RESEARCH ARTICLE
To See or Not to See: Do Front of Pack Nutrition Labels Affect Attention to Overall Nutrition Information? Laura Bix1*, Raghav Prashant Sundar1, Nora M. Bello2, Chad Peltier3, Lorraine J. Weatherspoon4, Mark W. Becker3 1 School of Packaging, Michigan State University East Lansing, MI, United States of America, 2 Department of Statistics, Kansas State University Manhattan, KS, United States of America, 3 Psychology Cognition and Cognitive Neurosciences Group, Michigan State University East Lansing, MI, United States of America, 4 Department of Food Science and Human Nutrition, Michigan State University East Lansing, MI, United States of America * [email protected]
Abstract OPEN ACCESS Citation: Bix L, Sundar RP, Bello NM, Peltier C, Weatherspoon LJ, Becker MW (2015) To See or Not to See: Do Front of Pack Nutrition Labels Affect Attention to Overall Nutrition Information? PLoS ONE 10(10): e0139732. doi:10.1371/journal.pone.0139732 Editor: Anderson de Souza Sant'Ana, University of Campinas, BRAZIL
Background Front of pack (FOP) nutrition labels are concise labels located on the front of food packages that provide truncated nutrition information. These labels are rapidly gaining prominence worldwide, presumably because they attract attention and their simplified formats enable rapid comparisons of nutritional value.
Received: July 22, 2015
Methods
Accepted: September 15, 2015
Eye tracking was conducted as US consumers interacted with actual packages with and without FOP labels to (1) assess if the presence of an FOP label increases attention to nutrition information when viewers are not specifically tasked with nutrition-related goals; and (2) study the effect of FOP presence on consumer use of more comprehensive, traditional nutrition information presented in the Nutritional Facts Panel (NFP), a mandatory label for most packaged foods in the US.
Published: October 21, 2015 Copyright: © 2015 Bix et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: All relevant data are within the paper and its Supporting Information files. Funding: The project described was supported by Award Number R21CA155818 from the National Cancer Institute. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Cancer Institute or the National Institutes of Health. Further, Laura Bix, one of the coauthors, has salary support through the Hatch Act (USDA) as a Michigan Ag Bio Station researcher.
Results Our results indicate that colored FOP labels enhanced the probability that any nutrition information was attended, and resulted in faster detection and longer viewing of nutrition information. However, for cereal packages, these benefits were at the expense of attention to the more comprehensive NFP. Our results are consistent with a potential short cut effect of FOP labels, such that if an FOP was present, participants spent less time attending the more comprehensive NFP. For crackers, FOP labels increased time spent attending to nutrition information, but we found no evidence that their presence reduced the time spent on the nutrition information in the NFP.
PLOS ONE | DOI:10.1371/journal.pone.0139732 October 21, 2015
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Do FOPs Impact Attention to Nutrition Information?
Competing Interests: Dr. Bix has had previous funding from large food companies, including Kraft Foods and Nestle. These companies were not involved in any aspect of this study, and the previous funding does not alter the authors' adherence to PLOS ONE policies on sharing data and materials. Abbreviations: AOI, Area of Interest; BMI, Body Mass Index; CDC, US Centers for Disease Control and Prevention; EFNEP, Expanded Food and Nutrition Education Program; FFQ, Food Frequency Questionnaire; FOP, Front of Pack Nutrition Labeling; MSUE, Michigan State University Extension; NFP, US Nutrition Facts Panel; SNAP, Supplemental Nutrition Assistance Program; FDA, US Food and Drug Administration; US, United States; WIC, Women Infants and Children.
Conclusions The finding that FOP labels increased attention to overall nutrition information by people who did not have an explicit nutritional goal suggests that these labels may have an advantage in conveying nutrition information to a wide segment of the population. However, for some food types this benefit may come with a short-cut effect; that is, decreased attention to more comprehensive nutrition information. These results have implications for policy and warrant further research into the mechanisms by which FOP labels impact use of nutrition information by consumers for different foods.
