The effective time course of preparation

Area of Science:

• Cognitive Psychology
• Human Factors
• Neuroscience

Background:

• Reaction time (RT) research often equates the preparation period with the foreperiod (FP).
• The FP is the interval between a warning stimulus (S1) and a reaction stimulus (S2).
• Effective preparation may extend beyond the FP, starting before or continuing after it.

Purpose of the Study:

• To investigate the temporal boundaries of nonspecific preparation in RT tasks.
• To determine if preparation starts before FP onset or continues after FP offset.
• To examine how factors like S1 duration, S2 luminance, and stimulus-response compatibility influence preparation timing.

Main Methods:

• Factorial design varying FP duration with S1 duration, S2 luminance, or stimulus-response compatibility across four experiments.
• Analysis of reaction time (RT) as a function of FP duration under different experimental conditions.
• Examination of RT-FP functions to infer the timing of nonspecific preparation.

Main Results:

• Nonspecific preparation commences at S1 onset for short FPs but shifts to FP offset for longer FPs.
• Preparation extends into the stimulus (S2) encoding stage.
• Nonspecific preparation ceases before the response selection stage.

Conclusions:

• The effective preparation period in RT tasks is dynamic and not solely defined by the FP.
• Preparation timing is influenced by FP duration and potentially other stimulus characteristics.
• Understanding preparation boundaries is crucial for accurately modeling cognitive processes in RT tasks.