What memory representation is acquired during nonword speech production learning? The influence of stimulus features and training modality on nonword encoding

Abstract

The purpose of this research was to investigate memory representations related to speech processing. Psycholinguistic and speech motor control theorists have hypothesized a variety of fundamental memory representations, such as syllables or phonemes, which may be learned during speech acquisition tasks. Yet, it remains unclear which fundamental representations are encoded and retrieved during learning and generalization tasks. Two experiments were conducted using a motor learning paradigm to investigate if representations for syllables and phonemes were acquired during a nonword repetition task. Additionally, different training modalities were implemented across studies to examine if training modality influenced memory encoding for nonword stimuli. Results suggest multiple representations may be acquired during training regardless of training modality; however, the underlying memory representations learned during training may be less abstract than current models hypothesize.

Keywords:

• speech
• motor learning
• memory

PUBLIC INTEREST STATEMENT

Speech-language pathologists focus on improving the communication of individuals who suffer from communication disorders. Treatments include training patients to speak in new and novel ways. However, it remains unclear what information is learned during speech therapy, and how this information can be used at a later time when therapeutic support is not available (e.g., in the patient’s home).

The focus of this research was to examine two specific speech variables, i.e., syllables and sounds, which were predicted to be fundamental to speech learning. Results indicated more variables were learned during speech training than originally predicted. These results also suggest individuals process speech stimuli differently during learning than has previously been theorized.

Generally, these results provide a theoretical basis for investigating new speech variables during motor learning, as well as updating theoretical models of speech production. In the long-term, such investigations may have clinical implications for speech therapy practices.

Acknowledgements

Portions of these data were presented at the American Speech-Language-Hearing (ASHA) Convention in November 2014, as well as the ASHA Convention in November 2016.

Additional information

Funding

This work was supported in part through funding received from the SHRS Research Development Fund (School of Health and Rehabilitation Sciences, University of Pittsburgh), as well as the Audrey Holland Endowed Research Award (Department of Communication Science and Disorders, University of Pittsburgh). The Grace Clements Research Endowment Award through the Department of Communication Sciences and Disorders at West Virginia University provided additional funding.

Notes on contributors

Kimberly M. Meigh

Kimberly Meigh is an assistant professor in the Department of Communication Sciences and Disorders at West Virginia University. She is interested in speech motor learning, psycholinguistic factors that influence speech processing and production, and exploring new memory models to understand how speech memory representations evolve during motor learning. In the WVU Speech Motor Control Lab, Meigh and her students examine these topics using reaction time paradigms, as well as acoustic and kinematic analyses. The goal of this work is to better understand theoretical models of speech motor control and learning in an effort to better inform clinical practice for speech-language pathologists.