This work was supported by a Programmi di Ricerca Scientifica di Rilevante Interesse Nazionale (PRIN) grant from Ministero Istruzione Universit&#224; e Ricerca (PRIN 2010, protocol number: 2010XPMFW4_009) awarded to GdP. We are also grateful to Caterina Bertini and Raffaella Marino for proofreading the manuscript and performing in the video.

Ethics statement: All procedures described in this protocol were developed and tested following ethical approval from the Ethics Committee of the Psychology Department of Bologna University (see also the Declaration of Helsinki23,53).
1. Participants
<ol>
	<li>Select a sample of healthy young adult females.
	<ol>
		<li>Recruit participants who are not on a diet, not taking psychoactive drugs, free of current or past psychiatric or neurological illness as determined by history, and...

The authors have nothing to disclose.

This article describes in detail a novel protocol aimed at reducing impulsive food choice in healthy young adult women. Critical steps in this protocol include sampling participants from the healthy female population, collecting self-report hunger level at the time of the experiment, selecting two foods with equivalent incentive value for each subject, submitting participants to an error task where each of two different error likelihoods (high and low, randomly interspersed across trials) are associated with one of the t...

Nowadays, it is crucial to help people face the rise of eating disorders1-4. These disorders reflect an overestimation of the incentive motivation associated with appetitive food, which induces individuals to seek and consume it as soon as possible (this has been shown especially with sweet high-fat foods5-6). This happens at the expense of future benefits that can result from being on a diet for a while, but for which the ability to exert eating control is necessary7-8. Indeed, people showing these abnormal behaviors have increased attentional bias toward edible cues9-10 and experience enhanced incentive value for primary rewards11. Moreover, even just looking at appetizing foodstuffs can cue the desire for consuming the food immediately, both in individuals with eating disorders and in the normal population12-13. In order to refrain from immediate gratification and not forego the long-term outcome (e.g., losing weight after a few months of diet), one must exercise great self-controlled and resist the innate, evolutionarily determined impulse to give into temptation and consume immediately. Exerting self-control, a concept that is interrelated to the notion of cognitive control in the field of the Neuroscience, means that one is capable of overcoming innate impulses for further consideration and, possibly, implementation of other, more appropriate behaviors14.
How do individuals engage in self-control strategies? Research has highlighted over the years that the capacity to refrain from automatic responses is heightened in error-full contexts15. Errors are well considered highly arousing and aversive events that, when encountered, elicit compensatory responses16. Specifically, they cue failure/loss in both performance and utility, thereby signaling that one needs to adjust levels of control over current and future behavior accordingly17. Moreover, errors can cue aversive learning, as a warning way to escape from error-prone, maladaptive behaviors, thus inducing the implementation of optimal choice responses18-21.
The present protocol shows how the association between tasty food items and errors can signal that engaging in a certain behavior would lead to a cost (i.e., reward loss), thus encouraging the implementation of compensatory self-control strategies, and thereby reducing impulsive food choice20,22. In the present protocol adapted from23, participants are preliminarily asked to self-report their hunger level at the time of the experiment and to rate six different food items. Based on the ratings, two foods with equivalent incentive value for each subject are selected for the subsequent task. Then, participants perform an error task (see reference24) in which the two previously selected food items cue different error rates (high and low) associated with performance: The error task is programmed so that in one trial condition, cued by one food, participants make a small number of errors, and in the other trial condition, cued by the other food, they make a much larger number of errors. Afterwards, participants&#39; intertemporal choice for each of the two primary rewards is measured (adapted from reference25). The ability to seek larger but delayed reinforcements instead of sooner gratification, which is crucial when facing tempting foods while being on a diet, is indeed crisply captured by intertemporal choice paradigms26. The longer the time one needs to wait for a good to be received and consumed, the more the subjective evaluation of this potential reward is weakened (i.e., the so-called temporal discounting phenomenon27-34). Poor decisions (i.e., higher propensity to choose close gratifications, namely increased temporal discounting for future gains) are considered as a core feature of impulsivity35 and a landmark of numerous disorders, including drug addiction and obesity36-45. After undergoing the procedure described in this protocol, participants show reduced impatient choice for the stimulus cueing high error rate, selectively. The effect is more evident when the hunger level reported by the subjects is low23. This occurs because hunger affects the immediate evaluation of food items46-49 by heightening the motivational value of primary rewards and, in turn, the discount rate of future amounts of those rewards7,50-52.
The advantage of this method first lies in its easy applicability. The error training preceding the intertemporal decision tasks is almost completely effortless, making it possible to be employed in diverse clinical settings. Second, the method produces the desired effect with hypothetical edible items, without the need to use real food. Third, participants were mainly unaware of the food-error association, making the subsequent effect on food preferences genuine, which might affect food decisions reliably in real life as well. Finally, participants tested in the study23 were all young females, but there is good reason to speculate that the effect of food-error pairing on intertemporal decisions would be the same on young males too, mainly because subjects in the present study were unaware of the intended effect.

