Autism and Sensory Processing

Michael Mohan

August 15, 2025

For individuals on the autism spectrum, navigating daily life often involves processing a world that feels fundamentally different from what neurotypical individuals experience. Sensory issues are common in people with autism and are even included in the diagnostic criteria for autism spectrum disorder. Each autistic person is unique, and this includes their personal sensory sensitivities. This comprehensive exploration delves into why sensory processing differences occur in autism, how they manifest, and what they mean for individuals and their families.

The CDC’s Autism and Developmental Disabilities Monitoring (ADDM) Network published its most recent surveillance report in 2023; it focused on data from 2020. The ADDM Network found approximately 1 in 36 children in the United States was estimated to have ASD. With this significant prevalence, understanding sensory processing differences becomes crucial for creating supportive environments and improving quality of life for autistic individuals.

The Foundation: What is Sensory Processing?

Sensory processing refers to how our nervous system receives, organizes, and responds to sensory information from our environment and our own bodies. For most people, this process occurs automatically and seamlessly. However, atypical sensory-based behaviors are a ubiquitous feature of autism spectrum disorders (ASD). In this article, we review the neural underpinnings of sensory processing in autism by reviewing the literature on neurophysiological responses to auditory, tactile, and visual stimuli in autistic individuals.

The sensory system involves eight different sensory modalities:

Visual (sight): Processing what we see
Auditory (hearing): Processing sounds and speech
Tactile (touch): Processing textures, temperatures, and physical contact
Olfactory (smell): Processing scents and odors
Gustatory (taste): Processing flavors and food textures
Vestibular (balance): Processing movement and spatial orientation
Proprioceptive (body awareness): Processing body position and muscle awareness
Interoceptive (internal awareness): Processing internal bodily signals like hunger, thirst, and fatigue

The Scale of Sensory Processing Differences in Autism

Research consistently demonstrates that sensory processing differences are not just common in autism—they’re nearly universal. The majority (74%; 95% confidence interval: 73.5%–74.5%) of the children studied had documented sensory features. This finding comes from one of the largest population-based studies examining sensory features in autism, analyzing data from over 25,000 autistic children.

Even more striking, the Centers for Disease Control and Prevention reported in 2018 that 1 in 59 children in the United States is diagnosed with ASD, with more than 90% estimated to show features of sensory disorganization. Additional research supports these findings, with studies showing recent estimates of prevalence of sensory symptoms of people with autism spectrum disorder (ASD) range from 69% to 93% in children and adults.

Global Perspective on Autism Prevalence

The recognition and diagnosis of autism varies significantly across different regions and countries. In contrast, the prevalence of ASD in European countries from 2008 to 2018 was 1/172 in Denmark, 1/125 in Norway, 1/64 in the UK, 1/806 in Portugal, 1/44, 1/175 in the Netherlands, 1/87 in Italy, 1/166 in Germany and 1/64 (3–4 years) or 1/100 (10–11 years) in Spain. These variations highlight the importance of standardized diagnostic approaches and the need for increased awareness globally.

Hypersensitivity: When the World Feels Too Much

Understanding Hypersensitivity

Hypersensitivity, or over-responsiveness, occurs when an individual’s sensory system reacts more intensely to stimuli than typically expected. Autistic people can experience both hypersensitivity (over-responsiveness) and hyposensitivity (under-responsiveness) to a wide range of stimuli. Most people have a combination of both. Many autistic people experience hypersensitivity to bright lights or certain light wavelengths (e.g., LED or fluorescent lights). Certain sounds, smells, textures and tastes can also be overwhelming.

This heightened sensitivity can manifest in various ways:

Auditory Hypersensitivity:
A large body of previous research has shown that auditory stimuli to have the greatest negative impact on engagement and/or educational performance for students with ASD. Individuals may experience pain or extreme distress from sounds that others find tolerable or even pleasant. This can include sudden loud noises, background sounds like air conditioning, or specific frequencies that seem to cut through their awareness.

Visual Hypersensitivity:
Bright lights, fluorescent lighting, or busy visual patterns can cause significant discomfort. Many autistic individuals need to wear sunglasses indoors or avoid certain environments due to overwhelming visual input.

Tactile Hypersensitivity:
Common clinical complaints are avoiding light touch to the head and body as occur with grooming and particular clothing. This can impact daily activities like wearing certain fabrics, receiving hugs, or tolerating haircuts.

The Impact of Sensory Overload

Sensory overload happens when an intense sensory stimulus overwhelms your ability to cope. This can be triggered by a single event, like an unexpected loud noise, or it can build up over time due to the effort it takes to cope with sensory sensitivities in daily life. Sensory overload can feel like intense anxiety, a need to escape the situation or difficulty communicating. When the brain has to put all of its resources into sensory processing, it can shut off other functions, like speech, decision making and information processing.

