What Causes Stuttering?

The mystery of a sometimes debilitating speech disorder is examined by cognitive neuroscientist

Automatic scoring of semantic fluency

In neuropsychological assessment, semantic fluency is a widely accepted measure of executive function and access to semantic memory. While fluency scores are typically reported as the number of unique words produced, several alternative manual scoring methods have been proposed that provide additional insights into performance, such as clusters of semantically related items. Many automatic scoring methods yield metrics that are difficult to relate to the theories behind manual scoring methods, and most require manually-curated linguistic ontologies or large corpus infrastructure. In this paper, we propose a novel automatic scoring method based on Wikipedia, Backlink-VSM, which is easily adaptable to any of the 61 languages with more than 100k Wikipedia entries, can account for cultural differences in semantic relatedness, and covers a wide range of item categories. Our Backlink-VSM method combines relational knowledge as represented by links between Wikipedia entries (Backlink model) with a semantic proximity metric derived from distributional representations (vector space model; VSM). Backlink-VSM yields measures that approximate manual clustering and switching analyses, providing a straightforward link to the substantial literature that uses these metrics. We illustrate our approach with examples from two languages (English and Korean), and two commonly used categories of items (animals and fruits). For both Korean and English, we show that the measures generated by our automatic scoring procedure correlate well with manual annotations. We also successfully replicate findings that older adults produce significantly fewer switches compared to younger adults. Furthermore, our automatic scoring procedure outperforms the manual scoring method and a WordNet-based model in separating younger and older participants measured by binary classification accuracy for both English and Korean datasets. Our method also generalizes to a different category (fruit), demonstrating its adaptability

Is semantic verbal fluency impairment explained by executive function deficits in schizophrenia?

Objective: To investigate if verbal fluency impairment in schizophrenia reflects executive function deficits or results from degraded semantic store or inefficient search and retrieval strategies. Method: Two groups were compared: 141 individuals with schizophrenia and 119 healthy age and education-matched controls. Both groups performed semantic and phonetic verbal fluency tasks. Performance was evaluated using three scores, based on 1) number of words generated; 2) number of clustered/related words; and 3) switching score. A fourth performance score based on the number of clusters was also measured. Results: SZ individuals produced fewer words than controls. After controlling for the total number of words produced, a difference was observed between the groups in the number of cluster-related words generated in the semantic task. In both groups, the number of words generated in the semantic task was higher than that generated in the phonemic task, although a significant group vs. fluency type interaction showed that subjects with schizophrenia had disproportionate semantic fluency impairment. Working memory was positively associated with increased production of words within clusters and inversely correlated with switching. Conclusion: Semantic fluency impairment may be attributed to an inability (resulting from reduced cognitive control) to distinguish target signal from competing noise and to maintain cues for production of memory probes

Prospective analysis of the relationship between adolescents' social anxiety, parents' behavior, and friendship formation

One hundred and twenty-two adolescents, aged 11 to 14, were followed for nine months subsequent to residential relocation. The relationships between adolescents' self-reported social anxiety, parent behavior (reported by adolescents and their parents), and the development of new friendships were analyzed. Data were collected immediately after the move, and also at three months and eight months post-move. Results suggest that adolescent social anxiety may be ameliorated by parental strategies for facilitating adolescent friendship formation which encourage the development of independence, emotional autonomy, and self-efficacy. Specifically, social evaluative anxiety is most likely to change soon after the relocation, with alterations in socially avoidant behavior coming later in the year. Parent behavior also appears to change in response to adolescents' social anxiety, with parents of socially anxious girls providing more protective and nurturant behavior following increases in social anxiety, while parents of socially anxious boys seem to respond with greater allowance of independence and autonomy. The development of adolescents' peer companionship was predicted by both adolescent social anxiety and parents friendship facilitation behavior, although the anticipated interaction of these effects was not obtained. Results are discussed in terms of potential implications for social anxiety theory, as well as clinically relevant interventions for adolescents in this life transition. Parallels are drawn between hypothesized developmental precursors to dependent and avoidant personality styles and potential pathways to subtypes of social anxiety.</p