We measured short-term and working memory capacity ( Digit Span tasks ) , cognitive flexibility and selective attention ( Word-Color Stroop Task ) , and executive functioning ( Trailmaking A and B tests ) at baseline and simulated altitudes equal to 17,500 ft ( 5334 m ) and 25,000 ft ( 7620 m ) in order to obtain more information about the role of altitude exposure on cognitive tasks important for optimal functioning in the aviation environment .