Introduction Given growing rates of obesity and associated increases in health costs, morbidity and mortality [1–4], numerous governments world-wide have expressed an interest in reducing obesity rates. As part of this effort, Front of Pack (FOP) nutrition labels are becoming prominent internationally [5]. These labels take varied forms, ranging from symbols that provide a global synopsis of a product’s overall healthfulness in summative fashion to those which include explicit details regarding key components commonly associated with health risks when consumed in excess (e.g. saturated fat, fat, sugar and salt). Increasingly, explicit labels are also overlaid with qualitative assessments relating to the specific components highlighted (e.g. a traffic light system, in which red stands for “eat sparingly”, amber for “eat in moderation” and green for “eat up”). In response to the increased use of FOP labels, and governmental calls for research investigating their effectiveness (Nathan, Lichtenstein, Yaktine, & Wartella, 2011; Office of Foods, Center for Food Safety and Applied Nutrition, Center for Veterinary Medicine, & Office of Regulatory Affairs, 2012; White House Task Force on Childhood Obesity, 2010), there has been a great deal of recent research on FOP labeling. In this study we fill two critical gaps in the existing literature. • First, we directly measure how FOP labels impact attention among participants not engaged in a nutrition-related task. • Second, we investigate how the presence of an FOP impacts attention to existing, more comprehensive, nutrition information (i.e., the Nutrition Facts Panel (NFP) in the US). To do so, we employ a novel method that allows high-resolution eye tracking while people interact with commercial quality packages.
Background Hodgkins et al. developed a system to classify FOP labeling as: directive, non-directive and semi-directive, and defined “directiveness” as the degree to which the labeling provides guidance about a food’s overall healthfulness [6]. ‘Non-directive’ labels simply offer a listing of nutrients and leave the burden of making the actual healthfulness interpretation to the consumer. Monochrome systems like the %GDA label in the EU and the Facts-up-Front program (also known as Nutrition Keys) [7], as well as the traditional Nutrition Facts Panel (NFP) in the US, are examples of non-directive labeling (Fig 1A). When overlaid with symbols or other qualitative assessments such as color, non-directive labels become ‘semi-directive’, offering a listing of key components while also providing a color-coded interpretation of the healthfulness of each relative to reference amounts (Fig 1B). Finally, simple icons, like the Choices Icon
PLOS ONE | DOI:10.1371/journal.pone.0139732 October 21, 2015
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Do FOPs Impact Attention to Nutrition Information?
Fig 1. (1A) Examples of Non-Directive labels (1B) Examples of Semi- directive FOPs (1C) Examples of Directive FOPs. doi:10.1371/journal.pone.0139732.g001
in the Netherlands [8], the Nordic Keyhole-utilized in Norway, Sweden and Denmark [9], and the now defunct Smart Choices label in the US [10] are examples of ‘directive’ labels, those which summarize and directly call out the overall healthfulness of a product in summative fashion (Fig 1C). Regardless of the approach taken (directive, semi-directive or non-directive), the rationale behind FOP labels is that presenting information regarding nutritional aspects of the product in a conspicuous and easy to understand manner will empower people to make healthier choices [11–14]. Most of the research investigating FOP labels focuses on the consumer’s ability to comprehend and use labels of various designs (for review see Vyth et al., 2012). With this focus, many studies have given people nutrition-relevant tasks and evaluated how well they perform the task which requires nutrition labeling, generally during trials which employ varied label designs. For instance, Borg & Westernhoefer (2009) asked people to select the healthy option in a two-alternative forced-choice scheme using packaging designs that included directive, semi directive and non directive methods of labeling. Researchers found that participants performed the selection task better with a color-coded FOP label, a type of semi-directive label. This finding was replicated by Australian researchers, who found that participants were five times more likely to correctly identify a food as healthy when food products were labeled with a traffic light FOP label (i.e. semi-directive) as compared with those which were monochromatic (i.e. non-directive) [15]. In general, it seems that color-coded FOPs, like the multiple traffic light design, are effective when people are asked to identify healthy foods (see Hawley et al 2013 for review). While this approach is important for identifying labels that are effective for people who have the goal of recognizing healthy food products, published research provides little information about a label’s impact on individuals who might not have an explicit nutrition-related goal. From an information-processing prospective, the existing literature focuses on a relatively late
PLOS ONE | DOI:10.1371/journal.pone.0139732 October 21, 2015
3 / 20
Do FOPs Impact Attention to Nutrition Information?
