Factors affecting stress placement for English nonwords include syllabic structure, lexical class, and stress patterns of phonologically similar words

Lexical stress assignment preferences in L2 German

Assigning stress to the appropriate syllable is consequential for being understood. Despite the importance, second language (L2) learners' stress assignment is often incorrect, being affected by their first language (L1). Beyond the L1, learners' lexical stress assignment may depend on analogy with other words in their lexicon. The current study investigates the respective roles of the L1 (English, French) and analogy in L2 German lexical stress assignment. Because English, like German, has variable stress assignment and French does not, participants included English- and French-speaking German L2 learners who assigned stress to German nonsense words in a perceptual preference and a production task. Results suggest a role of the L1, with English-speaking German L2 learners performing more like L1 German speakers. While French-speaking German L2 learners' performance could not be predicted by other factors, L2 German proficiency and the ability to produce analogous words were predictive of English-speaking German L2 learners' production performance.

Accuracy and Stability in English Speakers' Production of Japanese Pitch Accent

Standard Japanese uses pitch accent to distinguish words such as initially-accented hashi "chopsticks" and finally-accented hashi "bridge." Research on the second language acquisition of pitch accent shows considerable variation: in accuracy scores in identification, in different dominant accent types in production, and in the unstable accent types of repeated words. This study investigates pitch accent production in English-speaking learners of Japanese, asking how accuracy and stability vary (a) with amount of Japanese experience and (b) between learners. Two groups of learners (13 less experienced; 8 more experienced) produced 180 words in three contexts (e.g., ame "rain," ame da "it's rain," and ame ga furu "rain falls"). Three Japanese phoneticians identified the accent types of the words that the learners produced. The results showed no difference in accuracy or stability between the two groups and little inter-learner variation in accuracy: all had low accuracy. Although some learners had relatively high stability, they did not maintain accent type contrasts across contexts. These results suggest that first language English speakers do not encode pitch accent in long-term memory, raising questions for future research and language teaching.

Trochaic bias overrides stress typicality in English lexical development

This paper investigates whether typical stress patterns in English nouns and verbs are available as a prosodic cue for categorisation and accelerated word learning during first language acquisition. The stress typicality hypothesis states that left-stressed nouns and right-stressed verbs should be acquired earlier than the reverse configurations if stress effectively signals lexical class membership. In this view, class-typical stress patterns are expected to facilitate learning of novel items. A series of generalized additive models (GAMs) based on a comprehensive set of lexical data (CELEX) as well as a large set of age-of-acquisition (AoA) and concreteness ratings reveals that stress typicality plays a minor role in early acquisition, as it is generally superseded by a preference for left-hand (or 'trochaic') patterns in both nouns and verbs. This may be explained by general cognitive constraints (perceptual salience and recency) or exposure to the dominant pattern in the ambient language.

Autism-Centered Therapy for Childhood Apraxia of Speech (ACT4CAS): A Single-Case Experimental Design Study

Purpose A subset of children with autism spectrum disorder (ASD) has speech sound disorders, including childhood apraxia of speech (CAS). To date, virtually all speech treatment studies consider ASD an exclusionary criterion, resulting in little scientific evidence for treatment of CAS for children who also have ASD. This study proposes and tests a novel approach, Autism-Centered Therapy for Childhood Apraxia of Speech (ACT4CAS), as a theoretically and clinically informed speech treatment option for this population. Method Using a multiple-baseline design within and across participants, three children with co-occurring ASD and CAS received 11-18 treatment sessions. Treatment targets were individually designed and matched with untreated control words. Probes were administered at the start of each session to assess speech production accuracy perceptually. Changes in production accuracy were examined through visual inspection and quantified with effect sizes. Results Findings were mixed, with one child showing significant gains for half of the treated targets at follow-up and two children showing no clear improvement. Conclusions Preliminary evidence suggests potentially positive treatment effects for ACT4CAS when implemented as intended, although treatment intensity and disorder severity likely influence treatment outcome. Replication and comparison of ACT4CAS to other speech treatments is needed. Supplemental Material https://doi.org/10.23641/asha.14110445.

No Acoustic Correlates of Grammatical Class: A Critical Re-Examination of Sereno and Jongman (1995)

The present article describes an extended replication of a reading study by Sereno and Jongman (1995) that reported acoustic differences between noun and verb pronunciations of English disyllabic, non-stress-shifting homophone pairs, for example, answer (v) versus answer (n). The original findings point to a gradual influence of the typical stress patterns of both grammatical categories, with noun readings exhibiting a tendency toward trochaic and verb readings toward iambic pronunciation. However, the effects found by Sereno and Jongman (1995) did not consistently reach statistical significance and were based on a very small sample size. Employing a considerably larger group of speakers, the current replication fails to find the reported effects of the grammatical category. The null result obtained can be accounted for within speech production models that assume identical metrical templates for the homophone pairs tested and no direct influence of the grammatical category on the phonetics of stress assignment.

