Visual suffix effects on the Optacon: A test of changing state, primary linguistic, and attentional theories

Abstract

An experiment compared the effects of an alphabetic and a nonalphabetic suffix on the serial recall of letters of the alphabet presented with the visual display of the Optacon, a reading aid for the blind. The Optacon presents “changing state” stimuli, that is, those that change over time during presentation. The results showed generalized decrements from the suffixes in the absence of recency in the control condition and no specific end-of-sequence suffix effect. The findings contradict the theory that recency and end-of-sequence suffix effects, characteristic of most auditory, and a few visual, stimuli, are presented in the recall of all changing state stimuli, and provide some support for the Shand and Klima view that stimuli that map into the primary linguistic mode of the subject do exhibit such properties. Additionally, the finding that both an alphabetic and a square suffix led to equivalent decrements from a suffix contradict some attentional theories of the effects of suffixes on visual stimuli.