Landmark geometry and identity controls spatial navigation in rats

Abstract

In three experiments, a new reference memory procedure was used to examine how male rats search for consistently located food in a cue-controlled spatial environment. The animals searched the tops of 24 poles for six hidden baits in an enclosed circular arena containing a fixed configuration of six object landmarks. In Experiment 1, acquisition was faster and overall performance better for the consistent group (lO rats), in which the six baited poles were fixed relative to the landmarks for each session, than for the random group (4 rats), in which baited poles were randomly configured, Cue-control tests and computer simulations suggested that the consistent group relied on the landmarks to directly go to the baited poles, whereas the random group used them to employ a response strategy for searching the arena. Experiments 2 and 3 revealed that the number, identity, and geometric configuration of the landmarks were important to the consistent group's search performance, Overall, these results are most consistent with the use of a geometric representation by male rats which includes information about both the identity and the relative geometry of discrete landmarks in the surrounding spatial environment.In searching for food, many animals demonstrate an accurate working knowledge oftheir surrounding environment. Two general questions have been of interest in the investigation of this spatial behavior: What stimuli in the environment govern this behavior, and how are these stimuli encoded and used by animals for navigation? Although research addressing these basic questions has in-

Place and cue learning in turtles

“…Thus, the results of the present experiment suggest that reptiles, like mammals and birds, can use both guidance strategies by encoding individual cues in close proximity to the goal as beacons and place or mapping strategies by encoding the spatial relationships between the goal and multiple environmental distallandmarks to locate this goal (Balda, Bunch, Kamil, Sherry, & Tomback, 1987;Brodbeck & Shettleworth, 1995;Cheng, 1986;Cheng & Sherry, 1992;Clayton & Krebs, 1994;Cook & Tauro, 1999;Greene & Cook, 1997;Jacobs et aI., 1998;Kamil & Balda, 1985;Leonard & McNaughton, 1990;Olton & Samuelson, 1976;Roberts & Pearce, 1999;Sherry, 1984;Shettleworth, 1995;Shettleworth & Krebs, 1982;Spetch & Edwards, 1988;Strasser & Bingman, 1996;Suzuki, Augerinos, & Black, 1980).…”

Cue learning by rufous hummingbirds (Selasphorus rufus).

“…For example, Greene and Cook (1997) tested rats with configurations of landmarks that changed in visual identity, geometry, or both. They also switched positions of the landmarks.…”

Spatial pattern learning in rats: Conditional control by two patterns

“…Many studies and theoretical analyses of spatial learning in animals have focused on the means by which animals use spatial cues (landmarks) to discriminate their own spatial location or the locations ofgoals (e.g., Cartwright & Collette, 1983;Cheng, 1989;Cheng & Spetch, 1999;Gallistel, 1990;Greene & Cook, 1997;Morris, 1981;01-ton, 1978;Poucet, 1993;Thinus-Blanc, 1996). There is also clear evidence that animals can use internal cues to track their movement through space ("dead reckoning" or "path integration"; e.g., Brown & Moore, 1997;Etienne, Maurer, & Saucy, 1988;Gallistel, 1990;McNaughton, Chen, & Markus, 1991).…”

“…A number of studies have indicated that spatial patterns or geometric relations among perceived spatial locations control behavior (Cheng, 1986;Greene & Cook, 1997;Kamil & Jones, 1997;Spetch et aI., 1997). However, the spatial pattern that controlled the choices ofBrown and Terrinoni's rats was a pattern among hidden food items.…”