Alzheimer’s and full-spectrum lighting

PET scan of a human brain with Alzheimer's disease

Special lighting and window glass can help calm Alzheimer’s patients, improving their quality of life and making life easier for their caregivers, according to a yearlong SIUC (Southern Illinois University Carbondale – Fall 2005) study.

Melinda LaGarce, an associate professor of interior design, conducted the research, a follow-up to a preliminary study she did with two other SIUC researchers.
The research was designed to see if the effects of so-called “sundown syndrome” in Alzheimer’s patients could be moderated. As the sun declines in the afternoon, the agitation, aggression, and anxiety shown by many people afflicted with Alzheimer’s tends to worsen, sometimes dramatically. The effect begins as early as 2 p.m.

LaGarce designed two identical activity rooms in a local adult services center that provides day care for Alzheimer’s patients. Both rooms faced south, were furnished identically, had the same door and window placement, and had similar exterior views.

To the room’s users, including the staff, there was also no apparent difference in the lighting and window glass in the two rooms. One of the rooms, however, had full-spectrum rather than standard lighting and special window glass.

Full-spectrum light is a white light similar to noontime sunlight, whereas incandescent light is considerably yellower. Angled microslats in the window glass, which are detectable only on close inspection, blocked direct sunlight during the afternoon, letting in only reflected light.

Throughout the afternoon, a sensor progressively boosted the lighting in this experimental room to maintain a constant level of noontime-intensity light. The lighting/window combo removed any cues, such as shadows, light slant, or color of light, that the sun was setting.

The Alzheimer’s patients arrived at the center at noon and stayed until about 4 p.m. year-round. Unbeknownst to them, they were alternated every few weeks between the control room, without the special lighting conditions, and the experimental room. Hidden cameras in both rooms videotaped the group.

A team of specially trained undergraduate and graduate students watched the tapes and recorded instances of agitated or disruptive behaviors common to Alzheimer’s patients. They monitored 10 behaviors in all, including anxiousness, wandering, combativeness (such as hitting or throwing things), verbal disruptiveness (such as yelling), and repeating the same action obsessively.

As a quality control check, two members of the caregiving staff also recorded data as observers in the rooms. To ensure objectivity, neither the student team nor the day-care center staff was told how the two rooms differed or what the focus of the study was.

On average, agitation and disruptive behaviors dropped by half during the weeks when the patients were in the experimental room. The greatest reduction–55 percent–occurred in the fall, when the days are getting markedly shorter and the switch to standard time takes place.

Better yet, patients who had the highest levels of agitation in the control room experienced the most dramatic improvements in the experimental room.

The full article can be found here and further information here.

Related posts:

  1. Sun helps to battle skin cancer?
  2. Full-spectrum lighting (issue 8)
  3. Insufficient lighting in nursing homes.
  4. Who’s talking about full-spectrum lighting – issue 5
  5. Vitamin D Deficiencies At Epidemic Levels

Tags: , , , ,

Comments are closed.