Phonological short-term memory capacity and L2 oral performance

Phonological short-term memory (PSTM) capacity is the ability to retain verbal information briefly (Archibald & Gathercole, 2006). Since PSTM facilitates the storage of verbal material, one expects a positive relationship between PSTM and several aspects of second language (L2) learning. Some studies have found a relationship between PSTM and oral production skills, such as fluency (e.g., O'Brien et al., 2006). This paper reports on the results of a study that looked at the inter-relations between complexity, accuracy, and fluency (CAF), and between these dimensions and PSTM. One hundred and thirty-five L2 learners of Spanish participated in the study. Results showed that performance in one L2 speech dimension did not have a negative impact on performance in another dimension, but that as complexity increased or decreased, there was a better chance of fluency than accuracy also increasing or decreasing. PSTM capacity was related to complexity and fluency, but not to accuracy. These results were interpreted as lending some support to Skehan's Trade-off Hypothesis (Skehan, 2009).