Selective Masking and the “Lamp-Phosphor” Problem

Abstract

Mollon and Polden (1978) have suggested that selective backward masking, the greater masking of central than peripheral items in briefly-presented letter rows by a patterned stimulus, may be due to an advantage conveyed to the peripheral items by the more rapid onset of the short wavelengths emitted by tachistoscope lamps. This suggestion was evaluated by comparing report accuracy under mask and no mask conditions when the tachistoscope fields were viewed through yellow or red filters that eliminated all wavelengths below 510 and 590 nm, respectively. The results showed similar selective-masking effects with both filters. Since selective masking occurs even when the short wavelength emissions are eliminated, Mollon and Polden's suggested explanation for selective masking must be rejected.