When articulatory suppression does not suppress the activity of the phonological loop

Abstract

The purpose of this study is to examine whether the phonological loop works under the conditions where an individual is required to produce an irrelevant speech sound which constitutes the minimum load on the speech motor programming. In the first experiment, participants were tested for serial recall of visually presented letter sequences that were phonologically either similar or dissimilar, and had to remember each of the letter sequences under three learning conditions: a control and two articulatory suppression conditions (intermittent suppression and continuous suppression conditions). Results showed that the phonological similarity effects appeared in the control condition and also in the continuous suppression condition in which an irrelevant speech sound was continuously uttered by the participants. On the other hand, the phonological similarity effect disappeared in the intermittent suppression condition in which an ordinary articulatory suppression was performed. This pattern of results was replicated in the second experiment where participants were exposed to an irrelevant speech sound auditorily in all three conditions. In the third experiment, a simple tapping in synchronization with the irrelevant speech sound did not decrease the size of the phonological similarity effect. Possible relationships between phonological loop, speech motor programming and abstract phonological representations are discussed.