The effects of disinhibition and restraint on susceptibility to proactive interference: Exploring the relationship between food intake and cognitive-inhibitory control

Ashley A Martin, Purdue University

Abstract

Inhibitory deficits have been associated with overeating and weight gain in both human and non-human animals. Studies in rats have shown that deficits in memory inhibition (i.e., the ability to suppress unwanted or contextually-relevant thoughts) can lead to an increased responsiveness to food and environmental food cues. This result suggests that deficits in memory inhibition may reduce one's ability to control one's thoughts about food and eating, and that this increased preoccupation with food may result in excess food intake. However, studies have yet to examine whether deficits in memory inhibition are associated with overeating in humans. The present research explored whether individual differences in food intake control, as indicated by subjects' scores on the Disinhibition and Restraint scales of the Three Factor Eating Questionnaire, were associated with different susceptibilities to proactive interference (PI; memory intrusions indicative of impaired memory inhibition). Results showed that all subjects experienced more PI from food cues than non-food cues, and that the degree to which they could successfully prevent interference from food cues depended upon their Disinhibition and Restraint scores—for subjects with high Disinhibition scores, high levels of Restraint reduced their susceptibility to PI from food cues. This research also examined whether deficits in memory inhibition was related to deficits in behavioral control in a discrimination reversal task (Experiment 1) and attentional control in a dot probe task (Experiment 2), two types of inhibitory impairment that have been associated with obesity in humans. The amount of proactive interference experienced on the memory inhibition task was not significantly related to subjects' performance on either the behavior or attention task; however, this result should be interpreted cautiously as neither the discrimination reversal or dot probe task generated strong interference effects. These results suggest that it may be particularly difficult for individuals to refrain from thinking about food when confronted by food cues in the environment, highlighting the potential of memory inhibitory processes to influence food intake control. In addition, these results provide some preliminary evidence that an individuals' ability to control their food intake may be related to their ability to control their thoughts about food. Specifically, the results of this research highlights the possibility that Restraint may prevent food-related memory intrusions and thereby offset the tendency to overeat that is associated with Disinhibition. Future studies are needed to determine whether an increased ability to resist intrusive thoughts of food is actually associated with resistance to overeating.

Degree

Ph.D.

Advisors

Urcuioli, Purdue University.

Subject Area

Behavioral psychology|Psychology|Cognitive psychology

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