Relationship between working memory capacity and second language speech production

¶ … Linguistic Learning Studies

Differences in Conceptual Design:

The Kormos and Safar study (2008) seems to have been much better designed to produce meaningful results than the Mota study (2003). At the most fundamental level, the Kormos and Safar study manifested an explicit recognition of the degree to which the dependent variable (foreign language learning and performance) is inherently a function of many different variables besides memory. In that regard, the Kormos and Safar study even acknowledged the relevance of variables not traditionally associated with learning, even in the most general sense, such as those attributable to the expanded definitions of cognitive intelligence advanced by pioneers in human learning and education such as Howard Gardner (Kormos & Safar, 2008 p261). That study referenced variables as far-removed from memory as temperament and personality (Kormos & Safar, 2008 p261).

By contrast, the Mota study (2003) focused exclusively and one-dimensionally on the importance of working memory, seemingly without regard for the complex, multidimensional variables outside of memory that may influence the dependent variables measured (foreign language fluency, accuracy, and complexity (Mota, 2003 p69). Furthermore, whereas the Kormos and Safar study (2008) distinguished between the respective roles of working memory and phonological short-term memory in different aspects of language learning, the Mota study (2003) ignored phonological short-term memory altogether from the outset, instead presupposing that any measurable differences in language learning are attributable to differences in working memory alone. Finally, whereas the experimental design devised for the Kormos and Safar study (2008) specifically included both advanced foreign language learners and beginners (Kormos & Safar, 2008 p 264), the Mota study (2003) used only advanced foreign language learners.

Differences in Experimental Methodology:

The Kormos and Safar study (2008) employed a non-word span test (Kormos & Safar, 2008 p 264) to establish one independent variable (short-term memory) and a backward digit span test to establish another independent variable (working memory). Combined with the crucial inclusion of both advanced foreign language learners and beginners, this experimental methodology allowed the researchers to consider the disparate effects and possible roles of different cognitive processes involved in performance not directly attributable to working memory alone.

Conversely, the Mota study (2003) employed only a speaking (word) span test (Mota, 2003 p75) without any test of other cognitive processes potentially involved in foreign language learning and recall. Similarly, the non-word span test employed by the Kormos and Safar study, (2008) is a much more direct (and therefore, reliable) measure of raw memory, the word span test employed by the Kormos study (2003) introduces extraneous variables.

That is a function of the complex cognitive mechanisms involved in human language processing and speech, which Kormos explicitly acknowledges as possibly the most complex of all human cognitive processes (Levelt, 1995 in Kormos, 2003 p88). Given that characterization, the use of a word span test -- in which performance could quite conceivably measure other variables besides raw working memory, such as parallel recognition and various other associative or pneumonic devices -- instead of a non-word span test likely undermined the validity of the Mota study (2003) results.

Furthermore, the Kormos and Safar study (2008) employed standard objective academic tests of foreign language proficiency, whereas the Mota study (2003) employed a novel matrix of variables (fluency, accuracy, and complexity) to measure foreign language proficiency (Mota, 2003 p69). The former type of diagnostic test would appear to be an appropriately accurate and narrowly targeted measure of memory-based performance and learning in the realm of foreign language acquisition (Kormos & Safar, 2008 p265).

Meanwhile, the latter type of test would seem to introduce multiple extraneous variables in the realm of linguistic abilities much more general than those exclusively dependent on working memory. Particularly in light of the perspective of human cognitive learning advanced by Gardner and others (Kormos & Safar, 2008 p261), and the overall complexity of human speech (Levelt, 1995 in Kormos, 2003 p88), the use of diagnostic tests incorporating recognizable words would seem inadvisable for any research design intended to isolate the role of raw working memory that the Mota study (2003) sought to undertake.