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Description
There are several visual dimensions of food that can affect food intake, example portion size, color, and variety. This dissertation elucidates the effect of number of pieces of food on preference and amount of food consumed in humans and motivation for food in animals. Chapter 2 Experiment 1 showed that rats preferred and also ran faster for multiple pieces (30, 10 mg pellets) than an equicaloric, single piece of food (300 mg) showing that multiple pieces of food are more rewarding than a single piece. Chapter 2 Experiment 2 showed that rats preferred a 30-pellet food portion clustered together rather than scattered. Preference and motivation for clustered food pieces may be interpreted based on the optimal foraging theory that animals prefer foods that can maximize energy gain and minimize the risk of predation. Chapter 3 Experiment 1 showed that college students preferred and ate less of a multiple-piece than a single-piece portion and also ate less in a test meal following the multiple-piece than single-piece portion. Chapter 3 Experiment 2 replicated the results in Experiment 1 and used a bagel instead of chicken. Chapter 4 showed that college students given a five-piece chicken portion scattered on a plate ate less in a meal and in a subsequent test meal than those given the same portion clustered together. This is consistent with the hypothesis that multiple pieces of food may appear like more food because they take up a larger surface area than a single-piece portion. All together, these studies show that number and surface area occupied by food pieces are important visual cues determining food choice in animals and both food choice and intake in humans.
ContributorsBajaj, Devina (Author) / Phillips, Elizabeth D. (Thesis advisor) / Cohen, Adam (Committee member) / Johnston, Carol (Committee member) / Bimonte-Nelson, Heather A. (Committee member) / Arizona State University (Publisher)
Created2013
Description
The unpleasant bitter taste found in many nutritious vegetables may deter their consumption. While bitterness suppression by prototypical tastants is well-studied in the chemical and pharmacological fields, mechanisms to reduce the bitterness of foods such as vegetables remain to be elucidated. Here tastants representing the taste primaries of salty and sweet were investigated as potential bitterness suppressors of three types of Brassicaceae vegetables. The secondary aim of these studies was to determine whether the bitter masking agents were differentially effective for bitter-sensitive and bitter-insensitive individuals. In all experiments, participants rated vegetables plain and with the addition of tastants. In Experiments 1-3, sucrose and NNS suppressed the bitterness of broccoli, Brussels sprouts, and cauliflower, whereas NaCl did not. Varying concentrations of NaCl and sucrose were introduced in Experiment 4 to assess the dose-dependency of the effects. While sucrose was a robust bitterness suppressor, NaCl suppressed bitterness only for participants who perceived the plain Brussels sprouts as highly bitter. Experiment 5, through the implementation of a rigorous control condition, determined that some but not all of this effect can be accounted for by regression to the mean. Individual variability in taste perception as determined by sampling of aqueous bitter, salty, and sweet solutions did not influence the degree of suppression by NaCl or sucrose. Consumption of vegetables is deterred by their bitter taste. Utilizing tastants to mask bitterness, a technique that preserves endogenous nutrients, can circumvent this issue. Sucrose is a robust bitter suppressor whereas the efficacy of NaCl is dependent upon bitterness perception of the plain vegetables.
ContributorsWilkie, Lynn Melissa (Author) / Capaldi Phillips, Elizabeth D (Thesis advisor) / Cohen, Adam (Committee member) / Johnston, Carol (Committee member) / Sanabria, Federico (Committee member) / Arizona State University (Publisher)
Created2014
Description
The unpleasant bitter taste found in many nutritious vegetables may deter people from consuming a healthy diet. We investigated individual differences in taste perception and whether these differences influence the effectiveness of bitterness masking. To test whether phenylthiocarbamide (PTC) `supertasters' also taste salt and sugar with greater intensity, as suggested by Bartoshuk and colleagues (2004), we infused strips of paper with salt water or sugar water. The bitterness rating of the PTC strip had a significant positive linear relationship with ratings of both the intensity of sweet and salt, but the effect sizes were very low, suggesting that the PTC strip does not give a complete picture of tasting ability. Next we investigated whether various seasonings could mask the bitter taste of vegetables and whether this varied with tasting ability. We found that sugar decreased bitterness and lemon decreased liking for vegetables of varying degrees of bitterness. The results did not differ by ability to taste any of the flavors. Therefore, even though there are remarkable individual differences in taste perception, sugar can be used to improve the initial palatability of vegetables and increase their acceptance and consumption.
