Measuring screen brightness and generating triggers at stimulus onset

The Photo Sensor is a valuable tool to check the performance of a monitor or any experiment control software. This becomes essential if visual stimuli are planned to be presented on a tablet or cell phone display.

It can easily be attached to any screen with double-sided adhesive washers. Connected to the auxiliary input of an amplifier, it provides information on the brightness of the screen. In other words: The signal delivered by the sensor indicates when the screen turns brighter or darker.

Used in combination with StimTrak, a trigger is generated when the amount of light is higher than the (customizable) threshold, which means that the exact onset of any visual stimulus can be marked.