A person who finds it difficult to process everyday sensory information can experience sensory overload, or information overload. Too much information can cause stress, anxiety, and possibly physical pain. This can result in withdrawal, distressed behaviour or meltdowns.

Hyposensitivity: When the World Feels Too Little

Understanding Hyposensitivity

While hypersensitivity receives significant attention, hyposensitivity is equally important to understand. Hyposensitivity, also referred to as sensory underresponsivity or sensory seeking behavior, is a distinctive sensory processing pattern frequently observed in individuals with autism spectrum disorder (ASD). It describes a reduced sensitivity or diminished responsiveness to sensory stimuli compared to neurotypical individuals.

This can look like a constant need for movement; difficulty recognizing sensations like hunger, illness or pain; or attraction to loud noises, bright lights and vibrant colors. People who are hyposensitive may engage in sensory seeking to get more sensory input from the environment. For example, people with autism may stimulate their senses by making loud noises, touching people or objects, or rocking back and forth.

Common Signs of Hyposensitivity

Auditory Under-responsiveness: May not respond to their name being called, enjoy very loud music, or seem unaware of sounds that others find noticeable.

Visual Under-responsiveness: Sight Your child might like bright colours. They might hold items up to their eyes or sit close to the TV.

Tactile Under-responsiveness: Touch Your child might seek out different textures, rub their arms and legs against things, explore things using touch, enjoy tight hugs or wear tight-fitting clothing.

Movement and Balance: Sense of position, balance and movement Your child might have unstable balance, be more likely to enter other people’s personal space, or have difficulties with fine motor skills like handwriting or tying shoelaces.

The Neurological Underpinnings: Why These Differences Occur

Brain Processing Differences

Including 1136 participants (533 autistic individuals, 210 first-degree relatives, and 267 controls) from two independent study samples (PARIS and LEAP), we observed a statistically significant dSSP mean difference between autistic individuals and controls, driven mostly by a high dSSP variability, with an intermediated profile represented by relatives. Our genetic analysis tended to associate the dSSP and the hyposensitivity with mutations of the GABAergic pathway.

Research suggests that sensory processing differences in autism may be related to how the brain’s excitatory and inhibitory systems function. The balance between excitation (turning neural activity up) and inhibition (turning neural activity down) appears to be different in autistic brains, which can lead to either over-processing or under-processing of sensory information.

Early Development and Sensory Processing

Despite the high prevalence rates of symptoms and their centrality to ASD, little is known about the developmental trajectory of these symptoms. The main purpose of this study was to characterize the early developmental pattern of sensory symptoms in ASD.

Understanding when these differences emerge and how they develop over time is crucial for early intervention. Sensory hypersensitivity is a symptom often associated with autism spectrum disorder (ASD), as more than 90% of children who have ASD experience this sensory challenge.

The Real-World Impact: How Sensory Differences Affect Daily Life

Educational Environments

Classrooms provide a unique challenge for sensory processing. With the multiple visuals posted, numerous peers talking, noise from inside and outside the classroom, and close proximity of peers, students are exposed to multisensory stimulation from a variety of sources.

The educational setting presents numerous challenges for students with sensory processing differences. Traditional classrooms are often designed without consideration for sensory needs, leading to environments that can be overwhelming or understimulating for autistic students.

Family Life and Relationships

Sensory sensitivities can affect an autistic child’s whole family. For example, if your child is sensitive to noise, it might limit where your family goes or the kinds of activities your family does. Sensory sensitivities might also affect your child’s experience of school, including their attention, energy levels and emotions.

Social Participation

However, it is interesting to note that the differences between the ASD group and the clinical control group reach statistical significance only in the social participation and vestibular domain—represented by the “balance and motion” subscale—and are close to statistical significance in the proprioceptive domain—represented by the “body awareness” subscale. The differences observed in social participation can easily be explained by the fact that social deficits are one of the key features of autism.

Coping Strategies and Stimming Behaviors

Understanding Stimming

Repetitive movements, sounds, or fidgeting can help people with autism stay calm, relieve stress or block out uncomfortable sensory input. However, constant movement can sometimes seem inappropriate or disruptive in certain settings (like the workplace), so autistic people often feel like they need to suppress their stimming. When this happens, it becomes more and more difficult to self-regulate, leading to sensory overload, exhaustion or burnout.

Stimming behaviors serve important regulatory functions and should be understood as adaptive responses to sensory challenges rather than behaviors that need to be eliminated.

Practical Accommodations

Environmental Modifications:

Let your child try earplugs or noise-cancelling headphones to help with sound sensitivities. Have dimmable lights in your child’s bedroom, and keep sunglasses handy for sunny days.
You could make changes to the environment, such reducing fluorescent lighting, providing sunglasses, using blackout curtains and/or creating a workstation in the classroom – a space or desk with high walls or divides on both sides to block out visual distractions.

