Event Triggers

Here is a quick reference section on integrating Mentalab Explore hardware with third-party solutions.

Event markers allow you to timestamp important points in your EEG signal. There are three kinds of event markers presented in the diagram below. The first two are hardware-generated. The third is software-generated.

Button press (Hardware)

You can create an event marker in your EEG recording by pressing your amplifier’s button. Button press markers have numbered codes between 0 and 7. The event marker whose code is 7 will be followed by an event marker whose code is 0. For more information, see the Button Command Guide.

TTL pulse (Hardware)

You can use TTL pulses to generate event markers. These markers have a latency of around 200 microseconds. To do this, you will need three pieces of hardware:

• A USB to TTL pulse generator, called the Mentalab trigger stick¹.
• A trigger isolator: a specialized piece of hardware that prevents sudden noise.
• A USB to USB-C cable. This will connect the trigger stick to the trigger isolator.

The trigger stick connects to the USB port of your host machine. The isolator connects to your amplifier’s USB-C port.

Once configured, you can use any serial library, such as Python’s pyserial, to generate 10 μs pulses from your host machine to your amplifier.

TTL pulses are recorded in your amplifier’s marker file with code in_0. These markers will behave the same as push button markers.

Software marker

You can generate event markers using Mentalab software (Explore Desktop and the APIs), or using external software, like LSL, OpenViBE, and psychopy.

Explore Desktop, explorepy can generate software markers containing text values. These markers are recorded in the marker file with sw_ prefixed to the numbered marker code.

For more information or support, do not hesitate to get in contact at: support@mentalab.com