A study of exploratory behavior as an index of spatial knowledge in hamsters

Abstract

This experiment investigated the role of exploration in the formation of maps of the environment. The effects of spatial rearrangement of four familiar objects in an open field on subsequent exploratory behavior were studied in hamsters (Mesocricetus auratus). During two exploratory sessions, four groups of subjects were exposed to objects in a particular spatial relation to each other and to a distal pattern. During a testing session, the control group was exposed to the same situation as during the first two sessions, and the three experimental groups were exposed to various object rearrangements. The hamsters in the experimental groups, but not those in the control group, renewed their exploration of the objects during the testing session, as measured by the number of contacts with the objects and the time spent investigating them. Further analyses of the nature ofthe reinvestigated objects (i.e., displaced or nondisplaced) support the hypothesis that, through exploration, a long-lasting representation of the environment is built up on the basis of the topological relations among the objects, the overall geometric structure provided by the arrangement of the objects, and the relations between the objects and extra-apparatus landmarks.Following the pioneer studies by Hall (1934), who used the open field to test the effects of unfamiliar environments upon emotionality in rats, many experiments have been concerned with the intensity of exploratory reactions to new stimuli such as congeneric scents and illumination level and environmental complexity (e.g., Schenk, 1979), as well as water, food, or new objects introduced into a familiar environment (e.g., Cowan, 1976). In contrast to the number of experiments focusing upon the effect of the characteristics of new objects on the amount of exploration, few studies have attempted to provide evidence that exploratory reactions are also induced by new spatial arrangements of familiar objects. In one experiment, Wilz and Bolton (1971) allowed gerbils to explore an open field that contained either only one object, or a group of objects in fixed locations. After habituation (i.e., extinction of exploration), a new arrangement of the objects or a change in the location of the single object elicited a renewal of exploration as intense as a totally new situation would have done. Similar results were obtained in other experiments with gerbils (Cheal, 1978; ThinusBlanc & Ingle, 1985) and rats (Corman, Meyer, & Meyer, 1967;Corman & Shafer, 1968;Dember, 1956;Lukaszewska, 1978;Lukaszewska & Dlawichowska, 1982). Such data strongly suggest that exploratory be- 93havior involves the gathering of information not only about the qualities of the objects but also about their spatial relationships.Indirect evidence of this function of exploration is provided by the results obtained in spatial problem solving tests. Maier (1932) and, more recently, Stahl and Ellen (1974), Herrmann, Bahr, Bremner, and, and Ellen, Parko, Wages, Doherty, and Herrmann (1982) showed that rats need an exte...

Performance of goldfish trained in allocentric and egocentric maze procedures suggests the presence of a cognitive mapping system in fishes

“…Thus, whereas the fishes in the egocentric group only reached the new goal after visiting the unrewarded arm (formerly the rewarded arm), the fishes in the allocentric and ego-allocentric groups quickly learned to move toward the new goal by using the shortest trajectory. The reversal performances of the latter two groups reveal a capacity for rapidly detecting environmental changes (Poucet, Chapuis, Durup, & Thinus-Blanc, 1986;Thinus-Blanc et al, 1987;Welker & Welker, 1958). Warburton (1990) reported similar reversal learning differences in goldfish trained in an arena tank to find reward in either a directly or an indirectly cued location.…”

What Do Rats Learn About the Geometry of Object Arrays? Tests With Exploratory Behavior.

“…When one object was moved outward, away from the square, the hamsters spent a significantly increased amount of time in contact with the object in the novel position; that is, they exhibited dishabituation. Poucet et al (1986) concluded from this finding that the hamsters were responding to changes in the shape of the array. However, the animals could also have been responding to the change in position of the single relocated object relative to the walls of the arena and/or to the stripe on the wall or to a change in the distance or angle between specific pairs or triads of objects.…”

“…Hamsters (Poucet et al, 1986;Thinus-Blanc et al, 1987;Thinus-Blanc, Save, Poucet, & Buhot, 1991) and rats (Poucet, 1989;Poucet, Durup, & Thinus-Blanc, 1988) selectively reexplore one object when it is moved outward from a square array of objects. This is true regardless of whether the objects differ from each other (e.g., Thinus-Blanc et al, 1987, Experiment B) or are identical (Thinus-Blanc et al, 1987, Experiment G).…”

“…Experiments similar to that of Poucet et al (1986) have been conducted with hamsters (Thinus-Blanc et al, 1987;Thinus-Blanc, Durup, & Poucet, 1992), rats (Poucet, 1989;Save, Poucet, Foreman, & Buhot, 1992), and baboons (Gouteux, Vauclair, & ThinusBlanc, 1999). None of these experiments has been conducted under conditions entirely comparable to those used to demonstrate encoding of the shape of enclosures because, in all of them, animals have been provided with alternative means of encoding the locations of objects.…”

Three-dimensional space: locomotory style explains memory differences in rats and hummingbirds

“…to find food, mates and nests) within their environment. Until recently, however, the vast majority of research on navigation and spatial cognition has addressed the question of how animals return to rewarded locations in the horizontal plane, largely ignoring the vertical component ( [1][2][3][4][5][6] but see [7]). …”