Reaction to spatial novelty and exploratory strategies in baboons

Exploratory activity was examined in 4 young baboons with the aim of investigating the type of spa-tial coding (purely geometric and/or by taking into account the identity of the object) used for the con-figuration of objects. Animals were individually tested in an outdoor enclosure for their exploratory re-actions (contact time and order of spontaneous visits) to changes brought about to a configuration of different objects. Two kinds of spatial changes were made: a modification (1) of the shape of the con-figuration (by displacement of one object) and (2) of the spatial arrangement without changing the ini-tial shape (exchanging the location of two objects). In the second experiment, the effect of a spatial modification of the global geometry constituted by four identical objects was investigated. Finally, in the third experiment, a substitution of a familiar object with a novel one was performed without chang-ing the objects ' configuration. The baboons strongly reacted to geometrical modifications of the con-figuration. In contrast, they were less sensitive to modifications of local features that did not affect the initial spatial configuration. Analyses of spontaneous exploratory activities revealed two types of ex-ploratory strategies (cyclic and back-and-forth). These data are discussed in relation to (1) the dis-tinction between the encoding of geometric versus local spatial features and (2) the spatial function of exploratory activity