process, namely comprehension, by-passing the earlier stage of attentional selection. Bypassing the attentional interaction ignores the fact that one of the reasons to place nutritional information on the front of packs is to make it readily accessible so that it garners more attention [16]. Further, a great deal of research suggests that information must be attended in order to be consciously perceived [17–20]. In short, if a label fails to garner attention, then the cognitive processing of the label will be derailed before comprehension even becomes an issue; that is, if the consumer does not see the information, information processing gets truncated before reaching the point of understanding. Recognizing this gap in knowledge, recent studies have sought to investigate how different types of nutrition labels impact attention. A number of these studies use visual search tasks to investigate attention to nutrition labels. Many employ the reaction time required to find a nutrition-relevant search target as the dependent variable [21, 22]. Others have tracked eye movements while participants were given explicit, nutrition-relevant goals like identifying whether a product had low or high sodium content, or making a health judgment about a product [23–28]. These visual search paradigms generally support the claim that semi-directive (specifically, color–coded) FOP labels are effective at attracting attention. However, in all these visual search paradigms the participants were given nutrition-relevant tasks, predisposing them to attend the relevant information. So, much like research on comprehension, these studies are unable to speak to the ability of labels to garner attention from people who do not have an explicit nutritional goal. Other researchers have eye tracked participants while explicitly manipulating participants’ goals in order to compare those with a nutrition-related goal to others with taste or purchaserelated motivations [21, 22, 29–32]. In general, these studies show that participants with a nutrition related goal spend more time attending to nutritional information and that formats akin to the Traffic Light FOP label garner attention particularly well among that population [21, 22]. What is missing from these studies is an assessment of whether FOP design impacts the attention of those participants that do not have an explicit goal related to nutrition. In other words, the results do not speak to the question of how effective FOPs are among the general population. It is still unclear which designs best garner attention among participants without a nutrition relevant task. The distinction between participants with and without a nutrition-related goal is an important one practically and theoretically. From the practical standpoint, a label that garners attention, even among participants who are not explicitly seeking nutritional information, is likely to impact a greater segment of the population. From a theoretical standpoint, the two scenarios (with and without a nutritional goal) tap different attentional systems. Two systems are generally regarded as governing attention: a bottom-up system and a top-down system [33]. These systems are associated with distinct neural pathways, and have different time courses. When information search is goal-driven, attention is driven in a top-down fashion toward goal-relevant stimuli; whereas in the absence of goals, attention wanders to the most visually salient stimuli [33]. As a result, it is unclear whether or not a label that works well under volitional (topdown conditions) will also perform well under involuntary bottom-up conditions. Evidence from a single eye tracking study that investigated attention to packages with varied FOP labeling strategies among participants who were not given a nutritional goal is available [34]. A mobile eye tracker was used to track people’s gaze during a mock shopping task by recording the duration of time that each person gazed at the entire package as well as the number of times that their gaze was directed to the same. Presence or absence of a directive FOP (health logo) was crossed with that of a semi-directive FOP (traffic light), forming four possible label treatments. Under the guise of a shopping scenario, participants were asked to make a single selection from each of three categories of food products (ready meals, sweets and fruit juices) while their eye movements were tracked. Researchers reported subjects spent a significantly
PLOS ONE | DOI:10.1371/journal.pone.0139732 October 21, 2015
4 / 20
Do FOPs Impact Attention to Nutrition Information?