ContributorsWilkie, Lynn Melissa (Author) / Phillips, Elizabeth D. (Thesis advisor) / Cohen, Adam (Committee member) / Johnston, Carol (Committee member) / Arizona State University (Publisher)
Created2012
Description
In rehabilitation settings, activity limitation can be a significant barrier to recovery. This study sought to examine the effects of state and trait level benefit finding, positive affect, and catastrophizing on activity limitation among individuals with a physician-confirmed diagnosis of either Osteoarthritis (OA), Fibromyalgia (FM), or a dual diagnosis of OA/FM. Participants (106 OA, 53 FM, and 101 OA/FM) who had no diagnosed autoimmune disorder, a pain rating above 20 on a 0-100 scale, and no involvement in litigation regarding their condition were recruited in the Phoenix metropolitan area for inclusion in the current study. After initial questionnaires were completed, participants were trained to complete daily diaries on a laptop computer and instructed to do so a half an hour before bed each night for 30 days. In each diary, participants rated their average daily pain, benefit finding, positive affect, catastrophizing, and activity limitation. A single item, "I thought about some of the good things that have come from living with my pain" was used to examine the broader construct of benefit finding. It was hypothesized that state and trait level benefit finding would have a direct relation with activity limitation and a partially mediated relationship, through positive affect. Multilevel modeling with SAS PROC MIXED revealed that benefit finding was not directly related to activity limitation. Increases in benefit finding were associated, however, with decreases in activity limitation through a significant mediated relationship with positive affect. Individuals who benefit find had a higher level of positive affect which was associated with decreased activity limitation. A suppression effect involving pain and benefit finding at the trait level was also found. Pain appeared to increase the predictive validity of the relation of benefit finding to activity limitation. These findings have important implications for rehabilitation psychologists and should embolden clinicians to encourage patients to increase positive affect by employing active approach-oriented coping strategies like benefit finding to reduce activity limitation.
ContributorsKinderdietz, Jeffrey Scott (Author) / Zautra, Alex (Thesis advisor) / Davis, Mary (Committee member) / Barrera, Manuel (Committee member) / Okun, Morris (Committee member) / Arizona State University (Publisher)
Created2012
Description
A prior experiment by Li and colleagues found that when participants rated same sex faces in physical attractiveness, their self-reports of religiosity were higher in comparison to those that rated opposite sex faces. Could this be due to participants feeling their sexuality was threatened or misunderstood? In the current experiment, we attempted to replicate these findings and extend them by using a pseudo personality test that presented false feedback to participants. This feedback explained that their personalities were similar to homosexual or heterosexual people. Four hundred and fifty participants from Amazon Mturk were randomized into these conditions. We also measured homophobia, moral values, and the believability of the experiment. Results displayed no replication of the original findings. Men were more homophobic than women, while displaying lower moral values and religiosity. Those that self-reported being more homophobic also reported being more religious and moral. In conditions of sexual threat (homosexual personality, same sex faces) and sexual comfort (heterosexual personality, opposite sex faces), self-reports of moral values increased. Participants that reported believing the feedback displayed higher religiosity in both sexual threat and sexual comfort conditions. For a more concrete understanding of the relationship between religiosity, mating goals, and threats to sexuality, more research needs to be performed.
ContributorsHobaica, Steven Matthew (Author) / Cohen, Adam (Thesis director) / Knight, George (Committee member) / Neuberg, Steven (Committee member) / Barrett, The Honors College (Contributor) / School of International Letters and Cultures (Contributor) / Department of Psychology (Contributor) / College of Public Programs (Contributor)
Created2014-12
Description
Statistics are rising for adults who are overweight and/or obese, putting them at higher risk of developing serious health problems. Eating fewer portions of vegetable than the daily-recommended amounts contributes to this increase with. College students, being more susceptible to weight gain as they are transitioning from childhood to adulthood. Previous studies demonstrated that children ate more vegetables when repeatedly paired with a low-fat dip compared to when served plain. The current study examined whether this effect was also successful in college-aged subjects. A total of 148 (55 males, 91 females) college-aged students from an introductory psychology class at Arizona State University (Tempe, AZ) participated in the study. Subjects were randomly assigned to receive cauliflower or broccoli (raw) either served plain or with low-fat ranch dressing. Subjects showed a greater preference for and consumption of the vegetable plain that was previously given with dip than without dip. These findings suggest that serving vegetables with low-fat ranch dip two times can increase the liking and consumption of vegetables in college students.
