In Which Procrustean Bed Does the Sea Lion Sleep Tonight?

Abstract

Associative chains are limited in their ability to handle serial-order behavior involving remote associations among links in the chain, as in the words of a sentence. Sequential conditional associations may not necessarily result in mental representations of the stimulus sequences, limiting the ability to exceed the boundaries of the sequences explicitly taught. A variety of results suggest the development of mental representations of “words” and sequences of words in the dolphin Ake trained for comprehension of an artificial gestural language. Evidence for this level of representation is lacking or weak for the sea lion Rocky trained in a similar language. For the dolphin, but apparently not the sea lion, gestural signs were attached to concepts rather than to entities. Symmetry, advocated by Schusterman and Gisiner (1989) as the major test of reference is shown to be an inadequate if not an inappropriate test of reference. Misrepresentations of our published data base in claims of Schusterman and Gisiner are identified and the correct data, and our discussions of that data, are presented, exactly as they have appeared in our earlier published reports. The history of our early development of the relational sentence is reviewed and compared with the later history of its use with the sea lion. Impressions, given by Schusterman and Gisiner (1989), that Schusterman was not fully aware of our procedures for relational sentences, nor guided by us in their application to the sea lion, are corrected. I show that our work, contrary to claims of Schusterman and Gisiner (1989), has always accounted for differences in performance on relational and nonrelational sentences, has identified the major locus of difficulty on the relational sentence as memory for the indirect (goal) object, has distinguished between effects of various categories of goal objects, and has applied the theory of prospective and retrospective processes in working memory (Honig & Thompson, 1982) appropriately to the dolphin’s observed limitations on relational sentences. Finally, several problems are identified in the reporting or presentation of data for the sea lion by Schusterman and Gisiner (1988a, 1989).