Auditory expectations for newly acquired structures

Abstract

Our study investigated whether newly acquired auditory structure knowledge allows listeners to develop perceptual expectations for future events. For that aim, we introduced a new experimental approach that combines implicit learning and priming paradigms. Participants were first exposed to structured tone sequences without being told about the underlying artificial grammar. They then made speeded judgements on a perceptual feature of target tones in new sequences (i.e., in-tune/out-of-tune judgements). The target tones respected or violated the structure of the artificial grammar and were thus supposed to be expected or unexpected. In this priming task, grammatical tones were processed faster and more accurately than ungrammatical ones. This processing advantage was observed for an experimental group performing a memory task during the exposure phase, but was not observed for a control group, which was lacking the exposure phase (Experiment 1). It persisted when participants realized an in-tune/out-of-tune detection task during exposure (Experiment 2). This finding suggests that the acquisition of new structure knowledge not only influences grammaticality judgements on entire sequences (as previously shown in implicit learning research), but allows developing perceptual expectations that influence single event processing. It further promotes the priming paradigm as an implicit access to acquired artificial structure knowledge.

Keywords:

• Implicit learning
• Artificial grammar
• Priming
• Auditory expectations
• Tone sequences

Acknowledgments

This research was supported by a grant from the Agence Nationale pour la Recherche of the French Ministry of Research (NT05–3_45978).

Notes

¹ Similarly, in studies using artificial languages (whether verbal or musical), the task (i.e., judging words and part-words) also requires informing participants about the structural system (language, or language-like system).

² This musical priming task has been created in parallel to the lexical decision task used in semantic priming research: Targets are either words or nonwords, and data analyses focus on the processing of the target words. For the purpose of the priming task used in our present study, test sequences were presented with the target tone being played either in tune (respecting the Western tuning system) or out of tune. Together with the experimental manipulations contrasting grammatical and ungrammatical target tones, the experimental trials thus consisted of sequences with 25% of the trials containing a grammatical in-tune tone, 25% an ungrammatical in-tune tone, 25% a mistuned tone that was based on the grammatical tone, and 25% a mistuned tone that was based on the ungrammatical tone. The data analyses are restricted to the in-tune target tones (grammatical, ungrammatical) as the mistuned tones represent foils to define the experimental task.

³ The five tones defined a nondiatonic set. One might argue that these tones belong to the key of g minor, even if the tonic g (i.e., the most important and most frequently used tone of a key) is absent. To investigate whether grammatical and ungrammatical sequences might differ in the tonal stability of the used tones, we attributed to each tone a value reflecting their respective role in the tonal hierarchy of a minor key (these values were taken from Krumhansl, 1990, Table 2.1, p. 30). The average of these values (summed over tones in each sequence) did not differ between grammatical and ungrammatical test sequences (16.35 and 16.43, respectively; p = .595). Consequently, ungrammatical items cannot be detected because of the use of less stable tones (in reference to g minor).