An asymmetrical effect of similarity in the attenuation of stimulus suffix interference

Abstract

The effects of similarity between an eight-digit memory string (8) and a stimulus suffix (0) were studied in an immediate serial recall task. Four conditions (80, 80′, 8′0, and 8′0′) were created by the orthogonal variation of the addition and omission of a brief 1000 Hz tone (′) during the spoken presentation of the string and suffix, respectively. In Experiments I and II the potential contribution of attentional strategies was minimized and maximized, respectively, yet, in each instance, an asymmetrical attenuation of suffix interference was observed. The recall errors were reduced in condition 8′0 as opposed to the others, but not in Experiment III, in which a visual presentation was used and the tone replaced by overprinting the digits with a slash. These findings appear to be inconsistent with existing accounts of suffix interference. A new hypothesis considers suffix interference to be a manifestation of central backward masking, at least in part.