Habituation is Performance, Adaptation is Skill: Defining the Specialist’s Value
The Performance Trap
In many clinical settings, vestibular therapy is often reduced to repetitive symptom management—for example, instructing patients to repeat head turns or balance tasks until dizziness subsides. This approach, ‘performance,’ is the quantitative reduction of a response—a process known as ‘habituation.’ (Lacour & Bernard-Demanze, 2015)
The goal is simple: ‘do not respond’.
While habituation is often suitable in the acute injury phase, it is a minimal therapeutic goal. Counting tolerated head turns measures performance, not skill acquisition or underlying dysfunction.
The Mastery of Skill: Adaptation as Postural Learning
‘Adaptation’ refers to the acquisition of new neurological skills, signifying the development of novel coordination between the brain and body. In this context, adaptation refers to the brain's learning of new ways to process balance information, rather than merely reducing dizziness. As demonstrated by Tjernström, Zur, and Jahn (2016), rehabilitation adheres to the same biological principles as general memory format. This process transitions from short-term to long-term learning through ‘consolidation,’ a phase in which the brain converts temporary learning into a lasting, automatic skill.
During consolidation, which is when the brain stores and strengthens learning after practice, it reprocesses the training during periods of inactivity. The patient’s mental state is crucial; factors such as anxiety, reduced alertness, sedation, or sleep deprivation—frequently observed in patients with dizziness—impede neuroplasticity (the brain’s ability to reorganize and form new connections). If the brain is not adequately prepared, the acquired skill will not persist. Each exercise can influence subsequent ones, so this ‘layering aspect’ means that each new exercise builds on the previous one, rather than being a random movement. (Klatt et al, 2016)
Identifying the Sensory Mismatch
Clinical expertise is demonstrated by recognizing when a patient transitions from recovery to ‘maladaptation.’ Maladaptation refers to the body's development of inadequate compensations that do not fully restore function. According to Jahn (Munich Center of Neurosciences), some patients develop excessive dependence on a particular sensory system, leading to a ‘sensory mismatch’. A sensory mismatch occurs when the brain relies too heavily on one sense, such as vision, rather than balancing input from all senses. This phenomenon is especially evident in conditions such as ‘visual vertigo’ or ‘phobic postural vertigo.’
This mismatch is directly analogous to the ‘Visual Vestibular Mismatch’ (VVM) described by ‘Mallinson’ and ‘Longridge’ and the ‘PPPD’ criteria defined by ‘Jeffrey Staab, MD’. (Staab, 2020) In these cases, the brain is trapped in a state of high arousal and over-reliance on visual cues.
CRUCIAL TO UNDERSTANDING AS VRT SPECIALISTS: Simply repeating a movement (performance) does not fix this. We must use the skill of adaptation to force the brain to abandon these over-reliant strategies by forming new ‘internal models’.
Internal Models and Motor Programs
Clinical mastery requires the development of ‘internal models,’ mental representations or plans that help the body automatically perform movements with the right mix of sensory signals. In other words, internal models guide the body to move predictably and efficiently. (Smith & Krakauer, 2019)
CRUCIAL TO UNDERSTANDING AS VRT SPECIALISTS: These models enable individuals to perform ‘anticipated rather than merely reactive movements.’
To facilitate the formation of internal models, exercises must present sufficient challenge to stimulate learning; tasks that are too simple do not force the brain to adjust how it uses sensory information. (Appiah-Kubi et al., 2024)
A specialist recognizes that the objective is to teach the brain to ‘respond differently’ through the following mechanisms:
‘Inter-sensory Integration’ means coordinating and balancing input between vision (sight), the vestibular system (inner ear balance), and the somatosensory system (sensing body position and movement).
‘Intra-sensory Integration’ refers to challenging processing within a single sense system, for example, comparing how balance is maintained with eyes open versus eyes closed or even visual conflict.
‘Active Re-weighting’ (AKA: Adaptation Therapy) involves encouraging the brain to rely more on the vestibular (inner ear balance) input by challenging it across different reflex pathways: the VOR (vestibulo-ocular reflex, which keeps vision stable when the head moves), VCR (vestibulo-collic reflex, which keeps the neck stable), and VSR (vestibulo-spinal reflex, which helps the body maintain balance).
The Skill of the Clinician
The distinction between these two concepts fundamentally justifies the existence of our profession.
‘Technicians’ primarily facilitate habituation by repeating stimuli and relying on presynaptic changes to diminish the error signal.
‘VRT Specialists’ promote adaptation by identifying sensory mismatches and adjusting the challenge matrix to induce ‘Hebbian plasticity.’
CRUCIAL TO UNDERSTANDING AS VRT SPECIALISTS: It is essential to progress from mere task performance to genuine skill development. Practicing with a patient 55 different ways to put a pie in the oven is NOT skill development.
This progression requires the deliberate manipulation of velocities, accelerations, and cognitive demands to transition patients from static performance to the dynamic ability to navigate complex environments.
Conclusion
Habituation is a quantitative reduction in prior responses, whereas adaptation is a qualitative improvement in future capability. As clinicians, our value lies in facilitating the consolidation of new postural strategies. By addressing sensory mismatches described by Staab, Mallinson, and Jahn, we move beyond traditional methods to promote neurological expertise. (Tjernström et al., 2016)
Call to Action
Are you a technician or a clinician? How do you promote consolidation and cognitive readiness in your practice? Share your approach below.
References
Lacour, M. & Bernard-Demanze, L. (2015). Interaction between Vestibular Compensation Mechanisms and Vestibular Rehabilitation Therapy: 10 Recommendations for Optimal Functional Recovery. Frontiers in Neurology 5. https://doi.org/10.3389/fneur.2014.00285
Tjernström, F., Zur, O. & Jahn, K. (2016). Current concepts and future approaches to vestibular rehabilitation. Journal of Neurology 263. https://doi.org/10.1007/s00415-015-7914-1
(2018). Human Vestibulo-Ocular Reflex Adaptation: Consolidation Time Between Repeated Training Blocks Improves Retention. Journal of Neurophysiology 119(4), pp. 1371-1380. https://doi.org/10.1152/jn.00794.2017
(2005). Motor memory consolidation in sleep shapes more effective neuronal representations. Nature 437(7063), pp. 651-656. https://doi.org/10.1038/nature04068
(2016). The effect of vestibular rehabilitation on sleep disturbance in patients with chronic dizziness. Journal of Vestibular Research 26(6), pp. 537-544. https://doi.org/10.3233/VES-160589
(2016). A Conceptual Framework for the Progression of Balance Exercises in Persons with Balance and Vestibular Disorders. Journal of Neurology 263. https://doi.org/10.1007/s00415-015-7914-1
(2012). Vestibular Rehabilitation Therapy: Review of Indications, Mechanisms, and Key Exercises. Journal of Neurologic Physical Therapy 36(4), pp. 180-189. https://doi.org/10.1097/NPT.0b013e31826d0a0a