Effects of Caffeine on the Memory of Words List - Report Example

Experimental Report on the Effects of Caffeine on the Memory of Words List s 1.0 Introduction Caffeine is a common legal drug, which affects the body in several ways. It is found in many beverages including coffee, tea, coke, and many others. Caffeine has fast effects, including that of enhancing cognitive functions such as attention and memory. Toates (2006) mention that caffeine also increases alertness to situations and surroundings by inhibiting adenosine receptors, motor functions such as gross movement of the limbs, and enhancing the overall movements of the body. Caffeine has facilitator effects on memory and learning. It facilitates performance in tasks that involve working memory to a small extent. Caffeine works by blocking or increasing some neurotransmitters in the brain such as dopamine. Dopamine is responsible for pleasure and mood control. Caffeine increases the level of dopamine in the brain hence causing interest in things. Caffeine also blocks adenosine action by binding to adenosine receptors in the brain. This binding reduces brain weakness and makes it to remain alert. This explains why when one takes a cup of coffee, which contains caffeine, he or she becomes alert and grasp new information within a short time. Many studies have shown that caffeine enhances brain output. It has also been considered to increase memory creation and retention for example, in declarative memory, which most people use to remember lists of items. This memory boost occurs because of caffeine effect on adrenaline production. According to Nehlig (2010), caffeine activates the parts of the brain that stimulates adrenal glands to produce adrenaline. The study experimented on the effects of caffeine on the memory of word lists in a between-participants study of two healthy adult females. They were randomly assigned the conditions of decaffeinated coffee and caffeinated coffee. The subjects participated in the study for two days. Materials used in the study included 250 ml cups, caffeinated and decaffeinated coffee and stationery. The pilot study used between-participants design. The results of the pilot study are discussed within the presentation and analysis sections. The discussions involve actions for the main research project. 1.1 Aim of the experiment The aim of this experiment was to look at the effects of caffeine on the memory of word lists. 1.2 Hypotheses The alternative hypothesis indicates that a relationship exists between two things. In this experiment, the alternative hypothesis was, “there will be a statistically significant difference between the numbers of words recalled from the list after drinking caffeinated coffee when compared after drinking decaffeinated coffee.” Null hypothesis indicates that no relationship exists between two things. The null hypothesis for the experiment was, “there will be no statistically significant difference between the numbers of words recalled from a list after drinking caffeinated coffee when compared to that after drinking decaffeinated coffee.”A bi-directional hypothesis was used in the study since there was an expectation that a difference would exist between the two conditions of the independent variables. 1.3 Variables of the study A variable in an experimental study refers to a measurable characteristic that change. The variable may change from one group to another group. In any experiment, there must be two variables; the independent variable and dependent variable. An independent variables (IV) involves parameters that a researcher has control over them. In the study, the independent variables included drinking caffeinated coffee and drinking decaffeinated coffee. According to Gordon and Marian (2006), dependent variables (DV) include the characteristics that a researcher has no control over, and show the effect of manipulating independent variables. In this study, the DV included the number of words recalled from a list. 1.4 Bias The expected bias on the experiment was experimenter bias that occurs when the researcher gives the coffee to the participants since he or she knows the drink which contains caffeine and which does not. Another bias occurs when the participants knows the expected results from the caffeinated and decaffeinated coffee. In an attempt to reduce the biasness, a double blind technique was used. The purpose of this technique was to eliminate the bias in the study caused by the experimenter and get valid results. 2.0 Methods 2.1 Study design The study utilized a between-participants design. In this design, each participant took part in only one condition and hence each score or result represented a unique participant. Gordon and Marian (2006) says that this design had an advantage that there were few chances of the participants working out exactly the aim of the study. In addition, any differences reported between their results under the two conditions cannot stem from individual differences. 2.2 Participants The experimental study involved two female participants of ages between 35 and 45 years. They were given brief information on the aims and objectives of the experiment and their expected roles in the study. In considering the ethics of research, the participants were given information on similar previous studies. The outcomes and concerns of the studies were also explained. They were also assured of their safety during the experiment. They were allowed to raise concerns about the study that were addressed fully. After making an agreement, the participants signed a written consent to participate in the experiment. Participants were screened for any medical condition that may alter their response during the experiment. They were screened to determine current use of prescribed or over the counter medications that have a possibility of altering the study results. History about smoking was taken to rule out extraneous factors. Since large intake of caffeine can affect pregnancy, they were examined for pregnancy possibility in order to maintain safety. All the screening appeared negative hence the participants were fit for the experimental study. 2.3 Materials The materials used in the study included 3 cups of filter coffee made from one tablespoon of filtered coffee per cup and 3 cups of decaffeinated filter coffee from one tablespoon of filtered coffee per cup. Approximately each 250 ml cup or regular coffee will contain 85 mg of caffeine while decaffeinated contained approximately three mg of caffeine per 250 ml cup. Both types of coffee did not contain milk and sugar. Other materials included 250 ml cups, pens, list of 15 nouns and plain papers. 