IS THERE INHIBITION OF RETURN FOR ISOLUMINANT COLORS?
In the present study we replicate experiments of LupiaÃ±ez et al. (1997) who addressed the issue of inhibition of return with respect to the color of stimuli. In contrast to that study, using non-isoluminant stimuli, we employed two pairs of isoluminant colors varying along either the red-green or blue-yellow cardinal axes of a color space â€“ deutan or tritan confusion lines in the CIE 1976. Participants (normal trichromats; n=8) were exposed successively to the color pairs; their task was to respond to the second (target) stimulus by key pressing, whereby simple reaction times were measured. In different trial stimulus onset asynchrony (SOA) was varied: 100, 400, 700, 1000 and 1300 ms. At no SOA inhibition of return was found; instead, facilitation of return was demonstrated, this especially pronounced at the short SOA=100 ms. We found that participants were overall faster in the invalid condition when compared to the valid condition (F=25.986, p=0.001). We hypothesized that when isoluminants colors are employed as both cue and target, Inhibition of Return canâ€™t be establish.