To the right  is a demonstration of a Compound Matching-to-Sample Conditional Discrimination. It is a procedure used frequently to study attention to the individual elements of a compound stimulus. This particular example uses two different colors (red and green) and two line orientations (vertical and horizontal) to form four color/line compound stimuli. Follow the instructions below to begin your demonstration. Click mouse once on the white center key to start trial. This the READY SIGNAL Click again on the center key. This is the COMPOUND SAMPLE you should remember for the upcoming test. Now click on one or the other of the two side keys. These are the ELEMENT TEST STIMULI. Here, your memory is tested for either the color or the line orientation of the compound sample. If you match the sample correctly, you will be rewarded by the elevation and illumination (in yellow) of the food hopper just below the three pecking keys. This is a correct response. If you choose incorrectly, then you will experience a brief timeout in the dark. This means you made an incorrect response. The reason this is called a conditional discrimination is that the right and wrong choices are conditional or depend on the prior sample. Following either consequence, the READY SIGNAL will reappear indicating that another trial is ready to be conducted.