2.4 Procedure Experimenter bias refers to process where the person carrying out the experiment influences the results in order to give a certain outcome. In order to avoid the experimenter bias and unknown or uncontrolled variables, the participants were randomly allocated to the different conditions. For example, they were asked to write down a number from one to 10. In this case, odd numbers represented the caffeine condition while even numbers represented the placebo condition. The normal caffeine intake of both participants was 1-3 cups of coffee in a day. The participants were asked to avoid caffeine totally for twelve hours before the actual experiment. They were both tested for a period of two days. The participants took three cups of caffeinated coffee for one and a half hours. The placebo also consisted of three cups of decaffeinated coffee over the same period. After an absorption period of one and a half hours, the participants were tested on a list of fifteen nouns. The lists were same for the two conditions. The participants were allowed to look over the word lists for a minute. It was then taken away and the respondents told to write down as many words as they can remember within one minute. The results were then analyzed and baseline information compared with the experimental condition on the second day. 3.0 Results The results of the study were obtained and an analyzed. Microsoft excel was used to present the data in table form to illustrate the differences between the two groups. Column graphs were used to display the analyzed data that allowed easy comparison between the mean scores. The advantage of use of column graphs was the ease of comparing results at a glance. Inferential statistics were employed to assess the level of dispersion of the outcome of the experimental study. This also was intended to help in illustrating the outcome during conduction of full study. Student’s t-test was employed to compare the means of the two groups in order to be investigated if the null hypothesis was rejected. A null hypothesis is rejected when the result of interaction of the variables is the same. For example, in this study, taking of caffeine increases the number of words recalled. The null hypothesis becomes rejected when the p-value is less than 0.05. 4.0 Discussion The pilot study used only two participants to test the viability and validity of the project. It helped to identify errors that can be corrected to enable the main study be successful. In order to perfect the future experiment, and generate any statistical data that would reject the null hypothesis, a larger sample size of eight participants would be used in the full-scale experimental study. The sample of the full experiment will be obtained from workers at a supermarket. The workers are involved in various activities ranging from tellers to casuals. The population forms an ideal study population because most of the workers in businesses need to have good memory. Safety measures will be considered in the future study. According to Nehlig (2010), only a low dosage of caffeine will be given to the participants. In addition, further research using high dosages in a safe, clinical environment can be done to give a stronger statistical result. Comprehensive medical checkups shall also be conducted before the actual experiments. In any experimental study, there are factors that may alter the results. These factors can make the results difficult to interpreted or unreliable. The factors include confounding variables and extraneous variables. Extraneous variables (EV) involve those factors in a study environment that may have an effect on the dependent variables, but the researcher cannot control. EV can alter the experiment’s validity, making it impossible to determine whether the IV caused the effects or some extraneous factors. Gordon and Marian (2006) mention that if the researcher cannot control the EV, he or she can take into consideration during interpretation of results. The possible EV in the study environment may include high temperatures, cold temperatures, noise or flickering light. Confounding variables refer to a variable that a researcher cannot control or eliminate to avoid alteration of internal validity of the experiment. Confounding factors correlates negatively or positively with both the IV and the DV, hence cause difficulties in distinguishing the results of the study. For example, in this experiment, the prior use of tea or coke may produce same results as coffee since they all contain caffeine. Gordon and Marian (2006) says that in order to minimize the effects of extraneous variables, the study would be conducted at the same of the day, in the same room with same temperature and light. Random assignment of participants to different conditions and frequent monitoring of participants can minimize the effects of confounding factors. Finally, ethical considerations in an experimental study involve set of principles on how the researcher should conduct himself or herself when dealing with the study participants, research users and other colleagues. In this study, the ethical issues were considered before, during and after the pilot study, and will apply during the main experiment. Ethical concerns considered in the study included seeking consent from the participants that was obtained by explaining the aim of the study and their role. They were also assured about confidentiality of information they gave to the researcher. Information about any previous relevant research was discussed during the pilot study and will be given to the participants in the full study. The participants will also be given a choice to participate at will. Conclusion According to the study above, it shows that small sample and one design were used. Suggestions that come out of this include selection of large samples in different places to give an accurate representation of a large population. Different methods and designs can be combined to produce diverse results, minimize effects of confounding factors and reduce biasness. Moreover, sponsors can step up their effort to enable researchers to conduct their studies without difficulties and constraints due to limitations of study such as finances or inadequate materials. References Gordon, R. & Marian, P. (2006). A Gentle Guide to Research Methods. New York: McGraw-Hill International. Nehlig, A. (2010). Is caffeine a cognitive enhancer? Journal of Neuropsychology 3(6). 85–94. Toates, F.M. (2006). Biological Psychology. Harrisburg: Prentice Hall. Read More