longer time gazing at packages that contained a traffic light label compared to those that did not. However, the method only allowed the research team to make inference regarding eye movement with regard to the entire package. This raises the possibility that the FOP did attract attention to itself but whether or not the nutrition information was explicitly attended remains unclear. Interestingly, Koenugstorfer’s team noted that the presence of the semi-directive traffic light label interacted with the appearance of the directive design, a “Health Check Mark” designed to provide an overall evaluation of the healthfulness of the product, a directive design. When the Health Check appeared alone, people spent very little time viewing packages. But when the package displayed both a Health Check and the traffic light, people looked at the packages for significantly longer. This finding suggests that the traffic light was attended, altering the impact of the Health Check. The finding that the traffic light label may have altered the use of other nutritional information highlights a second gap in our knowledge. Specifically, that there is little data investigating how the presence of an FOP may impact attention to the more comprehensive information presented in the Nutritional Facts Panel (NFP). In our study, we employ a high-resolution eye tracking method that enabled us to isolate fixations on specific sections of the package to more precisely detect the attentional patterns when people without explicit, nutrition-related goals interacted with actual packages with and without FOP labels. This is important, because it has been suggested that the FOP could act either as a prime or shortcut for the more comprehensive, required nutritional information contained within the NFP. Determining whether the FOP primes or substitutes more complete nutrition information is an important area of inquiry for two reasons. Koenugstorfer’s work [34] supports the idea that the presence of different types of nutrition labels can influence the attention devoted to others. Additionally, it has been argued that an over-reliance on the limited nutrition information in an FOP may reduce a consumers’ ability to decide what is most appropriate for him/her based on individual needs [35, 36] (i.e. consumers should access the comprehensive information to make truly informed decisions regarding appropriate dietary choices). Our experiment allowed us to objectively investigate what portions of each package participants (not tasked with a nutrition-related task) viewed.
Objectives Using an Applied Science Laboratories 501 bright pupil, head mounted eye tracker (ASL Boston, MA), we tracked the gaze position of 55 participants as they interacted with novel cereal and cracker packages created for this research in order to: 1. Determine whether the presence of an FOP increased attention to nutrition information in participants that were not specifically charged with a task that required nutrition information. 2. Study the interplay between FOP labels and existing, comprehensive nutrition information (i.e. the NFP) to address whether the FOP is used in lieu of the NFP or primes nutritional information, making people more likely to use the NFP.
Materials and Methods Participants This study was approved under IRB 10–459 by the Social Science/Behavioral and Education Institutional Review Board (SIRB) at Michigan State University. Participant eligibility required: 18 years or older, not legally blind, and hard contact non-user (can interfere with the eye tracking device). Written consent was provided by all subjects and data was recorded by subject number.
PLOS ONE | DOI:10.1371/journal.pone.0139732 October 21, 2015
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Do FOPs Impact Attention to Nutrition Information?
To obtain a diverse sample that represented at-risk participants, we recruited adult participants from Michigan State University (MSU) campus list serves and extension programs housed at the Ingham County Health Department. The programs that helped us recruit participants from at-risk communities included: the Women Infants and Children (WIC) program, the Supplemental Nutrition Assistance Program (SNAP) and the Expanded Food and Nutrition Education Program (EFNEP) with the assistance of MSU Extension (MSUE). These are government supported programs that assist people with limited resources in acquiring the: food, knowledge, skills, attitudes and behaviors necessary for nutritionally sound diets We recruited a total of 74 participants, 12 of whom were not included in the study due to technical difficulties with the instrument calibration process, and hence their eye movements could not be tracked. Data collected from an additional seven subjects were excluded from analysis due to poor quality of the captured track (e.g. excessive eye blinks, movement of the head, etc.). As such, data from 55 (31 Female) participants were used for analysis. Participants ranged in age from 18 to 72 (M = 36.6, SD = 14.3). Table 1 presents the participant characteristics in terms of ethnicity, household income, education level, and weight status. For the purpose of statistical analyses, educational level was grouped into two categories, those that had completed a high school degree (or more) and those that had not. Similarly, income level was Table 1. Participant Characteristics. Characteristic