Communication Strategies:

Practise ways your child can let you know they need a break. For example, they could show you a card saying ‘break’.

Intervention Approaches and Support

Professional Support Options

Occupational therapists can assess your child’s sensory needs and develop a plan for managing them. Dietitians and speech pathologists might be able to help if your child has taste, smell and sound sensitivities that cause eating issues.

Evidence-Based Interventions

According to the results of this review, intervention with sensory integration in infants with ASD meets the criteria to be considered an evidence-based practice. The studies reviewed focused mainly on clinical settings and, therefore, we highlight the urgent need for further research to evaluate the effectiveness of sensory integration interventions in naturalistic settings such as homes and schools. This will help to obtain more representative data on how these interventions affect the daily lives of children with ASD.

Research indicates that sensory integration therapy shows promise, but more research is needed to understand which approaches work best for which individuals in real-world settings.

The Broader Context: Sensory Processing Across the Autism Spectrum

Individual Variability

Not all autistic children and teenagers have sensory sensitivities, but some might have several. And some children and teenagers might be oversensitive in some areas and undersensitive in others. Sensory sensitivities can also sometimes seem worse when children and teenagers are stressed or anxious. Autistic children and teenagers don’t usually outgrow their sensory sensitivities but often learn to manage them as they get older.

Co-occurring Conditions

Research shows that sensory processing differences often coincide with other challenges. We have observed sensory processing problems in 42–88% of children diagnosed with autism and approximately 50% of children diagnosed with ADHD. This highlights the importance of comprehensive assessment and support.

Future Directions and Research

The Need for Continued Research

In summary, this special issue represents an important step forward in our understanding of sensory features in autism and related conditions, but also underscores the many aspects of sensory development (and its disruptions) that require greater study. Specifically, more research is needed to understand the behavioral and neural underpinnings of these sensory features, their types, patterns and associated phenotypic characteristics. This can lead to the identification of relevant sensory subtypes that can help further categorize children for optimal treatments. Further, we need to know more about the developmental sequelae of altered sensory perception, reactivity and integration, and causal mechanisms that lead to the downstream consequences of atypical sensory development. More research is also needed on the impact of these sensory features, not only on brain development but also on daily life (positive and negative), quality of life, and mental health.

Emerging Understanding

Over the past decade, research on the sensory features of autism has expanded tremendously. We now recognize that most (over 70%) of individuals on the autism spectrum have sensory features that span a broad range of types, sensory modalities and patterns and that these sensory features frequently impact function, participation in activities and tasks, mental health, and quality of life. First-person accounts of the sensory experiences of some cognitively- and linguistically-able autistic persons add a wealth of information into the phenomenology of sensory features.

Creating Understanding and Acceptance

Moving Beyond Stereotypes

Understanding sensory processing differences in autism requires moving beyond stereotypes and recognizing the complexity and individuality of each person’s experience. Processing everyday sensory information can be difficult for autistic people. Any of their senses may be over- or under-sensitive, or both, at different times. These sensory differences can affect how they feel and act, and can have a profound effect on a person’s life. Here we help you to understand autism, the person and how to help.

Building Supportive Communities

Creating truly inclusive environments requires understanding that sensory differences are neurological variations rather than behavioral choices. When we understand that someone’s need for noise-canceling headphones, preference for certain lighting, or requirements for specific textures are legitimate accessibility needs, we can build more supportive and inclusive communities.

Conclusion: Embracing Neurodiversity

Sensory processing differences in autism represent a fundamental aspect of neurological diversity rather than deficits to be corrected. While these differences can create challenges in a world designed for neurotypical sensory processing, they can also represent unique strengths and perspectives.

The key to supporting autistic individuals lies in understanding, accommodation, and acceptance. By recognizing that sensory differences are real, significant, and worthy of respect, we can create environments where autistic individuals can thrive. This includes educational settings that consider sensory needs, workplaces that accommodate different sensory profiles, and communities that understand that stimming behaviors serve important functions.

As research continues to expand our understanding of sensory processing in autism, we move closer to a world where these differences are not just tolerated but embraced as part of human neurodiversity. The goal is not to eliminate sensory differences but to create a world where they are understood, accommodated, and valued.

For families, educators, employers, and community members, understanding sensory processing differences is crucial for creating inclusive environments. It’s about recognizing that what might seem like challenging behavior often reflects a neurological difference in how sensory information is processed and responded to.

The future of autism support lies in this understanding—moving from trying to make autistic individuals fit into neurotypical environments to creating environments that work for everyone, regardless of their neurological makeup. In doing so, we not only support autistic individuals but create more flexible, understanding, and inclusive communities for all.

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