Running head: ARTICLE CRITIQUE INSTRUCTIONS 1

Article Critique Instructions (30 points possible)

Ryan J. Winter

Florida International University

ARTICLE CRITIQUE INSTRUCTIONS 2

Purpose of The Article Critique Paper

1). Psychological Purpose

This paper serves several purposes, the first of which is helping you gain insight into

research papers in psychology. As this may be your first time reading and writing papers

in psychology, one goal of Paper I is to give you insight into what goes into such papers.

This article critique paper will help you learn about the various sections of an empirical

research report by reading at least one peer-reviewed articles (articles that have a Title

Page, Abstract*, Literature Review, Methods Section, Results Section, and References

Page—I have already selected some articles for you to critique, so make sure you only

critique one in the folder provided on Blackboard). This paper will also give you some

insights into how the results sections are written in APA formatted research articles. Pay

close attention to those sections, as throughout this course you’ll be writing up some

results of your own!

In this relatively short paper, you will read one of five articles posted on blackboard and

summarize what the authors did and what they found. The first part of the paper should

focus on summarizing the design the authors used for their project. That is, you will

identify the independent and dependent variables, talk about how the authors carried out

their study, and then summarize the results (you don’t need to fully understand the

statistics in the results, but try to get a sense of what the authors did in their analyses). In

the second part of the paper, you will critique the article for its methodological strengths

and weaknesses. Finally, in part three, you will provide your references for the Article

Critique Paper in APA format.

2). APA Formatting Purpose

The second purpose of the Article Critique paper is to teach you proper American

Psychological Association (APA) formatting. In the instructions below, I tell you how to

format your paper using APA style. There are a lot of very specific requirements in APA

papers, so pay attention to the instructions below as well as Chapter 14 in your textbook!

I highly recommend using the Paper I Checklist before submitting your paper, as it will

help walk you through the picky nuances of APA formatting.

3). Writing Purpose

Finally, this paper is intended to help you grow as a writer. Few psychology classes give

you the chance to write papers and receive feedback on your work. This class will! We

will give you feedback on this paper in terms of content, spelling, and grammar.

*Most peer-reviewed articles do include an abstract, but the articles you will see on Blackboard

lack an Abstract. There is a good reason for this, which you’ll find out about in a later paper!

ARTICLE CRITIQUE INSTRUCTIONS 3

Article Critique Paper (30 points possible)

Each student is required to write an article critique paper based on one of the research articles

present on Blackboard (only those articles listed on Blackboard can be critiqued – if you critique

a different article, it will not be graded). The article critique paper will account for 50 points. In

addition to deepening your understanding of conceptual issues discussed in lectures, this article

critique assignment is designed to improve critical thinking and writing skills. Please follow the

instructions and guidelines below. If you are unclear about any of this information, please ask.

What is an article critique paper?

An article critique is a written communication that conveys your understanding of a research

article and how it relates to the conceptual issues of interest to this course. There are five

elements emphasized in this critique: The title page (in APA formatting), summary of the article,

critique of the article, brief (one paragraph) summary of the article, and appropriate referencing

for the article. I suggest also looking at the example papers, which will give you a nice visual

image of APA style that you can mimic in your own paper.

This article critique paper will include 5 things:

1. Title page: 1 page (2 points)

• Use APA style to present the appropriate information: o A Running head must be included and formatted APA style

▪ The phrase “Running head” is at the top of the title page followed by a short title of your creation (no more than 50 characters) that is

in ALL CAPS. This running head is left-justified (flush left on the

page). Note that the “h” in head is all lower case! Look at the first

page of these instructions, and you will see how to set up your

Running head.

▪ There must be a page number on the title page that is right justified. It is included in the header

o Your paper title appears on the title page. This is usually 12 words or less, and the first letter of each word is capitalized. It should be descriptive of

the paper (For this paper, you should use the title of the article you are

critiquing. The paper title can be the same title as in the Running head or it

can differ – your choice)

o Your name will appear on the title page o Your institution will appear on the title page as well o For all papers, make sure to double-space EVERYTHING and use Times

New Roman font. This includes everything from the title page through the

references.

o This is standard APA format. ALL of your future papers will include a similar title page

2. Summary of the Article: 1 ½ page minimum, 3 pages maximum – 10 points)

An article critique should briefly summarize, in your own words, the article research question

and how it was addressed in the article. Below are some things to include in your summary.

• The CAPS portion of your running head should also appear on the first page of your paper, but it will NOT include the phrase “Running head” this time, only the

same title as the running head from the first paper in ALL CAPS. Again, see the

ARTICLE CRITIQUE INSTRUCTIONS 4

example paper. There is a powerpoint presentation on using Microsoft Word that

can help you figure out how to have a different header on the title page (where

“Running head” is present) and other pages in the paper (where “Running head”

is NOT present). You can also find how-to information like this using youtube!

