Also called Sensory Integration Dysfunction, Sensory Processing Disorder (SPD) is a disorder in which the brain cannot properly synthesize multisensory information. This causes hypersensitivity (over-responsiveness to stimuli) or hyposensitivity (under-responsiveness to stimuli). If a child is affected by hypersensitivity, they may have extreme or fearful responses to specific textures, sounds, and tastes. Conversely, children with hyposensitivity may seem fearless, inappropriately touching people and/or objects and putting themselves in dangerous situations due to their under-reaction to pain.