|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Home | Photo Gallary | About Myself | Events | Invest Center | Archives | |||||||||||||||||||||||||||||
| Back to Archives Page | ||||||||||||||||||||||||||||||||||
| When? November 4th, 2003 | ||||||||||||||||||||||||||||||||||
| Why ? Pshychology project | ||||||||||||||||||||||||||||||||||
| Visual Images and Taste | ||||||||||||||||||||||||||||||||||
| Can Visual Images Make Food Tastier? | ||||||||||||||||||||||||||||||||||
| Our sense of taste responds to only four qualities: sweet, sour, bitter and salty. But why do we claim that we sense hundreds of different tastes. Unlike vision and auditory senses smell and taste are chemical senses because their receptors are sensitive to chemical molecules rather than some form of energy (Passer and Smith 2001). This is partly why we claim that we experience more than four tastes. Passer and Smith (2001) say that taste experience combines qualities and those of other senses such as smell temperature and touch. Through out the history many experiments have been conducted to prove this. | ||||||||||||||||||||||||||||||||||
| Alberto and Green (2002) found that heating or cooling small areas of tongue can in fact cause sensation of taste. In addition they found that cooling can evoke one quality of taste where as warming the tongue can evoke different quality of taste. Their observation indicated that the human gustatory system contains sensitivity neurons that normally contribute to the sensory code for taste. More over taste sensation are not localized by to the location of taste buds, but rather to areas touched in the mouth (Todrank and Bartoshuk 1991). Their experiment of taste illusion insured that the taste of a substance in an unitary event and does not vary in intensity as the substance is moved throughout the mouth. This study also explains why we are not aware of the location of taste receptors as part of everyday experience. And why patients who suffer localized taste losses do not notice any change in taste experience. Matter of fact there was another study conducted to find out whether images can stimulate brain stem reflexes directly. It was hypothesized that actually experiencing a sour taste on one side of the tongue would enhance the clarity of the image, and hence increase salivation when recalling the sour taste (Drummond 1995). However he found out that salivation did not increase significantly during imaginary trials and he suggested that this might be due to other factors such as anxiety and discomfort. | ||||||||||||||||||||||||||||||||||
| The above studies conclude that our experience of taste is affected by so many factors such as temperature, touch and so on. Can visual images have an impact on our experience of taste? My hypothesis is that, if positive visual images of food are shown before the meal then it is more likely that people would perceive food tastier. On the other hand if negative images were shown, they would report the taste of the food negatively. | ||||||||||||||||||||||||||||||||||
| Non experimental / Correlational design | ||||||||||||||||||||||||||||||||||
| First two restaurants will be selected. At the point of selection experimenters will make sure that these two restaurants are producing same kind of food if not similar type of food. But there would be a major difference in the selected two restaurants. That is first restaurant will be having lots of food pictures around the eating area where as the second restaurant will have no pictures displayed at all. That will be the first variable measured. 20 subjects will be selected randomly from each restaurant, who enter and consume a meal in the restaurant. When the subjects leave the restaurant they will be asked to scale the tastiness of the meal they consumed. This scaling system will consist of numbers 1 to 9. The number 9 represents the meal was very delicious and number 1 represents the meal was no taste at all. The results of the scale system will be recorded for the both restaurants. And then the mean and the median of the data will be calculated. The mean for the collected data for 1st restaurant is expected to be higher than the mean for the collected data for 2nd restaurant. For example a person who enter and consume a meal in the 1st restaurant will rate the meal 6 on average where as for the same or similar type of meal in the 2nd restaurant on average a person would rate it 4. As a result of this Correlational study it is expected that there is a positive correlation between visual images and the individuals reporting the taste of the food. | ||||||||||||||||||||||||||||||||||
| Experimental design | ||||||||||||||||||||||||||||||||||
| The sample would consist of 30 subjects from Simon Fraser University BC, regardless of gender difference. These subjects will receive credits for psychology courses for participating in the experiment. These subjects will be randomly assigned for three groups; experimental group 1, experimental group 2 and control group. Each group will consist of 10 subjects. There will be two sessions in the experiment on two consecutive days. Each session will last for approximately 45 minutes. Each session will be conducted at the same time of the day in the same lab. These labs are temperature control and sound proof labs. On the first day subjects will be assigned in to groups and they will be in the same group on the second day as well. During the first session the subjects will be asked to fast for two hours prior to the experiment and they will be given a glass of water just before the experiment starts. Then they will be given a piece of pizza to eat. The ingredients and the size will be the identical for all the pizzas provided for the subjects. In addition the temperature at which they will be served will be the same. Because the temperature will have an impact on the taste (Green and Alberto 2002). Then the subjects will be asked to rate the tastiness of the pizza with a method of scaling system numbered from 1 to 9. Number 9 represents the pizza was delicious and number 1 represents it was no taste at all. Then the results will be recorded under individual subjects and by the group which they are assigned. In this experiment the dependent variable is the tastiness. This will be identified by how the individual subjects are reporting the taste based on the scaling system. | ||||||||||||||||||||||||||||||||||
