Some Evidence for Parallel Comparisons in a Letter Recognition Task

Abstract

Subjects were asked to judge successively presented letter trigrams “same” or “different.” The different stimuli were divided into four groups; not confusable (NC), acoustically confusable (AC), visually confusable (VC), and both visually and acoustically confusable (VC & AC). Reaction times (RT) were lengthened only by the double confusability. It is argued that comparisons are normally made in both channels, so that confusability in a single channel has no effect since the alternative channel is unimpaired. RTs are only increased when both channels are slowed down. A further experiment confirms this interpretation. When the situation is manipulated so that only the visual channel is employed, the VC group shows the same increase as the VC & AC group.