A sipometer for measuring motivation to consume and reward value of foods and beverages in humans: Description and proof of principle.

New methods, derived from animal work, for measuring food reward value (i.e. reinforcing value of food), and motivation (i.e. strength of desire) to consume, in humans are described and validated. A sipping device (sipometer) was developed that permits access to a liquid food or beverage on two reward schedules: continuous reinforcement (CR) and progressively increasing time spent exerting pressure on a straw (PR-schedule). In addition, a pictorial scale showing a cup, from which the 'amount wanted' could be marked was used to pre-test potential consumption. Intake, time spent sipping, breakpoint, and pressure exerted were the main dependent variables measured. Three pilot experiments were conducted. In Experiment 1, participants (n=8) consumed yogurt shakes after a 1-h or 21-h food deprivation period on both schedules. In Experiment 2, participants (n=8) sham-consumed (i.e. spit out) sweet and non-sweet beverages, utilizing both schedules. In Experiment 3, sham-consuming sweet and non-sweet beverages on both schedules and working for shake on the PR schedule were repeated, after three nights of either habitual sleep or short sleep duration (n=7) in a crossover design. In Experiment 1, participants sipped longer after 21-h vs. 1-h of food deprivation (13±3.0 vs. 8.0±2.1s; p=0.04), on the PR schedule. In Experiment 2, sham-intake (p=0.01) and sipping time (p=0.04) were greater for sweet than non-sweet beverages on the PR schedule and a similar, though not conventionally significant, effect was observed for exerted pressure (p=0.09). In both Experiment 2 and Experiment 3 after habitual sleep, on the PR schedule, cumulative pressure difference between sweet and non-sweet beverage increased with difference in amount wanted in the taste test. In contrast, after short sleep participants were less willing to work for sweet taste as their wanting increased, suggesting that sleep deprivation raises desire, but lowers behavioral output. Taken together these results demonstrate that the sipometer and associated ratings are reliable and useful measures of motivation to consume and reward value in humans. Participants were more motivated to obtain access to sweet beverages, especially when these were better liked than to obtain access to non-sweet beverages.

Hogenkamp PS ，Shechter A ，St-Onge MP ，Sclafani A ，Kissileff HR ... -  《-》

The relative reinforcing value of sweet versus savory snack foods after consumption of sugar- or non-nutritive sweetened beverages.

The effects of sugar-sweetened (SSB) and non-nutritive sweetened (NSB) beverages on the regulation of appetite, energy intake and body weight regulation remain controversial. Using a behavioral choice paradigm, we sought to determine the effects of consuming a SSB or NSB on appetite and the reinforcing value of sweet relative to salty/savory snack foods. In a randomized crossover study, 21 healthy weight adults consumed 360 ml of SSB (sucrose; 31 g) or NSB (sucralose; 4 g) with a standardized meal. Hedonic ratings for the sweet and salty/savory snack foods used for the reinforcement task were assessed prior to the start of the study. Satiety and the desire to eat foods with a specific taste profile were assessed before and every 30 min post-meal for 4 h. The relative reinforcing value of the snack foods was assessed using a computer-based choice task (operant responding with concurrent schedules of reinforcement) 4 h post-meal. Hedonic ratings did not differ between the most highly liked sweet and salty/savory snack foods. Beverage type did not influence measures of satiety or the desire to eat foods with a specific taste. However, sweet snacks were more (p < 0.05) reinforcing relative to salty/savory snack foods after consuming a NSB than after a SSB. In conclusion, this is the first study to demonstrate that NSB can increase the motivation to gain access to sweet snacks relative to salty/savory snack foods later in the day.

Casperson SL ，Johnson L ，Roemmich JN 《-》

Is it possible to dissociate 'liking' and 'wanting' for foods in humans? A novel experimental procedure.

Finlayson G ，King N ，Blundell JE 《PHYSIOLOGY & BEHAVIOR》

Progressive ratio (PR) schedules and the sipometer: Do they measure wanting, liking, and/or reward? A tribute to Anthony Sclafani and Karen Ackroff.

This paper honors the contributions made by Anthony (Tony) Sclafani and Karen Ackroff to both the Columbia University Seminar on Appetitive Behavior and to the field of ingestive behavior in general. We review their use of the progressive ratio (PR) licking paradigm, to determine whether the taste of sucrose, independent of its post-ingestive effects, is always positively reinforcing in animals. They demonstrated a monotonic increase in licking as concentration increased, and obtained results identical to those obtained with a lever-pressing paradigm, but licking was easier and more natural than lever pressing. The PR paradigm was translated to evaluate liquid food reward value in humans. An instrument (the sipometer) was devised that initially permitted a few seconds access to small amounts of a sweet beverage as the participants increased the time to obtain it in 3-5-sec increments. The device went through two refinements and currently delivers the reinforcer and measures the pressure exerted to obtain it. The sipometer is compared with other techniques for measuring motivation and reward. The use of the sipometer and the PR method are discussed in relation to the theoretical challenges inherent in measuring motivation and pleasure, from both psychological and behavioral economics perspectives, and why it is or is not important to separate these processes for both theoretical and practical applications.

Kissileff HR ，Herzog M 《-》

Responsiveness and Reliability of a Sipping Device to Measure Motivation in Normal-Weight Individuals and Bariatric Surgery Patients.

Hamm JD ，Laferrère B ，Albu JB ，Kini S ，Pi-Sunyer X ，Kissileff HR ... -  《Nutrients》