Management of sentence production demands

The efficacy of memory load on speech-based detection of Alzheimer's disease

Introduction

The study aims to test whether an increase in memory load could improve the efficacy in detection of Alzheimer's disease and prediction of the Mini-Mental State Examination (MMSE) score.

Methods

Speech from 45 mild-to-moderate Alzheimer's disease patients and 44 healthy older adults were collected using three speech tasks with varying memory loads. We investigated and compared speech characteristics of Alzheimer's disease across speech tasks to examine the effect of memory load on speech characteristics. Finally, we built Alzheimer's disease classification models and MMSE prediction models to assess the diagnostic value of speech tasks.

Results

The speech characteristics of Alzheimer's disease in pitch, loudness, and speech rate were observed and the high-memory-load task intensified such characteristics. The high-memory-load task outperformed in AD classification with an accuracy of 81.4% and MMSE prediction with a mean absolute error of 4.62.

Discussion

The high-memory-load recall task is an effective method for speech-based Alzheimer's disease detection.

The impact of visual and motor skills on ideational apraxia and transcortical sensory aphasia

BACKGROUND

Patients with extensive left hemisphere damage frequently have ideational apraxia (IA) and transcortical sensory aphasia (TSA). Difficulty with action coordination, phonological processing, and complex motor planning may not be indicative of higher-order motor programming or higher-order complex formation. We report on the effects of IA and TSA on the visual and motor skill of stroke patients.

PURPOSE

The study aims to address the question of whether IA and TSA in bilingual individuals are the results of an error of motor function alone or due to a combined motor plus and cognitive dysfunction effect.

METHOD

Twelve bilingual patients (seven males, and five females) were diagnosed with IA and TSA, and are divided into two groups of six patients. Then, 12 healthy bilingual controls were evaluated for comparing with both groups. Bilingual aphasia testing (BAT) and appropriate behavioral evaluation were used to assess motor skills, including coordination, visual-motor testing, and phonological processing.

RESULTS

Findings (pointing skills) show that the performance of the L1 and L2 languages are consistently significant (p < 0.001) in healthy individuals compared to the IA and TSA groups. Command skills for L1 and L2 languages were significantly higher in healthy individuals compared to IA and TSA controls (p < 0.001). Further, the orthographic skills of IA and TSA vs controls in both groups were significantly reduced (p < 0.01). Visual skills in the L1 language were significantly improved (p < 0.05) in IA and TSA patients compared to healthy controls after 2 months. Unlike orthographic skills which were improved in IA and TSA patients, languages in bilingual patients did not simultaneously improve.

CONCLUSION

Dyspraxia is a condition that affects both motor and visual cognitive functions, and patients who have it often have less referred motor skills. The current dataset shows that accurate visual cognition requires both cognitive-linguistic and sensory-motor processes. Motor issues should be highlighted, and skills and functionality should be reinforced along with the significance of treatment between IA and TSA corresponding to age and education. This can be a good indicator for treating semantic disorders.

Influences of Methodological Decisions on Assessing the Spatiotemporal Stability of Speech Movement Sequences

PURPOSE

The spatiotemporal index (STI) is a widely used approach for measuring speech pattern stability across multiple repetitions of a stimulus. In this study, we examine how methodological choices in the implementation of the STI (including the number of repetitions, length of stimuli, and parsing procedure) can affect its value.

METHOD

To evaluate how each methodological decision affects the STI, we use a synthetic data framework that allows for the generation of random productions of the template phrase "Buy Bobby a Puppy" at different stability levels. Within this framework, we conduct three experiments: Experiment 1 investigates the effects of the number of repetitions, Experiment 2 investigates the effects of stimulus length, and Experiment 3 investigates the effects of parsing errors.

RESULTS

In Experiment 1, we observed that STI values based on fewer repetitions will systematically underestimate larger repetition estimates. Experiment 2 showed that STI values will tend to be higher when calculated on longer (multimovement) stimuli independent of any differences in the stability of the underlying speech patterns. Finally, in Experiment 3, we showed that even minor parsing errors (≈ 10 ms) increase the value of the STI.

CONCLUSIONS

The results of this study illustrate that even minor choices in the implementation of the STI can have a noticeable impact on the resulting value. These findings highlight the care that needs to be taken when designing studies and comparing STI values across studies to ensure that different STI values are capturing real differences in motion pattern stability rather than trivial methodological variation.

