OpenSesame and NETStation Package Plugin

Comments

• imnotamember

  March 2017

  Hello Michael,

  I'm actually the developer for the Pynetstation Plug-In. It was a brief side-project for exactly the purposes you mentioned (getting out of the E-Prime universe). It worked to a point, but I'm a lowly grad-student with very little free time for maintenance/perfecting this project. I do plan on revisiting it this summer to make a more advanced and customizable version which you could easily integrate into any experiment. I'm sure you're more concerned with what can be done today though.

  Yes, when first working with this software there is typically a LOT more jitter than E-Prime (tested using EGI's offset kit). I typically find offsets for visual onset times to be in the range of +-15 ms. E-Prime usually comes out to about +-3 ms. That's huge, especially when you're recording at 1000hz. In discussing this issue with some colleagues, the discrepancy relates to your hypotheses in 3 potential situations:
  1) You're hypotheses are based on ERP's of early components (0ms-150ms after stimulus onset)
  2) You're hypotheses are based on ERP's of later components (150ms+ after stimulus onset)
  3) You're performing frequency analysis

  If you're in situation 1, this is really dangerous as you have smaller, more time-condensed components of interest. Doing an average of a P50 with +-15ms jitter would certainly flatten the component heavily, and be completely mis-representative of the actual component being studied (although P50 is typically audio related and doesn't bear on visual onset times, in which case you have more issue with audio timing than visual).

  If you're in situation 2, this is not as dangerous as your waveforms are more spread over time (typically the 300ms+ components) and therefor take less damage as a result of the jitter (it will effect the onset/offset of the components, but less the amplitude). There are the 150ms-300ms components which could be considered in greater danger, but those seem to do alright so far so I take that as they are such strong effects that spreading doesn't have as enormous an impact (still, an impact none the less).

  Finally, if you're in situation 3, then it depends. Are you doing time-frequency analyses or just frequency analyses? This will have more effect on time-frequency analyses, but potentially it isn't as major a problem as it is for ERP (I haven't had a chance to investigate this well enough to say). I have a sense that frequency analyses would be relatively safe but that's also debatable.

  In conclusion, I would say that if you have something you're very concerned about timing for, use PsychToolbox or PsychoPy at the moment. I've tried a number a ways to toy around with the timing of graphics cards/backends/system configurations to get timing as precise as E-Prime in OpenSesame, but haven't gotten it to work just yet. This millisecond timing precision issue could just be me doing something wrong, but I haven't had enough testers out there yet to confirm anything (welcome to the club!).

  If you have a chance and could run a simple experiment to test visual offsets with an EGI offset kit and send me the resulting offset file then I'll see if I can help, or at least add it to the files I've already collected on this issue to try and figure out the resolution.

  TL;DR
  It's not there yet.

  Best,
  Josh Zosky
• imnotamember

  June 2017

  UPDATES
  Hey Mike,

  I'm in the process of updating the PyNetstation Plug-in for better accuracy in timing and it should be completed very shortly. Can you tell me what graphics card you were using which reported the offset jitter? Also, which backend were you using? The PsychoPy backend is currently most reliable but hopefully the xpyriment backend will soon be just as reliable.

  Thanks,
  Josh
• neuropacabra

  July 2017

  Hey, we should start some communication again :-)

  Me and friend of mine would like to participate on getting OpenSesame working eith EGI system. So testin, some code...feel free to ask. I dont know the HW specs of computer - it is some W7 Geodesic SW preinstalled with E-Prime 2. Regular desktop (some Optiplex 7xxx).

  We used Expyriment backed and measured with photo diode the real onset to measure a jitter on about 100 image repetitions (trials = same pictures).

  I guess we should take a closer look at it, right?

  Thank you,
  Michael

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• imnotamember

  October 2017

  Hey Mike,

  Sorry for the delay. The academic year put an end to my earlier endeavors on this plugin.

  The plug-in should definitely be used with psychopy backend at the moment as it has a specific function which aids in timing accuracy of stimuli onset. That has proven to be relatively successful at keeping jitter at a maintainable amount (1ms~4ms). It definitely depends on the computer's strengths in processing/ram/graphics card though.

  I was recently brought to the attention of another method other than what is currently used to keep timing accuracy between PyNetstation and Netstation. Apparently EGI has (as of 300-series amplifiers) quietly implemented an NTP server which provides greater timing accuracy than the typical method. I'm planning on implementing that soon (within the next 3 weeks) and detailing my success/failure here for others.

  Once I get to test that I'll update the current repository with a fully tested and functional plug in that should be as good as it can get.

  Best,
  Josh

  P.S. If anyone else is interested in this please let me know. The more demand there is out there the more time I'll try dedicating.
• vserer

  November 2017

  Hi everybody,
  We are just about to start an endeavour of using an SMI eyetracker alongside a netstation 3 setup through OpenSesame, and I was wondering if anybody had an example paradigm they wouldn't mind us taking a look at in terms of setting up netstation triggers and that sort of thing.

  Cheers,
  Nathan
• imnotamember

  August 2019 edited August 2019

  Hey Nathan,

  Sorry for the crazy late response. I presume you got something going already (really sorry about that) but if you or anyone else is interested I'll be refining the plug-in soon to make it a fully integrated part of OpenSesame. There will also be some major updates regarding how the underlying code works. Stay tuned! (or email me directly with questions at: joshua.e.zosky@gmail.com

  Best,

  Josh
• mattm

  April 2021

  Just reviving this, what's the current best practice for sending triggers to Netstation using Opensesame?
• imnotamember

  April 2021

  Hi @mattm ,

  I'm the sole maintainer of the PyNetstation plug-in for OpenSesame and semi-maintainer of the `egi` module. Currently the most reliable way to send triggers to NetStation within OpenSesame is via inline scripts using the `egi` module as I haven't had time to update the plug-in in a couple years.

  This might require some coding knowledge on your behalf, but I've helped a number of people over the years get it integrated into their own set up and could potentially help you out if time allows (my schedule is pretty hectic now with a 1 year old and a dissertation to complete).

  Can you provide some details about your plans for using OpenSesame with NetStation and I'll see if I can help?

  Best,

  Josh
• mattm

  May 2021

  Thank @imnotamember, sorry for the late reply, a couple of other things jumped in front of me.

  I'm not afraid of coding (I have a software engineering degree), I'm happy to put something together from the egi module.