Lexical access in Portuguese stress

Categorical approaches to lexical stress typically assume that words have either regular or irregular stress, and imply that only the latter needs to be stored in the lexicon, while the former can be derived by rule. In this paper, we compare these two groups of words in a lexical decision task in Portuguese to examine whether the dichotomy in question affects lexical retrieval latencies in native speakers, which could indirectly reveal different processing patterns. Our results show no statistically credible effect of stress regularity on reaction times, even when lexical frequency, neighborhood density, and phonotactic probability are taken into consideration. The lack of an effect is consistent with a probabilistic approach to stress, not with a categorical (traditional) approach where syllables are either light or heavy and stress is either regular or irregular. We show that the posterior distribution of credible effect sizes of regularity is almost entirely (96.28%) within the region of practical equivalence, which provides strong evidence that no effect of regularity exists in the lexical decision data modelled. Frequency and phonotactic probability, in contrast, showed statistically credible effects given the experimental data modelled, which is consistent with the literature.

The development of linguistic stimuli for the Swedish Situated Phoneme test

The speech perception ability of people with hearing loss can be efficiently measured using phonemic-level scoring. We aimed to develop linguistic stimuli suitable for a closed-set phonemic discrimination test in the Swedish language called the Situated Phoneme (SiP) test. The SiP test stimuli that we developed consisted of real monosyllabic words with minimal phonemic contrast, realised by phonetically similar phones. The lexical and sublexical factors of word frequency, phonological neighbourhood density, phonotactic probability, and orthographic transparency were similar between all contrasting words. Each test word was recorded five times by two different speakers, including one male and one female. The accuracy of the test-word recordings was evaluated by 28 normal-hearing subjects in a listening experiment with a silent background using a closed-set design. With a few exceptions, all test words could be correctly discriminated. We discuss the results in terms of content- and construct-validity implications for the Swedish SiP test.

A Sound Explanation for Motor Cortex Engagement during Action Word Comprehension

Comprehending action words often engages similar brain regions to those involved in perceiving and executing actions. This finding has been interpreted as support for grounding of conceptual processing in motor representations or that conceptual processing involves motor simulation. However, such demonstrations cannot confirm the nature of the mechanism(s) responsible, as word comprehension involves multiple processes (e.g., lexical, semantic, morphological, phonological). In this study, we tested whether this motor cortex engagement instead reflects processing of statistical regularities in sublexical phonological features. Specifically, we measured brain activity in healthy participants using functional magnetic resonance imaging while they performed an auditory lexical decision paradigm involving monosyllabic action words associated with specific effectors (face, arm, and leg). We show that nonwords matched to the action words in terms of their phonotactic probability elicit common patterns of activation. In addition, we show that a measure of the action words' phonological typicality, the extent to which a word's phonology is typical of other words in the grammatical category to which it belongs (i.e., more or less verb-like), is responsible for their activating a significant portion of primary and premotor cortices. These results indicate motor cortex engagement during action word comprehension is more likely to reflect processing of statistical regularities in sublexical phonological features than conceptual processing. We discuss the implications for current neurobiological models of language, all of which implicitly or explicitly assume that the relationship between the sound of a word and its meaning is arbitrary.

Incorporating tone in the modelling of wordlikeness judgements

Various phonotactic models have been proposed for the prediction of wordlikeness judgements, most of which have focused primarily on segments. This article aims to model wordlikeness judgements when tone is incorporated. We first show how the two major determinants of wordlikeness judgements, i.e. phonotactic probability and neighbourhood density, can be measured when tone is involved. To test the role of the two determinants of wordlikeness judgements in a tone language, judgement data were obtained from speakers of Cantonese. Bayesian modelling was then used to model the judgement data, showing that phonotactic probability, but not neighbourhood density, influences wordlikeness judgements. We also show that phonotactic probability affects the tendency to judge items as absolutely perfect or more or less wordlike, while it does not affect judgements that an item is absolutely not wordlike. Implications of these results for phonotactic modelling and processes involved in wordlikeness judgements are discussed.

Relationship between early phonological processing and later phonological awareness: Evidence from nonword repetition

This study investigated whether individual differences in receptive vocabulary, speech perception and production, and nonword repetition at age 2 years, 4 months to 3 years, 4 months predicted phonological awareness 2 years later. One hundred twenty-one children were tested twice. During the first testing period (Time 1), children’s receptive vocabulary, speech perception and production, and nonword repetition were measured. Nonword repetition accuracy in the present study was distinct from other widely used measures of nonword repetition in that it focused on narrow transcription of diphone sequences in each nonword that differed systematically in phonotactic probability. At the second testing period (Time 2), children’s phonological awareness was measured. The best predictors of phonological awareness were a measure of speech production and a measure of phonological processing derived from performance on the nonword repetition task. The results of this study suggest that nonword repetition accuracy provides an implicit measure of phonological skills that are indicative of later phonological awareness at an age when children are too young to perform explicit phonological awareness tasks reliably.