Question

Restoring self-control when intoxicated. Does coffee or some other form of stimulation really allow a person suffering from alcohol intoxication to “sober up”? Psychologists from the University of Waterloo investigated the matter in Experimental and Clinical Psychopharmacology (February 2005). A sample of 44 healthy male college students participated in the experiment. Each student was asked to memorize a list of 40 words. The students were then randomly assigned to one of four treatment groups (11 students in each group). Students in three of the treatment groups were given two alcoholic beverages to drink prior to performing a word completion task. Students in group A received only the alcoholic drinks, Students in group AC had caffeine powder dissolved in their drinks, students in group AR received a monetary reward for correct answers, and students in group P(placebo) were told that they would receive alcohol, but instead received two drinks of a carbonated beverage (with a few drops of alcohol on the surface to provide an alcoholic scent). After receiving the drinks students rested for 25 minutes and then completed the word com- pletion task. Summary statistics of task scores are shown in the table below.

Variable SCORE

GROUP N

A 11

AC 11

AR 11

P 11

Mean StDev   

0.0636   0.2180

0.2655   0.1526

0.4400 0.1705

0.4000 0.1525

(c) (10 marks) Use a contrast to test if alcohol leads to a reduction in the mean number of recalled words. (Compare the mean for groups AR, AC, and A with the mean in group P).

Answer 1