1. The area-intensity relation of the stimulus at the absolute threshold level is well known.

2. The third condition occurs when the neighbor cell signal strength is above a second absolute threshold.

3. No absolute threshold has been determined to define a road density which is acceptable to grizzly bears.

4. During light adaptation this was true up to adaptive illumination of 105 times the absolute threshold (about 10 Trolands). At higher levels of illumination the response of the pupil was absent regardless the luminance of test light.