title: Human pupillary response to ramp changes in light intensity.
abstract: The dynamic behavior of the pupillary system was explored using different velocity ramp changes in light intensity. Ramp stimuli ranged in velocity from 0.02 to 8.00 log units/s and the responses were recorded from three subjects. For ramp velocity below 0.066 log units/s, the responses were mainly ramps. Above 1.0 log units/s ramp velocity, the responses were mostly steps. In the stimulus velocity range of 0.066 to 1.0 log units/s, the primary responses were step-ramps. The amplitudes of the initial step movement in step-ramp responses were found to be proportional to stimulus ramp velocity. Thus the pupillary system appears either to convert the total energy in a time interval or the rate of change of intensity of the ramp stimulus into a step signal for driving the pupillary plant output.
authors: Rutgers University, College of Engineering, Piscataway, New Jersey 08855-0909.
authors: G K
authors: GK
authors: Hung
authors: F
authors: F
authors: Sun
mesh_terms: D006801:Humans; D008027:Light; D010775:Photic Stimulation; D011680:Pupil / Q000502:physiology*