Understanding the Phonetic Characteristics of Speech Under Uncertainty-Implications of the Representation of Linguistic Knowledge in Learning and Processing

The Keys to the Future? An Examination of Statistical Versus Discriminative Accounts of Serial Pattern Learning

Sequence learning is fundamental to a wide range of cognitive functions. Explaining how sequences-and the relations between the elements they comprise-are learned is a fundamental challenge to cognitive science. However, although hundreds of articles addressing this question are published each year, the actual learning mechanisms involved in the learning of sequences are rarely investigated. We present three experiments that seek to examine these mechanisms during a typing task. Experiments 1 and 2 tested learning during typing single letters on each trial. Experiment 3 tested for "chunking" of these letters into "words." The results of these experiments were used to examine the mechanisms that could best account for them, with a focus on two particular proposals: statistical transitional probability learning and discriminative error-driven learning. Experiments 1 and 2 showed that error-driven learning was a better predictor of response latencies than either n-gram frequencies or transitional probabilities. No evidence for chunking was found in Experiment 3, probably due to interspersing visual cues with the motor response. In addition, learning occurred across a greater distance in Experiment 1 than Experiment 2, suggesting that the greater predictability that comes with increased structure leads to greater learnability. These results shed new light on the mechanism responsible for sequence learning. Despite the widely held assumption that transitional probability learning is essential to this process, the present results suggest instead that the sequences are learned through a process of discriminative learning, involving prediction and feedback from prediction error.

Phonetic characteristics of German unstressed vowels: The case of opa vs Oper

Kohler [Einführung in die Phonetik des Deutschen (Erich Schmidt Verlag, Berlin, Germany, 1995)] stated that German [ɐ] and [a] in unstressed syllables are merging. The present study tested this hypothesis. The contrast was found intact word-internally and word-finally. Neighborhood density enhanced its phonetic characteristics, but no effects of frequency and conditional probability were found.

Paradigmatic and Syntagmatic Effects in Estonian Spontaneous Speech

Recent evidence indicates that a word's paradigmatic neighbors affect production. However, these findings have mostly been obtained in careful laboratory settings using words in isolation, and thus ignoring potential effects that may arise from the syntagmatic context, which is typically present in spontaneous speech. The current corpus analysis investigates paradigmatic and syntagmatic effects in Estonian spontaneous speech. Following work on English, we focus on the duration of inflected and uninflected word-final /-s/ in content words, while simultaneously investigating whole words. Our analyses reveal three points. First, we find an effect of realized inflectional paradigm size, such that smaller paradigms actively used by the speakers lead to longer durations. Second, higher conditional probability is associated with shorter word forms and shorter segments. Finally, we do not directly replicate previous work on effects of inflectional status as in English word-final /-s/. Instead, we find that inflectional status interacts with conditional probability. We discuss the results in light of models of speech production and how they account for morphologically complex words and their paradigmatic neighbors.