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Late, not early mismatch responses to changes in frequency are reduced or deviant in children with dyslexia: an event-related potential study.

Halliday LF, Barry JG, Hardiman MJ, Bishop DV - J Neurodev Disord (2014)

Bottom Line: However, findings have been inconsistent, both for behavioural and electrophysiological measures.Conventional analyses revealed no significant differences between groups in the size of the MMN to either large or small frequency deviants.Rather, deficits in late-stage auditory processing appear to be a feature of this population.

View Article: PubMed Central - HTML - PubMed

Affiliation: Division of Psychology and Language Sciences, University College London, 2 Wakefield Street, London WC1N 1PF, UK ; Department of Experimental Psychology, University of Oxford, South Parks Road, Oxford OX1 3UD, UK.

ABSTRACT

Background: Developmental disorders of oral and written language have been linked to deficits in the processing of auditory information. However, findings have been inconsistent, both for behavioural and electrophysiological measures.

Methods: In this study, we examined event-related potentials (ERPs) in 20 6- to 14-year-old children with developmental dyslexia and 20 age-matched controls, divided into younger (6-11 years, n = 10) and older (11-14 years, n = 10) age bands. We focused on early (mismatch negativity; MMN) and late (late discriminative negativity; LDN) conventional mismatch responses and associated measures derived from time-frequency analysis (inter-trial coherence and event-related spectral perturbation). Responses were elicited using an auditory oddball task, whereby a stream of 1000-Hz standards was interspersed with rare large (1,200 Hz) and small (1,030 Hz) frequency deviants.

Results: Conventional analyses revealed no significant differences between groups in the size of the MMN to either large or small frequency deviants. However, the younger age band of children with dyslexia showed an enhanced inter-trial coherence in the theta frequency band over the time window corresponding to the MMN to small deviants. By contrast, these same children showed a reduced-amplitude LDN for the small deviants relative to their age-matched controls, whilst the older children with dyslexia showed a shorter and less intense period of event-related desynchronization over this time window.

Conclusions: Initial detection and discrimination of auditory frequency change appears normal or even enhanced in children with dyslexia. Rather, deficits in late-stage auditory processing appear to be a feature of this population.

No MeSH data available.


Related in: MedlinePlus

Average amplitude at principal component. Subplots divided according to DYS status and age band. Note that the average amplitude generated by principal components analysis is substantially larger than for the conventional N1-P2 response.
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Figure 2: Average amplitude at principal component. Subplots divided according to DYS status and age band. Note that the average amplitude generated by principal components analysis is substantially larger than for the conventional N1-P2 response.

Mentions: Responses to standards and deviants based on the spatial principal component are shown in Figure 2. Surprisingly, the DYS subgroups appeared to show a more mature pattern than the TD subgroups, with the DYS younger subgroup exhibiting a smaller P1 than their typically developing peers, and the DYS older subgroup showing what appeared to be a developing N1 component at around 100–150 ms. The TD younger subgroup, in contrast, showed a large P1 followed by a prolonged N2 component and a notable absence of the N1, whilst the TD older subgroup showed a smaller P1 but still no signs of the N1. These responses are consistent with previous literature for children of these ages at this inter-stimulus interval (e.g. [40]).


Late, not early mismatch responses to changes in frequency are reduced or deviant in children with dyslexia: an event-related potential study.

Halliday LF, Barry JG, Hardiman MJ, Bishop DV - J Neurodev Disord (2014)

Average amplitude at principal component. Subplots divided according to DYS status and age band. Note that the average amplitude generated by principal components analysis is substantially larger than for the conventional N1-P2 response.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4126817&req=5

Figure 2: Average amplitude at principal component. Subplots divided according to DYS status and age band. Note that the average amplitude generated by principal components analysis is substantially larger than for the conventional N1-P2 response.
Mentions: Responses to standards and deviants based on the spatial principal component are shown in Figure 2. Surprisingly, the DYS subgroups appeared to show a more mature pattern than the TD subgroups, with the DYS younger subgroup exhibiting a smaller P1 than their typically developing peers, and the DYS older subgroup showing what appeared to be a developing N1 component at around 100–150 ms. The TD younger subgroup, in contrast, showed a large P1 followed by a prolonged N2 component and a notable absence of the N1, whilst the TD older subgroup showed a smaller P1 but still no signs of the N1. These responses are consistent with previous literature for children of these ages at this inter-stimulus interval (e.g. [40]).

Bottom Line: However, findings have been inconsistent, both for behavioural and electrophysiological measures.Conventional analyses revealed no significant differences between groups in the size of the MMN to either large or small frequency deviants.Rather, deficits in late-stage auditory processing appear to be a feature of this population.

View Article: PubMed Central - HTML - PubMed

Affiliation: Division of Psychology and Language Sciences, University College London, 2 Wakefield Street, London WC1N 1PF, UK ; Department of Experimental Psychology, University of Oxford, South Parks Road, Oxford OX1 3UD, UK.

ABSTRACT

Background: Developmental disorders of oral and written language have been linked to deficits in the processing of auditory information. However, findings have been inconsistent, both for behavioural and electrophysiological measures.

Methods: In this study, we examined event-related potentials (ERPs) in 20 6- to 14-year-old children with developmental dyslexia and 20 age-matched controls, divided into younger (6-11 years, n = 10) and older (11-14 years, n = 10) age bands. We focused on early (mismatch negativity; MMN) and late (late discriminative negativity; LDN) conventional mismatch responses and associated measures derived from time-frequency analysis (inter-trial coherence and event-related spectral perturbation). Responses were elicited using an auditory oddball task, whereby a stream of 1000-Hz standards was interspersed with rare large (1,200 Hz) and small (1,030 Hz) frequency deviants.

Results: Conventional analyses revealed no significant differences between groups in the size of the MMN to either large or small frequency deviants. However, the younger age band of children with dyslexia showed an enhanced inter-trial coherence in the theta frequency band over the time window corresponding to the MMN to small deviants. By contrast, these same children showed a reduced-amplitude LDN for the small deviants relative to their age-matched controls, whilst the older children with dyslexia showed a shorter and less intense period of event-related desynchronization over this time window.

Conclusions: Initial detection and discrimination of auditory frequency change appears normal or even enhanced in children with dyslexia. Rather, deficits in late-stage auditory processing appear to be a feature of this population.

No MeSH data available.


Related in: MedlinePlus