ContributorsKim, Sophia L. (Author) / Phillips, Elizabeth Capaldi (Thesis director) / Bajaj, Devina (Committee member) / Cohen, Adam (Committee member) / Barrett, The Honors College (Contributor) / Harrington Bioengineering Program (Contributor)
Created2015-05
Description
The purpose of this study was to expand on existing parental socialization models of youth achievement motivation for engaging in physical activity. This study examined the extent to which youth affective reactions and expectancy-value beliefs mediated the relation between parental influence tactics and youth physical activity. More specifically, the direct and indirect effects of parents' positive, negative and sedentary-control tactics, the direct effect of parents' desire to change their child's physical activity, and the moderating role of the socio-emotional climate on the relation between parental influence tactics and child outcomes were investigated. Data were collected from 171 4th, 5th, 7th, 8th and 9th grade students and their parents. Pedometers were used to collect youth physical activity data and all participants completed questionnaires. Youth expectancy-value beliefs and negative affective reactions to parental influence tactics were both positively related to youth physical activity. Path analyses revealed that youth expectancy-value beliefs and negative affective reactions fully mediated the direct effects of positive and negative parental influence tactics on youth physical activity, respectively. Moreover, parents' desire to change their child's physical activity was negatively related to parent's use of positive influence tactics. Although several moderators were examined, none were statistically significant (lowest p >.05). The results suggest that additional explanatory power is gained by including a broader range of parental influence tactics and youth affective reactions in models of achievement motivation. The findings are in accord with prior recommendations made to parents with sedentary children.
ContributorsPugliese, John (Author) / Okun, Morris (Thesis advisor) / Tinsley, Barbara J (Thesis advisor) / Kulinna, Pamela (Committee member) / Knight, George (Committee member) / Arizona State University (Publisher)
Created2011
Description
Religion and the belief in supernatural agents have been assumed to play an important role in encouraging prosocial behavior. However, different studies conducted have shown a complex relation between religion and prosociality. For example, Darley & Batson (1973) found that religious people do not always help strangers. In the present study, Christian participants were primed with benevolent commandments attributed to either the Bible or past historical figures or secular, non-benevolent quotes (control). I then measured their willingness to help pick up envelopes dropped by either a Muslim (wearing a hijab) or non-Muslim confederate woman. The results show that subjects primed with Bible or presidential quotes about benevolence were more likely to be helpful to the Muslim confederate than those in the control group. Differences between the Bible and presidential condition were not significant. I conclude that an authority, whether it be a president or God, promoting benevolence can increase prosocial behaviors toward out-group members.
ContributorsMemon, Rabia (Author) / Cohen, Adam (Thesis director) / Knight, George (Committee member) / Okun, Morris (Committee member) / Barrett, The Honors College (Contributor) / College of Liberal Arts and Sciences (Contributor)
Created2012-12
Description
Social proof and mismatch of self-preference have been assumed to play an important role in the inference of value. They can be influential factors when it comes to decision-making in a mate-selection environment. In this thesis study, participants took an online survey in the form of a dating website. They answered a series of questions about the traits they would like to see in a potential mate. They were then presented with four potential mates and asked to rank them by their preferences. The results show that participants most preferred the potential mate with a high social proof and a low mismatch of self-preference and least preferred the potential mate with a low social proof and a high mismatch of self-preference. When comparing just social proof and mismatch of self-preference, there was not an interaction effect between the two. I conclude that even though social proof is a powerful influencing factor by itself, it did not have the power to trump the mismatch of self-preference.
ContributorsAkhter, Sumbal (Author) / Kwan, Virginia (Thesis director) / Knight, George (Committee member) / Cohen, Adam (Committee member) / Barrett, The Honors College (Contributor) / College of Liberal Arts and Sciences (Contributor)
Created2012-12
Description
The benefits of earning a college degree are clear, yet nearly half of first-time, full-time college students do not complete their degree within 6 years. Completing college is no simple task and students must regularly make decisions not to prefer the smaller, immediate rewards over the larger, future reward of graduation (i.e. temporal discounting). Recent research shows initial support that temporal discounting can be reduced by heightening future self-continuity. This thesis study pilot tested an ecological, scalable approach to increase future-self continuity by heightening three components, similarity, vividness and positivity, within the framework of social media. Participants completed measures of these components before and after simulating the creation of a social media profile for themselves 10 years after college graduation. A significant increase in perceived similarity to the future self from Time 1 to Time 2 was detected in a within-subjects test. The findings in this study are encouraging and may inform the development of interventions aimed at increasing future self-continuity in college students.
ContributorsSmyth, Heather Lynn (Author) / Kwan, Virginia S. Y. (Thesis director) / Presson, Clark (Committee member) / Okun, Morris (Committee member) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05