Modern neurorehabilitation continually seeks non-invasive interventions to accelerate motor recovery following central nervous system injury. Among these approaches, motor imagery mental practice represents an exceptionally promising modality. Clinicians define motor imagery as the active cognitive rehearsal of a physical task without overt muscular execution. Through mental rehearsal, individuals simulate sensorimotor experiences internally, activating motor pathways that mirror actual movement. Therapists frequently employ video demonstrations to guide this cognitive rehearsal. Visual observation provides valuable kinematic reference frames for the patient. However, activities of daily living inherently involve multisensory environments containing distinct auditory feedback alongside visual cues. For example, cutting paper with scissors produces rhythmic shearing sounds that guide motor pacing. A pilot study evaluated whether combined visual and auditory information enhances corticospinal excitability and subjective imagery vividness. By investigating these sensory conditions, the study illuminates how multisensory guidance strengthens motor representations. This clinical knowledge provides actionable insights for therapists designing structured rehabilitation protocols.

Neurobiology of Motor Imagery Mental Practice

Motor imagery relies on neural networks that overlap extensively with overt physical movement. Specifically, functional neuroimaging demonstrates that mental simulation recruits the primary motor cortex, premotor area, supplementary motor area, and cerebellum. In addition, the prefrontal cortex coordinates the executive planning necessary for accurate rehearsal. When an individual imagines a movement, the central nervous system suppresses spinal motor neurons to prevent physical contraction. Consequently, corticospinal pathways undergo subthreshold facilitation without producing overt motion. Transcranial magnetic stimulation serves as a gold standard to measure this facilitation. By delivering single magnetic pulses to the motor cortex, investigators record motor-evoked potentials in target peripheral muscles. Higher amplitudes indicate increased corticospinal excitability. Therefore, transcranial magnetic stimulation allows clinicians to quantify physiological engagement during mental simulation. When patients observe external cues, mirror neuron circuits in the premotor cortex decode action kinematics. Furthermore, adding auditory stimuli engages secondary motor regions through auditory-motor coupling mechanisms. As a result, multisensory integration enhances neural synchronization across distributed sensorimotor networks.

Evaluating Corticospinal Excitability Across Sensory Modalities

The pilot investigation evaluated eight healthy adults performing motor imagery of an activity of daily living: cutting paper with scissors. Investigators tested four sensory conditions: no information, auditory information alone, visual information alone, and combined audiovisual information. During each condition, researchers delivered single-pulse transcranial magnetic stimulation over the hand representation of the primary motor cortex. Concurrently, surface electromyography recorded motor-evoked potentials from the first dorsal interosseous and adductor pollicis muscles. The data demonstrated that corticospinal excitability differed significantly across the four conditions overall. Thus, external sensory stimulation actively influences descending motor pathways during mental rehearsal. However, post hoc analyses did not identify statistically significant differences between specific individual conditions. Several clinical factors explain this outcome. First, the small sample size restricted statistical power to detect subtle pairwise differences. Second, substantial inter-individual variability in baseline corticospinal responsiveness often masks modest physiological shifts. Third, cutting with scissors involves complex distal finger coordination that recruits diverse motor units. Nevertheless, the primary effect confirms that sensory input directly influences descending motor tracts.

Subjective Vividness and Multisensory Integration

Subjective vividness represents another essential parameter of motor imagery success. In clinical practice, patients who generate clear, realistic motor images achieve superior neuroplastic gains. In this study, participants rated subjective imagery vividness using a visual analog scale immediately after each condition. In contrast to corticospinal excitability, subjective vividness exhibited marked differences across conditions. Notably, the combined auditory and visual condition produced the highest vividness ratings among all test groups. Furthermore, visual information alone facilitated imagery vividness more effectively than auditory information alone. This finding aligns with established neurocognitive models of sensory processing. Visual feedback provides spatial coordinates, hand trajectories, and clear object interactions. Meanwhile, auditory feedback supplies rhythmic timing and confirms physical contact. When the brain receives synchronized audiovisual input, multisensory integration constructs a cohesive mental schema. Consequently, the individual experiences an immersive first-person motor simulation. Therefore, clinicians should avoid relying solely on visual cues. Instead, combining realistic action sounds with visual demonstrations significantly enriches mental simulation.