1. If you look at the header in pages 2 through 5 (including THIS current page 4 that you are reading right now!), you will see “Running head”

omitted. It simply has the short title (ARTICLE CRITIQUE PAPER

INSTRUCTIONS) all in caps, followed by the page number.

• The same title used on the title page should be at the top of the page on the first actual line of the paper, centered.

• For this paper, add the word “Summary” below the title, and have it flush left. Then write your summary of the article below that

• The summary itself will include the following: (Note – if the article involved more than one experiment, you can either choose to focus on one of the studies

specifically or summarize the general design for all of the studies)

1. Type of study (Was it experimental or correlational? How do you know?) 2. Variables (What were the independent and dependent variables? Be

specific with these. Define the terms independent and dependent variable

and make sure to identify how they are operationally defined in the article)

3. Method (Was there a random sample of participants? Was there random assignment to groups? What did the participants do in the study?). How

was data collected (online, in person, archival data, etc.)

4. Summary of findings (What were their findings?)

3. Critique of the study: 1 ½ pages minimum – 3 pages maximum – 8 points)

• This portion of the article critique assignment focuses on your own thoughts about the content of the article (i.e. your own ideas in your own words). For this section, please

use the word “Critique” below the last sentence in your summary, and have the word

“Critique” flush left.

• This section is a bit harder, but there are a number of ways to demonstrate critical thinking in your writing. Address at least four of the following elements. You can

address more than four, but four is the minimum.

• 1). In your opinion, how valid and reliable is the study? Why? (make sure to define what reliable and valid mean, and apply these definitions to the study you

are critiquing. Merely mentioning that it is valid and reliable is not enough – you

have to apply those terms to the article)

• 2). Did the study authors correctly interpret their findings, or are there any alternative interpretations you can think of?

• 3). Did the authors of the study employ appropriate ethical safeguards?

• 4). Briefly describe a follow-up study you might design that builds on the findings of the study you read how the research presented in the article relates to research,

articles or material covered in other sections of the course

• 5). Describe whether you feel the results presented in the article are weaker or stronger than the authors claim (and why); or discuss alternative interpretations of

the results (i.e. something not mentioned by the authors) and/or what research

might provide a test between the proposed and alternate interpretations

• 6). Mention additional implications of the findings not mentioned in the article (either theoretical or practical/applied)

ARTICLE CRITIQUE INSTRUCTIONS 5

• 7). Identify specific problems in the theory, discussion or empirical research presented in the article and how these problems could be corrected. If the

problems you discuss are methodological in nature, then they must be issues that

are substantial enough to affect the interpretations of the findings or arguments

presented in the article. Furthermore, for methodological problems, you must

justify not only why something is problematic but also how it could be resolved

and why your proposed solution would be preferable.

• 8). Describe how/why the method used in the article is either better or worse for addressing a particular issue than other methods

4. Brief summary of the article: One or paragraphs (4 points)

• Write the words “Brief Summary”, and then begin the brief summary below this

• In ONE or TWO paragraphs maximum, summarize the article again, but this time I want it to be very short. In other words, take all of the information that you talked

about in the summary portion of this assignment and write it again, but this time in

only a few sentences.

• The reason for this section is that I want to make sure you can understand the whole study but that you can also write about it in a shorter paragraph that still emphasizes

the main points of the article. Pretend that you are writing your own literature review

for a research study, and you need to get the gist of an article that you read that helps

support your own research across to your reader. Make sure to cite the original study

(the article you are critiquing).

5. References – 1 page (3 points)

• Provide the reference for this article in proper APA format (see the book Chapter 14 for appropriate referencing guidelines or the Chapter 14 powerpoint).

• If you cited other sources during either your critique or summary, reference them as well (though you do not need to cite other sources in this assignment – this is merely

optional IF you happen to bring in other sources). Formatting counts here, so make

sure to italicize where appropriate and watch which words you are capitalizing!

6. Grammar and Writing Quality (3 points)

• Few psychology courses are as writing intensive as Research Methods (especially Research Methods Two next semester!). As such, I want to make sure that you

develop writing skills early. This is something that needs special attention, so make

sure to proofread your papers carefully.

• Avoid run-on sentences, sentence fragments, spelling errors, and grammar errors. Writing quality will become more important in future papers, but this is where you

should start to hone your writing skills.

• We will give you feedback on your papers, but I recommend seeking some help from the FIU writing center to make sure your paper is clear, precise, and covers all needed

material. I also recommend asking a few of your group members to read over your

paper and make suggestions. You can do the same for them!

The key point is that your experimental paper should describe a “position” that you have taken

with respect to the content of the article. Please note that you do not need to refer to any other

sources other than the article on which you have chosen to write your paper. However, you are

welcome to refer to additional sources if you choose.

ARTICLE CRITIQUE INSTRUCTIONS 6

Other guidelines for the article critique papers

▪ 1). Pay attention to the page length requirements – 1 page for the title page, 1.5 pages to 3 pages for the summary, 1.5 pages to 3 pages for the critique, one or two paragraphs for

the brief summary, and 1 page for the references page. If you are under the minimum, we

will deduct points. If you go over the maximum, we are a little more flexible (you can go

over by half page or so), but we want you to try to keep it to the maximum page.

