Millisecond Forums

nBack with random failure

https://forums.millisecond.com/Topic20047.aspx

By Korsch - 11/4/2016

Hello there,
we run an experiment at the moment where we use a 2-back task with a set of 8 circles. However, some participants report that the goal stimuli are not shown. Instead there is just the neutral stimulus appearing over the whole time of the experiment. By a short flash during the presentation you can tell it is renewed with every trial. Record data shows that the keyboard input is still detected, but without influence. 
I have the feeling it particularly appears on older computers, but I am not sure...
What could cause this problem?
Thanks for your help.
By Dave - 11/4/2016

> I have the feeling it particularly appears on older computers

This would suggest defective graphics card drivers as the cause of the problem; particularly older nVidia drivers have bugs that prevent them from displaying stimuli as instructed. If that is the case, updating the drivers on those machines to the latest versions available from the system's or graphics card's manufacturer should resolve the issue.