Dual Coding and the Representation of Letter Strings
Sub-strings derived from four-letter strings (e.g. ABCD) were presented to subjects using a variation on Bransford and Franks' (1971) paradigm. Each strins was in either upper or lower case. Subjects were then tested for recognition of the strings, false recognition of translations of the strings into the other case, and false recognitions of new but legal strings. Subjects accepted previously seen strings most frequently, following by translations, with New strings accepted least often. This replicateds Rosenberg and Simon's (in press) findings with sentences and pictures that express the same concept. However, in the present experiment the two forms of a string were unbiased with respect to verbal or pictorial encoding. The forms in which a string could appear (upper or lower case) were not confounded with the two types of encoding (verbal and pictorial) hypothesized by a dual coding theory. The results supported the view that the previously reported difference between the original form and a translation is best explained by a model which uses a single representation that preserves some form distinctions.