Number of
Percent
Ethnicity White/Caucasian
23
41.8%
Black/African American
15
27.3%
Hispanic
2
3.6%
Asian
14
25.5%
Did not report
1
1.8%
To See or Not to See: Do Front of Pack Nutrition Labels Affect Attention to Overall Nutrition Information? Laura Bix1*, Raghav Prashant Sundar1, Nora M. Bello2, Chad Peltier3, Lorraine J. Weatherspoon4, Mark W. Becker3 1 School of Packaging, Michigan State University East Lansing, MI, United States of America, 2 Department of Statistics, Kansas State University Manhattan, KS, United States of America, 3 Psychology Cognition and Cognitive Neurosciences Group, Michigan State University East Lansing, MI, United States of America, 4 Department of Food Science and Human Nutrition, Michigan State University East Lansing, MI, United States of America * [email protected]
Abstract OPEN ACCESS Citation: Bix L, Sundar RP, Bello NM, Peltier C, Weatherspoon LJ, Becker MW (2015) To See or Not to See: Do Front of Pack Nutrition Labels Affect Attention to Overall Nutrition Information? PLoS ONE 10(10): e0139732. doi:10.1371/journal.pone.0139732 Editor: Anderson de Souza Sant'Ana, University of Campinas, BRAZIL
Background Front of pack (FOP) nutrition labels are concise labels located on the front of food packages that provide truncated nutrition information. These labels are rapidly gaining prominence worldwide, presumably because they attract attention and their simplified formats enable rapid comparisons of nutritional value.
Received: July 22, 2015
Methods
Accepted: September 15, 2015
Eye tracking was conducted as US consumers interacted with actual packages with and without FOP labels to (1) assess if the presence of an FOP label increases attention to nutrition information when viewers are not specifically tasked with nutrition-related goals; and (2) study the effect of FOP presence on consumer use of more comprehensive, traditional nutrition information presented in the Nutritional Facts Panel (NFP), a mandatory label for most packaged foods in the US.
Published: October 21, 2015 Copyright: © 2015 Bix et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: All relevant data are within the paper and its Supporting Information files. Funding: The project described was supported by Award Number R21CA155818 from the National Cancer Institute. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Cancer Institute or the National Institutes of Health. Further, Laura Bix, one of the coauthors, has salary support through the Hatch Act (USDA) as a Michigan Ag Bio Station researcher.
Results Our results indicate that colored FOP labels enhanced the probability that any nutrition information was attended, and resulted in faster detection and longer viewing of nutrition information. However, for cereal packages, these benefits were at the expense of attention to the more comprehensive NFP. Our results are consistent with a potential short cut effect of FOP labels, such that if an FOP was present, participants spent less time attending the more comprehensive NFP. For crackers, FOP labels increased time spent attending to nutrition information, but we found no evidence that their presence reduced the time spent on the nutrition information in the NFP.
PLOS ONE | DOI:10.1371/journal.pone.0139732 October 21, 2015
1 / 20
Do FOPs Impact Attention to Nutrition Information?
Competing Interests: Dr. Bix has had previous funding from large food companies, including Kraft Foods and Nestle. These companies were not involved in any aspect of this study, and the previous funding does not alter the authors' adherence to PLOS ONE policies on sharing data and materials. Abbreviations: AOI, Area of Interest; BMI, Body Mass Index; CDC, US Centers for Disease Control and Prevention; EFNEP, Expanded Food and Nutrition Education Program; FFQ, Food Frequency Questionnaire; FOP, Front of Pack Nutrition Labeling; MSUE, Michigan State University Extension; NFP, US Nutrition Facts Panel; SNAP, Supplemental Nutrition Assistance Program; FDA, US Food and Drug Administration; US, United States; WIC, Women Infants and Children.
Conclusions The finding that FOP labels increased attention to overall nutrition information by people who did not have an explicit nutritional goal suggests that these labels may have an advantage in conveying nutrition information to a wide segment of the population. However, for some food types this benefit may come with a short-cut effect; that is, decreased attention to more comprehensive nutrition information. These results have implications for policy and warrant further research into the mechanisms by which FOP labels impact use of nutrition information by consumers for different foods.
