By AnnaShu - 11/24/2014
Hi all,
I have a problem with TTL signals sent through parallel port to my EEG recording software SCAN 4.3.
I have designed a verbal dot probe paradigm in inquisit 3 and my cue signals work fine, however, target marker do not ppear in the SCAN software.
Here is how I have defined the ports:
###########################
cue ports
###########################
<port pleasant_L_signal>
/ port = lpt1
/ subport = data
/ items = ("00000001")
</port>
1
<port pleasant_R_signal>
/ port = lpt1
/ subport = data
/ items = ("00000011")
</port>
3
<port unpleasant_L_signal>
/ port = lpt1
/ subport = data
/ items = ("00000111")
</port>
7
<port unpleasant_R_signal>
/ port = lpt1
/ subport = data
/ items = ("00001111")
</port>
15
<port neutral3_L_signal>
/ port = lpt1
/ subport = data
/ items = ("00011111")
</port>
31
<port neutral3_R_signal>
/ port = lpt1
/ subport = data
/ items = ("00111111")
</port>
63
##########################
target ports
##########################
****************pleasant****************
<port pleasantleft_valid_signal>
/ port = lpt1
/ subport = data
/ items = ("11100000")
</port>
224
<port pleasantleft_invalid_signal>
/ port = lpt1
/ subport = data
/ items = ("11110000")
</port>
240
<port pleasantright_valid_signal>
/ port = lpt1
/ subport = data
/ items = ("01111111")
</port>
127
<port pleasantright_invalid_signal>
/ port = lpt1
/ subport = data
/ items = ("11111111")
</port>
255
***********unpleasant*******************
<port unpleasantright_valid_signal>
/ port = lpt1
/ subport = data
/ items = ("10000000")
</port>
128
<port unpleasantright_invalid_signal>
/ port = lpt1
/ subport = data
/ items = ("11000000")
</port>
192
<port unpleasantleft_valid_signal>
/ port = lpt1
/ subport = data
/ items = ("11111000")
</port>
248
<port unpleasantleft_invalid_signal>
/ port = lpt1
/ subport = data
/ items = ("11111100")
</port>
252
**************neutral*****************
<port neutral3left_valid_signal>
/ port = lpt1
/ subport = data
/ items = ("01010101")
</port>
85
<port neutral3left_invalid_signal>
/ port = lpt1
/ subport = data
/ items = ("01111110")
</port>
126
<port neutral3right_valid_signal>
/ port = lpt1
/ subport = data
/ items = ("01111000")
</port>
120
<port neutral3right_invalid_signal>
/ port = lpt1
/ subport = data
/ items = ("01111100")
</port>
124
and here is what my trials look like (one example):
<trial pleasantright_valid_isi50>
/ pretrialsignal = (lpt1, 96)
/ response = timeout (1700)
/ correctresponse = (112)
/ validresponse = (104, 112)
/ responsemessage = (noresponse, pnoresponse, 50)
/ responsemessage = (112, pkorrekt, 50)
/ responsemessage = (104, pfalsch, 50)
/ stimulustimes = [0=fixation; 500= pleasantright, neutral_1_left, pleasant_R_signal; 1000= erasewords_right, erasewords_left; 1050= proberight, pleasantright_valid_signal; 1200=eraseprobe_right]
</trial>
What have I done wrong? Any help is greatly appreciated!
Anna
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By Dave - 11/24/2014
Once a port stimulus is "displayed" via a <trial>'s /stimulustimes or -frames, it *remains* raised for the entire duration of the trial.
/ stimulustimes = [0=fixation; 500= pleasantright, neutral_1_left, pleasant_R_signal; 1000= erasewords_right, erasewords_left; 1050= proberight, pleasantright_valid_signal; 1200=eraseprobe_right]
To be able to discern between the two TTL signals highlighted above
<port pleasant_R_signal>
/ port = lpt1
/ subport = data
/ items = ("00000011")
</port>
<port pleasantright_valid_signal>
/ port = lpt1
/ subport = data
/ items = ("01111111")
</port>
you'll want to set all bits to low sometime between them. I.e. define
<port allbitstolow>
/ port = lpt1
/ subport = data
/ items = ("00000000")
</port>
and do something along the lines of
/ stimulustimes = [0=fixation; 500= pleasantright, neutral_1_left, pleasant_R_signal; 1000= erasewords_right, erasewords_left, allbitstolow; 1050= proberight, pleasantright_valid_signal; 1200=eraseprobe_right]
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By AnnaShu - 11/24/2014
Hi Dave,
Thank you very much, this works perfectly!
Anna
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