Researchers, investigating the link between daily coffee consumption and learning, claim that subjects who consumed one cup of coffee a day for one week (the equivalent of 50 mg per day) exhibited improvements in declarative memory. Furthermore, the study revealed that such improvements were longer-lasting than those witnessed in a control group served decaffeinated coffee (decaffeinated coffee contains negligible amounts of caffeine). After a week of learning a list of facts, the subjects who consumed one cup of coffee were able to recall these facts with significantly more accuracy.

While daily coffee consumption may aid in the process of forming a greater number of short-term memories and increase the likelihood that these memories will be stored in long-term memory, the study glosses over an important fact. Many exhibit sensitivities to caffeine, including headaches (both migraine and non-migraine), sleeplessness, heightened anxiety, and any number of factors that, when working either alone or in tandem, may actually lead to a decrease in the observed link between caffeine and learning. Nevertheless, despite the fact that the study represents a random sampling— and thus any number of subjects can exhibit any number of reactions to caffeine— if enough subjects continue to display signs of improvements in learning, then this result would not be inconsistent with the study’s findings. Still, until the researchers either release more details of this study, or subsequent studies are conducted, the extent to which those with caffeine sensitivity influenced the observed link between coffee consumption and memory will not be fully known.

The primary purpose of the passage is to

A. discredit the findings of a study due to flaws in the design of the study
B. point out a factor that may modify the extent of certain findings
C. show how results in a finding were unintentionally fabricated
D. bolster an argument concerning the interaction of learning and caffeine intake
E. expand on several oversights of a noteworthy study



Regarding coffee’s effectiveness on memory amongst those who do not display “sensitivities to caffeine,” the author assumes that

A. more rigorous analysis in the form of follow-up studies must be conducted
B. the researchers must be more forthcoming in their findings
C. this group displayed a uniform tendency
D. any positive effects will be negated by the effects exhibited by those with sensitivities to caffeine
E. this effectiveness was fleeting and tended to all but disappear within a week of the study



Select the sentence in which the author expresses an opinion toward the results of the study.