▪ 2). Page size is 8 1/2 X 11” with all 4 margins set one inch on all sides. You must use 12- point Times New Roman font (Note: these instructions are in 12 point Times New

Roman font).

▪ 3). As a general rule, ALL paragraphs and sentences are double spaced in APA papers. This includes the spacing in your Paper I: Article Critique Paper. It even includes the

references, so make sure to double space EVERYTHING

▪ 4). When summarizing the article in your own words, you need not continually cite the article throughout the rest of your critique. Nonetheless, you should follow proper

referencing procedures, which means that:

o If you are inserting a direct quote from any source, it must be enclosed in quotations and followed by a parenthetical reference to the source. “Let’s say I am

directly quoting this current sentence and the next. I would then cite it with the

author name, date of publication, and the page number for the direct quote”

(Winter, 2013, p . 4).

1. Note: We will deduct points if you quote more than once per page, so keep quotes to a minimum. Paraphrase instead, but make sure you still give the

original author credit for the material by citing him or using the author’s

name (“In this article, Smith noted that …” or “In this article, the authors

noted that…”)

o If you choose to reference any source other than your chosen article, it must be listed in a reference list.

▪ 5). PLEASE use a spell checker to avoid unnecessary errors. Proofread everything you write. I actually recommend reading some sentences aloud to see if they flow well, or

getting family or friends to read your work. Writing quality will become more important

in future papers, so you should start working on that now!

▪ If you have any questions about the articles, your ideas, or your writing, please ask.

Although we won’t be able to review entire drafts of papers before they are handed

in, we are very willing to discuss problems, concerns or issues that you might have.

BRIEF REPORT

Mind Over Milkshakes: Mindsets, Not Just Nutrients, Determine Ghrelin Response

Alia J. Crum Yale University

William R. Corbin Arizona State University

Kelly D. Brownell and Peter Salovey Yale University

Objective: To test whether physiological satiation as measured by the gut peptide ghrelin may vary depending on the mindset in which one approaches consumption of food. Methods: On 2 separate occasions, participants (n � 46) consumed a 380-calorie milkshake under the pretense that it was either a 620-calorie “indulgent” shake or a 140-calorie “sensible” shake. Ghrelin was measured via intravenous blood samples at 3 time points: baseline (20 min), anticipatory (60 min), and postconsumption (90 min). During the first interval (between 20 and 60 min) participants were asked to view and rate the (misleading) label of the shake. During the second interval (between 60 and 90 min) participants were asked to drink and rate the milkshake. Results: The mindset of indulgence produced a dramatically steeper decline in ghrelin after consuming the shake, whereas the mindset of sensibility produced a relatively flat ghrelin response. Participants’ satiety was consistent with what they believed they were consuming rather than the actual nutritional value of what they consumed. Conclusions: The effect of food consumption on ghrelin may be psychologically mediated, and mindset meaningfully affects physiological responses to food.

Keywords: mindset, nutrition, ghrelin, hunger, product labeling

Although often ignored, one’s mindset (thoughts, beliefs, and expectations) is a key component in various domains of health. The mere expectation to heal even in the absence of active phar- maceutical or chemical substances enhances the effect of medica- tion (e.g., Brody, 1980; Price, Finniss, Benedetti, 2008); one’s interpretation of events despite their objective characteristics de- termines the impact of stress and illness on the body (e.g., Cohen & Williamson, 1991; Park, 2006); and identifying housework as a good source of exercise can elicit corresponding physiological benefits without any changes in actual activity (Crum & Langer, 2007). Evidence continues to point to the idea that one’s state of mind influences the body, and we cannot easily separate the interdependence of mind and body (Langer, 2009).

Studies of food expectancies suggest an important role for a per- son’s mindset in determining taste and preference. For instance, people like the taste of Coke better when it is consumed from a brand-name cup (McClure et al., 2004); strawberry yogurt and cheese spreads are enjoyed less if they are labeled “low-fat” (Wardle & Solomons, 1994); adding vinegar to beer under the labeling “special ingredient” can actually improve taste ratings (provided the consumer is unaware that the “special ingredient” is vinegar; Lee, Frederick, & Ariely, 2006); and manipulating the perceived cost of wine to be more expensive (but not the wine itself) can result in heightened activity in the medial orbital frontal cortex, the pleasure center of the brain (Plassmann, O’Doherty, Shiv, & Rangel, 2008).

