Fluorescent lighting: a purported source of hyperactive behavior.

Seven first-grade children with conduct disorders and/or hyperactivity attended full-day sessions at a laboratory school classroom. During an 8-week period, the classroom lighting conditions alternated at the end of each week. During odd-numbered weeks, the classroom was illuminated by a standard cool-white fluorescent system. On even-numbered weeks, illumination was a daylight-simulating fluorescent system of equal footcandles with controls for purported soft X rays and radio frequency (RF). There were no effects of lighting conditions on hyperactive behavior as assessed by (a) independent observations of task orientation or (b) ratings of activity level. A Critical Flicker Fusion (CFF) measure, a reported indicator of visual-sensory fatigue, indicated that the daylight-simulating condition was associated with a decreasing CFF across weeks.