DOES DEPRIVATION AFFECT HUMAN S PERCEPTION OF SUBLIMINAL STIMULI? A Thesis Presented to the Faculty of California State University, Stanislaus

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1 DOES DEPRIVATION AFFECT HUMAN S PERCEPTION OF SUBLIMINAL STIMULI? A Thesis Presented to the Faculty of California State University, Stanislaus In Partial Fulfillment of the Requirements for the Degree of Master of Arts in Psychology By Agnieszka Dutkowska May 2018

2 CERTIFICATION OF APPROVAL DOES DEPRIVATION AFFECT HUMAN S PERCEPTION OF SUBLIMINAL STIMULI? by Agnieszka Dutkowska Signed Certification of Approval page is on file with the University Library Dr. William F. Potter Professor of Psychology Date Dr. Bruce Hesse Professor of Psychology Date Shannon Bianchi Lecturer of Psychology Date

3 2018 Agnieszka Dutkowska ALL RIGHTS RESERVED

4 TABLE OF CONTENTS PAGE List of Figures... vi Abstract... vii Does Deprivation Affect Human s Perception of Subliminal Stimuli?... 1 The Role of Motivation... 4 Thirst... 7 Subliminal Controversies... 8 Method Participants Settings Materials Design Procedure Interobserver Agreement Results Pretest Water Pretzels vs. Apple Conditions Reported Thirst Effect on Water Consumed (1-5 vs Admitted Thirst) Video Clips Pretzels vs. Apple Conditions Reported Thirst on Water Consumed (1-5 vs Admitted Thirst) Discussion Thirst Limitations Videos Limitations References iv

5 Appendices A. Study Consent Form B. Pilot Study Consent Form C. Picture of Water D. Questionnaire for Participant E. Questionnaire for Participant F. Questionnaire for Participant G. Questionnaire for Participant H. Pilot Study Participant Thank You Letter I. Study Participant Thank You Letter v

6 LIST OF FIGURES FIGURE PAGE 1. Water drunk after consumption Thirst after consumption Water drunk depending on participants thirst Videos scores depending on food condition Videos scores depending on participants thirst vi

7 ABSTRACT The aim of this research was to test whether manipulation of motivating operations had an impact on participants perception of subliminal stimuli. The research consisted of two days of investigation for each participant. The days differentiated from each other in consumption of food - salty pretzels and apples. Twenty-five psychology students took part in this study. After consumption, they were asked to watch two videos, where one consisted of an added subliminal message with a glass of water and the word WATER and the other video had blank subliminal message inserted. They assessed the videos and their subjective feeling of thirst. Results showed that participants motivation did not make an impact on perception of subliminal stimuli. vii

8 DOES DEPRIVATION AFFECT HUMAN S PERCEPTION OF SUBLIMINAL STIMULI? Subliminal stimuli are defined in most cases as those stimuli that are not strong enough to elicit a response (Klass, 1958). According to Klass (1958), this definition is not sufficient, so he incorporated the concept of the threshold. Threshold indicates that stimuli that do not affect the individual are said to be below the threshold of activating a response in that individual (Klass, 1958). For example, sometimes a smell is not intense enough to be detected but when it is more intense and the organism can detect it, it is said that the smell reached his threshold point (Klass, 1958). Undetected stimuli are known as subliminal. This means that subliminal stimuli actually exist but cannot be perceived by the organism. Another term that has been a basis for defining subliminal stimuli is conscious, subconscious and unconscious. Conscious, is defined as awareness (Klass, 1958). If individual reaches for a drink, because he or she feels thirsty, it is said that he/she is displaying a conscious act. On the other hand, subconscious is almost awareness. These are mental events that may impact organism s behavior later (Klass, 1958). It is seen in the following example: a man picks up his children from school every day. One day, children have gone to their grandmother s house, because there is a free day from school and even though Dad knows about it, he picks the road leading to school and finds himself going in the wrong direction. From a behavioral perspective, the man 1

9 2 was behaving in a way that would be normally be followed by reinforcement, but in this situation he was not paying attention, which resulted in going in the wrong direction. While unconscious can be named as a concept of human behavior, it is not possible to measure it or see it. The main difference between subconscious and unconscious is the fact that it is easy to recognize what occurred in the subconscious example, while it is hard to understand the unconscious controlled condition (Klass, 1958). Another term that should be considered while defining subliminal stimuli is perception. If a stimulus is complex, taking its shape, size, form, color and other characteristics into consideration, it is harder to perceive it in terms of speed and correctness in identifying it (Klass, 1958). Also, perception is facilitated when a particular stimulus is familiar to the organism (Klass, 1958). Moreover, stimuli that fit our expectations are perceived faster and more correctly than those that are different then it was thought they would be. Furthermore, the human body is programmed to detect things and perceive it differently when it needs it (such events are explained in terms of motivating operations, explained later on). For example someone who is hungry can find a carrot more delicious than he would if he was not hungry. Subliminal perception refers to any stimulus that is not perceived consciously however it still makes an impact on the individual (Treimer & Simonson, 1988). An example of such a stimulus can be a picture, flashed quickly, such that it is impossible to verbally label what that picture was. According to Merikle subliminal message is any stimulus that is perceived but has not been noticed (as cited in Egermann, Kopiez, & Reuter, 2006). Pratkanis and Greenwald outlined four different types of subliminal

