Our senses gather information from our surroundings, this is called sensory registration. This information is registered through our senses that include seeing, touching, hearing, smelling, tasting, proprioception and our vestibular system.
This term is used to describe the awareness of the temporal and spatial characteristics of the sensory input we gather from our environment including the qualities, similarities and differences amongst these sensations. Sensory discrimination dysfunction is defined by Van Jaarsveld (van Jaarsveld, 2011, p. 10) as difficulties with knowing the qualities of the sensory experiences within the sensory system thus not providing the child with the necessary information.
Thus when a child has a sensory discrimination disorder they need extra time to process sensory input they get from their environment according to (Miller, 2006, p. 37).
Smith Roley (Smith Roley, 2001, p. 57)called sensory modulation the physiological and behavioural responses to sensory input we receive.
After registration and discrimination the sensory information is then sent to the brain. The brain is alerted (sensory arousal occurs) to the new sensory input if it is meaningful. We inhibit input that isn’t relevant – habituation occurs. The intensity and length of the response may be determined through memory due to previous exposure . A child that has a sensory modulation disorder may over-respond, under respond or exhibit sensory seeking behaviour on the sensory input from their environment, thus their arousal level will not be appropriate to the situation.
We need just the right amount of arousal to function optimally in our daily roles e.g. school, social interaction, play, etc. Lombard (Lombard, 2007, p. 123) mentioned that the brain goes through 4 stages:
Optimal functional state – I am o.k
2nd functional state – I am stressed
3rd functional state – I am overloaded
Nil functional state – I am out of control
We move through these stages throughout the day, depending on the environmental impact.
Please see the following graph to understand the relationship between under-responsiveness, over-responsiveness, sensory-seeking behaviour and sensory-avoiding behaviour that can occur when a modulation difficulty is present. Miller (Miller, 2006, p. 28) stated that a degree of sensory seeking is normal in children while they learn and grow.
So why is sensory integration needed for learning?
During the upcoming months we will have a look at each one of these senses separately to increase your understanding of sensory integration and possible dysfunction of each system.