Temporal summation in dark-adapted 10-week old infants.
The effect of stimulus duration on the b-wave and psychophysical responses of dark-adapted 10-week-old infants and adult control subjects is reported. Both infant and adult b-wave sensitivities vary with stimulus duration, show summation for brief duration stimuli, critical durations estimated at 88-155 msec, and little variation in sensitivity for longer durations. There are however, substantial differences between the infant and adult psychophysical temporal summation functions. The infant function is described by a straight line, slope about -0.5, across all flash durations while adults show summation at durations less than 100 msec and critical durations of 136 to 151 msec. Adult, but not infant, b-wave integration times and b-wave rise and fall times show duration-dependent changes. Thus, both ERG and psychophysical measures demonstrate immaturities in the rod mediated function of the infant retina.
Fulton
A B
AB
Department of Opthalmology, Children's Hospital, Boston, MA 02115.
Hansen
R M
RM
Yeh
Y L
YL
Tyler
C W
CW
D000328:Adult; D003623:Dark Adaptation / Q000502:physiology*; D004596:Electroretinography; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D010775:Photic Stimulation; D010783:Photometry; D011601:Psychophysics; D012160:Retina / Q000502:physiology*; D012684:Sensory Thresholds / Q000502:physiology; D013997:Time Factors