EEG alpha activity reflects motor preparation rather than the mode of action selection

Deiber, Marie‐Pierre; Sallard, Etienne; Ludwig, Catherine; Ghezzi, Cathérine; Barral, Jérôme; Ibañez, Vicente · 2012 · OpenAlex-citations

DOI: 10.3389/fnint.2012.00059

archive: archived pipeline: cataloged verified

Get this paper ↗ (DOI — opens at the source; we link to it, we don't host it)

Summary

This study investigates whether EEG alpha-band activity (8–13 Hz) distinguishes between externally-driven and internally-driven modes of action selection, or if it primarily reflects motor preparation. The authors address a gap in understanding the neural dynamics of voluntary action, specifically contrasting actions cued by external stimuli versus those self-generated through free choice. To isolate motor preparation from execution, the researchers employed a motor priming paradigm using a preparatory stimulus (S1) and an imperative stimulus (S2). Thirty healthy participants performed unilateral finger presses under three conditions: "Full," where S1 specified the response hand; "Free," where participants freely selected the hand after S1; and "None," where S1 provided no information about the response side. EEG data were recorded using 64 scalp electrodes. The analysis focused on time-frequency power changes in the alpha band during the S1–S2 interval and calculated motor-related amplitude asymmetry (MRAA) to assess lateralized sensorimotor activity. Statistical comparisons included repeated measures ANOVAs on alpha power across defined regions of interest and correlations between MRAA amplitude and preparatory patterns. Behavioral results showed similar reaction times for Full and Free conditions, which were significantly faster than the None condition. EEG findings revealed that alpha event-related desynchronization (ERD) was strongest in the None condition, reflecting high attentional engagement due to uncertainty. In contrast, Full and Free conditions exhibited smaller posterior alpha ERD accompanied by midparietal alpha event-related synchronization (ERS), suggesting the inhibition of task-irrelevant visual processing once motor preparation began. Crucially, significant MRAA was observed in both Full and Free conditions, indicating lateralized motor preparation, but not in the None condition. Further analysis categorized trials by MRAA amplitude, revealing two distinct functional patterns: a "motor alpha pattern" characterized by large MRAA and midparietal ERS, and an "attentional alpha pattern" with small MRAA and dominant posterior ERD. These patterns appeared in both external and internal selection modes. The study concludes that alpha oscillatory activity does not differentiate between the mode of action selection (external vs. internal) but rather reflects the degree of motor preparation and associated attentional strategies. The presence of significant MRAA in both conditions indicates that the neural mechanisms for preparing a specific motor response are similar regardless of how the action was selected. The findings suggest that alpha dynamics distinguish between functional states of motor readiness and visuospatial attention, providing a refined understanding of how the brain organizes goal-directed behavior.

Provenance

The full processing record for this entry. Every stage of this paper's journey through the pipeline is logged — what ran, with which tool and model, how many attempts it took, and when it last completed.

Summary generated by qwen3.6-27b-prismaquant on 2026-06-25; verification: verified.

Topics

Ranked by relevance to this paper. Hover a topic for its definition.

• task switching