Name: psychophysical tracking method to measure taste preferences in children and adults
Uploaded: 2016-07-16T13:00:00
Description: Watch this Scientific Journal Video about Psychophysical Tracking Method to Measure Taste Preferences in Children and Adults at JoVE.com

This work was supported by the National Institute of Deafness and Other Communication Disorders (NIDCD), National Institutes of Health (NIH) [grant number R01 DC011287] and NIH postdoctoral training grant (T32-DC00014). The content is solely the responsibility of the authors and does not necessarily represent the official views of NIDCD or NIH. The funding agencies had no role in the design and conduct of the study; in the collection, analysis, and interpretation of the data; or in the preparation or contents of the manuscript.

This method has been approved by the Office of Regulatory Affairs at the University of Pennsylvania. For the research studies described herein, informed consent was obtained from each adult and informed assent from each child seven years of age or older.
1. General Considerations
<ol>
	<li>Conduct the preference test in a comfortable, private room that ideally has a sink for subjects to expectorate solutions during testing. If a sink is not available, give subjects a cup into which to expectorate.</li>
</ol>
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<ol>
	<li>Desor, J. A., Maller, O., Turner, R. E., Weiffenbach, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Preference for sweet in humans: infants, children and adults. In Taste and development: the genesis of sweet preference. , 161-172 (1977).</li><li>Mennella, J. A., Swaiman, K. F., Ashwall, S., Ferriero, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Taste+and+smell.">Taste and smell.</a> Pediatric Neurology: Principles and Practice. , 135-149 (2006).</li><li>Birch, L. L., Anzman-Frasca, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Learning+to+prefer+the+familiar+in+obesogenic+environments.">Learning to prefer the familiar in obesogenic environments.</a> Nestle Nutr Workshop Ser Pediatr Program. 68, 187-196 (2011).</li><li>Drewnowski, A., Rehm, C. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Consumption+of+added+sugars+among+US+children+and+adults+by+food+purchase+location+and+food+source.">Consumption of added sugars among US children and adults by food purchase location and food source.</a> Am J Clin Nutr. 100 (3), 901-907 (2014).</li><li>Department of Agriculture and U.S. Department of Health and Human Services. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Dietary Guidelines for Americans, 2010. 7th edn. , (2010).</li><li>Chambers, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Commentary:+conducting+sensory+research+in+children.">Commentary: conducting sensory research in children.</a> J Sens Stud. 20 (1), 90-92 (2005).</li><li>Laing, D. G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tests+for+screening+olfactory+and+gustatory+function+in+school-age+children.">Tests for screening olfactory and gustatory function in school-age children.</a> Otolaryngol Head Neck Surg. 139 (1), 74-82 (2008).</li><li>Mennella, J. A., Beauchamp, G. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optimizing+oral+medications+for+children.">Optimizing oral medications for children.</a> Clin Ther. 30 (11), 2120-2132 (2008).</li><li>Chen, A. W., Resurreccion, A. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Age+appropriate+hedonic+scales+to+measure+food+preferences+of+young+children.">Age appropriate hedonic scales to measure food preferences of young children.</a> J Sens Stud. 11 (2), 141-163 (1996).</li><li>Li, X. E., Lopetcharat, K., Drake, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Parents'+and+children's+acceptance+of+skim+chocolate+milks+sweetened+by+monk+fruit+and+stevia+leaf+extracts.">Parents' and children's acceptance of skim chocolate milks sweetened by monk fruit and stevia leaf extracts.</a> J Food Sci. 80 (5), 1083-1092 (2015).</li><li>Guinard, J. X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sensory+and+consumer+testing+with+children.">Sensory and consumer testing with children.</a> Trends Food Sci Technol. 11 (8), 273-283 (2000).</li><li>Popper, R., Kroll, J. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Conducting+sensory+research+with+children.">Conducting sensory research with children.</a> J Sens Stud. 20 (1), 75-87 (2005).</li><li>Leon, F., Couronne, T., Marcuz, M. C., Koster, E. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Measuring+food+liking+in+children:+a+comparison+on+non+verbal+methods.">Measuring food liking in children: a comparison on non verbal methods.</a> Food Qual Prefer. 10 (2), 93-100 (1999).</li><li>Mennella, J. A., Lukasewycz, L. D., Griffith, J. W., Beauchamp, G. