Does colour undergo the same reversed contrast effect observed for lightness in Agostini and Galmonte's Necker cube display?

Agostini and Galmonte (1997 Perception 26 Supplement, 27; 2002 Perception 31 Supplement, 7) presented a reversed-contrast display where a grey region surrounded by a black area appears darker than an identical grey region surrounded by white. Both higher- and lower-level factors affect simultaneously this configuration, but higher-level grouping factors prevail in determining the effect, that cannot be explained by assimilation. The present work investigates whether global grouping factors induction can be found also for colour. Agostini and Galmonte's display was reproduced by using red/yellow inducing colours (backgrounds/corners), whereas induced regions (dashed lines) were orange. There were also two control conditions: (i) inducer corners were the same orange as targets; (ii) disks having same area and colour (red/yellow) replaced the inducer corners. In these cases, we did not expect any effect. Observers had to judge the colour of the induced regions on a red/yellow Munsell Scale. Results replicate those obtained for lightness: Global factors determine the target perceived colour; ie, orange appeared reddish in the yellow corners/red background display, whilst it was perceived yellowish in the opposite configuration. No statistically significant difference was found for both controls. Therefore, we conclude that global induction overcomes local induction also for coloured displays. [Supported by MIURGrant2007E7PHM3.]