Food labels and perceptions also affect hunger as well as subse- quent food consumption. For example, people tend to modify their eating based on perceived calorie intake such that, when a high or low calorie preload is presented as high or low calorie, actual caloric content matters little as compared to perceived caloric intake. In general, when people think they have eaten a high calorie preload they report greater fullness and eat less in response, whereas when people believe they have eaten a low calorie preload they report more hunger and eat more in response (e.g., Polivy, 1976; Provencher, Polivy, & Herman, 2009; Wooley, Wooley, & Woods, 1975). These differences are often moderated by restrained eating such that highly restrained participants tend to eat even more after perceiving themselves as having consumed a high calorie preload, a phenomenon called coun- terregulatory eating (e.g., Knight & Boland, 1989; Polivy, 1976; Spencer & Fremouw, 1979).

This article was published Online First May 16, 2011. Alia J. Crum, Kelly D. Brownell, and Peter Salovey, Department of

Psychology, Yale University; William R. Corbin, Department of Psychol- ogy, Arizona State University.

We thank the Rudd Foundation and the Yale Center for Clinical Inves- tigation for financial and logistical support. We also thank Ellen Langer, Thomas Horvath, Shirley McCarthy, and Sonia Caprio for their intellectual guidance, Cathy Crum for her comments on this article, and Gibbs Graph- ics for the label design.

Correspondence concerning this article should be addressed to Alia J. Crum, Department of Psychology, Yale University, P.O. Box 208205, New Haven, CT 06520. E-mail: [email protected]

Health Psychology © 2011 American Psychological Association 2011, Vol. 30, No. 4, 424–429 0278-6133/11/$12.00 DOI: 10.1037/a0023467

424

In the past decade, investigators have improved our understand- ing of the molecular mechanisms that control food intake and body weight. Central to this line of research has been the identification and characterization of metabolic signals that serve as fundamental indexes of energy balance. A hormone that has proved to be particularly influential is the gut peptide ghrelin. Identified in 1999, ghrelin is an essential indicator of energy insufficiency. When energy intake is low or the stomach is empty, ghrelin is secreted from the endocrine cells of the stomach and transported in the bloodstream to the brain, where it binds with receptors in the arcuate nucleus and the ventromedial hypothalamus to produce the sensation of hunger and motivate consumption. As energy intake increases and nutrients are detected in the gastrointestinal tract, ghrelin levels are suppressed, thereby signaling to the brain via neural and endocrine mechanisms to reduce appetite and increase feelings of satiety (Baynes, Dhillo, & Bloom, 2006; Murphy, Dhillo, & Bloom, 2006).

In principle, the rise and fall of ghrelin occur systematically and in proportion to calories consumed to achieve a healthy metabolic balance (Zigman & Elmquist, 2003). However the communication between the metabolic and neurological systems is complex. Even subtle changes can have profound implications for health and homeostasis (Murphy et al., 2006). For example, among obese individuals, the usual postprandial reduction in ghrelin is absent or attenuated suggesting that abnormalities in the gut hormone sig- naling system may be associated with weight gain and obesity (Cummings, 2006). Peripheral or intracereroventricular adminis- tration of ghrelin in both humans and rodents has been shown to promote food intake and body weight gain (e.g., Theander-Carillo et al., 2006; Wren et al., 2001, as cited in Castañeda et al., 2010).

In light of the power of beliefs and expectations in affecting other physiological processes, we sought to determine whether subtle changes in the mindset associated with eating might influence the release of ghrelin in response to food consumption. Considering the moderating influence of restraint on the psychological effects of eating behavior and satiety (e.g., Heatherton, Polivy, & Herman, 1989) and the influence of restrained eating on the ghrelin response (Schur, Cummings, Callahan, & Foster-Schubert, 2008), restrained eating was also included in the analyses.

Method

Participants

Participants were recruited through fliers presenting the oppor- tunity to participate in a “Shake Tasting Study” at the Yale Center for Clinical Investigation in exchange for $75 for the two 2.5-hr sessions. These fliers were posted around the New Haven com- munity in both on- and off-campus locations in an attempt to recruit a diverse sample. Participants were between the ages of 18 and 35, within a normal to overweight range of body mass index (BMI; M � 22.5, SD � 4.04), and were prescreened for diabetes, pregnancy, chronic medical or psychiatric conditions, and food allergies to lactose or eggs. Fifty-three participants were recruited; however, two participants did not attend the second session, and five participants did not complete the preliminary survey. Data were analyzed using the 46 participants who completed all com- ponents of the study (65% women, 78% student, 22% member of

community; 56% White, 12% African American, 11% Asian American, 10% Hispanic/Latino, and 11% other).

Design and Procedure

Participants were scheduled for two, 2.5-hr sessions at the Yale Clinical Research Center Hospital Research Unit (HRU). These sessions were exactly 1 week apart, either at 8:00 a.m. or 8:20 a.m. after an overnight fast. At the first session, participants were told that the metabolic kitchen at the Yale Center for Clinical Investi- gation was working on designing two different milkshakes with different nutrient contents and that they would taste one milkshake in the first week and another milkshake the following week. They were told that the goal of the study was to evaluate whether the milkshakes tasted similar and to examine the body’s reaction to the different nutrients (high vs. low fat, high vs. low sugar, etc.).

