Sensory sensitivity refers to the way in which we react to stimuli around us. We have seven senses: sight, smell, taste, touch, hearing, vestibular (balance) and proprioception (body awareness). The information from these senses is processed by the brain and leads to a motor (physical) response. More recently, another sense has come to our attention called interoception.
This refers to our ability to respond to internal body cues, such as hunger and pain.
We learn to take in the right amount of sensory information to allow us to successfully engage with our environment. For example, when we are working at a computer, we will shut out background noises and concentrate on the screen, ignoring other visual stimuli.
However, some people have difficulty modulating sensory information and may either feel overwhelmed by too much sensation (hyper sensitivity) or receive too little sensory information (hypo sensitivity).
Adamson, Hare and Graham (2006) reported that 70% of children with Autistic Spectrum Disorder (ASD) have sensory differences to the normal population. Sensory processing impairment is included as one of the criteria for the diagnosis of people with ASD (American Psychiatric Association, 2013): ‘Hyper- or hyporeactivity to sensory input or unusual interests in sensory aspects of the environment (e.g., apparent indifference to pain/temperature, adverse response to specific sounds or textures, excessive smelling or touching of objects, visual fascination with lights or movement)’