Enhanced lower-limb motor imagery by kinesthetic illusion

Area of Science:

• Neuroscience
• Biomedical Engineering
• Rehabilitation Technology

Background:

• Lower-limb motor imagery (LMI) based brain-computer interfaces (BCIs) offer independence for hemiplegic patients.
• Limited LMI ability in BCI-illiterate individuals, such as stroke survivors, hinders BCI performance.

Purpose of the Study:

• To propose and validate a novel LMI-BCI paradigm incorporating kinesthetic illusion (KI).
• To enhance LMI ability and improve BCI performance through vibratory stimulation of the Achilles tendon.

Main Methods:

• Two research studies were conducted on 16 healthy subjects.
• Research 1: Assessed KI feasibility and EEG features during vibratory stimulation (V-rest) versus rest.
• Research 2: Compared LMI-BCI performance with KI (KI-LMI) versus without KI (no-LMI), analyzing classification accuracy, EEG features, and brain connectivity.

Main Results:

• Vibratory stimulation feasibility for KI induction was verified, providing a theoretical basis for LMI-BCI.
• KI enhanced mesial cortex activation and EEG features (ERD power, topographical distribution).
• KI improved offline accuracy by 6.88% to 82.19% (p<0.001) and simulated online accuracy (average 77.23% vs. 75.31%).

Conclusions:

• The proposed KI-induced LMI-BCI paradigm effectively enhances LMI ability.
• This novel approach shows promise for accelerating the practical application of LMI-BCI systems for rehabilitation.