Sustained attention with constant cuing every 20 seconds can be held for about 1 to 5 minutes.
Constant cuing within ACL 1.4 usually requires accommodation to sporadic attention.
Attention to tracking may be captured for 40 to 60 seconds and then attention to the cue vanishes. The lack of movement in the pupils of their eyes is a signal that attention has stopped. Repeating the original cues often continues the tracking process.
Sustained attention is measured by the length of time that a response can be sustained by repeated cuing. The assistance required to sustain attention can also be measured by the number of cues required per session or per minute.