Introduction Given growing rates of obesity and associated increases in health costs, morbidity and mortality [1–4], numerous governments world-wide have expressed an interest in reducing obesity rates. As part of this effort, Front of Pack (FOP) nutrition labels are becoming prominent internationally [5]. These labels take varied forms, ranging from symbols that provide a global synopsis of a product’s overall healthfulness in summative fashion to those which include explicit details regarding key components commonly associated with health risks when consumed in excess (e.g. saturated fat, fat, sugar and salt). Increasingly, explicit labels are also overlaid with qualitative assessments relating to the specific components highlighted (e.g. a traffic light system, in which red stands for “eat sparingly”, amber for “eat in moderation” and green for “eat up”). In response to the increased use of FOP labels, and governmental calls for research investigating their effectiveness (Nathan, Lichtenstein, Yaktine, & Wartella, 2011; Office of Foods, Center for Food Safety and Applied Nutrition, Center for Veterinary Medicine, & Office of Regulatory Affairs, 2012; White House Task Force on Childhood Obesity, 2010), there has been a great deal of recent research on FOP labeling. In this study we fill two critical gaps in the existing literature. • First, we directly measure how FOP labels impact attention among participants not engaged in a nutrition-related task. • Second, we investigate how the presence of an FOP impacts attention to existing, more comprehensive, nutrition information (i.e., the Nutrition Facts Panel (NFP) in the US). To do so, we employ a novel method that allows high-resolution eye tracking while people interact with commercial quality packages.
Background Hodgkins et al. developed a system to classify FOP labeling as: directive, non-directive and semi-directive, and defined “directiveness” as the degree to which the labeling provides guidance about a food’s overall healthfulness [6]. ‘Non-directive’ labels simply offer a listing of nutrients and leave the burden of making the actual healthfulness interpretation to the consumer. Monochrome systems like the %GDA label in the EU and the Facts-up-Front program (also known as Nutrition Keys) [7], as well as the traditional Nutrition Facts Panel (NFP) in the US, are examples of non-directive labeling (Fig 1A). When overlaid with symbols or other qualitative assessments such as color, non-directive labels become ‘semi-directive’, offering a listing of key components while also providing a color-coded interpretation of the healthfulness of each relative to reference amounts (Fig 1B). Finally, simple icons, like the Choices Icon
PLOS ONE | DOI:10.1371/journal.pone.0139732 October 21, 2015
2 / 20
Do FOPs Impact Attention to Nutrition Information?
Fig 1. (1A) Examples of Non-Directive labels (1B) Examples of Semi- directive FOPs (1C) Examples of Directive FOPs. doi:10.1371/journal.pone.0139732.g001
in the Netherlands [8], the Nordic Keyhole-utilized in Norway, Sweden and Denmark [9], and the now defunct Smart Choices label in the US [10] are examples of ‘directive’ labels, those which summarize and directly call out the overall healthfulness of a product in summative fashion (Fig 1C). Regardless of the approach taken (directive, semi-directive or non-directive), the rationale behind FOP labels is that presenting information regarding nutritional aspects of the product in a conspicuous and easy to understand manner will empower people to make healthier choices [11–14]. Most of the research investigating FOP labels focuses on the consumer’s ability to comprehend and use labels of various designs (for review see Vyth et al., 2012). With this focus, many studies have given people nutrition-relevant tasks and evaluated how well they perform the task which requires nutrition labeling, generally during trials which employ varied label designs. For instance, Borg & Westernhoefer (2009) asked people to select the healthy option in a two-alternative forced-choice scheme using packaging designs that included directive, semi directive and non directive methods of labeling. Researchers found that participants performed the selection task better with a color-coded FOP label, a type of semi-directive label. This finding was replicated by Australian researchers, who found that participants were five times more likely to correctly identify a food as healthy when food products were labeled with a traffic light FOP label (i.e. semi-directive) as compared with those which were monochromatic (i.e. non-directive) [15]. In general, it seems that color-coded FOPs, like the multiple traffic light design, are effective when people are asked to identify healthy foods (see Hawley et al 2013 for review). While this approach is important for identifying labels that are effective for people who have the goal of recognizing healthy food products, published research provides little information about a label’s impact on individuals who might not have an explicit nutrition-related goal. From an information-processing prospective, the existing literature focuses on a relatively late
PLOS ONE | DOI:10.1371/journal.pone.0139732 October 21, 2015
3 / 20
Do FOPs Impact Attention to Nutrition Information?
