Spatial performance is more sensitive to ethanol than nonspatial performance regardless of cue proximity

In rodents, ethanol produces a greater impact on the ability to perform spa tial reference memory tasks than nonspatial reference memory tasks. Such ev idence may reflect a selective disruption in the use of previously acquired spatial information. However, a nonmnemonic explanation has yet to be rule d out Tasks used to study ethanol's effects on spatial memory commonly requ ire subjects to utilize distal, or extramaze, cues to respond correctly. In contrast, many previously used nonspatial tasks could be solved using cues located on the maze itself. Because ethanol has been shown to disrupt sens ory processing, it is possible that previously observed differences in the effects of ethanol on spatial and nonspatial performance were actually due to differences in the proximity of relevant cues in the spatial and nonspat ial tasks and not to a selective disruption in spatial memory. The present study compares the effects of ethanol on the performance of spatial and non spatial reference memory tasks that require subjects to discriminate among extramaze cues for correct responding. Subjects were trained while sober to navigate to a goal arm on a 12-arm maze. In the spatial task, the goal arm was defined by its location with respect to a number of extramaze cues. In the nonspatial task, the goal arm was defined by the presence of a single extramaze cue located directly beyond the end of the arm. Subjects were tes ted under 1 of 4 doses of ethanol (0.0, 0.7, 1.4, and 2.1 g/kg). Performanc e on the nonspatial task was more resistant to the effects of ethanol than performance on the spatial task The results suggest that differences in the effects of ethanol on spatial and nonspatial performance are not due to di fferences in the proximity of relevant cues in previously used spatial and nonspatial tasks.