Millisecond Forums

reaction time measures accuracy influenced by background processes

https://forums.millisecond.com/Topic20463.aspx

By mariela - 1/10/2017

Dear Inquisit-Team,

in our research group we were discussion the two questions:
1) Can we run real-time anti-virus software at the same time as running experiments with inquisit or would these background processes impact the reaction time measures accuracy?
2) If there is an influence, is there any way that you could suppress background processes whenever inquisit scripts are running to ensure accuracy of reaction time measures?

Thanks and best,
Mariela
By Dave - 1/11/2017

mariela - Wednesday, January 11, 2017
Dear Inquisit-Team,

in our research group we were discussion the two questions:
1) Can we run real-time anti-virus software at the same time as running experiments with inquisit or would these background processes impact the reaction time measures accuracy?
2) If there is an influence, is there any way that you could suppress background processes whenever inquisit scripts are running to ensure accuracy of reaction time measures?

Thanks and best,
Mariela

1) Yes, you can have AV software running in the background, and on modern systems / under normal circumstances this should not affect RT measurement. It is however true that almost any background process can affect timing (display timing moreso than response timing). If, for example, the AV detects a virus right in the middle of an experiment and hence escalates its process priority / monopolizes the system's CPU, this might disrupt timing. So, as a coarse rule of thumb, you are right in that the fewer background processes the better.
2) It's not quite clear what you mean by "suppress" background processes; Inquisit cannot shut down or temporarily suspend background processes entirely (in case of AV that would be irresponsible). What Inquisit does when executing an experiment is, among other things, raise its process priority to ensure it gets sufficient processor cycles, memory etc. such as not to be disturbed -- timing-wise -- by other applications "stealing" processing cycles or other resources.
By mariela - 1/11/2017

Thank you very much for the quick reply!