Testing the attentional model of brightness contrast with relative area and figure-ground organization unconfounded

Abstract

Usin~gray-white metric patterns, for~hich figure-groun~relationships had been previously detern,llned, s~veral. features of .an attentional theory of brightness contrast were investigated. Experiment I, involving three subjects and the method of constant stimuli, showed that ground the unattended area, could be reliably perceived as brighter; responses were affected by both the type of pat~ern. and level of c~ntrast ratio. Experiment II, involving 40 subjects and the method of magnitude estimation, used metric patt.erns for which attentional factors were not confounded with relative area. The results supported the first study and further indicated the primary involvement of relative area rather than focus of attention in brightness contrast.