Lexical Planning in People Who Stutter: A Defect in Lexical Encoding or the Planning Scope?

Frontiers in Psychology

article

Liming Zhao¹  Miaoqing Lian² 

[1] Key Research Base of Humanities and Social Sciences of the Ministry of Education, Tianjin Normal University;Faculty of Psychology, Tianjin Normal University;Center of Collaborative Innovation for Assessment and Promotion of Mental Health

关键词: stuttering;    EXPLAN model;    lexical planning scope;    speech production;    lexical defects;   

DOI  :  10.3389/fpsyg.2021.581304

学科分类：社会科学、人文和艺术（综合）

来源: Frontiers

【 摘 要 】

Developmental stuttering is a widely discussed speech fluency disorder. Research on its mechanism has focused on an atypical interface between the planning (PLAN) and execution (EX) processes, known collectively as the EXPLAN model. However, it remains unclear how this atypical interface influences people who stutter. A straightforward assumption is that stuttering speakers adopt a smaller scope of speech planning, whereas a defect in word retrieval can be confounding. To shed light on this issue, we took the semantic blocking effect as an index to examine lexical planning in word and phrase production. In Experiment 1, for word production, pictures from the same semantic category were combined to form homogeneous blocks, and pictures from different categories were combined to form heterogeneous blocks. A typical effect of semantic blocking showing longer naming latencies for homogeneous blocks than heterogeneous ones was observed for both stuttering and fluent speakers. However, this effect was smaller for stuttering speakers, when it was subject to lexical defects in stuttering. In Experiment 2, for a conjoined noun phrase production task, the pictures referring to the first noun were manipulated into homogeneous and heterogeneous conditions. The semantic blocking effect was also much smaller for stuttering speakers, indicating a smaller scope of lexical planning. Therefore, the results provided more evidence in support of the EXPLAN model and indicated that a smaller scope of lexical planning rather than lexical defects causes the atypical interface for stuttering. Moreover, a comparison between these two tasks showed that the study findings have implications for syntactic defects in stuttering.

【 授权许可】

CC BY