About this exercise
The Sustained Attention to Response Task (SART) is a long vigilance paradigm.
Most trials are "go" (any digit except 3) so the motor response becomes automatic. The rare "no-go" (3) tests your ability to interrupt an established rhythm.
Errors tend to cluster late in the session as attention drifts — this is the hallmark of vigilance decrement.
Practice in 3-5 minute sessions improves your ability to sustain focus.