Problem with classical conditioning experiment

I would like to build an experiment in which participants are shown colored squares in the computer screen. Some of these visual stimuli will occasionally be paired with a mild electric shock to the wrist (reinforced presentation of stimuli), whereas others will not be paired with these shocks (non-reinforced presentation of stimuli). I will be assessing the skin conductance response of participants during all non-reinforced presentation of stimuli.

I have a computer with SuperLab 4.5 connected to a stim tracker via a USB cable. The stim tracker is connected to a STP100C interface (Biopac) via a CBL STP ribbon cable. The STP100C is connected to a GSR100C, a UIM100C, and an MP150 (all from Biopac), which in turn are connected to another computer with Acqkowledge 4.2 (Biopac systems). I also have a Grass stimulator that will be connected to the MP150 via a BNC cable.

My plan was to program SuperLab to trigger data collection in the Aqckowledge 4.2, which in turn will trigger electrical shocks (in trials with reinforced presentation of stimuli). However, I have not been able to do so and I don’t know what I’m doing wrong. Can anyone help me?

Thank you

Are you using the Digital Output Event type? Are you seeing the blue LED light that says “Marker” light up on StimTracker?

Yes, I am using the Digital Output and the LED light which says “marker” lights up in the stim tracker when the event occurs. When this happens, the Acqknowledge software detects the signal.

However, I am having difficulty in setting the stim tracker to trigger Acqknowledge to start data acquisition. Is it possibile to do this?

Thank you for your answer.

I contacted Biopac regarding your inquiry. Below is the response I received.

Trigger information can be sent to the MP150/100 to SuperLab using the STP100C Isolated Digital Interface module. The event trigger information coming from the visual presentation information is saved using the digital channels of the MP system. To externally trigger the MP150/100 from the presentation system, a JUMP100 Jumper Connector cable is also required.

From the visual presentation system:

  • Set the digital line that will send the trigger and assign it to a digital line (8-15) of the MP system.
  • Connect the JUMP100 between the appropriate digital I/O line on the rear of the UIM100C and the TRIG connector.
From AcqKnowledge software
  • Set to record the information on the respective digital I/O line and the external trigger option must be turned on.
  • Select [B]Setup channels[/B] from the MP menu.
  • Select [B]Digital [/B]from the Setup channels dialog and turn on the correct digital channel (check Acquire and Plot), then exit the dialog.
  • Select [B]Setup Triggering[/B] from the MP100/150 menu.
  • Select [B]Source External[/B] From the Setup Triggering dialog and set the appropriate trigger edge.
  • Click [B]Start[/B].
The system will wait to receive a trigger from the visual presentation system. A small "T" on the right-hand side of the Start button indicates that the system is waiting for a trigger.

Thank you for your answer, Monika. Since you have given me these instructions I have ordered this cable and expect it to arrive shortly.

I feel I am almost there and just have to adjust a few details before beginning my experiment.

I have another question. Since the 4 sec visual stimuli and the 200msec electrical shocks have to coterminate in my experiment (i.e., after 3.8 secs of visual stimulus presentation, participants will be shocked for 200msec), I thought about using the Digital output as a way of triggering electrical shocks. As I have written, I have an MP150 system and a S48 Grass Stimulator.

Thank you again for your help.


Use the Digital Output event type to control the 200 ms duration. Then use either a picture, or text event for your visual stimulus.