10 3 stimuli (as cited in Aylesworth, Goodstein, & Kalra, 1999). First, subthreshold stimuli refer to energy levels, and more precisely, to their strength or weakness in being detected (flashing words quickly enough), what has been called transduction below awareness. The second type is called masked stimuli and these are those that are hidden within another stimulus. Next, unattended stimuli are known as messages that are embedded in the way that cannot be distinguished in accompanying stimulus (e.g. woman s naked body in a pear). And the last one, figurally transformed stimuli, are words or images that are modified in a way so one cannot easily recognize it (message recorded backwards in popular music; blurred writing). Subliminal stimulation can be auditory and visual (Egermann et al., 2006). Experimental psychology started to be interested in the field of unconscious perception already in the 18th century (Kosikova & Pilarik, 2012). The first studies were conducted in order to examine if subliminal perception existed. For example, in 1980 Kunst-Wilson and Zajonc tried to show the influence of subliminal perception on affective reactions using behavioral measures. They exposed participants to irregular geometric forms for 1 millisecond. Next, perception was determined in two different ways: forced choice of recognition (shows awareness of the stimulus) and forced choice of preference (shows unconscious perception) (as cited in Kosikova & Pilarik, 2012). In 1957, James Vicary claimed to have conducted a study that became one of the most famous experiments in the field of subliminal perception (as cited in Kosikova & Pilarik, 2012). According to Vicary, 45 thousand viewers were exposed to subliminal messages Drink Coca-Cola and Eat popcorn for 3 milliseconds,

11 while they were watching a film in the cinema, which he claimed resulted in 4 enhancement of the sales of popcorn by 57.7% and the sales of Coca-Cola by 18.1% in a 6-week period. The study turned out to be fake and in 1967, Vicary confessed that the experiment was fabricate. The Role of Motivation One important dimension of perceiving subliminal stimulus is motivation. In psychology, motivation has been usually understood as an internal construct that causes people to behave in certain way. Behavior analysts talk about motivation as Motivative Operations. Michael (1982, 1993; Laraway, Snycerski, Michael & Poling, 2003) originally used the term establishing operations in order to describe two effects that are characteristic for a behavioral account of motivation: the value altering and evocative effect. Because of two different directions of functioning of both motivative circumstances, Michael s usage of term establishing operations was not showing their properties sufficiently (Langthorne & McGill, 2009). This led to proposition to use motivating operation, instead of establishing operation (Laraway et al., 2003) As noted, Motivative operations (MO) have two effects: The value-altering effect and the behavior-altering effect (Laraway et al., 2003). The first one refers to different aspects of the effectiveness of a reinforcer or punisher- the reinforcerestablishing effect, the reinforcer-abolishing effect, the punisher-establishing effect and the punisher-abolishing effect. The behavior altering effect refers to whether or not a response is evoked and concerns general effects: the evocative and the abative effect. The evocative effect pertains to an increase in frequency of behavior while the

12 abative effect pertains to a decrease in the frequency of behavior. The behaviors 5 evoked are directly related to MO in effect for instance when one is food-deprived, the behavior that increases in frequency is likely to provide food. Motivative operations have been divided into two broad categories: unconditioned and conditioned. Unconditioned MOs (UMOs) are those that are regulated by evolution and history of species, for example deprivation of food or water. Lack of these stimuli establishes them as reinforcers and evokes behaviors that have been reinforced by these stimuli in the past. Satiation of stimuli produces abolishing effect on the reinforcing value of these stimuli and abates those behaviors that obtained those reinforcers. On the other hand, conditioned motivating operations (CMOs) are learned over the organism s lifetime. This means that a stimulus that was neutral at first, has been continuously preceded or paired with an unconditioned motivating operation, already established conditioned motivating operation or with specific reinforcement or punishment. There are three types of conditioned motivating operations that have been identified: surrogate CMOs, reflexive CMOs, and transitive CMOs. This research will not be concerned with all those MOs but only with the surrogate CMO (CMO-S). (CMO-S), is characterized with neutral event that has been associated with unconditioned motivating operation or another conditioned motivating operation and vary the reinforcing or punishing effect of other stimuli and also, has an impact on the possibility of associated behaviors (Langthorne & McGill, 2009).