Unknown to the participants, the contents of the two milkshakes were identical. However, the labels depicting these beverages differed from Time 1 to Time 2: The indulgent condition presented the milkshake as a high fat, high calorie “indulgent” shake; the sensi- shake condition touted the milkshake as a low fat, low calorie “sen- sible” shake. The corresponding labels are presented in Figures 1 and 2. Please visit www.GibbsGraphicsArt.com/Crum.html to view the color versions of these designs.

At each session, an intravenous catheter was placed for blood drawing, and after a 20-min rest period, the first blood sample was drawn, followed by samples taken at 60 and 90 min. During the first interval (between 20 and 60 min) participants were asked to view and rate the label of the shake. During the second interval (between 60 and 90 min) participants were asked to drink and rate the milkshake. To control for speed of consumption, participants were instructed to consume the shake in its entirety within the first 10 min of this interval. Order of presentation of the two milkshakes was counterbal- anced so that approximately half (45%) of the participants received the sensi-shake in the first session and half (55%) of the participants received the indulgent shake in the first session.

Measures

Ghrelin. Ghrelin was measured using a double antibody RIA (GHRT-89HK) with intra-assay variability of 4 to 10%, and inter- assay variability of 4.8 to 12.8% (Millipore; St. Charles, MO). Samples were kept on ice during the collection period after which they were spun and plasma was stored at �70 °C until they were batch analyzed. Total amount of blood collected was 90 ccs (45 ccs per visit).

Taste ratings. During consumption, participants were asked to comment on various aspects of the milkshake including smell, appearance, and taste as well as enjoyment and healthiness. Re- sponses to these questions were assessed via 100-mm visual ana- logue scales ranging from 0 (not at all) to 100 (extremely).

Hunger ratings. Ten minutes prior to each ghrelin measure- ment, participants were asked to rate their subjective feelings of hunger. Responses to these questions were assessed via 100-mm visual analogue scales ranging from 0 (not at all) to 100 (ex- tremely).

Restrained eating. The Dutch Eating Behavior Question- naire (DEBQ; Van Strien, Frijters, Bergers, & Defares, 1986) was used to assess dietary restraint. Although this measure also has

425MIND OVER MILKSHAKES

subscales for emotional eating and external eating, only the re- straint subscale was analyzed in this study. We selected this scale over other measures of restraint because it has been identified as being a unidimensional measure of restraint (other scales of re- straint include items about disinhibition, combining successful and unsuccessful restraint into the same variable; e.g., Allison, Kalin- ski, & Gorman, 1992; Van Strien et al., 1986). Furthermore, we felt that this scale would be particularly relevant to the sample of interest because it has a highly stable factor structure across genders and weight categories (other scales show higher variability across weight and gender; e.g., Allison et al., 1992; Gorman &

Allison, 1995; Van Strien, 2007; Wardle, 1987). In the current sample, reliability of the restraint subscale was adequate (Cron- bach’s � � .82). In our analyses, restrained eating was dichoto- mized at the midpoint of the scale (separating those who reported restraining their eating sometimes or seldom from those who reported restraining their eating often or always).

Results

To assess the effect of the label manipulation on perceived healthiness and perceived tastiness of the milkshake, a mixed-

Figure 1. Indulgent shake label.

Figure 2. Sensible shake label.

426 CRUM, CORBIN, BROWNELL, AND SALOVEY

model analysis of variance (ANOVA) was conducted with shake type (indulgent, sensi-shake), restrained eating (nonrestrained, re- strained), and order (Session 1, Session 2) included as factors in the model. For perceived healthiness, these analyses revealed a significant main effect for type of shake, F(1, 89) � 42.50, p � .01, �2 � .33, with no significant main or interaction effects for restrained eating or for the order in which the shakes were con- sumed. Simple effects tests suggested that participants rated the sensi-shake as significantly healthier than the indulgent shake, t(44) � 15.61, p � .01. These differences are illustrated in Figure 3. There were no significant main or interaction effects of shake, order, or restrained eating on perceived tastiness of the shake.

To test the effect of shake condition on ghrelin and hunger, the data were first assessed using mixed-model ANOVA with time (baseline, anticipatory, postconsumption), shake type (indulgent, sensi-shake) and order (Session 1, Session 2) as fixed factors. Because the model failed to identify significant main effects or interactions involving order (suggesting that the ordering of the sessions did not elicit any reliable differences), the data were collapsed over order and analyzed using a 2 (shake type: indulgent, sensi-shake) � 3 (time: baseline, anticipatory, postconsumption) repeated-measures general linear model (GLM) with restrained eating as a between-subjects variable. Reflecting the different patterns of response hypothesized during the anticipatory and postconsumption phases, we expected a quadratic shake � time interaction effect.

