The name is absent

Copyright 2001 by the American Psychological Association, Inc.
0096-3445/01/$5.00 DOI: 10.1037//0096-3445.130.3.505

Rhesus Monkeys Use Geometric and Nongeometric Information
During a Reorientation Task

S. Gouteux and C. Thinus-Blanc

Center for Research in Cognitive Neuroscience

Rhesus monkeys (Macaca mulata) were subjected to a place finding task in a rectangular room perfectly
homogeneous and without distinctive featural information. Results of Experiment 1 show that monkeys
rely on the large-scale geometry of the room to retrieve a food reward. Experiments 2 and 3 indicate that
subjects use also nongeometric information (colored wall) to reorient. Data of Experiments 4 and 5
suggest that monkeys do not use small angular cues but that they are sensitive to the size of the cues
(Experiments 6, 7, and 8). Our findings strengthen the idea that a mechanism based on the geometry of
the environment is at work in several mammalian species. In addition, the present data offer new
perspectives on spatial cognition in animals that are phylogenetically close to humans. Specifically, the
joint use of both geometric and landmark-based cues by rhesus monkeys tends to demonstrate that spatial
processing became more flexible with evolution.

Most of the studies of spatial representations in animals rely on
the concept of cognitive map (Tolman, 1948), involving a kind of
"bird's eye view" of the environment, which makes it possible to
move efficiently in space between places charted on a map. Spatial
behaviors of several species have been studied in such a perspec-
tive, with the aim to demonstrate that animals do have spatial
representations endowed with adaptive properties. Indeed, many
animal species appear to be able to construct and use cognitive
maps to orient, ranging from fishes (Lopez, Broglio, Rodriguez,
Thinus-Blacc, & Salas, 1999) to monkeys (Joubert & Vauclair,
1986; Menzel, 1973, 1978), though the most extensive studies
have been conducted in rats at both the behavioral and brain level
(see Thinus-Blacc, 1996, for review).

Many environmental features are likely to serve as constitutive
elements of spatial representations, and understanding their nature
is relevant for a more extensive analysis of the spatial mapping

S. Gouteux and C. Thinus-Blanc, Center for Research in Cognitive
Neuroscience, National Center for Scientific Research, Marseille, France;
J. Vauclair, Centre for Research in Cognition, Language, and Emotion,
Universite de Provence, Aix en Provence, France.

This research was supported by the Centre National de la Recherche
Scientifique, by Grant 97-5-03224 from the Ministere de l'Education
Nationale, de l'Enseignement Superieur et de la Recherche and by Grant
1998 from the Societe Francophone de Primatologie. We thank Bernard
Arnaud for technical assistance and Alexa Riehle for allowing us to use her
monkeys. In addition, we thank N. Martin and I.C. Paphaichiez for assis-
tance with the experiments, V. Dasse for the statistical analysis, and Bruno
Poucet and Simon Benhamou for useful comments on an earlier version of
this article. Some of the experiments discussed in this article were previ-
ously presented at the sixth Annual Meeting of the Cognitive Neuroscience
Society, April 1999, Washington, DC.

Correspondence concerning this article should be addressed to S. Gou-
teux, Center for Research in Cognitive Neuroscience, National Center for
Scientific Research, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20,
France. Electronic mail may be sent to [email protected].
process. Among these features, the geometry of surfaces defined
by various types of discrete elements has recently been the target
of an increasing number of studies (see below). However, some
studies that belong to the traditional approach of cognitive maps
have indirectly addressed this issue. For instance, in a series of
reaction-to-change tests, hamsters explored four different objects
in an open field. After habituation (quantified by the number and
duration of contacts with the objects), a modification of the shape
of the initial object configuration was brought about. Such changes
induced a renewal of exploratory activity directed either selec-
tively to the displaced objects or to all of them, even if the objects
were identical (Thinus-Blacc et al., 1987). In contrast, modifying
the size of the configuration had no effect. Such results demon-
strate that hamsters had spontaneously encoded the geometry of
the object arrangement, given that a modification of this feature
induced strong reactions most likely being the result of the com-
parison between a stored representation of the initial arrangement
and the perception of the new one. The lack of reexploration of the
same configuration of a different size may correspond to the
formation of a geometric category. Other authors have reached the
same conclusion by using different kinds of situations (e.g.,
Greene & Cook, 1997, in rats; Kamil & Jones, 1997, in nutcrack-
ers; Suzuki, Augerinos, & Black, 1980).

Another means of tackling the problem of spatial processing in
animals has been promoted by Cheng (1986, 1987) and Cheng and
Gallistel (1984). These authors addressed the question of the
encoding of two types of environmental features: geometric con-
figuration and local cues. In a series of experiments, these authors
have demonstrated that geometric features are spontaneously taken
into account by rats and predominate over local cues, even when
the latter would allow rats to make the distinction between two
geometrically similar places, with only one being baited.

A distinctive feature of Cheng's experiments and of all the other
ones discussed in this article, is that a disorientation procedure was
conducted between the acquisition phase and the test, namely that

1   2   3   4   >   >>