13 An organism s behavior depends on many factors. Human behavior may be 6 influenced by sensory stimuli like sounds and smells or social stimuli like signs, gestures or verbal communication with others. Those stimuli that occur prior to operant behavior and alter this behavior are called antecedent stimuli. An antecedent stimulus causes a higher probability of occurrence or absence of given response when this stimulus is present. There are two types of controlling stimuli for operant behavior: discriminative stimuli (Sd) and extinction stimuli (S-delta). Discriminative stimuli signal the opportunity for reinforcement of an operant behavior, which means that the response is more likely to occur. On the other hand, an extinction stimulus signals that an operant behavior will not result in a reinforcer. The result is that a given response is less likely to occur. Summing up, stimulus control indicates the change of behavior that occurs because of presence of discriminative or extinction stimulus (Pierce & Cheney, 2008) Lotfizadeh, Edwards, Redner and Poling (2012) point out that an MO s behavioral effect can be interpreted as a simple direct consequence that has an impact on rate of responding if the level of the generalization gradient (but not the shape) is changed because of altering an MO. Nonetheless, if the shape and the level of the generalization are changed, the behavioral effect can be interpreted as an effect of the MO on rate of responding as well as on stimulus control. In the first case, stimuli that are alike to the Sd and the MO would both have an impact on the operant but their effect would not be connected to each other. In the second case, effects of the MO and effects of the Sd would be connected since the MO and Sd would interact

14 (Lotfizadeh et al., 2012). In 1965, Healey conducted a study where 12 hour and 23 7 hour food deprivation effects on generalization were examined. He trained 48 rats to run on the 24 in. runway on the end of which, there was a white square (79 cm 2 ) with a panel on the center. Rats were trained to open this panel in order to obtain the food. All training session were conducted using 400 Hz tone. In the training conditions, rats were divided into four groups of 12 rats, two after 12 hour of deprivation and two after 23 hour of deprivation. All four groups were exposed to 400 Hz tone and 200 Hz tone, but only two groups (one of each deprivation level) used the same white square with the panel from training sessions and the other two groups were tested with smaller, white square (32 cm 2 ). The researchers discovered that rats were running faster when the bigger square was used in the test conditions and when rats where under higher level of deprivation, while running speed was the lowest when rats were exposed to smaller square and when they were under lower level of deprivation. This study shows that the effects of an MO on stimulus control are enhanced under circumstances where compound Sds are involved. Results of this study cannot be appropriately defined by a conventional generalization gradient since a compound Sd controlled rats behavior: 400 Hz sound and 79 cm 2 square (as cited in Lotfizadeh et al., 2012). Thirst Igbokowe and Obika (2008) claimed that assessment of thirst and dryness of the mouth could only be measured using one s ability to distinguish this feeling and to report it. They also claimed that vetting such information might consist in examining

15 8 the amount of water drunk spontaneously by the participant. They conducted a study in order to examine the threshold for thirst perception using the visual analogue scale, on which participants were asked to mark the appropriate spot on the line, beginning from Not thirsty or Not dry extreme. The results showed that thirst perception and dryness of the mouth were similar between female and male group, which means that there were no significant difference between these two groups. They also concluded that the feeling of thirst is correlated with a dry mouth. Subliminal Controversies There are a lot of controversies when it comes to the public attitudes, regarding subliminal perception. In 1958, Haber tried to investigate public opinion about unconscious perception using a questionnaire. Over 320 individuals from San Francisco participated in the study. They were divided into groups according to their age, sex and education. Results showed that more than 50% of respondents had never heard about subliminal perception and those that did, tended to be younger and more educated men. Using subliminal messages was considered unethical by half of the individuals that heard about this concept and another half stated that it was ethical. More than 60% of all that had heard of it with 19% of those that had stated it was unethical, claimed that they would not stop watching TV, even though subliminal messages were being used. In 1983, Zanot, Pincus and Lamp discovered that 81% of 209 participants from the Washington D.C. area were aware of existence of subliminal messages in advertisement and they were convinced that subliminal advertising worked and was commonly used (as cited in Rogers & Smith, 1993).

16 9 Another study, conducted by Rogers and Smith in 1993, showed similar results. Four hundred households in Toledo (Ohio) were randomly selected, called and individuals were asked to answer a variety of questions, some about subliminal advertising. They reported that 74.3% of the participants had heard about subliminal advertising. They also concluded that people, who were more educated, tended to believe that subliminal messages worked. Many investigations have failed to show utility of using subliminal messages. Gable, Wilkens, Harris and Feinberg (1983) tried to find out whether sexual embeds in pictures were more preferred by participants than those without these embedded subliminal cues. Results showed that sexual symbols or words did not make an impact on participants choice of illustrations. Treimer and Simonson (1988) conducted a study where they examined whether weight loss program videos with subliminal messages would be more effective than those without any subliminal cues in actual weight loss. These researchers found that the videotape containing written and aural subliminal messages did not effectively produce weight loss, loss in percentage of body fat, or significant attitude changes in viewers, comparing to the video without subliminal messages. The current experiment was conducted in order to find out whether people are more vulnerable to the effects of subliminal water message while deprived of water rather than when they are satiated and not thirsty. This study is based on the assumption that MOs will have an impact on the effectiveness of subliminal messages. None of the previous studies tried to establish the effectiveness of

17 subliminal messages when deprivation was in effect. Because water deprivation 10 makes an organism seek water, it is hypothesized that in such a situation subliminal messages will work.

