Test implementation
Common system settings
- Screen refresh rate: 60 Hz
- Audio buffer: 512 samples (128 will not work reliably on all machines)
Test 1 - Stimulus presentation latencies
- Wait once 10 s before starting the procedure to allow equipment to be initialized
- Present a black screen for 300 ms (18 frames), followed by the simultaneous onset of a TTL pulse (
255, offset with0), a white square (top center of the screen, 400 x 400 pixels), and a sound (sine wave, 440 Hz), all lasting 200 ms (12 frames); repeat this 1000 times
Test 2 - Response time latencies
Keyboard
- Wait once 10 s before starting the procedure to allow equipment to be initialized
- Present a black screen for 300 ms (18 frames), followed by a white square (top center of screen, 400 x 400 pixels) for 200 ms (12 frames), and measure (and log) the subsequent keyboard response time; repeat this 1000 times
Serial port (PsychoPy, OpenSesame & Expyriment only)
- Wait once 10 s before starting the procedure to allow equipment to be initialized
- Present a black screen for 300 ms (18 frames), followed by a white square (top center of screen, 400 x 400 pixels) for 200 ms (12 frames), and measure (and log) the subsequent serial port response time; repeat this 1000 times
External equipment
Test 1 - Stimulus presentation latencies
- Record audio onsets and offsets at speaker jack
- Record visual onsets and offsets on screen
- Record the TTL pulses
Test 2 - Response time latencies
Keyboard
- Trigger keyboard response 100 ms after onset of white square at top center of screen
Serial port (PsychoPy, OpenSesame & Expyriment only)
- Trigger serial port response 100 ms after onset of white square at top center of screen