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evaluation+of+the+Monell+forced-choice,+paired-comparison+tracking+procedure+for+determining+sweet+taste+preferences+across+the+lifespan.">Evaluation of the Monell forced-choice, paired-comparison tracking procedure for determining sweet taste preferences across the lifespan.</a> Chem Senses. 36 (4), 345-355 (2011).</li><li>Coldwell, S. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gustation+assessment+using+the+NIH+Toolbox.">Gustation assessment using the NIH Toolbox.</a> Neurology. 80 (11), 20-24 (2013).</li><li>Beauchamp, G. K., Cowart, B. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preference+for+high+salt+concentrations+among+children.">Preference for high salt concentrations among children.</a> Dev Psychol. 26 (4), 539-545 (1990).</li><li>Cowart, B. J., Beauchamp, G. K., McBride, R., MacFie, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Early+development+of+taste+perception.">Early development of taste perception.</a> Psychological Basis of Sensory Evaluation. , 1-17 (1990).</li><li>Mennella, J. A., Pepino, M. Y., Reed, D. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genetic+and+environmental+determinants+of+bitter+perception+and+sweet+preferences.">Genetic and environmental determinants of bitter perception and sweet preferences.</a> Pediatrics. 115 (2), 216-222 (2005).</li><li>Mennella, J. A., Pepino, M. Y., Lehmann-Castor, S. M., Yourshaw, L. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sweet+preferences+and+analgesia+during+childhood:+effects+of+family+history+of+alcoholism+and+depression.">Sweet preferences and analgesia during childhood: effects of family history of alcoholism and depression.</a> Addiction. 105 (4), 666-675 (2010).</li><li>Mennella, J. A., Finkbeiner, S., Lipchock, S. V., Hwang, L. D., Reed, D. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preferences+for+salty+and+sweet+tastes+are+elevated+and+related+to+each+other+during+childhood.">Preferences for salty and sweet tastes are elevated and related to each other during childhood.</a> PLoS One. 9 (3), e92201 (2014).</li><li>Kim, J. Y., Prescott, J., Kim, K. O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Patterns+of+sweet+liking+in+sucrose+solutions+and+beverages.">Patterns of sweet liking in sucrose solutions and beverages.</a> Food Qual Prefer. 36, 96-103 (2014).</li><li>Pepino, M. Y., Mennella, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Factors+contributing+to+individual+differences+in+sucrose+preference.">Factors contributing to individual differences in sucrose preference.</a> Chem Senses. 30, 319-320 (2005).</li><li>Mennella, J. A., Finkbeiner, S., Reed, D. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+proof+is+in+the+pudding:+children+prefer+lower+fat+but+higher+sugar+than+do+mothers.">The proof is in the pudding: children prefer lower fat but higher sugar than do mothers.</a> Int J Obes (Lond). 36 (10), 1285-1291 (2012).</li><li>Pepino, M. Y., Mennella, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+cigarette+smoking+and+family+history+of+alcoholism+on+sweet+taste+perception+and+food+cravings+in+women.">Effects of cigarette smoking and family history of alcoholism on sweet taste perception and food cravings in women.</a> Alcohol Clin Exp Res. 31 (11), 1891-1899 (2007).</li><li>Schmidt, H. J., Beauchamp, G. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Adult-like+odor+preferences+and+aversions+in+three-year-old+children.">Adult-like odor preferences and aversions in three-year-old children.</a> Child Dev. 59 (4), 1136-1143 (1988).</li><li>Temple, E. C., Hutchinson, I., Laing, D. G., Jinks, A. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Taste+development:+differential+growth+rates+of+tongue+regions+in+humans.">Taste development: differential growth rates of tongue regions in humans.</a> Brain Res Dev Brain Res. 135 (1-2), 65-70 (2002).</li><li>Mennella, J. A., Bobowski, N. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+sweetness+and+bitterness+of+childhood:+Insights+from+basic+research+on+taste+preferences.">The sweetness and bitterness of childhood: Insights from basic research on taste preferences.</a> Physiol Behav. , (2015).</li><li>Bertino, M., Beauchamp, G. 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The Monell two-series, forced-choice, paired-comparison tracking technique detailed here has been consistently used to determine sweet taste preference among nearly 2,000 racially and ethnically diverse subjects as young as 5 years of age. The preference test, which for children is embedded within the context of a game, is sensitive to the cognitive limitations of children and is a much-needed method to fill the gap in age-appropriate psychophysical research methods for pediatric populations. If completed as described, w...