| During the second session just like the 1st session the subjects will be asked to fast for two hours prior to the experiment and they will be given a glass of water just before the experiment. Then the 1st experiment group will be exposed to various pictures of food including different kind of pizzas. They will be exposed for approximately 10 to 15 minutes before they will be given the pizza. This pizza they will be given will be the same pizza which they were given the previous day and ask them to consume it. The experimenters will make sure that they use the same ingredients and the temperature at which they will be served. Then simply subjects will be asked to rate the taste of the pizza on the same scale, 9 representing the pizza was very delicious and number 1 representing it was no taste at all. What the subjects will be unaware of is that they were given the same pizza as the previous day. Meantime the second experimental group will be exposed to rotten grouse pictures of food. Examples would include pictures of rotten pizzas, etc. The subjects of the 2nd experimental group will also be exposed to the visual images for approximately for 10 to 15 minutes before they will be given the piece of pizza. They will be asked to consume it and simply rate the taste of the food using the same scale. The control group will not be exposed to any visual images and they will be simply given the pizza and asked them to consume it. At the end they will rate the taste of the pizza using the same scale. In the experiment the dependent variable is visual images that the subjects are shown and it will be identified by showing the subjects various kinds of food images. | ||||||||||||||||||||||||||||||||||
| At the end of the experiment the results they obtained will be compared to see if there is any difference in the data. The data they obtained during session one and session two will be compared on individual basis. In other words the experimenters will seek to find out if there was any change in the way the individuals reported the taste on the standard scale. | ||||||||||||||||||||||||||||||||||
| It is more likely that the individuals who were in 1st experiment group would rate the pizza higher in the 2nd session than in the 1st session. For example if an individual rated the pizza 5 in the 1st session he/she will rate it 7 in the 2nd session. On the other hand individuals who were in the 2nd experimental group would rate the pizza lower in the 2nd session than they rated in the first session. However I expect the control group to rate the pizza the same or similar way in both sessions. That is if an individual who were in control group rated the pizza 5 in the 1st session would rate it 5 in the 2nd session as well. Any way in this experiment the way how the individual rate the food does not matter, what does matter is if there is a difference in the rating in the first session and the second session. | ||||||||||||||||||||||||||||||||||
| Conclusion | ||||||||||||||||||||||||||||||||||
| The Correlational study will show that the visual images and subjects reporting the taste of the food is positively related with positive pictures where as they are negatively related with negative images. In the 1st restaurant which is rich in visual images of food, the subjects are likely to report high rates of taste where as in the 2nd restaurant which is lack of pictures of food is more likely to report low rates of taste. How ever we can not come to a conclusion that the visual images can have an impact on how humans perceive taste, based on a Correlational study because it does not provide causation. It?s due to either bidirectional problem or simply the correlation could be a result of a third factor. In addition there are limitations on this Correlational study. First of all it is practically hard to find two restaurants which produce same food or meals and you have very little control over the method they use to cook. In addition the other environmental factors may influence the subjects reporting the taste of food. Some of those factors might be the mood of the subjects, the setting of the restaurant, time of the day and the hunger of the participants. | ||||||||||||||||||||||||||||||||||
| To overcome the limitations of Correlational study the experimental designs will be used along with the Correlational study. The experiment has been carefully designed to overcome the problem of extraneous variables. Alberto and Green (2002) found that heating or cooling small areas of tongue can in fact cause sensation of taste. In view of this the experimenters will use temperature control and sound proof labs. How ever there will be some limitations in the experiment. There will be no proper way of controlling the hunger of the participants even though they will be asked to fast for 2 hours prior to the experiment. And this can have an impact on how they rate the taste of pizzas. The results of the 1st experiment group are expected to have a positive relationship in rating. In other words there will be a positive difference in rating system. This positive relationship could be explained by visual images shown to the subjects have had an impact on how they have perceived taste. Positive images are related with positive difference. As a result subjects will report the food would in fact tastier when they were exposed to positive images. On the other hand the 2nd experimental group will have a negative difference in their rating. Which means that the negative images that they were exposed to is directly related with subjects perceiving taste of the food in a negative way. In other words they think the same food is now less tasty. Where as the subjects in the control group will report no taste difference in the 1st session and the 2nd session. This will conclude that the seeing images of food caused the subjects to perceive taste differently. As a result we can come to a conclusion that visual images have a great impact on our perception of taste. In view of this I believe that our five senses are interrelated and work together. In some cases it is hard to understand from which sense we perceive the stimulus. | ||||||||||||||||||||||||||||||||||
| References | ||||||||||||||||||||||||||||||||||
| Cruz, A., & Green, B. G. (2002). Thermal stimulation of taste. Nature, 403, 889-892. | ||||||||||||||||||||||||||||||||||
| Drummond, P. D. (1995). Effect of imagining and actually tasting a sour taste on one side of the tongue. Physiology & Behavior, 57, 373-376. | ||||||||||||||||||||||||||||||||||
| Passer, M. W. & Smith, Psychology: Frontiers and Application. Toronto, ON: McGraw-Hill. | ||||||||||||||||||||||||||||||||||
| Todrank, J., & Bartoshuk, L. M. (1991). A taste illusion: taste sensation localized by touch. Physiology & Behavior, 50, 1027?1031. | ||||||||||||||||||||||||||||||||||
| Back | ||||||||||||||||||||||||||||||||||