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			<td>Statistical Software</td>
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errors as a means of reducing impulsive food choice

Nowadays, the increasing incidence of eating disorders due to poor self-control has given rise to increased obesity and other chronic weight problems, and ultimately, to reduced life expectancy. The capacity to refrain from automatic responses is usually high in situations in which making errors is highly likely. The protocol described here aims at reducing imprudent preference in women during hypothetical intertemporal choices about appetitive food by associating it with errors. First, participants undergo an error task where two different edible stimuli are associated with two different error likelihoods (high and low). Second, they make intertemporal choices about the two edible stimuli, separately. As a result, this method decreases the discount rate for future amounts of the edible reward that cued higher error likelihood, selectively. This effect is under the influence of the self-reported hunger level. The present protocol demonstrates that errors, well known as motivationally salient events, can induce the recruitment of cognitive control, thus being ultimately useful in reducing impatient choices for edible commodities.

Representative results from the application of the protocol described above are reported here.
Error task
The validity of the Error task has been determined by the following results. Concerning the percentage of errors committed by participants, they showed a significantly higher number of errors in the HE than in the LE condition, a significantly higher number of erro...

Watch this Scientific Journal Video about Errors as a Means of Reducing Impulsive Food Choice at JoVE.com

Errors as a Means of Reducing Impulsive Food Choice

Giving in to temptation of tasty food may result in long-term overweight problems. This protocol describes how to reduce imprudent preference for edible commodities during hypothetical intertemporal choices in women by associating them with errors.

Nowadays, the increasing incidence of eating disorders due to poor self-control has given rise to increased obesity and other chronic weight problems, and ...

The overall goal of this behavioral experiment is to reduce impulsive preference for food during hypothetical intertemporal choices in women by associating food with errors. Given the present rise of eating disorders, this neuroscientific method she6ds light on the crucial role of self-control during food choice. The main advantage of this technique relies on its easy implementation and instructions by the means of a laptop even in clinical settings.Begin by escorting the participant into a quiet room and sitting them in front of a computer. Collect their demographics, including gender, age, level of education, fasting hours, height and weight. Next, provide the participant with an 11 point Likert scale to collect their self-ratings about feelings of hunger at that moment.Present a slide show presentation on the computer to randomly display six food pictures with high appetitive value in the female population, one at a time. While each food image is on the screen, simultaneously ask the participant to self-rate the motivation to consume that food item at the moment by using an 11 point Likert scale. Finally, collect the rating sheet and select the two highest rated food items as stimuli for the error task.Begin by setting up a modified error task to associate the two preselected food stimuli with two different error rates. Include two conditions in which one predicts a low probability of committing an error or LE, and the other predicts a high probability of committing an error, or HE.Use one of the two preselected food items as the cue for the LE condition, called LEFood, and use the other food item as the cue of the HE condition, called HEFood. Randomly intersperse the same number of trials for both conditions.Once the task has been designed, bring in the participant. Instruct the participant to respond as quickly as possible via a button press to the go signal, which is when the gray scale food item becomes colored, as well as to refrain from responding when a stop signal occurs, which is indicated by a red circle over the colored image. Additionally, inform the participant about all possible feedback, which can be the words correct, error, or too early.Finally, administer a few training trials as practice with one of the non-selected foods. Then, have the participant complete the error task. After completing the error task, administer two temporal-discounting tasks and a counterbalanced order across participants one at a time, in which one temporal discounting task measures the subjective value for LEFood and the other measures the subjective value for HEFood.Instruct the participant to make a choice between two options by imagining receiving the specified amount of reward at the specific time. Ask them to indicate their preference by pressing one of the two buttons. Inform them that these are only hypothetical foods and that there is no time limit to make a choice.For each trial, present a choice between 40 units of fictive food that can be obtained after a variable delay and a smaller amount of the same food available in the immediate present. Then, for the next trial, if the participant chose the smaller option in the previous trial, show a decreased amount for the smaller option. On the other hand, if the participant chose the larger option in the previous trial, show an increased amount for the smaller option.Repeat this procedure until the participant has made five choices at each delay condition. Then, have them complete a new series of choices at another delay condition. Finally, after completing the experiment, debrief the participant as to whether they were aware of the error manipulation during the error task, and if they think they chose in a different way during the temporal discounting tasks according to the two different foods.For the error task, participants showed a significantly higher number of errors during the stop trials in the HE condition compared to stop trials in the LE condition. Furthermore, no significant differences in the number of errors during go trials across HE and LE conditions were detected. The two temporal discounting tasks indicated that the discount rate of the HEFood was significantly smaller than the discount rate of the LEFood as determined by baseline hunger.To clarify the modulatory effect of baseline hunger on the discount rate for future outcomes, a regression analysis showed a significant association between the hunger level and the discount rate of the HEFood. Once mastered, this technique can be done in about one hour, if it's performed properly. After watching this video, you should have a good understanding of how to decrease food choice in patients, in healthy young adult women, by increasing their self-control.

errors-as-a-means-of-reducing-impulsive-food-choice

Research

JoVE Journal

Behavior

8.5K Views.  Justus-Liebig-Universität Giessen. The overall goal of this behavioral experiment is to reduce impulsive preference for food during hypothetical intertemporal choices in women by associating food with errors. Given the present rise of eating disorders, this neuroscientific method she6ds light on the crucial role of self-control during food choice. The main advantage of this technique relies on its easy implementation and instructions by the means of a laptop even in clinical settings.Begin by escorting the participant i...