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Two pulses seen as three flashes: a superposition analysis.

R W Bowen
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Abstract

If a single brief light pulse follows the offset of a light field by 0.1-0.3 sec, the pulse is seen as a double flash. This "double flash effect" is a suprathreshold phenomenon: the pulse must exceed detection threshold by 10 times or more for this temporal illusion to occur. A special case of this effect is demonstrated here: two brief, high-luminance pulses separated by 0.1 sec appear as three flashes. In a superposition analysis, hypothetical impulse response functions were added together with various delays to model flash perception. A biphasic impulse response (congruent with threshold flicker and pulse sensitivity) fails to predict perception of three flashes from two pulses. The analysis instead suggests that the visual response to a suprathreshold pulse has several alternating phases of excitation and inhibition.

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HumansModels, PsychologicalPhotic StimulationPsychophysicsSystems AnalysisTime FactorsVisual PerceptionJournal Article

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R W Bowen. 1989. Two pulses seen as three flashes: a superposition analysis.. https://doi.org/10.1016/0042-6989(89)90005-9

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