The sense of taste controls one of the most important decisions we make: whether to eat something or not. From birth, humans show a strong liking for sweet taste1-it attracts the newborn to mother&#39;s milk and signals the presence of calories from nutrient-dense foods (e.g., fruits)2. Although this inborn trait confers an advantage for survival in an environment of scarcity, an individual&#39;s liking for sweet coupled with a food environment that supplies sugar in abundance has resulted in overconsumption of sweetened foods3. Current estimates suggest that 13.1-17.5% of children&#39;s and 11.2-14.5% of adults&#39; total energy intake is derived from added sugars4; in both cases, levels are well above national and international dietary recommendations5,6.
Despite the importance of taste in determining food choice and intake, and the association between diet and health, methodologies to accurately assess taste hedonics are limited, particularly for use with pediatric populations7-9. One of the methods most commonly used with children is hedonic category scaling10-12, which involves choosing a response from a series of discrete alternatives that signify increasing preference. These alternatives are often depicted with smiley faces10 or with verbal descriptors ranging from &#34;super bad&#34; to &#34;super good&#34;13, and are useful for determining whether a child likes the taste of a stimulus or not. Ranking procedures, in which a subject is required to order several choices by how well they are liked (e.g., from most to least liked), are also frequently used and are intended to convey information on relative liking of stimuli13,14. Although both methods provide valuable information on two separate dimensions of hedonic response, neither directly assesses taste preference, specifically the concentration of a stimulus perceived to be of optimal palatability. The method described herein was specifically developed to determine an individual&#39;s most preferred level of a tastant through direct comparisons of pairs of stimuli of varying concentrations, bypassing the need to infer preference from ratings of stimuli evaluated individually in a sequential monadic manner, as is often practiced in psychophysical testing.
Here, we detail the protocol for the Monell two-series, forced-choice, paired-comparison tracking technique for determining sweet taste preferences15,16. The method was first developed for measuring salt preference17,18. It was later modified for measuring sucrose preference19,20, tested for measures of both reliability and validity15, and selected for the National Institutes of Health Toolbox Assessment for Neurological and Behavioral Function as the method of choice to assess children&#39;s sweet taste preference for clinical, epidemiological, and longitudinal studies16. The method, which typically takes no more than 15 min to complete, has been used to measure the most preferred level of sucrose among hundreds of children, adolescents, and adults15,19-25. In a study of 949 subjects, only 5% of the 356 children tested were unable to complete both series of the sweet preference test due to unfocused behavior or failure to understand the task15, highlighting the appropriateness of the method for pediatric populations.
In brief, following a 1-hr fast, consenting subjects are presented with pairs of sucrose solutions of varying concentrations (3-36%) in a two-series test, with the lower concentration presented in the first position in each pair in the first series. Subjects taste the pair of solutions and are instructed to point to the solution they prefer. Subsequent pairs of solutions are presented based on the subject&#39;s preferred concentration in the previous pair. The test continues until the subject selects the same sucrose concentration twice relative to both a lower and a higher concentration, or until the subject selects the lowest (3%) or highest (36%) concentration twice consecutively. The protocol is then repeated in reverse order, with higher concentrations presented in the first position in each pair. On average, the method requires 7 presentations of solution pairs16.
The described method is particularly effective for use with children because it accounts for several methodological concerns often overlooked in other psychophysical tests: (1) the method is short in duration and does not require a sustained attention span; (2) the two-series protocol in which solution concentrations are counterbalanced between the series controls for position bias; (3) the forced-choice procedure circumvents children&#39;s inclination to answer questions in the affirmative26; (4) use of a whole-mouth instead of a regional-tasting protocol accounts for age-related differences in the growth and size of the tongue27; and (5) instructing children to point to their most preferred concentration of sucrose addresses potential cognitive limitations by eliminating the need for a verbal response19.
Since its development, the Monell two-series, forced-choice, paired-comparison tracking technique has revealed consistent differences in sweet taste preference as a function of age15,28 , race/ethnicity15,23, taste receptor genotype19,24, family history of alcoholism20,25, and depressive symptomatology among pediatric populations20. In addition, sweet taste preference as measured by this method is associated with preference for sugar in foods and beverages15,19,21,22, providing evidence of criterion-related validity and a measure of insight into the association between an individual&#39;s sweet preference and their dietary sugar intake.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Sucrose</td>
			<td>Spectrum Chemical Mfg Corp</td>
			<td>SU103</td>
			<td></td>
		</tr>
		<tr>
			<td>Distilled water</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Corning Pyrex 1000 ml Class A Volumetric Flask</td>
			<td>Spectrum Chemical Mfg Corp</td>
			<td>988-24433</td>
			<td></td>
		</tr>
		<tr>
			<td>Boston Round 1000 ml Amber Glass Bottle</td>
			<td>Spectrum Chemical Mfg Corp</td>
			<td>842-17040</td>
			<td></td>
		</tr>
		<tr>
			<td>Boston Round 125 ml Amber Glass Bottle</td>
			<td>Spectrum Chemical Mfg Corp</td>
			<td>842-17031</td>
			<td></td>
		</tr>
		<tr>
			<td>Heathrow Scientific Multi-Function Stopwatch</td>
			<td>Spectrum Chemical Mfg Corp</td>
			<td>140-75046</td>
			<td></td>
		</tr>
		<tr>
			<td>McKesson Medi-Pack Medicine Cups</td>
			<td>Amazon</td>
			<td>46941200</td>
			<td></td>
		</tr>
		<tr>
			<td>Solo drinking cups</td>
			<td>Amazon</td>
			<td>SCCP16RLR</td>
			<td></td>
		</tr>
	</tbody>
</table>

