Conference Publication Details
Mandatory Fields
Hutch, W; Fourie, R;
College of Medicine and Health held Annual Research Day: From Molecules to Medicine
The investigation of a new methodological development using Mismatch Negativity in the diagnosis and rehabilitation of Aphasia: Current findings and applications in Healthcare Research.
Optional Fields
Background: The cortical correlates of language rehabilitation in aphasia
are current questions of major clinical importance1. Cortical mechanisms
can be investigated using a specific Event Related Potential (ERP), called
Mismatch Negativity (MMN). MMN is greatly dependent on feature specific
information. However, there are limited MMN studies using ¿natural¿,
finely controlled speech stimuli. Moreover, using such natural speech
stimuli in MMN investigations, may lead to more effective rehabilitation
strategies for language disorders.
Aims: (i) To develop natural-sounding English word and pseudoword speech
stimuli, thus creating a new method for controlling feature-specific
information. (ii) To determine the robustness of MMN responses to these
stimuli in healthy young adults.
Methods: Experimental stimuli were created from first principles and
included two English words: peace (real word) and ¿peash¿ (pseudoword).
The researchers recorded multiple repetitions of these stimuli uttered by a
male native speaker of (Hiberno) English and selected stimuli from these
repetitions whose vowels matched in fundamental frequency (F0), mean
energy and overall duration. To create the final stimuli, cross splicing was
used (Praat software). These stimuli were presented to each participant
(n=13) in a reverse oddball MMN paradigm using Compumedics Neuroscan®
Results: Carefully controlled natural speech stimuli were created. Robust
MMN responses were obtained to each stimulus when it occurred as a
deviant stimulus; that is, t (1, 12) = 4.35, p < .001 for the real word, and t
(1, 12) = 3.37, p < .006 for the pseudoword.
Conclusion: The method outlined above will facilitate a range of accurate
natural speech stimuli for use in MMN studies. Building on these results, the
cortical processes of language in fluent and non-fluent aphasics in
conjunction with clinical language assessments is currently underway. This
investigation may further our neurological understanding of aphasia
Grant Details