18 METHOD Participants Twenty-five students from a university in California were chosen for the study; twenty-one females and four males, ranging in age from 18 to 50 years. Students were found through Psychology Research Sign-Up System (SONA) or through advertisements. Participants were selected according to the following selection criteria: a) no food allergies b) no celiac disease or non-celiac gluten sensitivity c) no hypertension (high-blood pressure) d) no diabetes. Participants were not told about the purpose of the experiment. They were informed that it was examining the effects of different foods on preferences for advertisements (see appendix A). Moreover, another five students (three females and two males) from the same university were chosen for the pilot study to determine how quickly the pretzels induced thirst. The procedure was the same as for choosing participants for the study. The participants for the pilot study were also unaware of the main purpose of the experiment (see appendix B). All of the participants read and signed an informed consent form. Settings The research was conducted in two of the university s classrooms. In the first classroom, there were only one table and one chair. In the second classroom, participants sat down next to the desk with monitor and computer. Measurements 11

19 12 took place between 9 a.m. and 9 p.m., depending on participant s availability. Both individual s measures were taken during roughly the same period of the day and in the same room. Materials The standard computer display has refresh frequency of 60 Hz, thus the shortest possible time that a certain picture can be visible for is around 17 milliseconds. In order to shorten this time and display the subliminal messages as fast as it was possible, a 144 Hz refresh rate computer display was used and videos were prepared with 100 frames per second frame rate. This resulted in a10 milliseconds subliminal messages display. To assess the effect of thirst on the participant s perception of subliminal stimuli, a pair of videos was prepared; this pair consisted of two commercials. One video had an additional subliminal message, a glass of water and the word water and another video was prepared in the same way but instead of the subliminal cue (a glass of water with the word water ) a blank frame was inserted at the same time point in the video. Subliminal messages were inserted in 1 st, 29 th, 30 th and 31 st second of the clip. Besides the subliminal cue, there were no other differences between commercials in the pair. Those videos were an advertisement of a current product on the market: an LCD TV. The FFmpeg program was used to change the videos in order to place the subliminal stimuli into the advertisement (Bellard & Niedermayer, 2012). Twenty-five bags of salty pretzels 2 oz., one for each individual, were used in order to make participants thirsty and another five bags for the pretest. Moreover, 25 bottles of water 16.9 oz. (one for each individual) and 13

20 apples (one half for each individual) were prepared to induce water satiation in 13 another half of participants. Another 50 bottles of water 16.9 oz. were prepared in order to assess and compare participants thirst at the end of each procedure. Videos and thirst were assessed on two separate questionnaire based on 10 point Likert scale. (see appendix D and F) Design The design of the study was a repeated measures factorial design. The data were analyzed in an ANOVA to determine whether there was a statistically significant difference between rating scores of videos with subliminal message and nonsubliminal message based on whether participants were thirsty or not. It was hypothesized that participants would rate videos with subliminal water message higher when they were thirsty than when they were not thirsty. Procedure Before conducting the study, five participants chosen for the pretest were given a questionnaire based on 10 point Likert scale where they were asked to report on how thirsty they were, where 1 not at all and 10- very much. Reporting no more than fifth level of thirst was accepted in order to move to the next step which was consumption of a bag of salty pretzels and all of them passed. After consumption, participants were given the same questionnaire and asked to report every 5 minutes for a half an hour, on how thirsty they were, starting from rating their thirst right after consumption. The results of pretest were used in the study in order to determine the

21 14 amount of time participants would be asked to wait before assessing the videos. The average number of minutes that was needed to reach at least 6 was used in the experiment. In the result of the pretest, a one-minute period was established as needed for inducing thirst. The 25 participants were randomly assigned to one of two conditions. For 14 participants the first day consisted of getting a bag of salty food pretzels and the other 11 was given a half of an apple to eat and a bottle of water to drink. Participants were asked to come back for the second measurement around the same time as the first one had taken place (accepted deviation was 30 minutes) and during no longer period than 7 days. On the second session of the experiment each group was provided with the food they did not get in the first session. The other steps of the procedure were exactly the same. After being randomly assigned to a condition, participants were asked to leave their backpacks or bags and not touch it until the end of the experiment to eliminate the possibility that these participants accessed their own food or drink. Next, each participant was given the assigned food, then asked to eat it and wait in the first room. After the one-minute wait period, each participant was left in the second room alone after hearing the instructions how to play and assess the videos. Participants were asked to assess each video using the Likert type scale from 1 to 10 (where 1- I do not like it at all and 10 I like it very much). This step was followed by providing water to each participants and at the same time, giving them another questionnaire based on 10 point Likert scale, where they were asked to answer the question How thirsty do you feel now?, where 1 not at all and 10- very

22 much. At the end of each condition, the amount of water drunk by each participant was also measured. 15 Interobserver Agreement The interobserver agreement (IOA) was used for transcribing the Likert videos scores into the data analysis program. IOA was calculated by comparing the same data typed in by the experimenter and a second assistant. The agreement was 100%. Also, an IOA was calculated for water drinking recording; during 30% of sessions, two observers weighed out the remaining water after each participant finished drinking. An agreement was defined as the two measures being within + or 1 ounce. The IOA was calculated as agreements/(agreements + disagreements). Sixty-two percent of trials were observed and the total IOA was 100%.