Sentence Repetition as a Tool for Screening Morphosyntactic Abilities of Bilectal Children with SLI

The clinical significance of sentence repetition tasks (SRTs) for assessing children's language ability is well-recognized. SRT has been identified as a good clinical marker for children with (specific) language impairment as it shows high diagnostic accuracy levels. Furthermore, qualitative analysis of repetition samples can provide information to be used for intervention protocols. Despite the fact that SRT is a familiar task in assessment batteries across several languages, it has not yet been measured and validated in bilectal settings, such as Cypriot Greek, where the need for an accurate screening tool is urgent. The aims of the current study are three-fold. First, the performance of a group of (Cypriot) Greek-speaking children identified with SLI is evaluated using a SRT that elicits complex morphosyntactic structures. Second, the accuracy level of the SRT for the identification of SLI is explored. Third, a broad error analysis is carried out to examine and compare the morphosyntactic abilities of the participating children. A total of 38 children aged 5-9 years participated in this study: a clinical group of children with SLI (n = 16) and a chronological age-matched control group (n = 22). The ability of the children to repeat complex morphosyntactic structures was assessed using a SRT consisting of 24 sentences. The results showed that the SRT yielded significant differences in terms of poorer performance of children with SLI compared to typically developing peers. The diagnostic accuracy of the task was validated, since regression analysis showed that the task is sensitive and specific enough to identify children with SLI. Finally, qualitative differences between children with SLI and those with TLD regarding morphosyntactic abilities were detected. This study showed that a SRT that elicits morphosyntactically complex structures could be a potential clinical indicator for SLI in Cypriot Greek. The task has the potential to be used as a referral criterion in order to identify children whose language needs to be evaluated further. Implications for speech-language therapists and policy-makers are discussed.

Learning words and learning sounds: Advances in language development

Phonological development is sometimes seen as a process of learning sounds, or forming phonological categories, and then combining sounds to build words, with the evidence taken largely from studies demonstrating 'perceptual narrowing' in infant speech perception over the first year of life. In contrast, studies of early word production have long provided evidence that holistic word learning may precede the formation of phonological categories. In that account, children begin by matching their existing vocal patterns to adult words, with knowledge of the phonological system emerging from the network of related word forms. Here I review evidence from production and then consider how the implicit and explicit learning mechanisms assumed by the complementary memory systems model might be understood as reconciling the two approaches.

Disfluency characteristics of Kannada-English bilingual adults who stutter

The primary purpose of the present study was to investigate whether stuttering frequency differs between two languages in Kannada-English bilingual adults who stutter. The second purpose was to compare the relationship between grammatical class (content-function word dichotomy) and stuttering frequency in two languages. In addition, we also examined whether types of disfluencies vary between content and function words in two languages. Twenty-five bilingual adults who stutter that were proficient in both languages (mean age=22.5 years, SD=3.0) participated in the present study. Spontaneous speech samples were recorded in both Kannada and English and stuttering frequencies were calculated in both languages and for each type of grammatical category. Further, different types of disfluencies were noted for each type of grammatical category in both the languages. Results revealed significantly greater stuttering in L2 (English) compared to L1 (Kannada). In both the languages, significantly higher content words were stuttered compared to function words. When the comparison was done between two languages, significantly higher content words were stuttered in L1 compared to L2, whereas significantly higher function words were stuttered in L2 compared to L1. The types of disfluencies did not vary between content and function words and between two languages. Present results suggest that frequency and other aspects of stuttering may depend on the proficiency of the language.

Phonological constraints on children's production of English third person singular -s

PURPOSE

Children variably produce grammatical morphemes at early stages of development, often omitting inflectional morphemes in obligatory contexts. This has typically been attributed to immature syntactic or semantic representations. In this study, the authors investigated the hypothesis that children's variable production of the 3rd person singular morpheme -s interacts with the phonological complexity of the verb stem to which it is attached.

METHOD

To explore this possibility, the authors examined longitudinal data from the spontaneous speech of 6 English-speaking children between ages 1;3 and 3;6 (years;months) and elicited imitations from a cross-sectional study of 23 two-year-olds (mean age of 2;2).

RESULTS

The results showed that children produced third person singular morphemes more accurately in phonologically simple coda contexts (e.g., sees) as compared with complex coda contexts (e.g., needs). In addition, children produced -s more accurately in utterance-final position as compared with utterance-medial position.

CONCLUSIONS

The results provide strong support for the role of phonological complexity in explaining some of the variability in children's production of third person singular -s. This finding suggests that future research will need to consider multiple factors, including phonological and positional effects, in constructing a comprehensive developmental theory of both grammatical competence and processes of speech planning and production.

Developmental changes in the effects of utterance length and complexity on speech movement variability

PURPOSE

The authors examined the effects of utterance length and linguistic complexity on speech movement consistency for 210 participants between the ages of 5 and 22 years. Variability and durational analyses were conducted to (a) determine a more complete picture of the developmental course of earlier observations of the effects of linguistic constructs on speech motor variability and (b) describe trends for duration of the same sequence of words in different sentential contexts across development.

