Mind, Body, World- Foundations of Cognitive Science, 2013a

cues can be added as well. For instance, one arena wall can have a different colour
than the others (Cheng, 1986), or different coloured patterns can be placed at each
corner of the arena (Kelly, Spetch, & Heth, 1998).
One question of interest concerns the relative contributions of these different
cues for reorientation. This is studied by seeing how the agent reorients after it has
been returned to an arena in which cues have been altered. For example, the feature
cues might have been moved to new locations. This places feature cues in conflict with
geometric cues. Will the agent move to a location defined by geometric information,
or will it move to a different location indicated by feature information? Extensive use
of the reorientation task has revealed some striking regularities.
Some of the most interesting regularities found in the reorientation task pertain
to a particular error in reorientation. In an arena with no unique feature cues (no
unique wall colour, no unique pattern at each corner), geometric cues are the only
information available for reorienting. However, geometric cues cannot uniquely
specify a goal location in a rectangular arena. This is because the geometric cues at
the goal location (e.g., 90° angle, shorter wall to the left and longer wall to the right)
are identical to the geometric cues present at the diagonally opposite corner (often
called the rotational location). Under these conditions, the agent will produce rotational
error (Cheng, 1986, 2005). When rotational error occurs, the trained agent
goes to the goal location at above-chance levels; however, the animal goes to the
rotational location equally often. Rotational error is usually taken as evidence that
the agent is relying upon the geometric properties of the environment.
When feature cues are present in a rectangular arena, a goal location can be
uniquely specified. In fact, when cues are present, an agent should not even need
to pay attention to geometric cues, because these cues are not relevant. However,
evidence suggests that geometric cues still influence behaviour even when such cues
are not required to solve the task.
First, in some cases subjects continue to make some rotational errors even
when feature cues specify the goal location (Cheng, 1986; Hermer & Spelke, 1994).
Second, when feature cues present during training are removed from the arena in
which reorientation occurs, subjects typically revert to generating rotational error
(Kelly, Spetch, and Heth, 1998; Sovrano, Bisazza, & Vallortigara, 2003). Third, in
studies in which local features are moved to new locations in the new arena, there
is a conflict between geometric and feature cues. In this case, reorientation appears
to be affected by both types of cues. The animals will not only increase their tendency
to visit the corner marked by the feature cues that previously signaled the
goal, but also produce rotational error for two other locations in the arena (Brown,
Spetch, & Hurd, 2007; Kelly, Spetch, and Heth, 1998).
Rotational error is an important phenomenon in the reorientation literature,
and it is affected by a complex interaction between geometric and feature cues. A
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