Libet's Experiment: Questioning the Validity of Measuring the Urge to Move

Highlights

• Investigation of the timing of the urge to move (W) and the actual movement (M).
• Untrained subjects often confuse W time with M time.
• W time likely influenced by subjects' previous M task experience.
• W reports are probably inferred rather than introspectively perceived.

Abstract

• Subjective urge to move (W) is crucial in Libet-style experiments.
• Study assumes W time is inferred, not introspected.
• Used rotating spot method for gathering W and M reports.
• Uninformed subjects showed no significant difference between W and M when measured first.
• W values after M tasks were significantly earlier than before M tasks.

Introduction

• Libet’s research is significant in human volition and free will studies.
• Relies on introspective reports of mental states, especially the urge to move.
• The rotating spot method was used for W and M reports.
• Validity of M time measurement is supported, but W time is harder to grasp.
• W time may be artificially induced or influenced by expectations.

Experiment Assumptions

• W impression might be artificially induced and inferred.
• Influences on W reports could include previous experience or following events.
• Misleading auditory feedback and sensory feedback may affect W reports.

Participants

• Involved 35 subjects aged 19-41, recruited in two stages from various backgrounds.

Results

• No significant main effect of the order on W and M values.
• Bayes factor inconclusively suggests existence of condition effect.

Discussion

• Subjects’ ability to distinguish W from M may stem from training.
• If no true first urge to move exists, differentiation may be compliance-based.

Limitations and Recommendations

• Data from naive participants with no training.
• Results may not be comparable to studies with trained participants.
• Brief training might affect W and M values.

Conclusions

• No initial difference between W and M reports; differences appear after training.
• W reports differ significantly when measured before and after M tasks.

Funding

• Supported by Palack University Olomouc, Czech Republic.

Acknowledgments

• Thanks to Michal Kluka for language help.

These notes capture the essence of the study on questioning the validity of measuring the urge to move in Libet's experiment. It discusses the methodology, findings, and implications of the differences in reporting the urge to move and the actual movement.