A comparison of two methods of assessing representation-mediated food aversions based on shock or illness

Abstract

In experiments that measured food consumption, Holland (1981; Learning and Motivation, 12, 1-18) found that food aversions were formed when an exteroceptive associate of food was paired with illness, but not when such an associate was paired with shock. By contrast, measuring the ability of food to reinforce instrumental responding, Ward-Robinson and Hall (1999; Quarterly Journal of Experimental Psychology, 52B, 335-350) found that pairing an associatively-activated representation of food with shock readily established an aversion to that food. Two experiments considered the origins of these apparently discrepant results. The results did not support either the possibility that instrumental reinforcement power is a more sensitive measure of aversion learning than consumption, nor the hypothesis that illness particularly devalues properties of food representations that determine consumption (such as palatability) whereas shock devalues more general properties critical to reinforcement. The results suggested instead that whereas the effects of pairings of a food associate with illness are mediated by changes in the value of the food itself, the effects of pairings with shock are mediated by the conditioning of fear or other competing responses to the site of food delivery, and not by modification of the value of food itself.Many learning theorists assert that, as a result of associative learning, a conditioned stimulus (CS) comes to activate an internal representation of the unconditioned stimulus (US) with which it is paired. Research over the past 30 years shows that such associatively-activated US representations (Hall, 1996) share many properties with the USs themselves, and may substitute for them in a variety of behavioral functions (for a recent review, see Holland & Wheeler, 2008). For example, Holland (1981, Exp. 1) found that a food-illness association could be learned when an associatively-activated food representation was paired with illness. In that experiment, rats received pairings of a tone with a flavored food, designed to endow the tone with the ability to activate a representation of that food. Next, the tone was paired with an illness-inducing injection of lithium chloride (LiCl), in the absence of the food. Finally, food consumption was assessed in the rats' home cages, in the absence of the tone. As would be anticipated if the tone-activated representation of the food entered into an association with illness, consumption of the flavored food itself was reduced, relative to consumption of various control groups of rats that did not have the opportunity to associate a food representation with illness.

Toxic but Drank: Gustatory Aversive Compounds Induce Post-ingestional Malaise in Harnessed Honeybees

“…To this end, after CS-US conditioning, the US is paired with an aversive treatment (like an aversive gustatory substance or injection of a substance inducing malaise). Post conditioning treatments like associating the US with an unpleasant taste or with malaise are thought to devaluate the US representation (an effect termed US devaluation) [33] , [42] . The logic underlying this procedure is that if the stimulus representation of the US were associated with that of the CS, then changes in the value of the US would also alter responding to the CS.…”

Temporal maps in appetitive Pavlovian conditioning

“…The current studies along with previous work (Leising, Sawa, and Blaisdell 2007) represent demonstrations that temporal maps established from independent experiences with appetitive conditioning can also be integrated when those experiences involve common cues. An alternative account of many experiments, including the current ones, is based on the idea of representation mediated conditioning (Holland 2008; Holland 1981). For example, in Experiment 3, this account would posit that A and B become associated with the early and late parts of C, respectively.…”