The apparatus consists of a trapezoidal-shaped tank containing room temperature water, with a computer monitor spanning a clear glass wall at the wide end of the pool. Visual stimuli are generated and projected on each side of the monitor using computer software. A midline divider extends into the pool from the vertical centerline of the monitor, creating a Y-shaped maze (stem with two arms). A moveable clear Plexiglas platform is submerged below the side of the monitor displaying the reinforced stimulus.