Investigating the contribution of procedural and declarative memory to the acquisition of past tense morphology: Evidence from Finnish

Abstract

The present paper reports on a study that investigated the role of procedural and declarative memory in the acquisition of Finnish past tense morphology. Two competing models were tested. Ullman's (2004) declarative/procedural model predicts that procedural memory supports the acquisition of regular morphology, whereas declarative memory supports the acquisition of irregular morphology. In contrast, single-route approaches predict that declarative memory should support lexical learning, which in turn should predict morphological acquisition. One-hundred and twenty-four (N=124) monolingual Finnish-speaking children aged 4;0–6;7 completed tests of procedural and declarative memory, tests of vocabulary knowledge and nonverbal ability, and a test of past test knowledge. The results best supported the single-route approach, suggesting that this account best extends to languages that possess greater morphological complexity than English.

Keywords:

• Past tense morphology
• Language acquisition
• Finnish
• Memory

Acknowledgements

This research was supported by an Economic and Social Research Council grant to Evan Kidd (RES-000-22-2640). Preparation of the manuscript was supported by a Charles La Trobe Research Fellowship, also awarded to Kidd. We would like to thank Alexandre Nikolaev for his help with item selection, Jarrad Lum for his role in developing the tests, Jukka Hyönä and two anonymous reviewers for helpful comments, and all of the children and kindergartens that took part. Order of authorship is arbitrary.

Notes

¹Capital letters denote vowel harmony.

²We thank an anonymous reviewer for pointing this last estimate out to us.

³Note that this in no way means that a child who knows one verb and one inflection has productive knowledge of that inflection, since it is more likely that the children have acquired the complex form as a holistic form (Tomasello, 1992).

⁴Lum et al. (2010a) showed that handedness is not related to performance on the task, presumably because most children have a fair amount of practice using game pads. Therefore handedness was not likely to affect our results.

⁵The A-infinitive is not a base form like in English, since in Finnish verbs are always inflected. The A-infinitive, even though morphologically complex, is often the citation form of verbs.

⁶In Appendix 2 we have listed the number of phonological “friends” each item has in Finnish. Note that none have phonological enemies, except for two nonproductive stem-change verbs. The dual-route approach predicts that, since our verbs are comparatively low in frequency and should not be stored as whole forms, the effect of neighbourhood density on our fully productive items should therefore be negligible.

⁷Greenhouse–Geisser corrected.

⁸Nonparametric Wilcoxon-signed tests were computed for the si-regular, si-novel, and i-novel conditions because there was no variation in the top quartiles in their performance on the past tense task for these conditions.