23 RESULTS Overall, there was little difference between the thirsty group and the satiated group. The results of the experiment are as follows: Pretest Four participants reported that they were thirsty on at least level 6 right after the consumption of pretzels and one reported such thirst after five-minute period. The mean was taken out of their scores and in the result the videos in actual experiment were shown at least one minute after consumption. Water Pretzels vs. Apple Conditions The comparison of water consumption after what snack people ate shows significant difference between these two conditions; F(1,48)=18.93, p= and the average of water drunk after apple consumption was 0.5 oz. and the average of water drunk after pretzel consumption was 3.7 oz. 16

24 17 Also, the comparison of participants evaluation of their thirst on what snack they ate showed significant difference between the Apple and Pretzel conditions; F(1,48)=10.28, p= The mean Likert score of thirst after eating an apple was 4.4 and after eating pretzels amounts to 6.8. oz. pretzel apple number of participants Figure 1. Water drunk after consumption. Comparison of water drunk after consumption of an apple (left histogram) and pretzels (right histogram). apple thirst 10 pretzel number of 0 participants Figure 2. Thirst after consumption. Comparison of participants admitted thirst after consumption of an apple (left histogram) and pretzels (right histogram).

25 18 Reported Thirst Effect on Water Consumed (1-5 vs Admitted Thirst) Furthermore, results showed that participants tend to drink more when they assessed their thirst between 6 and 10 (M= 2.97 oz.) on the scale rather than participants that assessed their thirst from 1 to 5 (M= 1 oz.), F(1,48)=5.40, p=0.02. not thirsty oz. thirsty number of participants Figure 3. Water drunk depending on participants thirst. Comparison of water drunk between non-thirsty (left histogram) and thirsty (right histogram) participants. Video Clips Pretzels vs. Apple Conditions The comparison of how much participants liked the clips, so clips score across all thirst conditions, depending only on whether there was displayed a glass of water (M=7.28) or a white glimpse (M=7.12) as a subliminal message shows no significant difference between these two clips F(1,98)=0.14, p=0.7.

26 The participants ratings of the clip with the water subliminal message 19 depending on type of food that participants ate before assessing videos also showed no significant difference between F(1,48)=0.07, p=0.78. The mean Likert score of the water video after eating apples was 7.36 and after eating pretzels 7.2. Likewise, no significant difference was seen in the comparison of scores of a clip with the video clip containing a white frame depending on what food participants ate F(1,48)=0.06, p=0.79. The mean of the white video after consumption of an apple amounts to 7.2 and after consumption of pretzels Video score Apples Pretzels Food that participants ate Water Video White Video Figure 4. Videos scores depending on food condition. Comparison of mean scores of both, water (blue diamond) and white (red square) videos after eating apples and pretzels. The comparison of scores of both, white clip (M=7.2) and water clip (M=7.36) after eating pretzels shows no significant difference between these two video clips F(1,48)=0.08, p=0.77.

27 20 Similarly, no significant difference is identified between these two video clips after apple consumption F(1,48)=0.06, p=0.8, with means for the white clip M=7.04 and for the water clip M=7.2. There was also no difference between scores of the first (M=7.26) and the second video (M=7.14) clip that they saw during one measurement, regardless of the condition F(1,98)=0.08, p=0.77. Also, no significant difference is seen in scores of both videos comparing day one (M=7.4) and day two (M=7) of the study F(1,98)=0.93, p=0.3. Reported Thirst on Water Consumed (1-5 vs Admitted Thirst) When we only examined those participants who rated their thirst as low as 1-5 (21 measurements), we found that there was no significant difference between scores of videos with white glimpse (M=7.2) and water subliminal message (M=7) when participants stated that they were not thirsty; F(1,40)=0.10, p=0.75. Similarly, when we examined those participants who rated their thirst higher, between 6 and 10 (29 measurements), we found that no significant difference was reported between scores of videos with different subliminal message; F(1,56)=0.84, p=0.36. The mean score for water clip was 7.48 and for white clip Comparing the scores of participants who viewed the video with the white frames that were given by these participants that declared that they were not thirsty, so with 1-5 admitted thirst (M=7.23) and these that stated that they were thirsty, thus with 6-10 admitted thirst (M=7.03) shows no significant difference between these scores; F(1,48)=0.1, p=0.74.

28 21 Moreover, no significant difference is seen when comparing video ratings with water subliminal message between scores given by participants that were not thirsty (M=7) and these that were thirsty (M=7.48); F(1,48)=0.7, p=0.4. Video Score Not Thirsty Thirsty Water Video White Video Deprivation reported by participants Figure 5. Videos scores depending on participants thirst. Comparison of mean scores of both, water (blue diamond) and white (red square) videos when participants reported that they were thirsty or not.

