The Psychomotor Vigilance Task (PVT) and PVT-B are extremely sensitive tools for measuring sustained attention and reaction speed. In the PVT-B, any reaction time slower than 355 milliseconds is counted as a lapse. In the standard PVT, any reaction time slower than 500 milliseconds is considered a lapse.
A constant high lapse count often means the athlete is disengaging from the task, which can occur due to boredom, loss of focus, or mental fatigue, especially during longer testing periods such as the 5- and 10-minute PVT. When this happens, the results may not accurately reflect the athlete’s true performance capacity.
We have found that performing a PVT-B both before and after training is one of the most effective ways to monitor mental fatigue. However, this method can be tedious, and athletes may become bored or lose focus, leading to inflated lapse counts.
If disengagement is suspected, we recommend using the Psychological Fatigue Tolerance Test (PFTT) as an alternative or complementary measure. The PFTT is only 90 seconds in duration and is specifically designed to measure fatigue. While the PVT/PVT-B remains the gold standard for assessing mental fatigue, the PFTT is an excellent option when a shorter, more engaging test is needed.
As a guideline, a normal lapse count should be 0 for the pre-training PVT-B and no more than 5 for the post-training PVT-B. Lapse counts higher than this may indicate disengagement rather than true fatigue.
You can learn more about the PFTT here: Monitoring Mental Fatigue in Athletes