What is the Morris water maze?

Picture a round pool of water made cloudy so you can't see into it. Somewhere in it, a small platform sits just below the surface. Drop a rat or a mouse in and it swims, looking for a way out. At first it finds the platform by chance. Over the next trials it starts to use the things it can see around the room, such as posters, a door or a shelf, to work out where the platform must be. That is spatial learning, and you can watch it happen.

Here is how the original watermaze.org introduced it, back in 1998:

From the original watermaze.org (1998–2013)

Part I General Information

Introduction to the Morris Water Maze

Morris watermaze was devised by Prof Richard Morris (RGM Morris) in the early 1980s. The original video tracking was carried out using high speed electronic tracking apparatus developed by Richard Baker at HVS Image. Water Maze continues to be popular; in fact we think tracking the number of publications use has increased year on year. It is about place-learning and memory. Rats and mice are natural swimmers. They want to get out of the water, but swimming does not distress them. Two advantages of Morris water maze over others mazes are:
The rodent wants to get out, so it searches - it does not wait about.
In water there are no local cues (e.g. scent trails).

The figure shows an example of the basic apparatus, the Morris water Maze Pool kindly provided by Chris Janus, Ph.D. Assistant Professor Department of Neuroscience, Center for Translational Research in Neurodegenerative Disease (CTRND) at University of Florida College of Medicine.

Original text: watermaze.org Part I, General Information. From original material by Richard Baker. The Morris water Maze Pool kindly provided by Chris Janus, Ph.D. Assistant Professor Department of Neuroscience, Center for Translational Research in Neurodegenerative Disease (CTRND) at University of Florida College of Medicine. Reproduced unchanged. Copyright Richard Baker© 2013. All Rights Reserved.

Two things in that text are worth holding on to. The animal wants to get out, so it searches rather than sitting about. And water carries no scent trails, so the animal can't simply follow its own smell back to the platform.

Ready for the hardware? Head to the pool. Want the back story? Read where the water maze came from.

HVS Image has a companion page, what is the Morris water maze (MWM)?.

Sources

Morris (1981). Spatial localization does not require the presence of local cues. Learning and Motivation 12(2):239-260. doi:10.1016/0023-9690(81)90020-5
Morris (1984). Developments of a water-maze procedure for studying spatial learning in the rat. Journal of Neuroscience Methods 11(1):47-60. doi:10.1016/0165-0270(84)90007-4

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