Online psychophysics: reaction time effects in cognitive experiments.

Area of Science:

• Cognitive Psychology
• Psychological Methods
• Human-Computer Interaction

Background:

• Online data acquisition for behavioral research is increasing.
• Feasibility of online psychophysics requires further investigation.
• Comparing lab and online settings is crucial for data validity.

Purpose of the Study:

• Replicate five key experimental psychology paradigms online and in-lab.
• Assess the impact of technology and environment on data acquisition.
• Determine if online psychophysics can substitute or complement lab studies.

Main Methods:

• Implemented Stroop, Flanker, visual search, masked priming, and attentional blink tasks.
• Utilized three settings: classical lab, web-in-lab, and fully online (web).
• Controlled for software and design consistency across settings.

Main Results:

• Observed fixed additive timing offsets in web (37 ms) and online (87 ms) settings compared to lab.
• Successfully replicated task-specific effects, except for the priming paradigm.
• Found no significant differences in error rates across settings.
• Identified browser type as a potential factor influencing reaction times.

Conclusions:

• Online psychophysics is a feasible complement or substitute for lab-based data collection.
• Timing offsets are present but do not compromise data equality regarding error rates.
• Further research is needed to understand browser influences on reaction time data.