Being underreactive or undersensitive to sensory (or emotional) stimuli. This is a common feature of autistic spectrum condition and Sensory Integration Dysfunction (SID). See also: hypersensitivity.

Undersensitivity to sensory stimuli, characterized by a tendency either to crave intense sensations or to withdraw and be difficult to engage.

Under-sensitivity to sensory input, resulting in little or no response to noise, hot/cold, etc.

See " desensitisation".

A condition in which the body has a weakened or delayed reaction to a substance.