Understanding Sensory Modulation Disorder (SMD): Challenges, Symptoms, and Support Options
What is Sensory Modulation Disorder?
Sensory Modulation Disorder (SMD) falls within the broader category of sensory integration disorders. It refers to difficulties in an individual's ability to respond to sensory stimuli in a manner that is appropriate to their intensity and nature. In other words, a person with SMD may exhibit an exaggerated response to stimuli (hyperreactivity), a diminished or delayed response (hyporeactivity), or may continuously seek intense sensory input, a behaviour known as sensory seeking (Miller et al., 2007). Such dysregulation can significantly impact a person's daily functioning, including emotional regulation, attention, behaviour, and social interaction.
SMD is most commonly categorized into three subtypes:
Sensory Over-Responsivity (SOR) – an exaggerated response to typical sensory stimuli
Sensory Under-Responsivity (SUR) – a reduced or delayed response to sensory input
Sensory Seeking/Craving (SS) – a persistent craving for intense sensory stimulation (Miller et al., 2007)
This is a neurologically based disorder of sensory information processing, characterized by atypical responses to everyday sensory inputs. The core pathophysiological mechanism involves dysfunction within the central nervous system, which impairs the brain's ability to appropriately modulate the intensity of sensory signals (Bar-Shalita, 2019). This dysregulation can result in neutral or harmless stimuli being perceived as unpleasant or even painful, significantly impacting daily activities, social interactions, and emotional well-being (Bar-Shalita, 2019).
What Are the Characteristics of SMD?
The symptoms of Sensory Modulation Disorder (SMD) vary significantly depending on the type of sensory dysfunction, and recognizing them is key for timely intervention. Children who exhibit sensory hyperreactivity often show exaggerated responses to everyday stimuli, which may include discomfort from certain clothing textures, avoidance of physical contact, rejection of foods with specific textures, and heightened reactions to noise or light. Conversely, children with sensory hyporeactivity demonstrate a reduced responsiveness to external stimuli – they may appear insensitive to pain, fail to respond when their name is called, or overlook environmental changes that are obvious to others. Sensory seeking is expressed through constant movement, an intense need to touch people or objects, loud vocalizations, and repetitive activities like rocking – as if, regardless of the amount of sensory input received, their sensory needs remain unmet (Ben-Sasson et al., 2009).
Symptoms can be grouped according to various functional domains. According to Gal et al. (2025), SMD symptoms include:
Physical signs: such as unusually low or high pain thresholds, poor motor coordination, and frequent bumping into objects.
Emotional and behavioural manifestations: including sudden tantrums or aggression, heightened anxiety, symptoms of depression, and difficulties in forming and maintaining social relationships.
Cognitive characteristics: reduced attention span, hypersensitivity to loud or unpredictable sounds, and a tendency to become easily overwhelmed in group settings.
These sensory difficulties significantly impact daily functioning – they can disrupt routines such as dressing, eating, playing, or completing school tasks. Moreover, they are often linked to emotional dysregulation and elevated stress levels, further impairing the child’s ability to self-regulate and adapt to their environment (Schaaf & Davies, 2010).
Here is a video which represents how challenging it can be in everyday life:
Who Is Most Commonly Affected?
SMD is commonly observed in children with developmental difficulties such as Autism Spectrum Disorder (ASD), ADHD, and intellectual disabilities. However, it also occurs in children without formally diagnosed developmental disorders, particularly those exposed to early stress or traumatic experiences (Reynolds et al., 2011; Piek et al., 2008). SMD also has a high comorbidity with emotional dysregulation and anxiety disorders, as children with inadequate sensory responses often display increased emotional reactivity and difficulties with self-regulation (Lane et al., 2012; Gouze et al., 2009).
Therapeutic Approaches
The treatment of Sensory Modulation Disorder (SMD) encompasses a range of approaches, including sensory integration therapy, parent education, behavioural regulation strategies, and the utilisation of assistive technology. A key component is the individualised assessment and development of a therapy plan based on sensory processing profiles (Schaaf et al., 2014).
One innovative tool within therapy is SENcastle – a multisensory therapeutic device that combines various forms of sensory stimulation and supports children in developing self-regulation attention and reducing sensory overload. SENcastle is especially effective when used as a preparatory activity in therapy, helping to bring children into an optimal state for learning and communication.
Therapeutic goals include:
Achieving an appropriate level of arousal
Reducing reactivity to sensory stimuli
Increasing tolerance and adaptive behaviour
Enhancing self-confidence and social skills
Activities to Promote Sensory Modulation
Numerous activities can aid in regulating sensory processing, and they should be individualized according to the child’s needs:
For Sensory Over-Responsivity: deep pressure activities (such as being wrapped in a blanket), soft light projections, and gentle swinging in a secure setting.
For Sensory Under-Responsivity: stimulating play such as running, jumping on a trampoline, or using vibrating toys.
For Sensory Seeking: structured activities that allow for sensory exploration in a controlled environment – such as tactile bins, light-up platforms, and multisensory rooms.
SENcastle enables explicitly the implementation of many of these activities within a controlled environment that can be adapted to each user, making it an ideal tool for preschools, schools, and therapy centres.
References:
· Bar-Shalita, T., et al. (2019). Sensory Modulation Disorder and Pain. PMC.
· Ben-Sasson, A., Carter, A. S., & Briggs-Gowan, M. J. (2009). Sensory over-responsivity in elementary school: Prevalence and social-emotional correlates. Journal of Abnormal Child Psychology, 37(5), 705–716.
· Gal, E., et al. (2025). Sensory Modulation in Adolescents with Anxiety Disorders. PMC.
· Gouze, K. R., Hopkins, J., LeBailly, S. A., & Lavigne, J. V. (2009). Re-examining the epidemiology of sensory regulation dysfunction and comorbid psychopathology. Journal of Abnormal Child Psychology, 37(8), 1077–1087.
· Lane, S. J., Reynolds, S., & Thacker, L. (2012). Sensory over-responsivity and anxiety in children with ADHD. American Journal of Occupational Therapy, 66(5), 556–563.
· Miller, L. J., Anzalone, M. E., Lane, S. J., Cermak, S. A., & Osten, E. T. (2007). Concept evolution in sensory integration: A proposed nosology for diagnosis. American Journal of Occupational Therapy, 61(2), 135–140.
· Piek, J. P., Barrett, N. C., Allen, L. S., Jones, A., & Louise, M. (2008). The relationship between bullying and self-worth in children with movement coordination problems. British Journal of Educational Psychology, 78(2), 273–289.
· Reynolds, S., Lane, S. J., & Gennings, C. (2011). The moderating role of sensory over-responsivity in predicting behavioral problems. OTJR: Occupation, Participation and Health, 30(4), 163–171.
· Schaaf, R. C., & Davies, P. L. (2010). Evolution of the sensory integration frame of reference. American Journal of Occupational Therapy, 64(3), 363–367.
· Schaaf, R. C., Benevides, T., Kelly, D., & Mailloux, Z. (2014). Occupational therapy and sensory integration for children with autism: A feasibility, safety, acceptability and fidelity study. Autism, 18(6), 737–746.