Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

Supported by

Trackloss with Tobii

Hi everyone,

I'm using Open Sesame to run visual word experiments with a Tobii X2-60. I'd like to find a way to add a variable, so to register whether for each datapoint the data is "valid" or not. Basically we want to know if the subject was blinking or looking away. Looking at the tobii raw data, the tobii marks invalid data points in two ways:

the first is through the variable Validity: 0 if invalid, 1 if valid

the second is through the value it assign to X-Y eye-gaze position: -1 if invalid, other coordinates if valid

This is a link to the Opensesame file of my experiment, with all the materials and two sample output files, the raw from tobii and the log from Open Sesame.

Could anyone help to integrate "validity" into my script?




  • Hi Enzo,

    I haven't worked with the Tobii, but I suppose the validity variable is defined per sample. So at a sampling rate of 500Hz, you get every 2ms the information whether a sample was valid or not. During a trial you will have many samples, so you would need to define how many invalid samples would count as a blink or as looking away (There are probably recommendations online). Getting the sample is rather easy. In an `inline_script`, you can call `x,y = exp.pygaze_eyetracker.sample()`, but this will only give you a single sample. To monitor an entire trial, you would have to wrap everything into a (while) loop, including your stimulus presentation. Depending on how feasible that is in terms of your paradigm, it might make more sense to do this offline (during data analysis). So, basically parse the samples into events (saccades, fixations, blinks) and check per trial whether blinks occurred, or whether a fixation lies outside the allowed region.

    Hope this helps,


    Buy Me A Coffee

  • Hi Eduard,

    yes, as you suggest, I'm aiming at obtaining validity for each sample.

    Apart from getting the x and y coordinates from tobii through x,y = exp.pygaze_eyetracker.sample(), is possible to import also the value for an extra variable that I think is part of the tobii output, whose name is "validity"? I think that for each sample, the tobii gives back a binary value 0 or 1.



  • Hi Enzo,

    There might. You can check the github page of Pygaze to find the part in the tobii implementation that handles accessing Tobii information.

    However, if I remember correctly Tobii codes invalid samples as (-1, -1).

    So, it should be easy to define validity yourself, both online during your experiment as well as offline during analysis.


    if sample == (-1,-1): var.validity = 0
    else: var.validity =1

    hope this helps.


    Buy Me A Coffee

Sign In or Register to comment.

agen judi bola , sportbook, casino, togel, number game, singapore, tangkas, basket, slot, poker, dominoqq, agen bola. Semua permainan bisa dimainkan hanya dengan 1 ID. minimal deposit 50.000 ,- bonus cashback hingga 10% , diskon togel hingga 66% bisa bermain di android dan IOS kapanpun dan dimana pun. poker , bandarq , aduq, domino qq , dominobet. Semua permainan bisa dimainkan hanya dengan 1 ID. minimal deposit 10.000 ,- bonus turnover 0.5% dan bonus referral 20%. Bonus - bonus yang dihadirkan bisa terbilang cukup tinggi dan memuaskan, anda hanya perlu memasang pada situs yang memberikan bursa pasaran terbaik yaitu Bola168. Situs penyedia segala jenis permainan poker online kini semakin banyak ditemukan di Internet, salah satunya TahunQQ merupakan situs Agen Judi Domino66 Dan BandarQ Terpercaya yang mampu memberikan banyak provit bagi bettornya. Permainan Yang Di Sediakan Dewi365 Juga sangat banyak Dan menarik dan Peluang untuk memenangkan Taruhan Judi online ini juga sangat mudah . Mainkan Segera Taruhan Sportbook anda bersama Agen Judi Bola Bersama Dewi365 Kemenangan Anda Berapa pun akan Terbayarkan. Tersedia 9 macam permainan seru yang bisa kamu mainkan hanya di dalam 1 ID saja. Permainan seru yang tersedia seperti Poker, Domino QQ Dan juga BandarQ Online. Semuanya tersedia lengkap hanya di ABGQQ. Situs ABGQQ sangat mudah dimenangkan, kamu juga akan mendapatkan mega bonus dan setiap pemain berhak mendapatkan cashback mingguan. ABGQQ juga telah diakui sebagai Bandar Domino Online yang menjamin sistem FAIR PLAY disetiap permainan yang bisa dimainkan dengan deposit minimal hanya Rp.25.000. DEWI365 adalah Bandar Judi Bola Terpercaya & resmi dan terpercaya di indonesia. Situs judi bola ini menyediakan fasilitas bagi anda untuk dapat bermain memainkan permainan judi bola. Didalam situs ini memiliki berbagai permainan taruhan bola terlengkap seperti Sbobet, yang membuat DEWI365 menjadi situs judi bola terbaik dan terpercaya di Indonesia. Tentunya sebagai situs yang bertugas sebagai Bandar Poker Online pastinya akan berusaha untuk menjaga semua informasi dan keamanan yang terdapat di POKERQQ13. Kotakqq adalah situs Judi Poker Online Terpercayayang menyediakan 9 jenis permainan sakong online, dominoqq, domino99, bandarq, bandar ceme, aduq, poker online, bandar poker, balak66, perang baccarat, dan capsa susun. Dengan minimal deposit withdraw 15.000 Anda sudah bisa memainkan semua permaina pkv games di situs kami. Jackpot besar,Win rate tinggi, Fair play, PKV Games