{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,11,3]],"date-time":"2026-11-03T12:13:13Z","timestamp":1793707993412,"version":"4.6.1"},"reference-count":34,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2025,5,21]],"date-time":"2025-05-21T00:00:00Z","timestamp":1747785600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Hum. Neurosci."],"abstract":"<jats:sec><jats:title>Introduction<\/jats:title><jats:p>Motor imagery (MI) has emerged as a promising technique for enhancing motor skill acquisition and facilitating neural adaptation training. Attention plays a key role in regulating the neural mechanisms underlying MI. This study aims to investigate how attentional states modulate EEG-based lower-limb motor imagery performance by influencing event-related desynchronization (ERD) and the alpha modulation index (AMI) and to develop a real-time attention monitoring method based on the theta\/beta ratio (TBR).<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>Fourteen healthy right-handed subjects (aged 21\u201323) performed right-leg MI tasks, while their attentional states were modulated via a key-press paradigm. EEG signals were recorded using a 32-channel system and preprocessed with independent component analysis (ICA) to remove artifacts. Attentional states were quantified using both the traditional offline AMI and the real-time TBR index, with time\u2013frequency analysis applied to assess ERD and its relationship with attention.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>The results indicated a significant increase in ERD during high attentional states compared to low attentional states, with AMI values showing a strong positive correlation with ERD (<jats:italic>r<\/jats:italic>\u202f=\u202f0.9641, <jats:italic>p<\/jats:italic>\u202f&amp;lt;\u202f0.01). Cluster-based permutation testing confirmed that this <jats:italic>\u03b1<\/jats:italic>-band ERD difference was significant (corrected <jats:italic>p<\/jats:italic>\u202f&amp;lt;\u202f0.05). Moreover, the TBR index proved to be an effective real-time metric, decreasing significantly under focused attention. Offline paired <jats:italic>t<\/jats:italic>-tests showed a significant TBR reduction [<jats:italic>t<\/jats:italic><jats:sub>(13)<\/jats:sub>\u202f=\u202f5.12, <jats:italic>p<\/jats:italic>\u202f=\u202f2.4\u202f\u00d7\u202f10<jats:sup>\u22125<\/jats:sup>], and online analyses further validated second-by-second discrimination (Bonferroni-corrected <jats:italic>p<\/jats:italic>\u202f&amp;lt;\u202f0.01). These findings confirm the feasibility and efficacy of TBR for real-time attention monitoring and suggest that enhanced attentional focus during lower-limb MI can improve signal quality and overall performance.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusion<\/jats:title><jats:p>This study reveals that attentional states significantly influence the neural efficiency of lower-limb motor imagery by modulating ERD\/AMI and demonstrates that the TBR can serve as a real-time indicator of attention, providing a novel tool for optimizing attentional processes in motor skill training.<\/jats:p><\/jats:sec>","DOI":"10.3389\/fnhum.2025.1545492","type":"journal-article","created":{"date-parts":[[2025,5,21]],"date-time":"2025-05-21T05:25:22Z","timestamp":1747805122000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":3,"title":["Influence of attentional state on EEG-based motor imagery of lower limb"],"prefix":"10.3389","volume":"19","author":[{"given":"Penghai","family":"Li","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dongfang","family":"Yu","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Longlong","family":"Cheng","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kun","family":"Wang","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2025,5,21]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","first-page":"13","DOI":"10.20935\/AcadBiol7421","article-title":"Motor imagery as a tool for motor learning and improving sports performance: a mini review on the state of the art","volume":"13","author":"Agosti","year":"2020","journal-title":"Sport Sci"},{"key":"ref2","doi-asserted-by":"publisher","first-page":"81","DOI":"10.3389\/fnsys.2014.00081","article-title":"Changes in cerebellar activity and inter-hemispheric coherence accompany improved reading performance following Quadrato motor training","volume":"8","author":"Ben-Soussan","year":"2014","journal-title":"Front. 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