For ghrelin, the 2 (shake type: indulgent, sensi-shake) � 3 (time: baseline, anticipatory, postconsumption) repeated-measures GLM produced a reliable quadratic effect, F(1, 44) � 4.36, p � .04, �2 � .091. To be specific, participants exhibited a steeper rise in ghrelin in anticipation of the indulgent shake, followed by a significantly steeper reduction in this biological marker of hunger after consuming the shake. When drinking the shake in an indul- gent mindset, participants’ levels of ghrelin reflected a moderate level of physiological craving followed by a significant level of physiological satiety. On the other hand, when drinking the shake in a sensible mindset, participants exhibited flat or slightly in- creased levels of ghrelin over the course of consumption suggest- ing that, despite consuming the same nutrient contents, they were not physiologically satisfied. The 2 (restraint: nonrestrained, re-

strained) � 2 (shake type: indulgent, sensi-shake) � 3 (time: baseline, anticipatory, postconsumption) interaction was not sig- nificant nor was there a significant between-subjects effect of restrained eating.

Figure 4 provides a graphic representation of the effects of shake label on ghrelin as a function of mindset. To understand further the differences in ghrelin levels between the two types of shakes at the anticipatory and postconsumption time points, the interactions were decomposed by conducting separate analyses for the anticipatory and postconsumption intervals. These analyses suggest that the primary driver of the quadratic effect was the response to consuming the shake rather than anticipation of it, that is, the 2 (shake type: indulgent, sensi-shake) � 2 (time: anticipa- tory, postprandial) effect was significant, F(1, 44) � 5.75, p � .02, �2 � .12, whereas the 2 (shake type: indulgent, sensi-shake) � 2 (time: baseline, anticipatory) effect was not, F(1, 44) � 0.94, p � .34, �2 � .02. For the measure of hunger, these analyses produced no significant main or interaction effects as a function of shake, time, or restrained eating.

Discussion

When participants drank the indulgent shake, they had a signif- icantly steeper decline in ghrelin than when they drank the sensible shake. The observed pattern of ghrelin response is consistent with what one might observe if participants actually consumed bever- ages with differing caloric contents (i.e., high vs. low energy intake; Taheri, Lin, Austin, Young, & Mignot, 2004). However, in this case the distinctive ghrelin profiles were psychologically mediated; they were dependent on the perceived expectancies of the milkshakes’ nutritional contents as opposed to objective nutri- tional differences.

That we obtained these results independent of the intrinsic properties of food challenges the typical assumption with respect to the physiology of food intake and, in so doing, may provide a missing link in the inexact science of weight and metabolic main- tenance. Although the caloric balance equation seems simple and straightforward (Ayyad & Andersen, 2000), these findings suggest that the psychological mindset of sensibility while eating may actually dampen the effect of ghrelin. Although the effect of such psychologically mediated differences on subsequent consumption or long-term alterations in weight were not measured in this particular study, future research on the impact of this phenomenon on metabolic maintenance is warranted. Elevated ghrelin levels can cause increased body weight and fat gain through increased caloric consumption, decreased energy expenditure, and a shift away from the metabolic utilization of adiposity as an energy source (Murphy et al., 2006; Zigman & Elmquist, 2003). Ghrelin antagonists produce the opposite effect: increasing energy expen- diture, decreasing food intake, and producing long term fat reduc- tion and weight loss (Castañeda et al., 2010). The relatively flat ghrelin profiles in response to consuming the shake in a sensible mindset may be placing participants in a psychologically challeng- ing state marked by increased appetite and decreased metabolism.

1 Cummings (2006) suggested that weight had an impact on ghrelin. However, when weight was entered as a covariate, the analyses remained significant for both the overall effect, F(1, 42) � 4.59, p � .04, � � .10, and the postconsumption effect, F(1, 42) � 5.19, p � .03, � � .11.

Figure 3. Differences in perceived healthiness as a function of shake label. Error bars reflect standard errors of the mean.

427MIND OVER MILKSHAKES

This study did not find any significant differences with respect to subjective hunger regardless of mindset after participants con- sumed the milkshake. This result may have been a function of the measurement timing (hunger levels were assessed 10 min prior to ghrelin changes as opposed to simultaneously or subsequently), or the manner in which hunger was measured (visual analogue scale). Additional research endeavoring to understand better how varying ghrelin levels are related to subjective hunger and subsequent consumption would be useful.

Studies incorporating subsequent consumption would also be important for placing these findings in the context of the literature on restrained eating. Although restrained eating was not a signif- icant moderator of the psychological mediated ghrelin response in this study, a long line of research supports the fact that restrained eaters respond differently to food and label cues as well as well as to perceived intake than those who are not restraining their eating (e.g., Herman & Polivy, 1984; Knight & Boland, 1989). It is possible that important differences between restrained and nonre- strained eaters may emerge in different variations of the test, in studies that also assess subsequent consumption and counterregu- latory eating, or in evaluating the extent to which this phenomenon has meaningful implications in a more naturalistic progression (the sensible label manipulation may have temporarily elicited the mindset of restraint even in those individuals who do not consis- tently report themselves as being restrained).

