Timing of the intention to act reflects action feedback expectancy

Area of Science:

• Neuroscience
• Cognitive Psychology

Background:

• The neurocognitive basis of intention is debated, with theories focusing on predictive or postdictive processes.
• Understanding intention's timing is crucial for discerning predictive versus postdictive mechanisms.

Purpose of the Study:

• To investigate whether the expectancy of sensory feedback influences the perceived timing of intention.
• To explore the role of uncertainty in action-related sensory feedback on intention judgments.

Main Methods:

• Utilized the Libet clock method to measure perceived intention timing ('W' judgments).
• Manipulated the certainty of receiving haptic feedback during voluntary actions across two experiments.
• Experiment 1: 100% feedback, 0% feedback, or 50% random feedback.
• Experiment 2: 100%, 75%, and 25% probability of haptic feedback.

Main Results:

• Perceived intention timing ('W') was delayed under conditions of sensory feedback uncertainty (50% in Experiment 1).
• A linear delay in 'W' judgments was observed as the probability of haptic feedback decreased in Experiment 2.
• These delays occurred regardless of the actual presence or absence of feedback, highlighting the role of expectancy.

Conclusions:

• The expectancy of action-related sensory feedback plays a significant role in determining the reported time of intention.
• Findings support the idea that intention timing is not solely based on internal predictive models but is modulated by sensory expectancies.