Definitions - page 3 Peabody Picture Vocabulary Test - Revised (PPVT-R) A testing instrument which assesses comprehension of single spoken words through a picture pointing task. Peripheral Vision Side vision; the ability to see objects and movement outside of the direct line of vision Pervasive Developmental Disorder (PDD) 1. Extreme distortions or delays in the development of social behavior and language. 2. A term used to describe drug exposure to children while in the womb. Results of this exposure can cause extremely short attention spans. Behavior disorders, limited or no processing skills, and/or difficulty understanding spoken words. Respite Temporary care given to an individual for the purpose of providing a period of relief to the primary caregivers. Respite is used to decrease stress in the homes of persons with disabilities or handicaps, thereby increasing caregivers' overall effectiveness. Sensory Integration A form of occupational therapy in which special exercises are used to strengthen the patient's sense of touch (tactile), sense of balance (vestibular), and sense of where the body and it's parts are in space (proprioceptive). It appears to be effective for helping patients with movement disorder or severe under- or over- sensitivity to sensory input. Tactile Sense of touch. Tactile Defensiveness Not being able to tolerate being touched or touching things with texture. Token Reinforcement Systems (also sometimes referred to as "reward system") A system in which students may earn plastic chips, marbles, "checkmarks" or other tangible items that may be exchanged for activities, food items, special privileges, or other rewards for positive behavior changes. Also referred to as a "token economy". Vision Therapy The use of special eye exercises to address eye defects such as strabismus. Some vision therapists also claim that eye exercises can help people with neurological or learning disabilities. This approach is not proven for the latter use, although some patients do report improvement.