Objective and Subjective Clustering Methods for Verb Fluency Responses From Individuals With Alzheimer's Dementia and Cognitively Healthy Older Adults.

PURPOSE: The verb fluency task has been researched using a variety of analysis methods and shown its sensitivity to declines in executive functioning and lexical retrieval abilities in various neurogenic populations. Few studies to date, however, have analyzed clusters and switches in the task, and there is a lack of robust analysis methods that preclude subjectivity and potential rater bias. The purpose of this study was to investigate the reliability when using subjective clustering methods and to determine the feasibility of using an objective clustering method to determine verb fluency performance in individuals with Alzheimer's dementia (IwDs) and cognitively healthy older adults (CHOAs). METHOD: Responses from a verb fluency task were obtained from IwDs and CHOAs. Group differences were examined using an objective clustering method for multiple variables regarding clustering and switching. We also calculated the intrarater, interrater, and intermethod reliability using intraclass coefficients. RESULTS: Significant group differences were found when utilizing the objective clustering method in all variables except the average cluster size, with IwDs performing poorer than CHOAs. Intrarater reliability was excellent. Interrater reliability between two authors and intermethod reliability between the objective and subjective methods were variable ranging from moderate to good. CONCLUSIONS: The results from using the objective clustering method in this study are consistent with the previous literature, making it a viable option for clustering analyses on the verb fluency task, which naturally minimizes subjectivity and rater bias. Alternatively, employing a thoroughly validated and reliable subjective approach can also mitigate potential rater bias and improve replicability across studies. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.24061017.

Neural synchrony reflects closure of jabberwocky noun phrases but not predictable pseudoword sequences.

Successful language comprehension requires the combination of individual words into larger linguistic units. In the present minimal-phrase study, we used electroencephalography (EEG) to investigate whether syntactic combination is indexed by changes in neural synchrony, while testing for both token-based and type-based effects. To do this, we analysed intertrial phase coherence (ITPC) elicited by reading two item (words or pseudowords) phrases that were either unifiable or nonunifiable. Results indicated that type-based unifiable phrases elicited increased ITPC relative to all other conditions in the frequency band corresponding to the rate of phrases (0.5 Hz) but not the rate of words (1 Hz). Conversely, we observed a complementary pattern for the N400, which was more sensitive to token-based effects. These findings provide evidence that the combination of single words into larger syntactic structures may be indexed by the synchronous firing of assemblies of neurons oscillating at the rate of phrases during reading.

Autistic preschoolers' engagement and language use in gross motor versus symbolic play settings.

Background and aims: Although adjustment of the environment is recommended as a support strategy in evidence-based interventions for children with autism, the impact of doing so (and the how and why) is not well understood. One essential environmental factor to consider when providing supports for preschool-aged autistic children is the play setting, specifically, the materials available in the child's play context. The aim of this study was to compare engagement states and number of utterances produced by preschool-aged autistic children within symbolic vs. gross motor play settings. Examining the relationship between gross motor play settings and children's social engagement and spoken language use is particularly important to explore for autistic children given differences in their sensory processing, motor skill development, and choice of and interaction with toys relative to neurotypical peers. Methods: Seventy autistic children aged 25-57 months were videotaped during natural play interactions with a parent. Children's social engagement and number of spoken utterances were examined in five minutes each of play with symbolic toys and play with gross motor toys. Continuous time-tagged video coding of the child-caregiver engagement states was conducted, and the child's frequency of spoken language was identified using language sample analysis. The specific variables examined were; (a) engagement with caregiver, (b) engagement with objects only, (c) unengaged (no evident engagement with objects or people), and (d) total number of spoken utterances. The relationship between play setting (symbolic vs gross motor) and child language and engagement state variables was examined with linear mixed effects modelling. Results: Significant main effects were revealed for the interaction between play setting and autistic children's engagement. Young autistic children were more likely to engage with caregivers in play environments with gross motor toys (moderate effect) and also were more likely to have periods of unengaged time (not overtly directing their attention to objects or people; small effect) in this setting. Further, when in a setting with symbolic toys, autistic children were more likely to spend their time focusing attention solely on objects (large effect). No interaction was found between play setting and total number of utterances spoken by autistic children. Conclusions and implications: This study confirmed the importance of continued research focused on understanding the relationship between children's play settings and their social engagement and language use. Although preliminary, findings support the idea that there is an interaction between preschool-aged autistic children's social engagement and their play settings. Further, our results suggest that there can be value in clinicians differentiating children's play settings (i.e., gross motor vs symbolic) when assessing and supporting social engagement capacities of young autistic children.

