Psyc 1200: Comparison of Experimental and Correlational ResearchEssay Preview: Psyc 1200: Comparison of Experimental and Correlational ResearchReport this essayExperimental Research Question: Is short-term memory hindered by the consumption of alcoholic beverages, compared to the consumption of imitation alcoholic beverages?
Both the test and control groups will consist of randomly selected volunteers who have been identified as individuals who consume alcohol and are of legal drinking age. The procedure will be identical for both groups, but the control group will be given non-alcoholic beverages that mimic the taste of alcoholic beverages. Assignation to groups will be random and researchers will be unaware of the group to which participants are assigned. Participants are asked to fast for 4 hours prior to testing and are given a baseline breathalyzer test at the onset. They are asked to remember a sequence of 7 random numbers over a period of 10 seconds. Following a 3-minute distractor film, the participants are asked to recall the number sequence. The participants then drink either a beverage of 30mL of alcohol diluted to ~20-25% alcohol by volume or the control beverage, followed by a 5-minute wait. Participants are asked to rate how intoxicated they feel on a scale and a breathalyzer test is administered. The memory test is readministered with a new random sequence of numbers. The process is repeated until the participants blood alcohol level is measured at 0.15 (Virginia Tech, n.d.) or at the point at which they rate themselves as “too drunk,” whichever occurs first. The dependent variable in this experiment is the short-term memory recall test and the independent variable is the consumption of either alcoholic. A t-test would be used to analyze whether individuals who consumed alcohol had lower short-term memory recall scores than individuals who did not consume alcohol.
Correlational Research Question: Do individuals who drink alcohol heavily have lower short-term memory scores, compared to moderate, casual or non-drinkers?
Participants are randomly selected volunteers who are of legal drinking age. Participants are surveyed on their average frequency of alcohol consumption and identified as non-drinkers (those who consume no alcohol), heavy drinkers (those who drink an average of > 2 drinks per day for men, and > 1 drink per day for women ) (Centre for Disease Control and Prevention, 2010), and moderate drinkers whose drinking habits fall between heavy and non-drinkers. The short-term memory test from the experimental design above (recalling a sequence of 7 random numbers) is administered to the participants. An r-test would be used to analyze whether there is a negative correlation between individuals who tend to consume alcohol regularly and short-term recall scores.
The response rate is also calculated using a self-report measure of drinking time. Participants who consumed as much or more than 2 drinks per day were also rated as moderately to moderately drunk in the time series and as heavy drinkers in the time series. The interaction term also predicts the difference between the responses of the participants from the two groups.
We also calculated sample weights for the time series of 1.2 s in each individual, assuming that all participants at one place who consumed ≥ 3 drinks per day averaged 2 s of drinking time and that the time series differed by 1.2 s within the last 1 s (>3 drinks per day). This provides additional information to support the use of the “overall” time series over most individuals with limited capacity for recall, particularly those with high and low drinking rates and other factors that may lead to poor recall (e.g., increased consumption of alcohol). Our results suggest that heavy drinking reduces recall of a variable by up to 1,000 times after adjustment for demographic factors but significantly reduces the total response rate of the participants.
The short, randomization method may be more reliable and may be more cost-efficient. Further studies are needed to determine its feasibility over the long term, and if a cost-effective approach is found, we would encourage everyone to participate in the study and make comparisons publicly available.
—Dr. G.F. Miller, MD. Rheumatology, Biobehavioral, and Health, NonsecÂriÂary Medical College, New York 1001350: http://www.ncbi.nlm.nih.gov/pubmed/61091028.
Assessment, Analysis and Statistical Methods
Statistical Analysis of Participants.
The standard (Nondifferentiated) version (C) was compiled by Dr. D.J.G. Mann and colleagues that were jointly developed at the National College of Epidemiology, National Cancer Institute, National Institutes of Health, Bethesda, MD 21710. Statistical analysis includes baseline data on participants, duration of drinking, and the prevalence of alcohol use. To avoid possible bias by the participants not having completed their assessment, the standard was based on the estimate of 2 s of drinking time available in the past 15 days for all drinkers. The mean of the two groups was calculated based on the weighted mean of all participants and calculated (i.e., all participants were aged ≥ 35 years). A random design was also used to exclude individuals who had consumed ≥ 2 drinks for one or more consecutive periods of time in the previous 12 months. The results are shown in Table 4. It is reported herein by the authors that the adjusted mean of the participants’ responses to the survey was 5.2 SD shorter than for the control group. In order to account for variation by time, the adjusted mean was calculated as: (1) 1.
The authors have reported here that most studies use a 2- or 3-item (R)–response (i.e.: 1.6 or 2.0 OR) to describe the overall effect sizes on the responses to the study interventions. They find that one-hundred-three per cent of participants, however, describe both the effects of any intervention on short-term recall and overall short-term memory improvement over a 1-h period of time. This finding is significant in that the researchers provide this in a meta-analysis which is published in the journal Cognition (2010).
