title: A sipometer for measuring motivation to consume and reward value of foods and beverages in humans: Description and proof of principle.
abstract: 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.
authors.affiliation: Department of Neuroscience, Uppsala University, Uppsala, Sweden; New York Obesity Nutrition Research Center, Columbia University Medical Center, New York, USA(1).
authors.forename: P S
authors.initials: PS
authors.lastname: Hogenkamp
authors.affiliation: New York Obesity Nutrition Research Center, Columbia University Medical Center, New York, USA(1); Institute of Human Nutrition, Columbia University, New York, USA; Department of Medicine, Columbia University Medical Center, New York, USA.
authors.forename: A
authors.initials: A
authors.lastname: Shechter
authors.affiliation: New York Obesity Nutrition Research Center, Columbia University Medical Center, New York, USA(1); Institute of Human Nutrition, Columbia University, New York, USA; Department of Medicine, Columbia University Medical Center, New York, USA.
authors.forename: M-P
authors.initials: MP
authors.lastname: St-Onge
authors.affiliation: Department of Psychology, Brooklyn College, City University of New York, Brooklyn, USA.
authors.forename: A
authors.initials: A
authors.lastname: Sclafani
authors.affiliation: New York Obesity Nutrition Research Center, Columbia University Medical Center, New York, USA(1); Institute of Human Nutrition, Columbia University, New York, USA; Department of Medicine, Columbia University Medical Center, New York, USA. Electronic address: hrk2@cumc.columbia.edu.
authors.forename: H R
authors.initials: HR
authors.lastname: Kissileff
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D004327:Drinking Behavior / Q000502:physiology*; D005247:Feeding Behavior / Q000502:physiology*; D005260:Female; D005508:Food Deprivation; D005518:Food Preferences / Q000502:physiology*; D006801:Humans; D009042:Motivation / Q000502:physiology*; D011237:Predictive Value of Tests; D012044:Regression Analysis; D012201:Reward; D012892:Sleep Deprivation / Q000503:physiopathology; D055697:Taste Perception / Q000502:physiology*; D013997:Time Factors; D064232:Visual Analog Scale; D055815:Young Adult
keywords: Consummatory behavior; Liking wanting; Motivation; Reinforcing value; Reward