippocampus.