A Behavior Systems View of Conditioned States during Long and Short CS-US Intervals

In the behavior systems view, a long CS–US interval should differentially condition a general search mode and related behavior, while a short CS–US interval should differentially condition a focal search mode and related behavior. Two experiments paired a long or a short CS with food, and then, during an extinction test, compounded the CS with an unconditioned probe-stimulus of a rolling ball-bearing. Presuming that the long CS differentially conditions a general search mode, and that unconditioned contact of a moving stimulus is characteristic of that mode, presentation of the long CS should facilitate interaction with the ball-bearing. Similarly, presuming that a short CS differentially conditions a focal search mode, and that feeder-directed responses are characteristic of this mode, presentation of a short CS should facilitate nosing in the food-tray. Consistent with these predictions, ball-bearing contact increased in rats receiving the long CS, while nosing in the food-tray was higher with the short CS.