Coding of Outcomes
Theoretical variables
Of primary interest in this study was the effect of exercise on cognitive
processes identified by the four theoretical positions (speed, visuospatial,
controlled processing, and executive control). Therefore, each task (or
condition within a task) was categorized as to whether each of the four
theoretical positions would predict that the task would be differentially
sensitive to improvements in aerobic fitness. A task was coded as 1 for a
given theoretical position if it should show differential improvement according
to that position, and given a 0 otherwise.
Effect sizes were coded as belonging to the speed category if the
task represented a measure of low-level neurological functioning, such
as simple reaction time (e.g., the speed with which one can make a
manual response to a flash of light) or finger-tapping speed. Likewise,
effect sizes were coded under the visuospatial category if the task
tapped the participants’ ability to transform or remember visual and
spatial information (e.g., viewing three line drawings and then replicating
them from memory as in the Benton Visual Retention Task). Effects
coded to represent controlled processes were from tasks that
require, at least initially, some cognitive control (e.g., pressing one key
when presented with the letter C, but pressing a different key for the
letter M, as in a choice reaction time task), but do not have those char-