An experimental investigation of the role of iconic gestures in lexical access using the tip-of-the-tongue phenomenon

The tip-of-the-tongue (TOT) state was induced in participants to test Butterworth & Hadar's (1989) theory that iconic gestures have a functional role in lexical access. Participants were given rare word definitions from which they had to retrieve the appropriate lexical item, all of which had been rated high in imageability. Half were free to gesture and the other half were instructed to fold their arms. Butterworth & Hadar's theory (1989) would predict, first, that the TOT state should be associated with iconic gesture and, second, that such gestures should assist in this lexical retrieval function. In other words, those who were free to gesture should have less trouble in accessing the appropriate lexical items. The study found that gestures were associated with lexical search. Furthermore, these gestures were sometimes iconic and sufficiently complex and elaborate that naive judges could discriminate the lexical item the speaker was searching for from a set of five alternatives, at a level far above chance. But often the gestures associated with lexical search were not iconic in nature, and furthermore there was no evidence that the presence of the iconic gesture itself actually helped the speaker find the lexical item they were searching for. This experimental result has important implications for models of linguistic production, which posit an important processing role for iconic gestures in the processes of lexical selection.