Response collection
Button boxes
We have two 4-button optical button boxes for use with the MEG. Usually all 8 outputs will be connected to the trigger box in the stimulus cabinet. The channels used are 9-16. These boxes can be used with the table insert for the MEG seat. They are a bit slippery and produce an audible click when pressed, and it might be good to put them on a mouse mat for these reasons (the mat prevents the table insert to resonate with the button click, making it a bit quieter).
ImageLink(buttonboxes.pgn, //MegCBU, height=700)
Elekta Neuromag also supplied us with two button panels, which work in a different way. There's no button but a strip of material that has to be pushed down. The normal button boxes will click when switching, but these EN panels don't give any tactile feedback. They also have a tendency to come on again if the strip is pushed deeper, producing the sequence on-off-on-off-on for a single press and release.
These panels can also be used 'upside down' and will then detect when a finger is put down. This requires the subject to lift their finger in between responses.
Testing the burron boxes
The EN trigger box on the desk has small LEDs next to each channel that show the incoming or outgoing signal. When a button is pressed, and the the box has been connected properly, one of the lights will come on. To check which channel is being activated on the PIO card or the parallel port there's a small program on the machine, called PortTest that will show the signals coming into either the PIO card or the paralle port.