Implicit Learning of Form-Meaning Connections

Implicit Learning of Form-Meaning Connections Janny Leung (janny@cantab.net) Research Centre for English and Applied Linguistics, University of Cambridge, English Faculty Bldg. , 9 West Rd., Cambridge, CB39DP, UK John N. Williams (jnw12@cam.ac.uk) Research Centre for English and Applied Linguistics, University of Cambridge, English Faculty Bldg. , 9 West Rd., Cambridge, CB39DP, UK Abstract Cohen, & Corkin, 1988) can learn novel word forms, as assessed by tests of implicit memory such as fragment completion and priming. But they seem to have great difficulty learning new vocabulary; for example they are unable to recognise or use words that they have been exposed to over long periods after the onset of amnesia. Amnesics are unable to recall specific experiences – they have impaired episodic memory. So their inability to acquire vocabulary implies that episodic memory is involved in learning form-meaning mappings, perhaps through conscious comparison processes between different occasions of use of a word (Ellis, 1994). However, more recent evidence suggests that amnesics can learn vocabulary after all (e.g., Vargha-Khadem et al., 1997). These studies count against the claim that vocabulary learning is necessarily dependent upon conscious memory for specific episodes of word use. Rather, the process of abstracting the meaning of words from experience may occur implicitly. But even if we allow for implicit meaning abstraction in memory, there remains the question of how the requisite data gets into memory in the first place. For example, when a novel word is encountered, is it necessary to attend to the connection between that word and a (hypothesised) meaning? In the context of first language acquisition, Merriman (1999) argues that when the “principle of mutual exclusivity” is violated the child will “seek out, discover, and dwell on features that are uniquely associated with the second label” (ibid., p. 350). And in adult second language acquisition Doughty & Williams (1998) stress not only attention to form and meaning, but also their integration within the learning episode (ibid., p.245). These quotations imply that learners need to attend to relationships between forms and meanings. However, these arguments are merely speculative, and we know of no experimental investigations of implicit (as opposed to incidental) learning of form- meaning connections. In researching these issues we have chosen to focus on function, rather than content, words. This makes it possible to examine potential interactions with prior grammatical knowledge and allows us to address the issue of whether some kinds of regularity are more readily learned implicitly than others because they capitalise on linguistic concepts that the learner already possesses. The starting point was an earlier study (Williams, 2005) in which subjects first learned four determiner-like words: We report two experiments that used derived attention paradigms to examine implicit learning of associations between forms and meanings in semi-artificial languages. Both experiments examined learning of rules governing article usage, and the dependent measure was the time to locate objects referred to by article-plus-noun expressions in pictures. Learning was measured by slow-downs in search times when the learned associations were violated. Experiment 1 demonstrated implicit learning of associations between articles and the accompanying noun’s thematic role in a sentence. Experiment 2 found no implicit learning of an association between articles and the position of the object referred to by the noun in a scene (only explicit learning effects were obtained). We explain this difference in terms of the possibility for interactions between implicit learning and grammatical knowledge. Introduction Studies of implicit learning have generally focused on the learning of rules and associations concerning forms in a single modality, for example letters in artificial grammar experiments, or spatial locations of visual stimuli in serial reaction time experiments. In the case of natural language systems learning such form-form associations might contribute to the acquisition of syntactic rules, but there remains the problem of learning how those forms relate to meanings. In this research we address the issue of whether people become sensitive to associations between forms and meanings without an intention to learn them, and without awareness of what they are. The issue of learning form-meaning connections is usually considered in the context of vocabulary acquisition. Ellis (1994) argues that learning form-meaning connections is dependent upon declarative memory. For one thing, variables that are known to affect episodic memory also influence vocabulary learning, e.g. intelligence, depth of processing, meta-cognitive and mediational strategies. Gupta & Dell (1999) make a similar argument on purely computational grounds, pointing out that the arbitrariness of form-meaning mappings makes them very difficult to assimilate using the kinds of implicit (in their view, connectionist) learning mechanisms that underlie skill learning. Important evidence is also provided by research on amnesia. For example, amnesics such as H.M. (Gabrieli,