Relation between level of food deprivation and rate of schedule-induced attack

The relation between food deprivation and schedule-induced attack was investigated in four White Carneaux pigeons. Attack toward a mirror target was induced by a schedule of reinforcement in which 3-sec food presentations occurred at alternate intervals of 15 and 120 sec (multiple fixed-time 15-sec fixed-time 120-sec schedule). A continuous tone was presented during the 15-sec periods; it was absent during the 120-sec periods. Each pigeon was tested at 65, 80, and 95% of its free-feeding weight in ascending, descending, and ascending orders, respectively. Two relations were apparent; an inverse relation between body weight and rate of attack, and a tendency for rate of attack to increase during the experiment. Reduction or elimination of attack when the mirror was covered with brown paper for some sessions indicated that the results were due neither to changes in activity that might covary with weight nor to habituation to the experimental situation.     

Prepared to eat: how immediate affective and motivational responses to food cues are influenced by food deprivation

Three studies examined how food deprivation influences the immediate valence of food stimuli as well as spontaneous motivational tendencies toward them. We assumed that immediate reactions towards food stimuli should be tuned to the basic needs of the organism. In Study 1, the immediate valence of food names as a function of need state was assessed using an Implicit Association Test (IAT) in a quasi‐experimental design. Food deprivation led to a more positive immediate valence of food items. In Study 2, these results were replicated using the Extrinsic Affective Simon Task. In Study 3, immediate motivational reactions toward pictorial food stimuli were assessed. As hypothesized, approach reactions were facilitated for participants tested before as compared to after lunch, even in a sample with eating disorders. We thus conclude that the immediate valence of edible objects partially reflects regulation in the service of need fulfillment. Copyright © 2006 John Wiley & Sons, Ltd.     

Effects of food deprivation on free-operant avoidance behavior

Lever pressing was maintained by Sidman's shock-postponement procedure and Herrnstein and Hineline's shock-frequency-reduction procedure with rats. Food deprivation to 80% and 70% of the animals' body weights on free feeding resulted in decreased response rates in both avoidance paradigms tested. Reinstatement of free-feeding conditions increased body weights and response rates and decreased shock rates. The effects of food deprivation were not dependent upon any particular avoidance parameters, or types, intensities, or durations of electric shock. These results mean that weight control is essential in long-term studies of avoidance behavior, and in studies of the effects on avoidance behavior of physiological interventions, such as hypothalamic lesions, that themselves may produce weight changes.