Landmark use by pigeons in a touch-screen spatial search task

Abstract

Pigeons obtained food by pecking at an unmarked target location on a video screen equipped with a touch-sensitive frame. The target area was located near the top edge of the screen in Experiment 1 and near the left edge of the screen in Experiment 2. On baseline trials, a graphic landmark was located below and left of the target (Experiment 1) or below and right of the target (Experiment 2). In both experiments, baseline search distributions showed a single peak and were roughly symmetrical about the target area in both horizontal and vertical dimensions. On occasional test trials, the landmark was shifted horizontally, vertically, or diagonally by 1.5 em or 3 em. In both experiments, landmark shifts in the dimension parallel to the nearest edge produced systematic shifts in the peak place of search. Landmark shifts in the dimension perpendicular to the nearest edge produced inconsistent (Experiment 1) or relatively small (Experiment 2) shifts in peak place. The magnitude of the behavioral shift was always less than the magnitude of the landmark shift and was not consistently greater when the landmark was shifted by 3 em than when it was shifted by 1.5 em. These results demonstrated that pigeons can accurately locate an unmarked target area in a two-dimensional vertical arena and that their use of landmarks for spatial localization is similar in severa! respects to that found in open-field spatial search tasks.Many organisms pilot their way back to desired locations by the use of visual landmarks. Some aspects of the spatial relationships between the goal and the surfaces and objects that surround it are encoded and later used to seek the goal. Landmarks are used both to get to the vicinity of the goal over long distances and to pinpoint the goal once the animal is in its vicinity. Gallistel (1990, ch. 5) gives numerous examples of such piloting. The most convincing experimental strategy for demonstrating that an animal uses landmarks in spatial search is to systematically shift landmarks surrounding a goal. If the animal then systematically shifts its searching behavior in space, this indicates that it is relying on the shifted landmarks. Variants of this method have been used to show that landmarks are used by rats (Cheng, 1986;Suzuki, Augerinos, & Black, 1980), gerbils (Collett, Cartwright, & Smith, 1986), hamsters (Etienne, Teroni, Humi, & Portenier, 1990), nutcrackers (Vander Wall, 1982), pigeons (Cheng, This research was supported by NSERC operating grants to the first and second authors. We wish to thank Siew Tan, Stefne Madison, and Lonna Cunningham for assistance with various aspects of this research. Requests for reprints should be addressed to Marcia Spetch, Department of Psychology, University of Alberta, Edmonton, AL Canada TOO 2E9 (e-mail: marcia@ualtamts). 1988Spetch & Edwards, 1988), octopuses (Mather, 1991), ants (Wehner & Raeber, 1979), bees (Cartwright & Cotlett, 1982Dyer & Gould, 1983;von Frisch, 1977), and digger wasps (Tinbergen, 1972).In a series of recent studies on spatial localization...

Multiple cue use and integration in pigeons (Columba livia)

“…This difference likely 334 reflects the physical properties of the two cues, with the large, blue cue providing edge or 335 boundary information and the small, red cue serving as a discrete landmark. The pattern of 336 results is consistent with previous studies that have found differences in control by edges and 337 discrete landmarks in birds, with distance from an edge being more important than distance 338 along that edge (Cheng & Sherry, 1992;Spetch, Cheng, & Mondloch, 1992).…”

Bayesian integration of spatial information.

“…Pigeons can learn to search for an unmarked goal location on a computer monitor, with graphic objects as landmarks and responses recorded by a touch-sensitive frame (touch screen; e.g., Spetch, Cheng, & Mondloch, 1992; for a review, see Cheng, Spetch, Kelly, & Bingman, 2006). In a touch-screen study on both pigeons and humans, Spetch (1995) demonstrated overshadowing in landmark use.…”

Encoding of spatial information in images of an outdoor scene by pigeons and humans

“…Trials of the same type were combined across test sessions. These data were then used to compute the peak place of searching in the horizontal and vertical dimensions, using the iterated median procedure as described in Cheng (1989) and Spetch et al (1992). This procedure determines the middle ofthe highest region in the distribution.…”

“…Two types of evidence indicate that a subject uses a particular landmark: (I) the subject shifts its search location in response to landmark shifts, and (2) accurate search is disrupted by the absence of the landmark. In a series of experiments using a laboratory task in which food is hidden on the floor of a spatial arena, Cheng and his colleagues (e.g., Cheng, 1988Cheng, , 1989Cheng, , 1994Cheng & Sherry, 1992) have clearly demonstrated that pigeons use visual landmarks to locate a hidden goal, and they have identified several principles of pigeons' landmark-based search.Pigeons' landmark-based search has also been investigated in a touch-screen task in which pigeons search for an unmarked goal on the surface of a monitor (Spetch, Cheng, & Mondloch, 1992;Spetch & Mondloch, 1993;Spetch & Wilkie, 1994 …”

“…Pigeons' landmark-based search has also been investigated in a touch-screen task in which pigeons search for an unmarked goal on the surface of a monitor (Spetch, Cheng, & Mondloch, 1992;Spetch & Mondloch, 1993;Spetch & Wilkie, 1994 …”