Assertion: coffee's caffeine | /r/CapableOf | improve subject
Facets:
value: for 5 hours
type: TEMPORAL
Source sentences:
text: Caffeine was able to improve the subjects’ psychomotor vigilance task on the first two days of restricted sleep for 5 hours every night, yet on the third night, the effect of two daily 200 mg doses of caffeine was lost on the subjects.