Instructions:

The three rectangles arrayed in a horizontal row correspond to left, center, and right keys in an experimental chamber. Clicking your mouse on an illuminated key moves the procedure to the next stage. (A square is illuminated when a smaller, bright rectangle appears within it.) Begin by clicking on the center illuminated rectangle, equivalent to requiring a pigeon to move to the center of the chamber. This response produces a complex stimulus, with a target at either global or local level, behind the center window and illuminates the left and right keys. A peck to the correct side key leads to reinforcement (a yellow light corresponding to food presented to a pigeon) or to an error leading to a blackout followed by a new trial. (This task is a simplified version of the actual task pigeons experienced.) See if you can learn what the local and global targets are. (If you have trouble, see Figure 3.)