The effects of chocolate on the improvement of short-term memory have been controversial. Most findings have been inconsistent, whereas others indicate enhancing effects of chocolate on the ability to impair the working and short-term memory. Increase in the memory capacities results in high retention of more information and quick encoding of information. According to Hunt (2003), habitual consumption of chocolate has increased by 20% over the last decade in that the current average consumption is 280 mg/day (Freud, 1966). Chocolate contains caffeine, which has well-known effects on the central nervous system, including wakefulness, alertness, motor activity and motivation. It also has ositive effects on the basic psychomotor tasks, attention, reaction time and visual vigilance (Hezz & Bene, 2013).
This issue has led to the scientific research on the false recognition and recall. In 1995, McDermott and Roediger modified and revived the Deese paradigm used to examine false recognition and recall of chemically-associated words (Roediger & McDermott, 1995).
The participants then performed a recognition test, then recall the test of the words studied, non-studied words and non-presented theme words. The purpose of the study was to examine false memory increase after consumption of chocolate using the Deese-Roediger-McDermott Paradigm. The first group of this paradigm comprised of women who had consumed chocolate. It is the improved memory group in the study. The second group comprised of men who had consumed chocolate. It is the repressed memory group.
The research study applied double-blind, repeated measures’ design with four groups (0 mg, 100 mg, 200 mg, and 400 mg of consumed chocolate). The study focused on the contrasts taking the form of one-tailed t-tests because of the hypothesis.
Fifty men and fifty women were randomly selected among the volunteers from the community. They were in good health, non-smokers and did not use any nicotine and prescription medication apart from oral contraceptives. Written consent was obtained from the participants and procedures have been approved by Research Institute for Environmental Medicine. For the control group, the participants were recruited via newspaper notices requesting for people to participate in a memory study. The participants were confirmed on the basis of their ability to do a math test, recall and recognition tests. Control group comprised of men and women who had not consumed chocolate.
To conduct a study, a version of the Deese-Roediger-McDermott paradigm that allows variations in semantic associate was used. There were also used the modified critical target by Roediger-McDermott and 24 15-word studies (Winograd, Peluso, & Glover, 1998). The list was divided into six groups of four words, with each group assigned a 0-, 3-, 9-, 12-, and 15-item list length. The 0- group was not studied hence the participants used a group consisting of 3 items. Randomized design was used to counterbalance in that all subjects received 24 study lists. Participants were given pencils and booklets to write the answers of the recall test. The words in each list were presented with the help of a tape recorder and in a continuous sequence hence allowing the reading of a new word every three seconds. After the final word the participants were given a simple two digit math problem to solve. After twenty five seconds they were requested to recall the words from the list they had earlier heard on the tape recorder. After the elapse of the time they were instructed to attend to the next task. In addition eighty-item list recognition test followed recall and presentation of the list. Two items from the twenty studied list were used in the recognition test. Forty items were not studied in the recognition list. Twenty items of the forty nine studied to become false targets while the remaining 20 served as the control words. The items converged in the non-studied list become false target controls, 4 items. From the four non-studied lists, 2 items from each were labeled true-target controls. To ensure identical length of words, there was a random selection of true targets and true target control of the recognition tests from among the first 3 words in each list.
The study focused on contrasts taking the form of one-tailed t-tests because of the hypothesis. DRM data were analyzed with repeated measures of analysis of variance (ANOVA) under the groups of 0 mg, 100 mg, 200 mg, and 400 mg. of chocolate consumption as a within-subjects variable. After the yield from the ANOVA, significant main effect, t-tests were performed for comparison. All statistical analyses were performed using SPSS 12.0. Effect-size correlation for each contrast was computed on the data for the 3, 6, 9, 12, and 15-items lists. From the data, one way analysis of variance exhibited no differences in the performance of semantic associate list. For true-target controls, F (2, 28) _ 1.27, p _ .30 while for false-target controls, F (2, 28) _ 1.41, p _ .26. According to the hypothesis, participants with improved memories should score higher in the math tests and with false recognition and recall, it fell short for false recall in that its results were, t (30) _ 1.56, p _ .07, r _ .27. False recognition was significant from the results, which were t (28) _ 2.47, p _ .01, r _ .42. In applying contrast weights of 1, 1, and 2 to mean false recognition and recall rates of repressed and recovered memory, the findings confirmed the hypothesis for false recognition (t (28) _ 3.45, p _ .01, r _ .55) and false recall (t (30) _ 3.33, p _ .01, r _ .520).
The study examined effects of chocolate consumption of a range dose (0- 400mg) on the math test and false recognition and recall using the Deese-Roediger-McDermott (DRM) paradigm. From the findings, participants who had consumed chocolate and those under control exhibit almost the same results in false recognition and false recall of semantic associates. The improved memory, and control groups did not differ in terms of true recognition and true recall rates hence the findings are consistent with the researched studies. The results of the study are also consistent with the hypothesis that effects of chocolate consumption on the memory are not significant in solving math tests and in recognition and recall. The inclusion of control group showed that recognition and false recall were not confined to participants who had consumed chocolate. The outcome data were content with the hypothesis that chocolate consumption had no major impact on the memory increase hence both groups equally prone to the false memory created by the caffeine in chocolate. Even though the results of contrast analysis were the same for both recognition and recall, false recognition rates were higher than false recall rates for all groups. The explanation for this scenario is that the recall test was done immediately after the study of the word list as opposed to the recognition test, which was done after all the lists had been studied. From the analysis, recognition paradigm is more sensitive to the development of false memories than the recall paradigm. Accuracy of memories depends on the experience and details that arise from monitoring rather than from the consumption of caffeine.
The sample size was small with respect to the hypothesis tested. The study did not screen participants on the disorders related to the prior medication and oral contraceptives to women. The findings of the study are also subject to criticism in that human memory deficits may be due to the results of cognitive deficits hence prone to false memory.
In conclusion, writing a research report requires extensive literature reading and research using secondary data. The introduction and discussion were demanding though, they formed the basis of the research. The results of the false report were hard to analyze in that some of them exhibited content that required more research. The experience from this analysis will assist me in a future research in that I have gained knowledge on how to create the problem situation, justify, test and discuss the final findings.
Freud, A. (1966). The ego and the mechanisms of defence (Rev. ed). Madison, CT: International Universities Press.
Hezz, K. & Bene (2013). The effects of experimentally induced stress on false recognition. Journal of brain science Memory, (10), 1-6.
Hunt, R. (2003). Two contributions of distinctive processing to accurate memory. Journal of Memory and Language. (48), 811-825.
Roediger, H. L., III, & McDermott, K. B. (1995). Creating false memories? Remembering words not presented in lists. Journal of Experimental Psychology: Learning, Memory, and Cognition, (21), 803-814.
Winograd, E., Peluso, J. P., & Glover, T. A. (1998). Individual differences in susceptibility to memory illusions. Applied Cognitive Psychology. (12), 5-27.