To illustrate this, the authors (Toback et al. 2010) used this same study (R) to compare long-term effects of different cognitive interventions on short-term memory and short-term memory of adults for a 20-year follow-up. After accounting for age, race/ethnicity, smoking, alcohol use (e.g., in a group that was only abstaining from alcoholic beverages at week 1), and physical activity, they found an overall effect size of 1 to 10% (P < .001). However, these effects were not statistically significant in larger groups (Toback et al. 2010), especially in men. We suspect therefore, that the effects were mainly mediated by short-term memory on short-term memory. Because of possible differences in measures of perception, judgement, and behaviour between the group from whom the effects were observed (see Table 2), the authors have decided not to consider long-term effects beyond the longer-term effects of either intervention (see Supplemental Material for further discussion). However, the authors suggest that similar differences could be created by different means. A previous study (Dewley et al. 2009) found no evidence for a negative effect of the individual's habitual alcohol consumption on short-term memory. One of the researchers, however, stated that, "a large meta-analysis of 16 European (and 10 European–wide) trials of cognitive interventions and short-term memory found that long-term effects were strongest in the treatment group", that "Long-term effects in people who took a combination of alcohol, alcoholics, and non-drinkers were not seen" (Supplementary Table 2), and that, "The authors reported no evidence for negative effects of one type [alcoholics] on short-term memory". There is, however, evidence for both effect sizes with regard to long-term memory. Despite these similarities, we hypothesize that these effects are mediated principally by short-term memory deficits in some populations. In the past, our study has shown that the cognitive functions of non-responders and drinkers have changed in response to the interventions. However, a new study (Lehmann 2008) indicates that a small effect size for non-responders (0.04 per cent) does not result in a significant effect size for drinkers (0.03 per cent). Although some of the effects did not reach statistical significance and may have
The authors have reported here that most studies use a 2- or 3-item (R)–response (i.e.: 1.6 or 2.0 OR) to describe the overall effect sizes on the responses to the study interventions. They find that one-hundred-three per cent of participants, however, describe both the effects of any intervention on short-term recall and overall short-term memory improvement over a 1-h period of time. This finding is significant in that the researchers provide this in a meta-analysis which is published in the journal Cognition (2010).
To illustrate this, the authors (Toback et al. 2010) used this same study (R) to compare long-term effects of different cognitive interventions on short-term memory and short-term memory of adults for a 20-year follow-up. After accounting for age, race/ethnicity, smoking, alcohol use (e.g., in a group that was only abstaining from alcoholic beverages at week 1), and physical activity, they found an overall effect size of 1 to 10% (P < .001). However, these effects were not statistically significant in larger groups (Toback et al. 2010), especially in men. We suspect therefore, that the effects were mainly mediated by short-term memory on short-term memory. Because of possible differences in measures of perception, judgement, and behaviour between the group from whom the effects were observed (see Table 2), the authors have decided not to consider long-term effects beyond the longer-term effects of either intervention (see Supplemental Material for further discussion). However, the authors suggest that similar differences could be created by different means. A previous study (Dewley et al. 2009) found no evidence for a negative effect of the individual's habitual alcohol consumption on short-term memory. One of the researchers, however, stated that, "a large meta-analysis of 16 European (and 10 European–wide) trials of cognitive interventions and short-term memory found that long-term effects were strongest in the treatment group", that "Long-term effects in people who took a combination of alcohol, alcoholics, and non-drinkers were not seen" (Supplementary Table 2), and that, "The authors reported no evidence for negative effects of one type [alcoholics] on short-term memory". There is, however, evidence for both effect sizes with regard to long-term memory. Despite these similarities, we hypothesize that these effects are mediated principally by short-term memory deficits in some populations. In the past, our study has shown that the cognitive functions of non-responders and drinkers have changed in response to the interventions. However, a new study (Lehmann 2008) indicates that a small effect size for non-responders (0.04 per cent) does not result in a significant effect size for drinkers (0.03 per cent). Although some of the effects did not reach statistical significance and may have
The authors have reported here that most studies use a 2- or 3-item (R)–response (i.e.: 1.6 or 2.0 OR) to describe the overall effect sizes on the responses to the study interventions. They find that one-hundred-three per cent of participants, however, describe both the effects of any intervention on short-term recall and overall short-term memory improvement over a 1-h period of time. This finding is significant in that the researchers provide this in a meta-analysis which is published in the journal Cognition (2010).
To illustrate this, the authors (Toback et al. 2010) used this same study (R) to compare long-term effects of different cognitive interventions on short-term memory and short-term memory of adults for a 20-year follow-up. After accounting for age, race/ethnicity, smoking, alcohol use (e.g., in a group that was only abstaining from alcoholic beverages at week 1), and physical activity, they found an overall effect size of 1 to 10% (P < .001). However, these effects were not statistically significant in larger groups (Toback et al. 2010), especially in men. We suspect therefore, that the effects were mainly mediated by short-term memory on short-term memory. Because of possible differences in measures of perception, judgement, and behaviour between the group from whom the effects were observed (see Table 2), the authors have decided not to consider long-term effects beyond the longer-term effects of either intervention (see Supplemental Material for further discussion). However, the authors suggest that similar differences could be created by different means. A previous study (Dewley et al. 2009) found no evidence for a negative effect of the individual's habitual alcohol consumption on short-term memory. One of the researchers, however, stated that, "a large meta-analysis of 16 European (and 10 European–wide) trials of cognitive interventions and short-term memory found that long-term effects were strongest in the treatment group", that "Long-term effects in people who took a combination of alcohol, alcoholics, and non-drinkers were not seen" (Supplementary Table 2), and that, "The authors reported no evidence for negative effects of one type [alcoholics] on short-term memory". There is, however, evidence for both effect sizes with regard to long-term memory. Despite these similarities, we hypothesize that these effects are mediated principally by short-term memory deficits in some populations. In the past, our study has shown that the cognitive functions of non-responders and drinkers have changed in response to the interventions. However, a new study (Lehmann 2008) indicates that a small effect size for non-responders (0.04 per cent) does not result in a significant effect size for drinkers (0.03 per cent). Although some of the effects did not reach statistical significance and may have
The experimental method would be more effective in identifying whether alcohol use hinders short-term memory, since the only difference between the test and control groups is alcohol consumption. The correlational method is not able to establish a causal relationship between