Evidence for Strengthening of Lexical-Phonological Connections After a Phonological Treatment for Anomia

EasyChair Preprint 6378

Abstract

Changes in speech error production pre- to post-treatment may provide more nuanced insights into the mechanisms underlying generalization, in contrast to more commonly used measures such as overall naming accuracy. The mechanisms underlying generalization were investigated by measuring pre- to post-treatment changes in speech error profiles, which were quantified according to the Semantic-Phonological (SP) computational model of lexical retrieval, within the Interactive Activation theoretical framework. The present study reports on pooled data from three previously published studies involving 24 adults (M =62.54 years old; SD =14.41) with chronic (M =43.63 months post-onset; median =18.50; SD =53.89) post-stroke aphasia. Participants were treated three times a week with the Phonological Components Analysis (PCA) protocol, which is a sound-based treatment, using guided self-cueing to stimulate word-retrieval. Generalization to an untrained naming task, the Philadelphia Naming Test (PNT), was assessed pre- and post-treatment. Primary outcome measures were pre- and post-treatment PNT naming accuracy, and individual pre- and post-treatment semantic s- and phonological p-weights, which were obtained using WebFit, an online computational modelling tool. Pre- to post-treatment, mean PNT naming accuracy significantly improved, and the number of omissions and nonword errors significantly decreased. Notably, average phonological p-weights significantly improved pre- to post-treatment, whereas semantic s-weights did not change. Results suggest that generalized naming improvements after PCA therapy are mediated by a strengthening of lexical-phonological connections (i.e., p-weights) in the word retrieval network. PCA therapy may induce stronger spreading activation between lexical and phonological nodes, resulting in more precise lexical activation, and increased accessibility of words.

Keyphrases: aphasia, generalization, interactive activation model, treatment

@booklet{EasyChair:6378,
  author    = {Tijana Simic and Laura Laird and Elizabeth Rochon and Chloé Brisson and Camille Paulino Ramirez and Rudra Patel and Carol Leonard},
  title     = {Evidence for Strengthening of Lexical-Phonological Connections After a Phonological Treatment for Anomia},
  howpublished = {EasyChair Preprint 6378},
  year      = {EasyChair, 2021}}