SSVEP Stimulator using MATLAB and Psychtoolbox

This is a 4 classes (or more) flickering stimulator for Steady State Evoked Potential experiment. The software generate four different target as can be seen in this video. Youtube demo video This tool presents a stable flickering frequencies which are usable for BCI applications.

Key parameters

• Current supported target: 4 different frequencies
• Supported frequencies: [6.66, 7.5, 8.75, 10, 12, 15, 20] Hz

Prerequisites:

• 64-Bit Matlab version 7.14 (R2012a) or later
• Psychtoolbox 3: http://psychtoolbox.org/
• System Requirements: any Nvidia or AMD graphic card, built-in Intel graphic cards do not work properbly (more at Psychtoolbox website)

How to use

• Install Psychtoolbox 3
• Download this repository to your computer
• Add lcms.m and square_flicker.m to MATLab searching directory
• Run square_flicker function. A window with 4 flickering frequency should be appeared on your desktop.

Discussion

• The methodology of this software https://beta.groups.yahoo.com/neo/groups/PSYCHTOOLBOX/conversations/topics/20675

Credits

• Josh, LCMS Matlab function (Least Common Multiple Set): https://www.mathworks.com/matlabcentral/fileexchange/24670-least-common-multiple-set
• Hubert Cecotti, Ivan Volosyak, Axel Graser. Reliable visual stimuli on LCD screens for SSVEP based BCI. The 2010 European Signal Processing Conference (EUSIPCO-2010), Aug 2010, Aalborg, Denmark.
• Psychtoolbox 3.

LICENSE - "MIT License"

Author: Bob and you.