process, namely comprehension, by-passing the earlier stage of attentional selection. Bypassing the attentional interaction ignores the fact that one of the reasons to place nutritional information on the front of packs is to make it readily accessible so that it garners more attention [16]. Further, a great deal of research suggests that information must be attended in order to be consciously perceived [17–20]. In short, if a label fails to garner attention, then the cognitive processing of the label will be derailed before comprehension even becomes an issue; that is, if the consumer does not see the information, information processing gets truncated before reaching the point of understanding. Recognizing this gap in knowledge, recent studies have sought to investigate how different types of nutrition labels impact attention. A number of these studies use visual search tasks to investigate attention to nutrition labels. Many employ the reaction time required to find a nutrition-relevant search target as the dependent variable [21, 22]. Others have tracked eye movements while participants were given explicit, nutrition-relevant goals like identifying whether a product had low or high sodium content, or making a health judgment about a product [23–28]. These visual search paradigms generally support the claim that semi-directive (specifically, color–coded) FOP labels are effective at attracting attention. However, in all these visual search paradigms the participants were given nutrition-relevant tasks, predisposing them to attend the relevant information. So, much like research on comprehension, these studies are unable to speak to the ability of labels to garner attention from people who do not have an explicit nutritional goal. Other researchers have eye tracked participants while explicitly manipulating participants’ goals in order to compare those with a nutrition-related goal to others with taste or purchaserelated motivations [21, 22, 29–32]. In general, these studies show that participants with a nutrition related goal spend more time attending to nutritional information and that formats akin to the Traffic Light FOP label garner attention particularly well among that population [21, 22]. What is missing from these studies is an assessment of whether FOP design impacts the attention of those participants that do not have an explicit goal related to nutrition. In other words, the results do not speak to the question of how effective FOPs are among the general population. It is still unclear which designs best garner attention among participants without a nutrition relevant task. The distinction between participants with and without a nutrition-related goal is an important one practically and theoretically. From the practical standpoint, a label that garners attention, even among participants who are not explicitly seeking nutritional information, is likely to impact a greater segment of the population. From a theoretical standpoint, the two scenarios (with and without a nutritional goal) tap different attentional systems. Two systems are generally regarded as governing attention: a bottom-up system and a top-down system [33]. These systems are associated with distinct neural pathways, and have different time courses. When information search is goal-driven, attention is driven in a top-down fashion toward goal-relevant stimuli; whereas in the absence of goals, attention wanders to the most visually salient stimuli [33]. As a result, it is unclear whether or not a label that works well under volitional (topdown conditions) will also perform well under involuntary bottom-up conditions. Evidence from a single eye tracking study that investigated attention to packages with varied FOP labeling strategies among participants who were not given a nutritional goal is available [34]. A mobile eye tracker was used to track people’s gaze during a mock shopping task by recording the duration of time that each person gazed at the entire package as well as the number of times that their gaze was directed to the same. Presence or absence of a directive FOP (health logo) was crossed with that of a semi-directive FOP (traffic light), forming four possible label treatments. Under the guise of a shopping scenario, participants were asked to make a single selection from each of three categories of food products (ready meals, sweets and fruit juices) while their eye movements were tracked. Researchers reported subjects spent a significantly
PLOS ONE | DOI:10.1371/journal.pone.0139732 October 21, 2015
4 / 20
Do FOPs Impact Attention to Nutrition Information?
