Mechanically Induced Motor Tremors Disrupt the Perception of Time.

Area of Science:

• Cognitive Neuroscience
• Human Motor Control
• Psychophysics

Background:

• Research indicates a strong link between motor activity and time perception.
• Concurrent movements can alter and improve time estimations.
• A proposed mechanism suggests movements offer a secondary duration estimation channel, integrated with sensory input.

Purpose of the Study:

• To critically test a framework where motor noise impacts time perception.
• To investigate if introducing artificial tremor into movements increases temporal estimation noise.
• To determine how motor noise effects vary with sensory modality precision.

Main Methods:

• Human participants performed robotic arm movements while estimating time intervals.
• Auditory and visual modalities were used for time estimation.
• Artificial tremor (1-3 N amplitude or 4-12 Hz frequency) was introduced to the robotic arm.

Main Results:

• Increased tremor frequency led to noisier duration estimates.
• The impact of motor noise was greater on less precise modalities (visual) compared to more precise ones (auditory).
• A drift-diffusion model successfully replicated the observed effects of motor noise on time perception.

Conclusions:

• Movement-based timing mechanisms are directly influenced by motor noise.
• Artificial tremor is a useful tool for studying the relationship between motor noise and perception.
• Findings support the framework that sensory and motor systems interact in time perception.