[open] How to record TTL from MRI ?
Hi expert and O.S. users,
We would like to use OpenSesame for the first time to build a fMRI experiment. Since we have to change our presentation computer, we wonder what sort of ports we need…
Our experiment needs:
- to send video and audio and a TTL to an external device,
- to receive input from the response button and TTL from fMRI.
Our SR box (NNL) use a USB connection
The TTL from MRI can connected to the PC by a parallel port or another port as we want.
If we well understood the tutorial, the TTL toward an device could be sent by way of the parallel port.
The perfect PC would have at least: windows ; parallel port (TTL output) ; serial port (TTL input) ; USB (SR box).
Thus, OpenSesame would be able to manage our experiment, right ?
but it would be easier to have a laptop (so without all these ports) :
1/ Is there another way to sent the TTL (serial? USB?)
2/ Is it safe to use the USB as an emulation of the serial port ?
Every tips and hints about our installation would be nice !
thank you
Isabelle
PhD
NeuroPain from France
Comments
Hi Isabelle,
I believe @sebastiaan has answered this one already, so you might have seen his answer before (and you might have replied), but it was lost due to a server malfunction.
As far as the MRI scanner goes: I believe most TTL pulses are still sent via either parallel or serial ports. So it would be good to have a PC with both of those. OpenSesame allows you to communicate with these ports, using the parallel and the serial plug-ins.
As you say, there are USB connections that emulate a serial port (OpenSesame can communicate with these in the same way as you would with a normal serial port). Whether there are timing issues with these, I would not be able to tell you. I would imagine that these are in the order of milliseconds, so even in an event-related fMRI design you should be ok. But please do check with the manufacturers of these products, and preferably with one or more MRI geeks as well!
Good luck!
Hi !
Thank you Sebastiaan and Edwin.
So I can read and send trigger on both parallel and serial port with OpenSesame. Good point.
I wanna check all devices…
thanks again.
Isabelle