Translating Mental Rehearsal to Occupational Therapy

Occupational therapy aims to re-establish independence in everyday functional tasks, such as dressing, eating, and personal hygiene. Standard rehabilitation emphasizes high-repetition physical practice. However, patients with severe motor impairments cannot execute movements safely or independently. For these patients, mental practice serves as an indispensable rehabilitation bridge. Mental rehearsal enables patients to practice multi-step tasks without physical exhaustion or excessive frustration. Moreover, occupational therapists can easily record instructional video clips displaying natural task acoustics. For instance, therapists can record first-person videos of buttoning garments, holding eating utensils, or cutting paper. When patients watch and listen to these synchronized recordings during mental rehearsal, they reconstruct rich sensorimotor memories. In addition, practitioners can implement home programs using digital tablets or personal smartphones. Patients can independently complete structured visualization sessions between clinical appointments. Consequently, sensory-guided mental practice increases therapeutic dosage without demanding extra clinical personnel. This practical model expands access to high-intensity neurorehabilitation across healthcare settings.

Clinical Implications for Neurological Rehabilitation

Stroke represents a prominent cause of persistent physical disability, frequently producing upper limb hemiparesis. Restoring functional movement after neurological damage requires consistent, repetitive sensorimotor activation. Sensory-guided motor imagery stimulates peri-infarct cortical zones and preserved corticospinal projections. Furthermore, mental rehearsal recruits mirror neuron networks that survive subcortical cerebrovascular events. Because mental practice carries no danger of falls or joint strain, therapists can initiate training during hyperacute recovery phases. In addition, patients experiencing post-stroke depression or learned non-use regain therapeutic momentum through cognitive engagement. Clinicians can also pair motor imagery with functional electrical stimulation, virtual reality, or robotic training devices. By coupling audiovisual media with internal movement intent, clinicians accelerate functional neuroplasticity. Similarly, individuals with Parkinson disease or incomplete spinal cord trauma benefit from multisensory mental practice. These protocols mitigate bradykinesia and improve temporal movement coordination. Therefore, incorporating synchronized auditory and visual stimuli into mental practice represents a reliable, evidence-based method to optimize neurorehabilitation outcomes.

How does multisensory feedback improve motor imagery performance?

Multisensory feedback provides synchronized auditory and visual cues that reinforce internal motor representations. Consequently, sensory inputs activate corresponding cortical areas within the motor network. When clinicians combine visual demonstrations with auditory cues, patients reconstruct the temporal sequence and kinematics of the task more accurately. Therefore, this multisensory integration substantially enhances the subjective vividness of mental simulation. It also primes the corticospinal pathways more effectively for functional rehabilitation exercises.

Can mental practice replace physical therapy in neurorehabilitation?

Mental practice cannot entirely replace physical therapy, but it serves as a powerful adjunctive intervention. Active physical movement remains essential to preserve joint mobility, muscle bulk, and peripheral sensorimotor feedback. However, mental rehearsal allows safe, repetitive motor training when severe paresis prevents voluntary muscle contraction. Furthermore, clinicians can combine mental practice with subsequent active exercises. Consequently, this combined rehabilitation model accelerates motor relearning and functional independence in daily tasks.

Which patients benefit most from sensory-guided motor imagery?

Patients recovering from acute or subacute stroke frequently experience significant benefits from sensory-guided motor imagery. In addition, individuals with traumatic brain injuries, incomplete spinal cord trauma, or Parkinson disease show positive responses. Patients with severe hemiparesis who cannot move their limbs gain an accessible rehabilitation pathway through mental simulation. Furthermore, occupational therapists use these protocols to retrain complex activities of daily living before attempting physical execution with adaptive equipment.

Disclaimer: This content is for informational and educational purposes only... Refer to the latest local and national guidelines for clinical practice.

References

• Nakashima A et al. Impact of Auditory and Visual Information on Corticospinal Excitability and Vividness in Mental Practice Using Motor Imagery: A Pilot Study in Healthy Adults. Occup Ther Health Care. 2026 Oct 12. doi: 10.1080/07380577.2026.2744793. PMID: 42861463.
• Liu KP, Chan CC, Lee TM, Hui-Chan CW. Mental imagery for promoting rebuild of daily task independence in people after stroke: a randomized controlled trial. Clin Rehabil. 2004;18(5):528-536.
• Kraeutner SN, Eppler CY, Hermenegildo D, Bardouille T, Boe SG. Neural correlates of motor imagery and execution: a multimodal neuroimaging review. Front Hum Neurosci. 2020;14:317.