29 DISCUSSION Thirst As expected, participants tended to drink more water after eating pretzels than after eating apples. What is also interesting is the fact that they also claimed to be more thirsty after eating pretzels. This result confirms Igbokwe s and Obika s (2008) position, that measurement and assessment of thirst can be done using one s reports about the feeling of thirst. Limitations In this experiment, participants were asked to drink water from 16.9 oz. water bottles, which were measured after the end of the experiment. Nine, full, unopened bottles were weighed and they varied between 18.3 and 18.4 oz., furthermore, eight, full, unopened bottles with the duct tape were weighed and their weigh varied between 18.3 and 18.5 oz. It is suggested that future researchers make sure to weigh each water dose prior to giving it to each participant for a more accurate measure. Videos Data seemed to be reliable since there was no difference in comparison of all scores between first and second video during one meeting, nor in comparison of all scores between the first and second day of measurements. The results of this research did not support the main hypothesis. There was 22

30 no difference between assessment of video with and without the water 23 subliminal message after eating neither pretzels nor apples. This leads to assumption that in this case, motivation did not make effect on perception of subliminal stimuli and the outcomes of the experiment support previous studies. Limitations This experiment was limited in a few ways and some changes may be implemented for further investigations. Only 25 students participated in the studythis may have been a huge limitation, therefore, a bigger sample is desirable. The generalization of presented results is limited since participants were only students and most of them (21 out of 25) were women. Examining more diverse group of people may show different results. Only one pair of videos was prepared, which also could have an impact on the lack of difference between scores of videos. An investigation with various conditions may be helpful in this case. Not only preparing and using larger set of commercials may be more effective but also using two different videos in one pair and having the same subliminal message in one pair. Compering more than two videos to each other may also result in different outcome. The commercial used for this experiment was colourful and dynamic. As stated above, subliminal messages were inserted in 1 st, 29 th, 30 th and 31 st second of the clip, since there were sudden changes of image and participants could not notice the subliminal message. Participants were not asked to report whether they had seen or not a subliminal message. This may be an important factor in the experiment,

31 showing whether subliminal messages were too brief or too long. Future studies 24 might incorporate this after they have their main measures. In this experiment the stimulus shown on the video was visual (written and graphic) but not audible it was a picture of a glass filled with water and the word WATER (see appendix C). Other researchers tried also different ways of inserting the subliminal cue, for example Gable et al., (1983) embedded word Sex in pictures, so they were visible for participants throughout the whole time while being exposed to the picture. The study failed to show that people tend to prefer pictures with embedded sexual cue than those without them. Treimer and Simonson (1988) wanted to test whether subliminal messages would make an impact on participants weight loss, for this purpose they used not only written but also audible subliminal cues and inserted them into weight loss program videos. The researchers did not find the differences in weight loss, loss in percentage of body fat, or attitude changes between participants that had used videotape with subliminal messages and participants that had used videotape without any subliminal messages. All these experiments used different types of subliminal cues and all of them failed to support their hypotheses. This leads to assumption that further researches may have to come up with different ways of inserting and matching subliminal cues and to examine their effectiveness. The subliminal message used in this study and the commercial were not assessed before conducting the experiment. It is hard to determine whether subliminal cue was strong enough to elicit desire for water. Also, the video should be neutral for

32 25 the participants, which was not assessed. The commercial could be too distracting or could elicit other, stronger feelings that could overlap the effect of subliminal message. None of the experiments mentioned above incorporate such assess in their experiments but this may be an important factor in subliminal investigations. Another factor to consider for modification for further investigations is examining different phenomenon, more precisely a behavior rather than subjective assessment of videos on scale from 1 to 10. Furthermore, if behavior is measured, the number of exposures to the subliminal message may also be taken into consideration. For example, to observe the change in shopping habits in the consumers exposed repeatedly to clips with water subliminal messages or clips with no subliminal messages. As it is seen on the last graph (Figure 5) even though the significant difference was not found between the preference scores of the different videos when participants were thirsty or not, there is a slight discrepancy between. Perhaps with a larger sample size and a different subliminal cue, this difference might become more noticeable. In conclusion, the sight of the water should be an SD for water consumption when thirsty and presumably results in a higher preference score for the water video but this experiment did not show the effectiveness of motivation in perceiving subliminal messages. The field of subliminal perception is still controversial. The goal of described research was to evaluate this area of study and further investigations are recommended in order to explore this topic.

