The discrepancy in timing between synchronous signals and visual stimulation should not be underestimated

Area of Science:

• Cognitive Psychology
• Human-Computer Interaction
• Neuroscience

Background:

• Response latency is vital for understanding human behavior.
• Inaccurate timing between devices can compromise experimental validity.
• Existing synchronization methods like serial port signals and optical signals have limitations.

Purpose of the Study:

• To investigate methods for reducing time errors in response latency measurements.
• To compare the accuracy of serial port synchronization signals and optical signals.
• To develop a calibration formula for improving timing accuracy.

Main Methods:

• Utilized Psychtoolbox for generating visual stimuli.
• Employed serial port synchronization signals to assess their accuracy.
• Investigated the influence of stimulus position and refresh rates on timing.
• Developed and applied a calibration formula for optical signal timing.

Main Results:

• Serial port synchronization signals showed variable lead times influenced by refresh rate and stimulus position.
• Higher refresh rates and specific operating systems (Linux, IOPort()) improved serial port signal accuracy.
• Optical signals, with a proposed calibration formula, achieved a mean time error of -0.23 to 0.08 ms.
• Optical signals demonstrated superior accuracy and reliability compared to serial port signals.

Conclusions:

• Optical signals are recommended over serial port synchronization for accurate time synchronization in behavioral experiments.
• The developed calibration formula significantly enhances the precision of response latency measurements.
• Findings offer valuable insights for experimental design and improving data accuracy in cognitive and behavioral research.