Response-locked ERPs

mservant

Hi,
I been a Psychopy user for years and I recently moved to OpenSesame. The interface is fantastic and I enjoy it very much.
Similar to PsychoPy, OpenSesame samples RT at the monitor's refresh rate. In general I have no problem with this (cf. Ulrich & Giray, 1989), except when I do response-locked ERP analyses or trial-to-trial EMG analyses. In these particular cases, it seems important to get a precise timestamp for the response (and the associated trigger), although I am not sure whether this would have any impact on electrophysiological results (any comment on this issue is welcome). I was wondering whether Sol Simpson's iohub module can be easily accessed within OpenSesame, or whether OpenSesame has his own module for running a process not tethered to the monitor's refresh rate.
Thanks again for the fantastic software!

_**ps: **_is there any teaching ressource for OpenSesame (english or french)?

sebastiaan

Hi Mathieu,

In these particular cases, it seems important to get a precise timestamp for the response (and the associated trigger), although I am not sure whether this would have any impact on electrophysiological results (any comment on this issue is welcome).

It probably has no practical effect. But as a matter of principle I can see why you'd like to be as precise as possible.

I was wondering whether Sol Simpson's iohub module can be easily accessed within OpenSesame

I have never used it myself, so I cannot give you detailed instructions. But yes, I imagine it's possible if you use the psycho backend. That would be an interesting exercise.

or whether OpenSesame has his own module for running a process not tethered to the monitor's refresh rate.

No

_**ps: **_is there any teaching ressource for OpenSesame (english or french)?

I assume you've already seen the tutorials on the documentation site? There are even two French tutorials, which @lvanderlinden made some years ago. But they're a bit out of date. And there are YouTube tutorials.

Cheers!
Sebastiaan

mservant

Thank you Sebastiaan!