# Lapses and mean reaction time in Psychomotor Vigilance Test (PVT)

I am analyzing Psychomotor Vigilance Test (PVT) data. Can somebody tell me if I have to include reaction times associated to "laspes" when I calculate the mean reaction time?

I am analyzing Psychomotor Vigilance Test (PVT) data. Can somebody tell me if I have to include reaction times associated to "laspes" when I calculate the mean reaction time?

## All Answers (7)

Riccardo Russo· University of EssexStephan Bandelow· Loughborough UniversityJoy Perrier· Netherlands Institute for NeuroscienceJoy Perrier· Netherlands Institute for NeuroscienceI checked the mean reaction time distribution and it's log-normal. So, I will log transform RTs. I have to do that for each subject havn't it?

Concerning the other approach, what is the goal? Observe distribution of mean RTs ?

Thanks!

Stephan Bandelow· Loughborough UniversityNot sure what 'the other approach' refers to, but if you meant counting lapses then it would be to make explicit distinction between a slow response and a lapse. Since lapses are simply slower than whatever cut-off you choose, the actual RT on these becomes irrelevant. Hence you can only count the number of lapses, and that would be best treated as a Poisson distribution (for counts of discrete events in a given unit of time or space).

I hope this makes sense,

Stephan.

Joy Perrier· Netherlands Institute for NeuroscienceJoy

Stephan Bandelow· Loughborough UniversityStephan.

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