Dysfunction of a sensory system can produce either:

• A. It only causes over-reaction
• B. It only causes under-reaction
• C. It can cause either over-reaction or under-reaction
• D. It has no effect on reaction

Answer: (C)

Dysfunction in a sensory system can alter how a child responds to input, leading to either heightened or diminished reactions. In pediatric occupational therapy, these patterns are described as hyperreactivity (over-reaction) and hyporeactivity (under-reaction). For example, a child who is tactile hyperreactive may cry, withdraw, or scream when touched or with certain textures. A child who is tactile hyporeactive may not notice light touch or temperature changes and may seek out stronger input to feel sensation. Both possibilities are recognized outcomes of sensory processing differences, and some children may show one pattern in some situations and another in different contexts, or even alternate between patterns over time.

The other statements don’t fit because the dysfunction does not strictly cause only over-reaction, and not only under-reaction, and it can indeed affect how a child attends to or tolerates sensory input.