psychophysical tracking method to measure taste preferences in children and adults

The Monell two-series, forced-choice, paired-comparison tracking method provides a reliable measure of sweet taste preferences from childhood to adulthood. The method, which is identical for children, adolescents, and adults, is of short duration (&#60; 15 min), does not rely on sustained attention or place demands on memory (which would yield spurious age differences), and minimizes the impact of language development, making this method amenable to the cognitive limitations of pediatric populations. In this whole-mouth tasting method, subjects are asked to taste (without swallowing) pairs of solutions of different sucrose concentrations and to point to the solution they prefer. Each subsequent pair contains the participant&#39;s preceding preferred concentration and an adjacent stimulus concentration. The procedure continues until the subject chooses either a given concentration of sucrose when paired with both a higher and a lower concentration, or the highest or lowest concentration two consecutive times. Subjects are prevented from reaching response criteria on the basis of first or second position bias by the two-series design of the method, which counterbalances the order of solution presentation within each pair between the series (the weaker concentration is presented first in Series 1, second in Series 2). The geometric mean of the two sucrose concentrations chosen in Series 1 and 2 is an estimate of the participant&#39;s most preferred level of sucrose. Sucrose preference as determined with this laboratory-based measure has been shown to be associated with preference for sugars in foods and beverages and with taste receptor genotype, family history of alcoholism, and race/ethnicity, as well as depressive symptomatology among pediatric populations. The method has real-world relevance and has been applied to determine most preferred level of other tastes (e.g., salt), making it a valuable psychophysical tool.

