OpenSesame

Selecting words is only the first step in preparing a psycholinguistic experiment. This post uses lexsync to match high- and low-frequency items, balance them across lists, and export timed PsychoPy and OpenSesame scripts that send electroencephalography (EEG) triggers, plus a jsPsych version that logs event markers.

The result shows a varying delay of around 2 seconds on average. It would be very helpful for us if we could cut down this delay, as it adds up. To try to achieve this, I reduced the number of variables logged, from the default 363 to 34 important variables. Unfortunately, this change did not result in a reduction of the delay.

Python inline script for OpenSesame that sends EEG triggers via serial port for event-related potential experiments, adapting solutions from various platforms to work with serial rather than parallel ports.

I'm sending the triggers in a binary format because Python requires this. For instance, to send the trigger 1, I run the code serialport.write(b'1'). I have succeeded in sending triggers in this way. However, I encounter two problems. First, the triggers are converted in a way I cannot entirely decipher. For instance, when I run the code serialport.write(b'1'), the trigger displayed in BrainVision Recorder is S 49, not S 1 as I would hope (please see Appendix below). Second, I cannot send two triggers with the same code one after the other. For instance, if I run serialport.write(b'1'), a trigger appears in BrainVision Recorder, but if I run the same afterwards (no matter how many times), no trigger appears. I tried to solve these problems by opening the parallel port in addition to the serial port, but the problems persist.

Solution for randomly intermixing stimuli from two different loops in OpenSesame by distributing sentence words across columns and using conditional Run if statements to control presentation.

Python inline script for OpenSesame that automatically loads participant-specific parameters from a CSV file, enabling complex counterbalancing schemes beyond the standard interface options.