33 REFERENCES

34 27 REFERENCES Aylesworth, A. B., Goodstein, R. C., & Kalra, A. (1999). Effect of archetypal embeds on feelings: An indirect route to affecting attitudes, Journal of Advertising, 28(2), Bellard, F., & Niedermayer, M. (2012). FFmpeg. Available from org. Egermann, H., Kopiez, R., & Reuter, C. (2006). Is there an effect of subliminal messages in music on choice behavior, Journal of Articles in Support of the Null Hypothesis, 4(2), Gable, M., Wilkens, H.T., Harris, L., & Feinberg, R. (1987). An evaluation of subliminally embedded Sexual Stimuli in Graphics, Journal of Advertising, 16(01). Igbokwe, V.U., & Obika, L.F.O. (2008). Thirst perception and dryness of mouth in healthy young adults Nigerians, African Journal of Biomedical Research, 11(2008), Klass, B. (1958). The ghost of subliminal advertising, Journal of Marketing, 23(2), Kosikova, K., & Pilarik, L. (2012). Unconscious visual perception in the decision making process, Studia Psychologica, 54(4). Langthorne, P., & McGill, P. (2009). A Tutorial on the Concept of the Motivating Operation, Behavior Analysis in Practice, 2(2),

35 28 Laraway, S., Snycerski, S., Michael, J., & Poling, A. (2003). Motivating operations and terms to describe them: some further refinements, Journal of Applied Behavior Analysis, 36(3), Lotfizadeh, A. D., Edwards, T. L., Redner, R., & Poling, A. (2012). Motivating operations affect stimulus control: a largely overlooked phenomenon in discrimination learning, The Behavior Analyst, 35(1), Pierce, D. W., & Cheney, C. D. (2013). Behavior Analysis and Learning, New York, NY: Psychology Press. Rogers, M., & Smith, K. H. (1993). Public perception of subliminal advertising: Why practitioners shouldn t ignore this issue, Journal of Advertising Research, 33(2), Treimer, M., & Simonson, M. (1988). Subliminal Messages, Persuasion and Behavior Change, The Journal of Social Psychology, 128(4),

36 APPENDICES

37 30 APPENDIX A STUDY CONSENT FORM 1. This research study will examine effects of different food intake on assessing advertisements. If you agree to participate, you will be asked to follow the instructions given to you by the researcher during the study. 2. You are free to discontinue your participation at any time without penalty. You may also skip any survey questions that make you feel uncomfortable. Even if you withdraw from the study, you will receive any entitlements that have been promised to you in exchange for your participation, such as extra credit. 3. Participation in this research study does not guarantee any benefits to you. However, possible benefits include the fact that you may learn something about how research studies are conducted and you may learn something about this area of research (advertisement). 4. You will be given additional information about the study after your participation is complete. 5. If you agree to participate in the study, you will receive additional information

38 6. on assessing the videos, food to eat before watching the videos, and water at the end of each session All data from this study will be kept from inappropriate disclosure and will be accessible only to the researchers and their faculty advisor. The researchers are not interested in anyone s individual responses, only the average responses of everyone in the study. 8. The present research is designed to reduce the possibility of any negative experiences as a result of participation. Risks to participants are kept to a minimum. However, if your participation in this study causes you any concerns, anxiety, or distress, please contact the Student Counseling Center at (209) to make an appointment to discuss your concerns. 9. This research study is being conducted by Agnieszka Dutkowska. The faculty supervisor is Dr. William Potter, Professor, Department Chair, Department of Psychology and Child Development, California State University, Stanislaus. If you have questions or concerns about your participation in this study, you may contact the researcher at (209) or by adutkowska@csustan.edu

39 If you would like to obtain information about outcome of the study, please do not hesitate to contact the researcher (Agnieszka Dutkowska: 11. If you have any questions about your rights as a research participant, you may contact the Campus Compliance Officer of California State University Stanislaus at IRBadmin@csustan.edu. 12. By signing below, you confirm that you have a student status at California State University Stanislaus. 13. By signing below, you confirm you will show up twice during the week period, during the same period of time, which will be prearranged with the researcher. 14. By signing below, you confirm you do NOT have ANY of these: a) food allergies b) celiac disease / non-celiac gluten sensitivity c) hypertension (high-blood pressure) d) diabetes

40 15. You will be provided with a blank, unsigned copy of this consent form at the 33 beginning of the study. 16. By signing below, you attest that you are 18 years old or older. 17. By signing below, you are indicating that you have freely consented to participate in this research study. PARTICIPANT S SIGNATURE: DATE:

41 34 APPENDIX B PILOT STUDY CONSENT FORM 1. This pilot study aims to determine how quickly salty food induces thirst in people. This pilot study is a part of a bigger research project that examines the effects of different food intake on assessing advertisements. If you agree to participate, you will be asked to follow the instructions given to you by the researcher during the study. 2. You are free to discontinue your participation at any time without penalty. Even if you withdraw from the study, you will receive any entitlements that have been promised to you in exchange for your participation, such as extra credit. 3. Participation in this research study does not guarantee any benefits to you. However, possible benefits include the fact that you may learn something about how research studies are conducted and you may learn something about this area of research (advertisement). 4. You will be given additional information about the study after your participation is complete. 5. If you agree to participate in the study, you will receive additional information on

