e-prime sending markers to biopac Acqknowledge

[Janet D. Larsen]

I have the Biopac MP100 with the STP100C.  I have 8 EEG amplifiers with which I hope to record EEGs while participants do a lexical decision task with related and unrelated priming words, half of which are masked.  That gives me six types of trials that participants will experience (related primes, unrelated primes and nonwords, with each being either masked or not masked.)  I wrote the lexical decision program in e-prime and have collected pilot data.  I have a very nice unconscious priming effect for the primed words.  Now I want to see if I can replicate the findings of a N400 response for the priming effect reported by Kiefer.  Here is what I think I need to do.  I want to send the AcqKnowledge system a signal which will insert a marker indicating the type of stimulus in the EEG record at the beginning of each trial.  The AcqKnowledge system has a provision for user defined event markers, inserted by pressing a function key.  In AcqKnowledge, I have defined the function ke!
ys as the different trial types and, when I press the function keys, the appropriate markers appear in the EEG record.  Within my e-prime program I am trying to send a signal from the computer which presents the stimuli to participants through the parallel port on the STP100C. I have inline code that is sending (or is supposed to send) the code for the function keys out the parallel port, but this does not put makers in the record like pressing the function keys does.  

Looking at suggestions about how to do this, I have been trying the Writeport &H378, <code for key> approach.  With some help from my IT friends I have been able to establish that e-prime is actually sending a signal to the STP100C.  There is not, however, a marker being place in my AcqKnowledge record.  I have tried sending the HEX code for function keys and the ASCII code for function keys, and neither works. Any suggestions?

Janet D. Larsen, Ph. D,
Professor of Psychology
Chair, Department of Psychology
John Carroll University
University Heights, OH 44118
Phone  216-397-4363
FAX 216-397-1633
e-mail  larsen at jcu.edu