Dear Chris, 

thank you very much for your initiative. I will be very glad to put up your summary on the website (note that it should be as objective as possible and stick closely to the facts). The problem with comparing eyetrackers in depth is that most sites only have one device.

In my view you're correct about the sampling rate leaving only the SR Research device at the moment. As far as IR illumination is concerned I can also report, that you can spot the SR Research illuminator, when the lights in the MSR are dimmed low or off. However, from my experience with eyetrackers that seems to be always the case (SR Reserach and ASL long range products?).
Two things that you didn't mention in your list of criteria are:
(1)  the level of residual artefacts in the MEG signals or, equivalently,  the closest possible distance to the eye that you can reach without unacceptably large artefacts.
(2) Software and hardware interoperability with MEG devices (i.e. output to generic ADC channels of the MEG, compatibility of sampling rates (eyetracker/MEG) ) and stimulus presentation software.

Since you're relatively close, you could also have a look at our installations in the MRI (ASL longrange, Resonance technology goggles) and MEG (SR Research) in Frankfurt.

Michael Wibral
(Section Editor of the "Instrumentation - Peripherals" section)






-----Ursprüngliche Nachricht-----
Von: "Christopher Bailey" <[log in to unmask]>
Gesendet: Sep 24, 2010 5:44:59 PM
An: [log in to unmask]
Betreff: On MEG-compatible eye-trackers

>Dear MEG Community,
>
>We are building an MEG-lab here in Aarhus, Denmark, and are in the
>process of sorting out our peripherals. There is not much in the
>"Instrumentation - Peripherals" -section on the website, so I would
>like to ask everyone out there with experience on eye-tracking in an
>MEG-setting the following questions. I will gladly take on the task of
>writing up a summary to be placed on the website for future reference!
>
>I would like to hear about the pros and cons associated with the
>MEG-compatible eye-tracking solutions currently on the market. I've
>been able to identify three vendors:
>
>1) SMI (http://www.smivision.com/en/gaze-and-eye-tracking-systems/products/iview-x-mri-meg.html)
>2) SR Research (http://www.sr-research.com/solutions_meg.html)
>3) ASL (http://asleyetracking.com/site/Products/EYETRAC6Series/LongRangeOptic/tabid/69/Default.aspx)
>
>I do realise there are quite a few dimensions along which to compare
>these devices, but would appreciate any insight you may have. If
>sampling rate were the only deciding factor, there would surely be
>only one way to go (2).  Another factor could be the light source
>("pure" IR vs. "ups-there's-a-little-visible-light-too") illuminating
>the iris. We would also be keen on hearing if
>fMRI-compatibility/-usability has had anything to do with your choice
>of MEG eye-tracker.
>
>Btw: Our Elekta Neuromag-system will be installed in January 2011.
>
>Best regards,
>
>Chris
>--
>Christopher Bailey, MSc
>MEG Engineer, MINDLab Core Experimental Facility
>Center of Functionally Integrative Neuroscience (CFIN)
>Aarhus University, Denmark
>
>Postal address:
>B. 10G, DNC 5th floor, Norrebrogade 44
>Aarhus University Hospital, 8000 Aarhus C
>Denmark
>
>tel. cell: +45-2674-9927
>tel. office: +45-8949-9944
>fax office: +45-8949-4400