Navigating Sensory Extremes: Understanding Overstimulation and Understimulation in Autism Spectrum Disorder and ADHD

Sensory processing is a critical component of how we interact with our environment. For individuals with Autism Spectrum Disorder (ASD) and Attention-Deficit/Hyperactivity Disorder (ADHD), managing sensory input can be particularly challenging. Both conditions often involve unique sensory sensitivities that can lead to overstimulation and understimulation, impacting behavior, emotional well-being, and daily functioning. This article explores the concepts of overstimulation and understimulation, their neurological underpinnings, and their effects on individuals with ASD and ADHD. By deepening our understanding of these sensory states, we can develop more effective strategies to support those with sensory processing sensitivities, enhancing their ability to navigate their environments and improve their quality of life.

Overstimulation

• What it is: Overstimulation occurs when the brain receives more sensory input than it can handle. For example, a computer with too many programs open can start to slow down or freeze.
• Why it happens: In individuals with ASD, the part of the brain that filters sensory information (the reticular activating system) may not work as effectively. This can cause what’s known as sensory overload.
• What it feels like: Imagine being in a room where every light is flickering at a different speed, music is blaring from multiple sources, and you can feel every fabric of your clothing—all at once.
• Common responses: This might make someone feel irritable or anxious. To cope, they might cover their ears, hide their eyes, or rock back and forth.

Examples of Overstimulation:

1. A child at a birthday party becomes overwhelmed by the loud music and screaming, leading to a meltdown.
2. An adult in a busy office space becomes stressed due to overlapping conversations and ringing phones, requiring frequent breaks.

Understimulation

• What it is: Understimulation happens when there is not enough sensory input to keep the brain engaged. This is similar to how you might feel bored in a too-quiet environment.
• Why it happens: When the brain doesn’t get enough stimulation, it can cause feelings of boredom or apathy. This could be due to lower activity in brain areas responsible for attention and alertness, like the prefrontal cortex.
• What it feels like: Imagine sitting in a plain white room with no windows, doing nothing for hours. You might start feeling restless or look for something to do to keep your mind active.
• Common responses: Someone might start tapping their feet, fidgeting, or seeking out sensory experiences to “wake up” their brain.

Examples of Understimulation:

1. A student in a quiet, unengaging classroom may start daydreaming or doodling to keep themselves mentally stimulated.
2. An adult working from home might find themselves repeatedly checking their phone or getting up to walk around.

Conclusion

Understanding overstimulation and understimulation is crucial, especially for those with sensory processing sensitivities like ASD. Recognizing the signs can help create a supportive environment that adjusts the level of sensory input to a comfortable range for each individual. Whether it’s using noise-cancelling headphones to reduce noise or providing engaging activities to prevent boredom, tailored strategies can significantly improve daily functioning and quality of life.

Overstimulation doesn’t always have to be in social situations…

Overstimulation occurs when sensory input exceeds an individual’s ability to process it effectively, leading to sensory overload.

1. Social Settings: Social interactions often require rapid verbal and non-verbal cues, facial expressions, and body language processing. For individuals with ASD, these elements might be difficult to interpret, leading to overstimulation. Similarly, for people with social anxiety, the fear of being judged or scrutinized can trigger overstimulation.
2. Noisy Environments (like grocery stores or schools): Noisy environments challenge the brain to focus on relevant sounds while filtering out background noise. This filtering process can be inefficient in individuals with sensory processing issues and overwhelming environments like busy stores or classrooms.
3. Taking Tests: The pressure of performance, time constraints, and the need to recall information rapidly can overstimulate anyone, particularly those with anxiety or ADHD. The stress associated with these situations can exacerbate difficulties in concentration and processing.
4. Navigating Traffic: Driving requires constant sensory input processing—visual signals, auditory signals from the radio or other cars, and the physical sensation of driving. This can be particularly taxing for someone who struggles with sensory integration.
5. Masking in Social Settings: For individuals with ASD, ‘masking’—suppressing natural behaviours to conform to social norms—can be mentally exhausting. The sustained effort to appear neurotypical can lead to burnout and overstimulation by the end of the day.
6. Suppressing Natural Behaviors (like fidgeting in ADHD): Fidgeting helps manage attention and focus for individuals with ADHD. Being forced to suppress such behaviors in structured environments like classrooms can lead to increased stress and overstimulation.

Brain’s Response to Overstimulation

The brain processes sensory information through pathways that help discern relevant stimuli from irrelevant background noise. In neurotypical individuals, this filtering is efficient. However, in conditions like ASD and ADHD, these pathways might not filter effectively, leading to an overload of information. The brain’s attempt to compensate for noisy environments or focus during stressful situations (like tests or social interactions) can exhaust cognitive resources, leading to symptoms like irritability, fatigue, and sometimes, shutdowns or meltdowns as coping mechanisms.

Understanding and managing overstimulation involve recognizing the signs of sensory overload and employing strategies such as sensory breaks, the use of noise-cancelling headphones, structured routines, and mindfulness practices that help regulate sensory input and maintain sensory balance.