Behavioural Processes 86 (2011) 206–215
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Behavioural Processes
journal homepage: www.elsevier.com/locate/behavproc
Development of maze navigation by tufted capuchins (Cebus apella)
Jing Pan
a
, Erica H. Kennedy
b
, Tomas Pickering
a
, Charles R. Menzel
c
,
Brian W. Stone
a
, Dorothy M. Fragaszy
a,∗
a
Department of Psychology, University of Georgia, Psychology Building, Athens, GA 30602, USA
b
Department of Psychology, Frostburg State University, 101 Braddock Road, Frostburg, MD 21532, USA
c
Language Research Center, Georgia State University, 3401 Panthersville Road, Decatur, GA 30034, USA
article info
Article history:
Received 9 June 2010
Received in revised form 19 October 2010
Accepted 30 November 2010
Keywords:
Detour
Planning
Spatial learning
Topological organization
Vector information
Cognition
abstract
Theories of spatial navigation hypothesize that animals use vector or topological information to choose
routes, often including detours, to move objects or themselves to goals. We assessed adult capuchin
monkeys’ (Cebus apella) navigation through 192 virtual two-dimensional mazes that incorporated detour
problems. Six monkeys initially were significantly less likely to choose the correct paths when detours
were required than when not. Three of the six monkeys repeatedly practiced the 192 mazes to asymptotic
mastery; the other three did not practice the mazes again. In a subsequent transfer test, each monkey
made correct choices equivalently often on familiar and novel mazes, which suggests that they used gen-
eral planning skills for maze navigation. Of the three monkeys that practiced the 192 maze-set repeatedly,
one efficiently detoured and the other two significantly improved detouring compared to their initial per-
formance. Two monkeys, contrary to their performance when completing the 192 maze-set for the first
time, made correct choices at the same rate as chimpanzees. Some evidence suggested that two monkeys
used topological information, but utilization of vector information was obvious for all monkeys. Our find-
ings suggest that the boundaries of any individual’s navigational abilities are not predicted by species,
but depend on experience.
© 2010 Elsevier B.V. All rights reserved.
1. Introduction
This study reports how capuchin monkeys (Cebus apella)
become skilled at navigating two-dimensional mazes. Animals
in many orders (Collett, 2002), including primates (Janson and
Byrne, 2007), show strategic goal-oriented navigation. Testing how
non-human primates move a cursor from a start to a goal on com-
puterized mazes provides insights on how they plan paths (e.g.,
Fragaszy et al., 2003; Iversen and Matsuzawa, 2001; Menzel and
Menzel, 2007; Sato et al., 2004). Planning is defined as formu-
lating in advance an organized method for action (Friedman and
Scholnick, 1997, p. xi).
Based on how the future action is stored in memory, planning
can be dichotomized into two forms, planned solutions and plan-
ful solutions (e.g., Willatts, 1990). In a planned solution, the solver
retains the whole sequence of moves in working memory. In a
planful solution (also called forward search), each step is solved
∗
Corresponding author. Tel.: +1 706 542 3036; fax: +1 706 542 3275.
E-mail addresses: ustcpanjing@gmail.com (J. Pan), ehkennedy@frostburg.edu
(E.H. Kennedy), tomas.pickering@gmail.com (T. Pickering), lrccrm@langate.gsu.edu
(C.R. Menzel), brianwstone@gmail.com (B.W. Stone), dfragaszy@gmail.com
(D.M. Fragaszy).
independently (Willatts, 1990). As choices constitute steps in the
maze problem, we can test whether the number and the order of
choices will influence a subject’s choice of path to evaluate if the
subject uses planned solutions (Aim I). If a planned solution is used,
the subject will make a higher proportion of correct choices when
there are fewer choices in a maze because it is easier to remember
fewer choices (Baddeley, 2005; Fragaszy et al., 2003), and a higher
proportion of correct choices at choice points that are nearer to
the start because it is easier to remember the earlier elements in a
sequence of future movements (i.e., the proximity effect in prospec-
tive memory) (Hitch and Ferguson, 1991). If these patterns are not
evident, the subject does not use a planned solution and may use a
planful solution.
A planful solution can make use of multiple heuristic visu-
ospatial cues at each choice point concurrently. We consider two
potential cues: vector information and topology. These two prop-
erties are readily perceptible to individuals with a bird’s-eye view
of a computerized two-dimensional maze with binary choices
(as our subjects had). With regard to topology, the property of
connectivity is the most important for planning paths through a
two-dimensional maze. Connectivity is a mathematical concept
first described by Euler in his famous analysis of “the Seven Bridges
of Königsberg” problem as the existence of an edge (bridge) linking
two vertices (land masses) (Gross and Tucker, 2001). Euler showed
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doi:10.1016/j.beproc.2010.11.006