Figure 2 contains the tracking grid results from one representative subject. This subject&#39;s most preferred level of sucrose, 4.2% w/v, was determined by calculating the geometric mean of the sucrose concentrations chosen in Series 1 (6% w/v) and Series 2 (3% w/v). In cases where the subject only completes one of the series, the geometric mean obviously cannot be calculated. Further analysis can focus on data obtained from Series 1 separately from Series 215...

Watch this Scientific Journal Video about Psychophysical Tracking Method to Measure Taste Preferences in Children and Adults at JoVE.com

Psychophysical Tracking Method to Measure Taste Preferences in Children and Adults

Sweet taste has powerful hedonic appeal among people of all ages, particularly children. Described herein is a reliable and valid method that can be used to determine the level of sweetness most preferred, making it a valuable psychophysical tool for scientists.

The Monell two-series, forced-choice, paired-comparison tracking method provides a reliable measure of sweet taste preferences from childhood to ...

The overall goal of this psychophysical method is to determine an individual's most preferred level of sweetness from childhood to adulthood. This method can help answer key questions on taste to determine what factors are related to taste preferences, including dietary intake, age, ethnicity and various measures of health. The main advantage of this technique is that it can be used in young children to directly determine if and how their preferences for taste are different from each other as well as older individuals.Demonstrating this procedure will be Dr.Nuala Bobowski, a post-doctoral fellow of my laboratory. Begin by obtaining one liter volumetric flasks, one liter amber glass bottles and 100 milliliter amber glass bottles for the preparation, storage and dispensing of five solutions. For testing, obtain the following materials:30 milliliter disposable medicine cups for solutions, drinking cups containing water for rinsing in between trials, a stopwatch to monitor inter-pair and inter-series intervals, distilled water for solution preparation and rinsing, and a cup for expectoration if a sink is not available.Then obtain a sheet of paper labeled with the numbers one and two, representing the order of tasting, and a tracking grid for recording data. Next, clean and sterilize all bottles in an autoclave. Label each bottle with the date and stimulus label A, B, C, D and E.According to this table, weigh the appropriate amount of sucrose to make solutions A through E.Make one solution at a time by placing the appropriate grams of sucrose in a one liter volumetric flask and fill to the line on the flask with distilled water.Mix to dissolve the sucrose. Then, once the sucrose is dissolved, transfer the solution to the appropriately labeled one liter amber glass bottle. Store each bottle with solution in the refrigerator at four degrees Celsius for a maximum of one week.Finally, construct a tracking grid to record subject data. Label each grid with a series number, either one or two, and the concentrations of the sucrose solutions. Include space to record the start and end times of each series as well as a column on each grid to record notes during the test.Prior to the testing day, instruct the subject to not eat or drink for at least one hour before testing. Two hours before testing, remove the solutions from the refrigerator, and transfer approximately 100 milliliters of each to the appropriately labeled 100 milliliter amber glass bottles. Then allow the solutions to equilibrate to room temperature.Next, seat the subject at a table in front of the sheet or paper labeled with the numbers one and two, and allow him or her to acclimate to the testing room and the tester for at least 10 minutes. Inform the subject that he or she is going to play a game with things to taste from two different cups. Inform the subject that he or she will have to taste what is inside the first cup, swish it around in his or her mouth without swallowing and spit out the solution when told to do so in the sink or cup.Then tell the subject that he or she will rinse his or her mouth with water, taste what is in the second cup in the same manner and ultimately point to which cup he or she liked better. Tell the subject that there are no right or wrong answers and that we simply want to know which of the pair tastes better. For series one, begin by placing two cups respectively containing five milliliters of solution B and five milliliters of solution D on a sheet of paper labeled with the numbers one and two in front of the subject.Place solution B directly on number one and present it to be tasted first. Then place solution D directly on number two and have the subject taste it second. Using the tracking grid, underline the concentration that is presented first, which is solution B.Next, instruct the subject to taste the solution in position one by swishing.After five seconds, instruct the subject to expectorate, rinse his or her mouth out with water and to expectorate again. Then instruct the subject to taste the solution in position two by swishing and to expectorate after five seconds. Ask the subject to point to the solution that he or she liked better.Circle the X on the tracking grid that corresponds to the subject's preferred concentration. Next, have the subject rinse his or her mouth twice with water and expectorate. Wait one minute before presenting the next pair of solutions.For the second comparison of solutions in series one, pair the preferred concentration from comparison one with the next-lowest concentration. For example, if the subject preferred solution D in the first pair, present the second pair consisting of solution D and the next-lowest concentration, solution C.Place solution C in position one and solution D in position two. Indicate which solutions are being presented by marking Xs on the grid and underline the X that corresponds to the solution presented in position one.Repeat this process until the subject chooses the same concentration twice consecutively when presented with both a lower and higher adjacent concentration or when the subject chooses either the lowest or highest concentration twice consecutively. Record each subject's preferred concentration from series one on the grid and wait three minutes before beginning series two. For series two, pour five milliliters of each of solutions B and D into disposable cups.Place solution D on number one and solution B on number two in front of the subject. Underline the concentration that is presented first on the grid, which is solution D.Instruct the subject to taste and expectorate the solutions in the same manner as done for series one. For the second comparison of solutions in series two, pair the preferred concentration from the first comparison with the next-highest concentration.For example, if the subject prefers solution D in the first pair, present the second pair consisting of solution D and the next-highest concentration, solution E.Place solution E in position one. Finally, record the subject's preferred concentration from series two by circling it on the grid. The determination of the participant's preferred level of sucrose was estimated by calculating the geometric mean of the final concentration chosen in each series.Here the geometric means from both series one and two are shown for data collected from 930 children, adolescents and adults. This figure illustrates that the most-preferred level of sucrose is significantly higher for children and adolescents than it is for adults. After watching this video, you should have a good understanding of how to conduct the Monell two-series forced-choice pair-comparison tracking method for determining sweet taste preferences throughout the lifespan.Thanks for watching, and good luck with your experiments.

