FACILITATION AND RETARDATION OF FLAVOR AVERSION CONDITIONING FOLLOWING PRIOR EXPOSURE TO THE CS

Two sets of experiments on flavour aversion conditioning in rats exami ned the effects of the following factors: the nature of the flavour se rving as the conditioned stimulus (CS), which was either a compound of monsodium glutamate, sucrose and quinine, or an elemental flavour, ei ther sucrose or dilute acid; the amount of the CS rats consumed on a s ingle conditioning trial-4 ml or 1 ml; and whether rats had been pre-e xposed to the CS before this conditioning trial. There were three main findings. First, conditioning to an elemental CS was unaffected by th e amount consumed on the conditioning trial, but conditioning to 1 ml of the compound CS was poorer than to 4 ml. Second, pre-exposure produ ced a latent inhibition effect if the CS was an elemental flavour, or if rats were allowed to drink 4 mi of the compound solution on their c onditioning trial. But, third, pre-exposure facilitated conditioning i n rats given only 1 mi of the compound solution as their CS.