METHOD

Lower-lip movement was recorded during the production of "buy Bobby a puppy" spoken in isolation as well as embedded as a phrase in 2 longer, more complex sentences.

RESULTS

Compared with young adults, children demonstrated higher variability in producing repeated movement sequences for the target word sequence across all conditions. Also, for all age groups except young adults, increased processing demands resulted in significantly increased movement trajectory variability. Duration analyses suggest that around age 9 years, children begin to use adult-like pre-speech processes to plan the timing of sentence internal phrases, and maturation of these planning processes continues through late adolescence.

CONCLUSION

These results provide further evidence for language-motor interactions and for a protracted course of speech motor development that continues well into adolescence.

Potential interactions among linguistic, autonomic, and motor factors in speech

Though anecdotal reports link certain speech disorders to increases in autonomic arousal, few studies have described the relationship between arousal and speech processes. Additionally, it is unclear how increases in arousal may interact with other cognitive-linguistic processes to affect speech motor control. In this experiment we examine potential interactions between autonomic arousal, linguistic processing, and speech motor coordination in adults and children. Autonomic responses (heart rate, finger pulse volume, tonic skin conductance, and phasic skin conductance) were recorded simultaneously with upper and lower lip movements during speech. The lip aperture variability (LA variability index) across multiple repetitions of sentences that varied in length and syntactic complexity was calculated under low- and high-arousal conditions. High arousal conditions were elicited by performance of the Stroop color word task. Children had significantly higher lip aperture variability index values across all speaking tasks, indicating more variable speech motor coordination. Increases in syntactic complexity and utterance length were associated with increases in speech motor coordination variability in both speaker groups. There was a significant effect of Stroop task, which produced increases in autonomic arousal and increased speech motor variability in both adults and children. These results provide novel evidence that high arousal levels can influence speech motor control in both adults and children.

Influences of utterance length and complexity on speech motor performance in children and adults

The possible influences of utterance length and complexity on speech motor performance were examined by assessing the effects of increased processing demands on articulatory movement stability. Eight 5-year-old children and 8 young adults repeated a 6-syllable phrase in isolation (baseline condition) and embedded in sentences of low and high syntactic complexity. Lower lip movements for the target phrase were analyzed to produce the spatiotemporal index (STI), an index that reflects the stability of lip movement over 10 repetitions of the phrase. It was predicted that movement stability would be lower (reflected by higher values of the STI) for the phrase when it was spoken embedded in complex sentences and that, compared to adults, children's movement output would be more negatively affected by increased processing demands. The STI was significantly increased for the phrase spoken in the complex sentences compared to the baseline condition, and STIs of the children were consistently higher than those of the adults across conditions. These findings provide novel evidence that speech motor planning, execution, or both are affected by processes often considered to be relatively remote from the motor output stage.

Altered Auditory Input and Language Webs to Improve Language Processing Skills

A method of altering auditory input and a structured set of listening tasks are described. The parameters of rate, prosody, and pattern of pausing are modified in the Altered Auditory Input (AAI) technique to make language input easier for the child with language delays to process. This technique is used during play activities, reading to the child, language activities, faceto-face conversation, and structured listening tasks called Language Webs. The Language Webs are a set of highly redundant, hierarchical picture identification listening tasks. The goal of these approaches is to improve language processing in children with language difficulties so that they can both access their current language knowledge and learn new language.

A Format for Identifying Interactions Among Measures of Communication Skills

A format for longitudinally tracking interactions among measures representing different domains of communication was developed in response to calls for integrative approaches to language assessment. This longitudinal case study examined measures of segmental phonology, nonsegmental phonology, and syntax/morphology in a child with language impairment in order to illustrate the effectiveness of this format in identifying interactions. The format detected trade-offs and co-occurrences, which changed during the 6 1/2 yearsof study. The results support Crystal’s (1987) "bucket" theory of language and the value of integrative approaches to assessment.

The influence of sentence elicitation variables on children's speech production

This study investigated the potential influence of adult-modeled sentences on the speech production of 15 children with speech delays of unknown origin. Two comparison tokens of target words containing sounds with inconsistently realized phonemes were sampled in picture descriptions elicited with and without adult-modeled descriptive sentences. Ten listeners made forced-choice paired-comparisons to identify the children's relatively more advanced word productions. From 205 total comparisons, listeners identified 130 word pairs that included one token more advanced than the other. Significantly more of the children's advanced word productions occurred in sentences elicited with an adult model sentence. Discussion considers theoretical and clinical perspectives of an assumption that variables facilitating children's language production may benefit speech production.