explain this to me in simple terms: Analyses of covariance (ANCOVAs) examined the main effects of drug ingested and drug expected on post-test subjective mood and drug effects while controlling for baseline measure of that effect. Analyses of variance (ANOVAs) were used to examine the main effects of drug ingested and drug expected on cognitive perfor- mance. Due to the small sample size, we were underpowered to detect significant expectation x drug ingested effects. Thus, the models examined the main effects entered simultaneously; when significant main effects emerged, planned contrasts comparing the expect Adderall/receive caffeine group to the other three groups were examined