Visual stimulus generator VisGen

VisualGen is a flexible digital stimulus device for generation of optokinetic, smooth pursuit, saccade and fixation stimulus. Large scale stimulation could be achieved by use of video projectors displaying the calculated stimulus:

• Optokinetic bar, chess board or star patterns of programmable size, color, speed and direction
• Linear or sinusoidal oscillating smooth pursuit stimulus of programmable speed and direction
• Free programmable fixation target sequences
• Picture stimulus (BMP / JPG / GIF / PNG) for best subject attention to stimulation
• User defined targets, profiles and tests

We do not recommend to use LCD monitors for data collection in experiments using short duration stimulus displays (e.g., 1-3 refreshes). While LCD monitors are continuously illuminated and the scanning of the video memory can be conceptualized the same as a CRT, the time for a pixel to change state (i.e., rise or fall time) when it is instructed to do so is significantly different from CRT monitors and most current rise and fall times are longer than a single refresh (e.g., 20-50 ms). These characteristics of an LCD monitor can theoretically lead to inconsistent stimulus transactions.