Memory drum theory: alternative tests and explanations for the complexity effects on simple reaction time

Area of Science:

• Human motor control
• Cognitive psychology
• Neuroscience

Background:

• The memory drum theory posits that simple reaction time (SRT) is influenced by response complexity.
• Previous research by Henry & Rogers (1960) established a foundational understanding of this relationship.

Purpose of the Study:

• To investigate the memory drum theory's prediction regarding SRT and response complexity.
• To explore alternative explanations for SRT, premotor time, and motor time by examining factors like anatomical unit, extent, and target size.

Main Methods:

• Experiment 1 replicated Henry and Rogers' SRT condition with 9 participants.
• Experiment 2 involved 11 participants, testing the impact of anatomical unit, extent, and target size on SRT, premotor time, and motor time.

Main Results:

• Experiment 1 replicated previous findings, supporting the memory drum theory's prediction.
• Experiment 2 revealed that increased anatomical unit primarily affected motor time, suggesting peripheral influences.
• Reduced target size increased SRT, premotor time, and motor time, with premotor time potentially linked to joint equilibrium adjustments.

Conclusions:

• While the memory drum theory's core prediction holds, alternative factors significantly modulate reaction time components.
• Motor time delays appear to stem from peripheral electromechanical factors rather than central neuromotor programming.
• Target size reduction impacts response initiation dynamics, influencing both premotor and motor phases.