Behavioral Strategy Shifts with
Training: Rats on an Elevated Plus Maze.
Jennifer Tropp & Etan J. Markus
Behavioral Neuroscience Division, Department of Psychology, University of Connecticut, Storrs, CT 06269
Abstract
Rats use a multitude
of cues within the environment to guide their behavior. The purpose
of this study was to investigate the degree to which reliance on local
cues, visual extra-maze cues, and other sources of information changes
with training. Female Fischer
344 rats were trained consecutively for 24 days on a four-arm radial maze
reference memory task. The correct arm could be located by its relation
to the 'outside world', a large, white illuminated poster, or to a local
insert on the goal arm. Within two weeks, the animals were consistently
choosing the goal arm regardless of how they were placed on the maze.
Four and 10 days after reaching asymptotic performance a probe trial was
given to determine what strategy the animals were using to solve the task.
During the probe trial both the visual extra-maze cue and the local cues
were rotated 90 degrees clockwise and counterclockwise respectively and
the animals’ choice of arm recorded. This probe revealed which cues
had the greatest influence on each animal’s behavior. Initially
the animals tend to use all three types of cues equally in solving the
task. With additional training there was a shift towards predominantly
using visual extra-maze information, and ignoring information outside of
the testing environment. Thus, the use of environmental information
is dynamic, even within a specific task, and changes with the extent of
the training.