A simulated experiment to explore robotic dialogue strategies for people with dementia.

Introduction: Persons with dementia (PwDs) often show symptoms of repetitive questioning, which brings great burdens on caregivers. Conversational robots hold promise of helping cope with PwDs' repetitive behavior. This paper develops an adaptive conversation strategy to answer PwDs' repetitive questions, follow up with new questions to distract PwDs from repetitive behavior, and stimulate their conversation and cognition. Methods: We propose a general reinforcement learning model to interact with PwDs with repetitive questioning. Q-learning is exploited to learn adaptive conversation strategy (from the perspectives of rate and difficulty level of follow-up questions) for four simulated PwDs. A demonstration is presented using a humanoid robot. Results: The designed Q-learning model performs better than random action selection model. The RL-based conversation strategy is adaptive to PwDs with different cognitive capabilities and engagement levels. In the demonstration, the robot can answer a user's repetitive questions and further come up with a follow-up question to engage the user in continuous conversations. Conclusions: The designed Q-learning model demonstrates noteworthy effectiveness in adaptive action selection. This may provide some insights towards developing conversational social robots to cope with repetitive questioning by PwDs and increase their quality of life.

Detecting Alzheimer's Disease Using Natural Language Processing of Referential Communication Task Transcripts.

BACKGROUND: People with Alzheimer's disease (AD) often demonstrate difficulties in discourse production. Referential communication tasks (RCTs) are used to examine a speaker's capability to select and verbally code the characteristics of an object in interactive conversation. OBJECTIVE: In this study, we used contextualized word representations from Natural language processing (NLP) to evaluate how well RCTs are able to distinguish between people with AD and cognitively healthy older adults. METHODS: We adapted machine learning techniques to analyze manually transcribed speech transcripts in an RCT from 28 older adults, including 12 with AD and 16 cognitively healthy older adults. Two approaches were applied to classify these speech transcript samples: 1) using clinically relevant linguistic features, 2) using machine learned representations derived by a state-of-art pretrained NLP transfer learning model, Bidirectional Encoder Representation from Transformer (BERT) based classification model. RESULTS: The results demonstrated the superior performance of AD detection using a designed transfer learning NLP algorithm. Moreover, the analysis showed that transcripts of a single image yielded high accuracies in AD detection. CONCLUSION: The results indicated that RCT may be useful as a diagnostic tool for AD, and that the task can be simplified to a subset of images without significant sacrifice to diagnostic accuracy, which can make RCT an easier and more practical tool for AD diagnosis. The results also demonstrate the potential of RCT as a tool to better understand cognitive deficits from the perspective of discourse production in people with AD.

Systematic analysis of goal-related movement sequences during maternal behaviour in a female mouse model for Rett syndrome.

Rodent dams seek and gather scattered pups back to the nest (pup retrieval), an essential aspect of maternal care. Systematic analysis of the dynamic sequences of goal-related movements that comprise the entire behavioural sequence, which would be ultimately essential for understanding the underlying neurobiology, is not well-characterized. Here, we present such analysis across 3 days in alloparental female mice (Surrogates or Sur) of two genotypes; Mecp2Heterozygotes (Het), a female mouse model for Rett syndrome and their wild type (WT) siblings. We analysed CBA/CaJ and C57BL/6J WT surrogates for within-strain comparisons. Frame-by-frame analysis over different phases was performed manually using DataVyu software. We previously showed that surrogate Het are inefficient at pup retrieval, by end-point analysis such as latency index and errors. Here, the sequence of searching, pup-approach and successful retrieval streamlines over days for WT, while Het exhibits variations in this pattern. Goal-related movements between Het and WT are similar in other phases, suggesting context-driven atypical patterns in Het during the pup retrieval phase. We identified proximal pup approach and pup grooming as atypical tactile interactions between pups and Het. Day-by-day analysis showed dynamic changes in goal-related movements in individual animals across genotypes and strains. Overall, our approach (1) highlights natural variation in individual mice on different days, (2) establishes a "gold-standard" manually curated dataset to help build behavioural repertoires using machine learning approaches, and (3) suggests atypical tactile sensory processing and possible regression in a female mouse model for Rett syndrome.

