TY - JOUR
T1 - Neuromagnetic speech discrimination responses are associated with reading-related skills in dyslexic and typical readers
AU - Thiede, A.
AU - Parkkonen, L.
AU - Virtala, P.
AU - Laasonen, M.
AU - Mäkelä, Jyrki P.
AU - Kujala, T.
PY - 2020/8
Y1 - 2020/8
N2 - Poor neural speech discrimination has been connected to dyslexia, and may represent phonological processing deficits that are hypothesized to be the main cause for reading impairments. Thus far, neural speech discrimination impairments have rarely been investigated in adult dyslexics, and even less by examining sources of neuromagnetic responses. We compared neuromagnetic speech discrimination in dyslexic and typical readers with mismatch fields (MMF) and determined the associations between MMFs and reading-related skills. We expected weak and atypically lateralized MMFs in dyslexic readers, and positive associations between reading-related skills and MMF strength. MMFs were recorded to a repeating pseudoword /ta-ta/ with occasional changes in vowel identity, duration, or syllable frequency from 43 adults, 21 with confirmed dyslexia. Phonetic (vowel and duration) changes elicited left-lateralized MMFs in the auditory cortices. Contrary to our hypothesis, MMF source strengths or lateralization did not differ between groups. However, better verbal working memory was associated with stronger left-hemispheric MMFs to duration changes across groups, and better reading was associated with stronger right-hemispheric late MMFs across speech-sound changes in dyslexic readers. This suggests a link between neural speech processing and reading-related skills, in line with previous work. Furthermore, our findings suggest a right-hemispheric compensatory mechanism for language processing in dyslexia. The results obtained promote the use of MMFs in investigating reading-related brain processes.
AB - Poor neural speech discrimination has been connected to dyslexia, and may represent phonological processing deficits that are hypothesized to be the main cause for reading impairments. Thus far, neural speech discrimination impairments have rarely been investigated in adult dyslexics, and even less by examining sources of neuromagnetic responses. We compared neuromagnetic speech discrimination in dyslexic and typical readers with mismatch fields (MMF) and determined the associations between MMFs and reading-related skills. We expected weak and atypically lateralized MMFs in dyslexic readers, and positive associations between reading-related skills and MMF strength. MMFs were recorded to a repeating pseudoword /ta-ta/ with occasional changes in vowel identity, duration, or syllable frequency from 43 adults, 21 with confirmed dyslexia. Phonetic (vowel and duration) changes elicited left-lateralized MMFs in the auditory cortices. Contrary to our hypothesis, MMF source strengths or lateralization did not differ between groups. However, better verbal working memory was associated with stronger left-hemispheric MMFs to duration changes across groups, and better reading was associated with stronger right-hemispheric late MMFs across speech-sound changes in dyslexic readers. This suggests a link between neural speech processing and reading-related skills, in line with previous work. Furthermore, our findings suggest a right-hemispheric compensatory mechanism for language processing in dyslexia. The results obtained promote the use of MMFs in investigating reading-related brain processes.
KW - Applied linguistics
KW - Behavioral neuroscience
KW - Clinical psychology
KW - Cognitive neuroscience
KW - Cognitive psychology
KW - Dyslexia
KW - Magnetoencephalography (MEG)
KW - Mismatch field (MMF)
KW - Reading skills
KW - Speech processing
KW - Verbal working memory
UR - http://www.scopus.com/inward/record.url?scp=85089739657&partnerID=8YFLogxK
U2 - 10.1016/j.heliyon.2020.e04619
DO - 10.1016/j.heliyon.2020.e04619
M3 - Article
AN - SCOPUS:85089739657
SN - 2405-8440
VL - 6
JO - Heliyon
JF - Heliyon
IS - 8
M1 - e04619
ER -