42 6. questionnaires, food to eat before filling out the questionnaires, and water at the end of each session All data from this study will be kept from inappropriate disclosure and will be accessible only to the researchers and their faculty advisor. The researchers are not interested in anyone s individual responses, only the average responses of everyone in the study. 8. The present research is designed to reduce the possibility of any negative experiences as a result of participation. Risks to participants are kept to a minimum. However, if your participation in this study causes you any concerns, anxiety, or distress, please contact the Student Counseling Center at (209) to make an appointment to discuss your concerns. 9. This research study is being conducted by Agnieszka Dutkowska. The faculty supervisor is Dr. William Potter, Professor, Department Chair, Department of Psychology and Child Development, California State University, Stanislaus. If you have questions or concerns about your participation in this study, you may contact the researcher at (209) or by adutkowska@csustan.edu 10. If you would like to obtain information about outcome of the study, please do not hesitate to contact the researcher (Agnieszka Dutkowska: adutkowska@csustan.edu)

43 If you have any questions about your rights as a research participant, you may contact the Campus Compliance Officer of California State University Stanislaus at IRBadmin@csustan.edu. 12. By signing below, you confirm that you have a student status at California State University Stanislaus. 13. By signing below, you confirm you will show up two days in the row, during the same period of time, which will be prearranged with the researcher. 14. By signing below, you confirm you do NOT have ANY of these: e) food allergies f) celiac disease / non-celiac gluten sensitivity g) hypertension (high-blood pressure) h) diabetes 15. You will be provided with a blank, unsigned copy of this consent form at the beginning of the study. 16. By signing below, you attest that you are 18 years old or older.

44 By signing below, you are indicating that you have freely consented to participate in this research study. PARTICIPANT S SIGNATURE: DATE:

45 38 APPENDIX C PICTURE OF WATER

46 39 APPENDIX D QUESTIONNAIRE FOR PARTICIPANT Please, provide an answer for following question. Circle the appropriate number. Before consumption How thirsty do you feel right now? not at all very much

47 40 APPENDIX E QUESTIONNAIRE FOR PARTICIPANT Please, provide an answer for following question. Circle the appropriate number. How thirsty do you feel right now? Just after consumption not at all very much How thirsty do you feel right now? 5 minutes after consumption not at all very much

48 How thirsty do you feel right now? minutes after consumption not at all very much How thirsty do you feel right now? 15 minutes after consumption not at all very much How thirsty do you feel right now? 20 minutes after consumption not at all very much

49 42 How thirsty do you feel right now? 25 minutes after consumption not at all very much How thirsty do you feel right now? 30 minutes after consumption not at all very much

50 43 APPENDIX F QUESTIONNAIRE FOR PARTICIPANT Please, provide an answer for following questions. Circle the appropriate number. What do you think about video 1? I do not like it at all I like it very much What do you think about video 2? I do not like it at all I like it very much

51 44 APPENDIX G QUESTIONNAIRE FOR PARTICIPANT Please, provide an answer for following question. Circle the appropriate number. How thirsty do you feel right now? not at all very much

52 45 APPENDIX H PILOT STUDY PARTICIPANT THANK YOU LETTER You participated in the pilot study that aimed to determine the amount of time needed to induce thirst after consumption of a 2 oz. bag of pretzels. These results were used to calculate the time that participant in actual study would be asked to wait before showing them videos. You were told that this experiment aimed to compare the results of assessments of the videos, obtained after eating different foods. This experiment was conducted in order to find out whether people are more vulnerable to the effects of a subliminal water message while deprived of water rather than when they are not thirsty. Subliminal messages can be described as those that cannot be perceived consciously by the organism but they still make an impact on the individual. In the other words, subliminal messages can be any stimuli that you are not aware of, but still makes you behave in certain way. In this study subliminal message (a glass of water with the word WATER ) was put, and flashed so quickly participants could not recognize it, in one of the videos that they watched and assessed. Most of the previous studies showed no utility of using subliminal messages. However, those studies did not manipulate such factors like motivation. It is known that, when you are thirsty you

53 are seeking a drink, so your motivation for getting one is high. This is why in this 46 study, participants ate different foods in order to see whether they would assess videos with and without subliminal message differently when they were thirsty. My prediction was that videos with the subliminal message would get better scores than the one without subliminal message from participants that ate pretzels before assessing videos. In other words, I predicted that subliminal message would work but when participants were more motivated to perceive them. All the information that were collected in this study will be kept safe from inappropriate disclosure, and there will be no way of identifying your responses in the data archive. I am not interested in anyone s individual responses; rather I want to look at the general patterns that emerge when all of the participants responses are put together. If you need to discuss the nature of the research have any questions about the study or would like to learn about the results of the study, you may contact me (Agnieszka Dutkowska, adutkowska@csustan.edu). If you have questions about your rights as a research participant, you may contact the Campus Compliance Officer of CSU Stanislaus at IRBadmin@csustan.edu. If participation in the study caused you any concerns, anxiety, or distress, you may contact the Student Counseling Center at (209)