The Effects of Fluency Enhancing Conditions on Sensorimotor Control of Speech in Typically Fluent Speakers: An EEG Mu Rhythm Study.

Objective: To determine whether changes in sensorimotor control resulting from speaking conditions that induce fluency in people who stutter (PWS) can be measured using electroencephalographic (EEG) mu rhythms in neurotypical speakers. Methods: Non-stuttering (NS) adults spoke in one control condition (solo speaking) and four experimental conditions (choral speech, delayed auditory feedback (DAF), prolonged speech and pseudostuttering). Independent component analysis (ICA) was used to identify sensorimotor µ components from EEG recordings. Time-frequency analyses measured µ-alpha (8-13 Hz) and µ-beta (15-25 Hz) event-related synchronization (ERS) and desynchronization (ERD) during each speech condition. Results: 19/24 participants contributed µ components. Relative to the control condition, the choral and DAF conditions elicited increases in µ-alpha ERD in the right hemisphere. In the pseudostuttering condition, increases in µ-beta ERD were observed in the left hemisphere. No differences were present between the prolonged speech and control conditions. Conclusions: Differences observed in the experimental conditions are thought to reflect sensorimotor control changes. Increases in right hemisphere µ-alpha ERD likely reflect increased reliance on auditory information, including auditory feedback, during the choral and DAF conditions. In the left hemisphere, increases in µ-beta ERD during pseudostuttering may have resulted from the different movement characteristics of this task compared with the solo speaking task. Relationships to findings in stuttering are discussed. Significance: Changes in sensorimotor control related feedforward and feedback control in fluency-enhancing speech manipulations can be measured using time-frequency decompositions of EEG µ rhythms in neurotypical speakers. This quiet, non-invasive, and temporally sensitive technique may be applied to learn more about normal sensorimotor control and fluency enhancement in PWS.

The perceived impact of stuttering on personality as measured by the NEO-FFI-3.

The NEO-FFI has been widely used to demonstrate personality differences between people who stutter (PWS) and those who do not. These differences can be interpreted as indicators of internal sources of disability that contribute to handicaps associated with stuttering. The aim of the current study was to use this same tool to determine the perceived impact of stuttering on personality in order to provide a similar indicator of how external factors may contribute to the stuttering disability. A total of 49 non-stuttering young adults were given the NEO-FFI-3 after watching a video of someone stuttering (moderately to severely) and after watching a video of someone speaking fluently. Participants were asked to answer test items while imagining that they had spoken like the persons in the videos for their entire lives. When asked to assume the stuttering perspective, participants reported themselves to be significantly more neurotic (P < 0.01) and less extraverted (P < 0.01) than when they assumed the perspective of the fluent speaker. The large differences (∼10 points; greater than one standard deviation) in these domains between the fluent and stuttered perspectives are consistent with existing stereotypes about PWS. These differences are greater than and only partially consistent with differences in personality found between PWS and non-stuttering individuals. The findings support the notion that external factors (e.g. listener reactions and stereotypes about PWS) contribute strongly to the manner in which stuttering restricts function and results in handicaps.

Effects of language experience on the discrimination of the Portuguese palatal lateral by nonnative listeners.

The purpose of this study was to investigate (1) whether manner or place takes precedence over the other during a phonological category discrimination task and (2) whether this pattern of precedence persists during the early stages of acquisition of the L2. In doing so, we investigated the Portuguese palatal lateral approximant /ʎ/ since it differs from English /l/ only by the place of articulation, and from English /j/ only by the manner of articulation. Our results indicate that monolinguals' perception of the non-native sound is dominated by manner while Portuguese learners show a different pattern of results. The results are interpreted as being consistent with evidence suggesting that manner may be neurophysiologically dominant over place of articulation. The study adds further details to the literature on the effects of experience on language acquisition, and has significant clinical implications for bilingualism in general, and foreign accent training, in particular.

Synchrony Detection of Linguistic Stimuli in the Presence of Faces: Neuropsychological Implications for Language Development in ASD.

