response event to writeport oddities

[Michiel Spape]

Hi,
Without thinking too long about your problem, does it make any sense if, in my quick reading, your question basically boils down to that you want to send a serial message or whatnot at the time of both the stimulus and the response? I'd say there are some pretty easy ways of doing this, depending on whether you want the stimulus object to stay there once a button is pressed (I can imagine you don't):
- how about using offsetsignaldata, as well as onset?
But as said, you probably don't want that. Then, another quick way would be to add another slide that looks exactly as your imagedisplay, but sets in directly after the stimulus object is terminated and has duration of StimulusDisplayMaxDuration - RT. Thus, another slide shows exactly (just turn off onset sync) as the previous slide stops, unbeknownst to the subject. Obviously, this next slide you can then have send stuff over the serial port.

Was that it, or did I miss something crucial? Sometimes, solutions can be pretty simple, though (I mean, I expect your problem is more complicated, but I wouldn't want you to waste precious time if you're just stuck on what might well be something very simple - a programming tip of the tongue phenomenon, so to speak)...
Cheers,
Mich


Michiel Spapé
Research Fellow
Perception & Action group
University of Nottingham
School of Psychology

-----Original Message-----
From: e-prime at googlegroups.com [mailto:e-prime at googlegroups.com] On Behalf Of andrew hill
Sent: 08 April 2010 17:12
To: e-prime at googlegroups.com
Subject: response event to writeport oddities

hi folks,

any chance this makes sense to someone?  i've been pulling my hair out metaphorically for a bit on this.

i've got a trial procedure that mimics a typical CPT, e.g. an ImageDisplay that shows either a distractor or a target for 50ms, and then a fixation slide for most of the trial. in more detail:

TrialProc:
----------------------
InLineStimMarker 
InLineResponse 
ImageDisplay (shows a stimulus requiring response or a distractor requiring nonresponse)
InLineFixDuration (Fixation.Duration = random(950,1450)
Fixation

The InLineStimMarker does a :

WritePort &H378, 0
ImageDisplay.OnsetSignalEnabled = True
ImageDisplay.OffsetSignalEnabled = True
ImageDisplay.OnsetSignalPort = &H378
ImageDisplay.OffSignalPort = &H378

and then a bunch of loops looking up a c.GetAttrib to figure out what the current stimulus type is, and set OnsetSignalData to a numerical value. this works great - sending in the codes as appropriate to BioSemi ActiveTwo, at the onset of each stimulus.   

the problem is with InLineResponse, which I've tried putting various places, and tried various code.

what I want to do is look up the response accuracy, and put it in the EEG record at the time of the response.  of course, since this is a CPT, most of the trials don't have a response, which is ok.  

the ones that do require pushing a keyboard button, and i'd like to code a 100/200 response accuracy into the EEG record when that button is pushed, but i'm not having any luck at all.

i've tried something like this:

If ImageDisplay.ACC = "1" Then
Writeport &H378, 100
else
Writeport &H378, 200
end if 

but that just puts the 100/200 codes at the time of stimulus image, and not at/during the response.

any suggestions?

thanks,
andrew

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