INVERSE-INTENSITY EFFECT IN DURATION OF VISIBLE PERSISTENCE

Duration of visible persistence can vary inversely with stimulus inten sity. This inverse-intensity effect is obtained by varying the intensi ty of the stimuli or of the background, provided that the variations e xtend into the mesopic range. A similar relationship-known as the Ferr y-Porter law-holds for the critical frequency at fusion (CFF). The aut hors propose that studies of CFF, 2-pulse threshold, and visible persi stence can be encompassed within 1 conceptual framework in which the e ffect is modeled by the progressive reduction in the temporal extent o f the positive phase of the system's response as th: level of light ad aptation changes from scotopic to photopic. In this context, the autho rs present an integrative scheme in which G. Sperling and M. M. Sondhi 's (1968) formal model and M. Coltheart's (1980) neurophysiological co njecture are shown to be compatible and complementary accounts of the effect.