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Visual problems that occur early in life can have major impact on a child's development. Without verbal communication and only based on observational ...

Assessing Working Memory in Children: The Comprehensive Assessment Battery for Children &#8211; Working Memory (CABC-WM)

The Comprehensive Assessment Battery for Children - Working Memory (CABC-WM) is a computer-based battery designed to assess different components of ...

An Electrophysiology Protocol to Measure Reward Anticipation and Processing in Children

We present a protocol designed to measure the neural correlates of reward in children. The protocol allows researchers to measure both reward anticipation ...

Elevated Plus Maze Test Combined with Video Tracking Software to Investigate the Anxiolytic Effect of Exogenous Ketogenic Supplements

The overall goal of this study is to describe the methodology of the elevated plus maze (EPM) test in combination with a video tracking software. The ...

Using the Visual World Paradigm to Study Sentence Comprehension in Mandarin-Speaking Children with Autism

Sentence comprehension relies on the ability to rapidly integrate different types of linguistic and non-linguistic information. However, there is ...

Comparing Eye-tracking Data of Children with High-functioning ASD, Comorbid ADHD, and of a Control Watching Social Videos

Children with autism spectrum disorders (ASD) are known to have sensory-perceptual processing deficits that weaken their abilities to attend and perceive ...

Using a Real-Time Locating System to Measure Walking Activity Associated with Wandering Behaviors Among Institutionalized Older Adults

A real-time locating system (RTLS) can be used to track the walking activity of institutionalized older adults in long-term care who are at risk for ...