We altered food labels to isolate the effect of the mindset in response to an experimental manipulation. In the real world, label manipulation for other purposes is common. Companies supple- ment mandated calorie labeling with health claims that stretch the healthy or hedonic attributes of their product in an effort to increase consumption. Furthermore, these claims are often inac- curate and misleading (Hasler, 2008). A product may be labeled “low-fat” (because it is lower in fat than a full fat option) but still be a high-fat food. A food product might be a good source of fiber but still have a sugar content that is exorbitantly high. This juxtaposition of unhealthy nutrients with healthy proclamations may be especially dangerous. Not only is the product itself un- healthy, but the mindset of sensibility might correspond to an inadequate suppression of ghrelin, regardless of the actual nutrient makeup.

Meaningful differences in ghrelin response that were indepen- dent of changes in actual nutrients have important implications

given recent interest in exploring the physiological and pharma- cological use of gut peptides as a means to manage weight (Baynes et al., 2006; Zigman & Elmquist, 2006). We argue that, much like placebo effects, alterations in mindset—what one believes and expects to be eating—have the potential to elicit a seemingly inappropriate sense of satiation. This is an intriguing addition to the growing literature supporting the mindset’s pervasive, yet often unexpected, influence on physiological states. Additional research endeavoring to understand better how psychological factors influ- ence the biological impact of food is particularly warranted. Per- haps if we can begin to approach even the healthiest foods with a mindset of indulgence, we will experience the physiological sat- isfaction of having had our cake and eaten it too.

References

Allison, D. B., Kalinsky, L. B., & Gorman, B. S. (1992). A comparison of the psychometric properties of three measures of dietary restraint. Psy- chological Assessment, 4, 391–398.

Ayyad, C., & Andersen, T. (2000). Long-term efficacy of dietary treatment of obesity: A systematic review of studies published between 1931 and 1999. Obesity Reviews, 1, 113–119.

Baynes, K. C. R., Dhillo, W. S., & Bloom, S. R. (2006). Regulation of food intake by gastrointestinal hormones. Current Opinion in Gastroenterol- ogy, 22, 626–631.

Brody, H. (1980). Placebos and the philosophy of medicine: Clinical, conceptual, and ethical issues. Chicago, IL: University of Chicago Press.

Castañeda, T. R., Tong, J., Datta, R., Culler, M., & Tschöp, M. H. (2010). Ghrelin in the regulation of body weight and metabolism. Frontiers in Neuroendocrinology, 31, 44–60.

Cohen, S., & Williamson, G. M. (1991). Stress and infectious disease in humans. Psychological Bulletin, 109, 5–24.

Crum, A. J., & Langer, E. J. (2007). Mind-set matters: Exercise and the placebo effect. Psychological Science, 18, 165–171.

Cummings, D. E. (2006). Ghrelin and the short- and long-term regulation of appetite and body weight. Physiology & Behavior, 89, 71–84.

Gorman, B. S., & Allison, D. B. (1995). Measures of restrained eating. In D. B. Allison (Ed.), Handbook of assessment methods for eating behav- iors and weight related problems: measures, theory, and research (pp. 149–184). Thousand Oaks, CA: Sage.

Hasler, C. M. (2008). Health claims in the United States: An aid to the public or a source of confusion? The Journal of Nutrition, 138, 1216S– 1220S.

Heatherton, T. F., Polivy, J., & Herman, C. P. (1989). Restraint and internal responsiveness: Effects of placebo manipulations of hunger state on eating. Journal of Abnormal Psychology, 98, 89–92.

Herman, C. P., & Polivy, J. (1984). A boundary model for the regulation of eating. Research Publications—Association for Research in Nervous and Mental Disease, 62, 141.

Knight, L. J., & Boland, F. J. (1989). Restrained eating: An experimental disentanglement of the disinhibiting variables of perceived calories and food type. Journal of Abnormal Psychology, 98, 412–420.

Langer, E. J. (2009). Counterclockwise: Mindful health and the power of possibility. New York, NY: Random House.

Lee, L., Frederick, S., & Ariely, D. (2006). Try it, you’ll like it: The influence of expectation, consumption, and revelation on preferences for beer. Psychological Science, 17, 1054–1058.

McClure, S. M., Li, J., Tomlin, D., Cypert, K. S., Montague, L. M., & Montague, P. R. (2004). Neural correlates of behavioral preference for culturally familiar drinks. Neuron, 44, 379–387.

Murphy, K. G., Dhillo, W. S., & Bloom, S. R. (2006). Gut peptides in the regulation of food intake and energy homeostasis. Endocrine Reviews, 27, 719–727.

Figure 4. Ghrelin over time as a function of shake mindset. Label was viewed beginning at Minute 20. Shake was consumed beginning at Minute 60. Postconsumption interaction effect is significant at p � .02. Overall quadratic effect is significant at p � .04. pg/ml � picograms/milliliter.

