Exploratory Feasibility Study: Vibration-Induced Kinesthetic Illusion Intensity Correlates with Motor Planning and Control Brain Activation

Objectives: Kinesthetic illusions (KI), defined as the perception of movement without actual limb motion, can be induced via tendon vibration and engage motor-related brain regions. This pilot fMRI study examined the relationship between KI vividness and neural activation. Methods: Five healthy right-handed participants (mean age 27 ± 5.4 years) underwent fMRI during pneumomechanically induced vibration at the dominant wrist to elicit KI. An activation paradigm with four runs, each using varying stimulation parameters, was applied. After each run, participants rated KI vividness on a 0–4 scale. Neural activation was analyzed, and associations with subjective ratings were assessed using a linear mixed-effects model. Results: Significant activation (p < 0.001, uncorrected) was observed in regions associated with action selection, motor initiation, and internal movement simulation. KI vividness ratings were positively correlated with ROI activation (β = 2.62, standard error = 0.73, p = 0.012, R² = 0.44). Conclusions: Greater KI vividness is associated with increased activation in motor-related brain regions, suggesting that KI may enhance neural engagement. These findings support the potential of KI as a non-invasive approach to stimulate motor circuits and promote neuroplasticity. Due to the small sample size, results should be considered preliminary and hypothesis-generating.