• Description

StimTracker event marker, for connection to a variety of  EEG/ERP recording devices and a PC's parallel port.

StimTracker enables you is to send event markers from the stimulus presentation computer to a recording device, providing a USB port for this purpose, but it can also handle a range of events including: up to four photosensors, voice key, two audio channels and six TTL inputs.

Plug to Your EEG Recorder. Play.

Worry no more about stripping or splicing cables. StimTracker comes with everything you need to connect to EEG/ERP recorders and eye trackers.


同步EEG/ERP/眼動儀   記錄系統 包括光感應、聲音與其他系統

Compatible EEG/ERP Systems

  • AD Instruments
  • Brain Products
  • ANT Neuro
  • BIOPAC Systems
  • BioSemi
  • Mega Electronics
  • MindWare
  • Neuroscan
  • NIRx

Compatible Eye Trackers

  • ASL
  • SMI
  • Tobii

Mark Any Event

Your EEG or eye tracker data is vastly more useful if it includes markers that tell you precisely when certain events occurred. Except for codes sent via USB, the onset of events is detected autonomously by StimTracker, allowing it avoid delays incurred by operating systems and produce accurate markers.

Get Your Timings in Sync

When using a version of StimTracker that supports an eye tracker, event markers can also go out simultaneously to any of the supported EEG models. This guarantees that both sets of data are using the same timebase — an important criterion when analyzing the data.

All Digital

To insure the repeatability that rigorous research requires and to prevent accidental changes the controls are 100% digital and easy to use.

A Sharp Eye for Stimuli

Several prototypes were built and tested before settling on a light sensor that offered the optimum balance of speed and light frequency response. Built with its own tiny housing that is unobtrusive and practical to use.

Software Support

StimTracker has all the electronics needed to detect the onset of events and produce markers. But you can also send event codes via USB, e.g. to describe the trial being presented or whether the participant’s response was correct.


Cedrus Light Sensor

The Cedrus Light Sensor is available in two colours: black and white. Notches are molded in on three sides to allow for easy positioning on the screen.


  • Response time (dark to light) - 0.05 milliseconds
  • Response time (light to dark) - 4 milliseconds
  • Spectral sensitivity - 360-970 nm (visible light)

The response and release times are dependent on the amount of light.

The Cedrus Lightsensor is small, measuring a mere 8mm (W) by 20mm (L) including the wire’s strain relief (8 by 14mm without it).

External Input Latencies

For best performance, none of the external input sources are routed via the microprocessor. The delays between input and output are:

  • Light sensors: Less than 0.01 milliseconds - This is the latency due to StimTracker and does not include the light sensor’s response time
  • Voice Key: Less than 0.05 milliseconds after voice level rises above threshold
  • Audio: Less than 0.05 milliseconds after voice level rises above threshold
  • Digital Input: Less than 0.01 milliseconds - The latency for sending an event code depends on the baud rate selected through the driver. At the recommended 115,000 baud rate, the three byte command needed for sending an event marker takes 0.36 milliseconds to transfer.USB Port Latency

Once received, StimTracker processes the command and produces the output in less than 0.1 milliseconds.

There may be additional latencies introduced by the host computer, operation system, application, or a combination of the above, over which StimTracker has no control.

StimTracker for Tobii TX300 Eye Tracker

provides a versatile solution for you to reliably and accurately synchronize screen stimuli and eye tracking data down to an average timing accuracy of 1.7 msec. This model allows for a light sensor output to be sent simultaneously to a Tobii TX300 eye tracker and one of the many EEG amplifier models that StimTracker already supports (as well as a PC parallel port), providing researchers with a common timebase. 

A StimTracker order ships with the following:

  • StimTracker unit
  • One white Cedrus Light Sensor
  • One black Cedrus Light Sensor
  • A universal AC adapter (100-240V)
  • USB cable
  • An audio cable
  • 5 extra double-sided adhesives for the Cedrus Light Sensors