428 CRUM, CORBIN, BROWNELL, AND SALOVEY

Park, C. L., & Helgeson, V. S. (2006). Introduction to the special section: Growth following highly stressful life events–current status and future directions. Journal of Consulting and Clinical Psychology, 74, 791–796.

Plassmann, H., O’Doherty, J., Shiv, B., & Rangel, A. (2008). Marketing actions can modulate neural representations of experienced pleasantness. Proceedings of the National Academy of Sciences, USA, 105, 1050– 1054.

Polivy, J. (1976). Perception of calories and regulation of intake in re- strained and unrestrained subjects. Addictive Behaviors, 1, 237–243.

Price, D. D., Finniss, D. G., & Benedetti, F. (2008). A comprehensive review of the placebo effect: Recent advances and current thought. Annual Review of Psychology, 59, 565–590.

Provencher, V., Polivy, J., & Herman, C. P. (2009). Perceived healthiness of food. If it’s healthy, you can eat more! Appetite, 52, 340–344.

Schur, E. A., Cummings, D. E., Callahan, H. S., & Foster-Schubert, K. E. (2008). Association of cognitive restraint with ghrelin, leptin, and insulin levels in subjects who are not weight-reduced. Physiology & Behavior, 93, 706–712.

Spencer, J. A., & Fremouw, W. J. (1979). Binge eating as a function of restraint and weight classification. Journal of Abnormal Psychology, 88, 262–267.

Taheri, S., Lin, L., Austin, D., Young, T., & Mignot, E. (2004). Short sleep duration is associated with reduced leptin, elevated ghrelin, and in- creased body mass index. Public Library of Science Medicine, 1, 210.

Theander-Carrillo, C., Wiedmer, P., Cettour-Rose, P., Nogueiras, R., Perez-Tilve, D., Pfluger, P., . . . Muzzin, P. (2006). Ghrelin action in the brain controls adipocyte metabolism. The Journal of Clinical Investiga- tion, 116, 1983.

Van Strien, T., Frijters, J. E. R., Bergers, G. P. A., & Defares, P. B. (1986). The Dutch Eating Behavior Questionnaire (DEBQ) for assessment of restrained, emotional, and external eating behavior. International Jour- nal of Eating Disorders, 5, 295–315.

Van Strien, T., Peter Herman, C., Engels, R. C. M. E., Larsen, J. K., & van Leeuwe, J. F. J. (2007). Construct validation of the restraint scale in normal-weight and overweight females. Appetite, 49, 109–121.

Wardle, J. (1987). Eating style: A validation study of the Dutch Eating Behaviour Questionnaire in normal subjects and women with eating disorders. Journal of Psychosomatic Research, 31, 161–169.

Wardle, J., & Solomons, W. (1994). Naughty but nice: A laboratory study of health information and food preferences in a community sample. Health Psychology, 13, 180–183.

Wooley, O. W., Wooley, S. C., & Woods, W. (1975). Appetite for palatable food as a function of the caloric density of the previous meal. Journal of Comparative and Physiological Psychology, 89, 619 – 625.

Wren, A. M., Seal, L. J., Cohen, M. A., Brynes, A. E., Frost, G. S., Murphy, K. G., . . . Bloom, S. R. (2001). Ghrelin enhances appetite and increases food intake in humans. Journal of Clinical Endocrinology & Metabolism, 86, 5992.

Zigman, J. M., & Elmquist, J. K. (2003). Minireview: From anorexia to obesity—The yin and yang of body weight control. Endocrinology, 144, 3749–3756.

Zigman, J. M., & Elmquist, J. K. (2006). In search of an effective obesity treatment: A shot in the dark or a shot in the arm? Proceedings of the National Academy of Sciences, USA, 103, 12961–12962.

Correction to Crum et al. (2011)

The brief report “Mind over milkshakes: Mindsets, not just nutrients, determine ghrelin response” by Alia J. Crum, William R. Corbin, Kelly D. Brownell, and Peter Salovey (Health Psychology, Advance online publication. May 16, 2011. doi:10.1037/a0023467), included a citation and refer- ence error.

In the second paragraph on the first page, the Allison & Uhl 1964 citation is incorrect. The corrected sentence and full citation is below. All versions of this article have been corrected.

“For instance, people like the taste of Coke better when it is consumed from a brand-name cup (McClure et al., 2004); strawberry yogurt and cheese spreads are enjoyed less if they are labeled “low-fat” (Wardle & Solomons, 1994); adding vinegar to beer under the labeling “special ingre- dient” can actually improve taste ratings (provided the consumer is unaware that the “special ingredient” is vinegar; Lee, Frederick, & Ariely, 2006); and manipulating the perceived cost of wine to be more expensive (but not the wine itself) can result in heightened activity in the medial orbital frontal cortex, the pleasure center of the brain (Plassmann, O’Doherty, Shiv, & Rangel, 2008).”

Lee L., Frederick S., & Ariely D. (2006). Try it, you’ll like it: The influence of expectation, consumption, and revelation on preferences for beer. Psychological Science, 17, 1054–1058.