longer time gazing at packages that contained a traffic light label compared to those that did not. However, the method only allowed the research team to make inference regarding eye movement with regard to the entire package. This raises the possibility that the FOP did attract attention to itself but whether or not the nutrition information was explicitly attended remains unclear. Interestingly, Koenugstorfer’s team noted that the presence of the semi-directive traffic light label interacted with the appearance of the directive design, a “Health Check Mark” designed to provide an overall evaluation of the healthfulness of the product, a directive design. When the Health Check appeared alone, people spent very little time viewing packages. But when the package displayed both a Health Check and the traffic light, people looked at the packages for significantly longer. This finding suggests that the traffic light was attended, altering the impact of the Health Check. The finding that the traffic light label may have altered the use of other nutritional information highlights a second gap in our knowledge. Specifically, that there is little data investigating how the presence of an FOP may impact attention to the more comprehensive information presented in the Nutritional Facts Panel (NFP). In our study, we employ a high-resolution eye tracking method that enabled us to isolate fixations on specific sections of the package to more precisely detect the attentional patterns when people without explicit, nutrition-related goals interacted with actual packages with and without FOP labels. This is important, because it has been suggested that the FOP could act either as a prime or shortcut for the more comprehensive, required nutritional information contained within the NFP. Determining whether the FOP primes or substitutes more complete nutrition information is an important area of inquiry for two reasons. Koenugstorfer’s work [34] supports the idea that the presence of different types of nutrition labels can influence the attention devoted to others. Additionally, it has been argued that an over-reliance on the limited nutrition information in an FOP may reduce a consumers’ ability to decide what is most appropriate for him/her based on individual needs [35, 36] (i.e. consumers should access the comprehensive information to make truly informed decisions regarding appropriate dietary choices). Our experiment allowed us to objectively investigate what portions of each package participants (not tasked with a nutrition-related task) viewed.
Objectives Using an Applied Science Laboratories 501 bright pupil, head mounted eye tracker (ASL Boston, MA), we tracked the gaze position of 55 participants as they interacted with novel cereal and cracker packages created for this research in order to: 1. Determine whether the presence of an FOP increased attention to nutrition information in participants that were not specifically charged with a task that required nutrition information. 2. Study the interplay between FOP labels and existing, comprehensive nutrition information (i.e. the NFP) to address whether the FOP is used in lieu of the NFP or primes nutritional information, making people more likely to use the NFP.
Materials and Methods Participants This study was approved under IRB 10–459 by the Social Science/Behavioral and Education Institutional Review Board (SIRB) at Michigan State University. Participant eligibility required: 18 years or older, not legally blind, and hard contact non-user (can interfere with the eye tracking device). Written consent was provided by all subjects and data was recorded by subject number.
PLOS ONE | DOI:10.1371/journal.pone.0139732 October 21, 2015
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Do FOPs Impact Attention to Nutrition Information?
To obtain a diverse sample that represented at-risk participants, we recruited adult participants from Michigan State University (MSU) campus list serves and extension programs housed at the Ingham County Health Department. The programs that helped us recruit participants from at-risk communities included: the Women Infants and Children (WIC) program, the Supplemental Nutrition Assistance Program (SNAP) and the Expanded Food and Nutrition Education Program (EFNEP) with the assistance of MSU Extension (MSUE). These are government supported programs that assist people with limited resources in acquiring the: food, knowledge, skills, attitudes and behaviors necessary for nutritionally sound diets We recruited a total of 74 participants, 12 of whom were not included in the study due to technical difficulties with the instrument calibration process, and hence their eye movements could not be tracked. Data collected from an additional seven subjects were excluded from analysis due to poor quality of the captured track (e.g. excessive eye blinks, movement of the head, etc.). As such, data from 55 (31 Female) participants were used for analysis. Participants ranged in age from 18 to 72 (M = 36.6, SD = 14.3). Table 1 presents the participant characteristics in terms of ethnicity, household income, education level, and weight status. For the purpose of statistical analyses, educational level was grouped into two categories, those that had completed a high school degree (or more) and those that had not. Similarly, income level was Table 1. Participant Characteristics. Characteristic
Number of
Percent
Ethnicity White/Caucasian
23
41.8%
Black/African American
15
27.3%
Hispanic
2
3.6%
Asian
14
25.5%
Did not report
1
1.8%