A Novel Investigation of Generalized Motor Program Theory: Syllable Stress as a Motor-Class Variable

PURPOSE

This experiment evaluated syllable-stress position as a motor class directed by a syllable-sized generalized motor program. Reaction times were predicted to be slower for stimuli with untrained stress patterns outside the trained motor class. Furthermore, reaction times were predicted to be stable for untrained stimuli within the same motor class regardless of phonetic similarity.

METHOD

Twenty-three young adults with typical speech and hearing participated in a motor-learning study comprised of motor-class training and a judgment task. Reaction times derived from the judgment task were evaluated using a within-subject repeated-measures design to evaluate the effects of syllable-stress position on stimulus type.

RESULTS

Reaction times were not significantly different across proposed syllable-stress motor-class boundaries. However, reaction times for the stimuli within the same motor class were significantly different. To be specific, slower reaction times were associated with untrained stimuli that were phonetically similar to the trained stimuli.

CONCLUSIONS

The proposed hypotheses for syllable stress as a motor class were not met. Results indicate that multiple stimulus features, including syllable stress and phoneme similarity, may be encoded into memory during motor learning. Future research should evaluate how phonetic similarity of stimuli may influence motor-learning outcomes.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.5116837.

Children's abstraction and generalization of English lexical stress patterns

The current study investigated school-aged children's internalization of the distributional patterns of English lexical stress as a function of vocabulary size. Sixty children (5;3 to 8;3) participated in the study. The children were asked to blend two individually presented, equally stressed syllables to produce disyllabic nonwords with different resulting structures in one of two frame sentences. The frame sentences were designed to elicit either a noun or verb interpretation of the nonword. Children's receptive vocabulary was also assessed. The results indicated that children more readily blended syllable pairs that resulted in trochaic-compatible word structures than in iambic-compatible structures. This effect was strongest in young children with large vocabularies. As for stress placement, all children were sensitive to the effect of word structure, but only children with the largest vocabularies were sensitive to the biasing effect of grammatical category (noun = trochee; verb = iamb). The study results are discussed with reference to the observation that speech motor skills develop in tandem with lexical acquisition and the hypothesis that phonological knowledge emerges in part from abstraction across lexical representations.

Prefixes repel stress in reading aloud: Evidence from surface dyslexia

This study examined the importance of prefixes as sublexical cues for stress assignment during reading aloud English disyllabic words. In particular, we tested the hypothesis that prefixes repel stress (Rastle & Coltheart, 2000) by investigating the likelihood with which patients with surface dyslexia assign second-syllable stress to prefixed words. Five such patients were presented with three types of disyllabic words for reading aloud: 'regular' prefixed words with weak-strong stress pattern (e.g., remind); 'irregular' prefixed words with strong-weak stress pattern (e.g., reflex); and non-prefixed words with strong-weak stress pattern (e.g., scandal). Results showed that all five patients frequently regularized the strong-weak prefixed words by pronouncing them with second syllable stress. These regularization errors provide strong evidence for the functional role of prefixes in stress assignment during reading. Additional computational simulations using the rule-based algorithm for pronouncing disyllables developed by Rastle and Coltheart (2000) and the CDP++ model of reading aloud (Perry et al., 2010) allowed us to evaluate how these two opponent approaches to reading aloud fare in respect of the patient data.

Neuro-cognitive foundations of word stress processing - evidence from fMRI

BACKGROUND

To date, the neural correlates of phonological word stress processing are largely unknown.

METHODS

In the present study, we investigated the processing of word stress and vowel quality using an identity matching task with pseudowords.

RESULTS

In line with previous studies, a bilateral fronto-temporal network comprising the superior temporal gyri extending into the sulci as well as the inferior frontal gyri was observed for word stress processing. Moreover, we found differences in the superior temporal gyrus and the superior temporal sulcus, bilaterally, for the processing of different stress patterns. For vowel quality processing, our data reveal a substantial contribution of the left intraparietal cortex. All activations were modulated by task demands, yielding different patterns for same and different pairs of stimuli.

CONCLUSIONS

Our results suggest that the left superior temporal gyrus represents a basic system underlying stress processing to which additional structures including the homologous cortex site are recruited with increasing difficulty.

Native Thai speakers' acquisition of English word stress patterns

The influence of syllabic structure, lexical class and stress patterns of known words on the acquisition of the English stress system was investigated in ten native Thai speakers. All participants were adult learners of English with an average length of residence in the US of 1.4 years. They were asked to produce and give perceptual judgments on 40 English non-words of varying syllabic structures in noun and verb sentence frames. Results of the production data suggested that syllables with a long vowel attracted stress more often than syllables containing a short vowel and nouns received initial stress more often than verbs. Additionally, regression analyses with the three factors as predictors suggested that Thai participants' pattern of stress assignment on non-words was significantly influenced by the stress patterns of phonologically similar real words. These results were compared and contrasted to those found in previous work with Spanish-English and Korean-English bilinguals.