parallel port connection from Arduino to Neuroscan EEG - LED flash trigger

Hello fellow Matlabers,

I've written a codefor a neuroscience experiment on Arduino where i present LED flashes at a specific rate. I've also got a parallel port with a single jumper cable (connected to PIN8). The purpose of the experiment is to see brain response to stimuli but i am pretty clueless on how to do. I've figured that i need to use some form of the code from here http://apps.usd.edu/coglab/psyc770/IO64.html but i don't know how to move onfrom there. Any help on the following would be greatly appreciated

1) Where on Arduino should i slot the parallel port jumper cable and how do i make matlab send trigger from the slot to the EEG?

2) What code is needed to send a trigger to the EEG everytime the voltage is >0 aka light is on?