Psychology
Because the sense of sight is contrast sensitive, the brightness contrast of a
space determines its emotional impact.
Emotional Impact
Subjective impressions of space are a func-
tion of brightness contrast: the relationship
of surfaces that are lighted (the focus or
foreground) to those that are left in compar-
ative darkness (the surround or background).
It is possible, of course, to simply introduce
general illumination into a room to permit
vision. But establishing the emotional
impact of an interior through the manipula-
tion of brightness contrast is the real chal-
lenge for the creative designer.
Reliance on published standards for
illuminance on theworkplaneleads uninten-
tionally to environments that are sterile and
unstimulating. Proper attention to the manip-
ulation of brightness contrast as a principal
technique for the design of lighting systems
results in environments that are inviting,
inspiring, and supportive of the tasks to be
performed.
If all objects and surfaces in a room
receive equal emphasis from light, contrast
is lost. Over time, the lack of contrast causes
people to feel listless and depressed. With-
out contrast, the environment produced has
the quality of a cloudy, overcast day.
People feel more alert, energetic, and
positive on a sunny day, which is marked by
bright highlights and crisp shadows. By pro-
viding brightness contrast, an environment
may be created that has the attributes of a
sunny day. In truth, the significant difference
between a “dull, dreary day” and a “bright,
cheerful” one is the quality of light.Degrees of Stimulation
Some activities and tasks benefit from a high
degree of stimulation to encourage partici-
pation and increase enjoyment. Other activi-
ties and tasks benefit from a minimum of
contrast to help a person feel contented,
comfortable, focused, and relaxed. Although
individuals react differently to the same envi-
ronment, there is a high degree of similarity
in people’s reactions to light.
Environmental psychologists use the
termshigh-loadand low-loadto describe