MEASURING AGE-DEPENDENCE OF COLOUR AFTERIMAGE PERCEPTION

Afterimages are common and frequent perceptual phenomena of everyday life. A typical appearance is the negative "ghost" image of a bright light source when we turn away from it. In the case of significant colour contrast, the afterimage can be coloured. The perceived false image's strength decreases gradually and completely disappears in a (10-100) s timescale. The underlying processes have multiple components: a quick adaptation on the retinal level, and a slower adaptation on the neural level. Several studies discuss these mechanisms, but there are still important questions to be answered. In our research, we apply the top-level, blackbox style approach: instead of focusing on the inner details, we ask human test subjects to test and measure the duration and "strength score" of the same light-transitions. Our goal is to find the main features that affect the duration and subjective strength of the colour afterimages. Specifically, we examine whether the age and gender of the test subjects or the colourimetry parameters affect these parameters. Two set of experiments were performed: colour-colour transitions with 41 and colour-grey transitions with 16 test subjects between 19 and 62. We found that gender has no measurable influence, but age makes a difference in high significance. Both experiment types confirmed that over 40 years the average duration of colour afterimages decreases.