responses and fmri triggers simultaneously through parallel port

[Ecker, Johannes]

Hi,

 

I have a question concerning the parallel port use in e-prime and how to
use multiple devices through it. We have a response mouse and the
scanner triggers both connected to the parallel port, the mouse uses the
data pins 2-9 and the fmri trigger pulses (TTL) are read in through pin
10. For instance I have a slide to which the participant has to give an
answer through the response mouse, but this response should not
terminate the slide. This should be timed by the fmri-triggers. The
scanner sends 26 pulses in one TR (2.5 sec). So I added 2 port devices
in the Input/Duration Tag of the slide, one for the mouse and one for
the TTL Signals. The mouse is on address 378 and the TTL on 379. The
Mouse device has 2 allowable values, and the Correct Response is coded
in a previous list. I set the mouse on "Duration: Infinite" and "End
Action: none", and the TTL is set to "Duration: Infinite" and "End
Action: Terminate", and under "Advanced" I set the Maxcount to the
amount of triggers that the Slide should be on screen. However, as soon
as I press a button on the mouse, the slide does not go away.
Apparently, it ignores the other port device (TTL) and keeps going for
the set duration (infinite) of the device used. If I don't press any
mouse button, the experiment runs through without problems. Can anyone
tell me how to get the mouse responses without interfering with the
Maxcount of the other TTL port device?

 

Many thanks,

Johannes

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