Children with autism spectrum disorders (ASD) may be impaired in their ability to detect audiovisual synchrony and their ability may be influenced by the nature of the stimuli. We investigated the possibility that synchrony detection is disrupted by the presence of human faces by testing children with ASD using a preferential looking language-based paradigm. Children with low language abilities were significantly worse at detecting synchrony when the stimuli include an unobscured face than when the face was obscured. Findings suggest that the presence of faces may make multisensory processing more difficult. Implications for interventions are discussed, particularly those targeting attention to faces.

Measuring and supporting language function for children with autism: evidence from a randomized control trial of a social-interaction-based therapy.

In a report of the effectiveness of MEHRIT, a social-interaction-based intervention for autism, Casenhiser et al. (Autism 17(2):220-241, 2013) failed to find a significant advantage for language development in the treatment group using standardized language assessments. We present the results from a re-analysis of their results to illustrate the importance of measuring communicative language acts (formally called "speech acts"). Reanalysis confirmed that children in the MEHRIT group outperformed the community treatment group on measures of MLUm, number of utterances produced, and various speech act categories. The study underscores the importance of functional language measures in guiding and evaluating treatment for children with autism, and suggests that MEHRIT is effective in improving children's use of language during parent-child interactions.

Learning through interaction in children with autism: preliminary data from asocial-communication-based intervention.

The study evaluates a social-communication-based approach to autism intervention aimed at improving the social interaction skills of children with autism spectrum disorder. We report preliminary results from an ongoing randomized controlled trial of 51 children aged 2 years 0 months to 4 years 11 months. Participants were assigned to either a target treatment or community treatment group. Families in the target treatment group were given 2 hours of therapy and coaching each week in an intervention emphasizing social-interaction and the parent-child relationship. Children in the community treatment group received a variety of services averaging 3.9 hours per week. After 12 months, outcomes were measured to determine changes in the groups in social interaction and communication. In addition, a regression analysis was conducted to determine whether changes in social interaction skills were associated with language development. Results suggest that children in the treatment group made significantly greater gains in social interaction skills in comparison to the community treatment group, but no between-group differences were found for standard language assessments. Initiation of joint attention, involvement, and severity of language delay were found to be significantly associated with improvement of language skills in children with autism. Finally caregiver skills targeted by the intervention were found to be significantly associated with changes in children's interaction skills.

Fast mapping between a phrasal form and meaning.

This is the first study to investigate experimentally how children come to learn mappings between novel phrasal forms and novel meanings: a central task in learning a language. Two experiments are reported. In both studies 5- to 7-year-old children watched a short set of video clips depicting objects appearing in various ways. Each scene was described using a novel verb embedded in a novel construction. Children who watched the videos and heard the accompanying description were able to match new descriptions that used the novel construction with new scenes of appearance. Moreover, our results suggest a facilitative effect for the disproportionately high frequency of occurrence of a single verb in a particular construction (such as has been found to exist in naturalistic input to children). While the fast mapping might be taken as an indication of innate knowledge that is specific to language, analogous effects in non-linguistic categorization tasks suggest that children are acquiring the new phrasal form with general cognitive skills.

Children's resistance to homonymy: an experimental study of pseudohomonyms.

Research in diachronic linguistics has shown that homonyms are often dispreferred in language. This study proposes that this trend is mirrored in the difficulties that children encounter in mapping homonyms. Two experiments are presented in support of this proposition. In Experiment 1, 16 preschool children (mean age = 4;6) are shown to perform quite well on tasks requiring them to assign novel meanings to nonsense words. They perform poorly, however, on tasks requiring them to assign a different, unrelated meaning to a known word. Experiment 2 (N = 18, mean age = 4;5) shows that preschoolers' performance on this task, however, improves when a known word appears in a syntactic frame that is not appropriate for the word (as when a verb appears in a noun syntactic frame), thereby providing a strong indication that a new meaning is appropriate.

The role of prediction in construction-learning.

It is well-established that (non-linguistic) categorization is driven by a functional demand of prediction. We suggest that prediction likewise may well play a role in motivating the learning of semantic generalizations about argument structure constructions. We report corpora statistics that indicate that the argument frame or construction has roughly equivalent cue validity as a predictor of overall sentence meaning as the morphological form of the verb, and has greater category validity. That is, the construction is at least as reliable and more available than the verb. Moreover, given the fact that many verbs have quite low cue validity in isolation, attention to the contribution of the construction is essential.