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Fast and slow readers of the Hebrew language show divergence in brain response ∼200 ms post stimulus: an ERP study.

Korinth SP, Breznitz Z - PLoS ONE (2014)

Bottom Line: In both tasks stronger event related potentials (ERPs) were observed for faster readers in time windows at about 200 ms.Unlike in previous studies, ERP waveforms in relevant time windows did not correspond to N170 scalp topographies.The results support the notion of visual processing ability as an orthography independent marker of reading proficiency, which advances our understanding about regular and impaired reading development.

View Article: PubMed Central - PubMed

Affiliation: Goethe University Frankfurt am Main, Department of Neurocognitive Psychology, Frankfurt am Main, Germany; Center for Individual Development and Adaptive Education of Children at Risk (IDeA), Frankfurt am Main, Germany.

ABSTRACT
Higher N170 amplitudes to words and to faces were recently reported for faster readers of German. Since the shallow German orthography allows phonological recoding of single letters, the reported speed advantages might have their origin in especially well-developed visual processing skills of faster readers. In contrast to German, adult readers of Hebrew are forced to process letter chunks up to whole words. This dependence on more complex visual processing might have created ceiling effects for this skill. Therefore, the current study examined whether also in the deep Hebrew orthography visual processing skills as reflected by N170 amplitudes explain reading speed differences. Forty university students, native speakers of Hebrew without reading impairments, accomplished a lexical decision task (i.e., deciding whether a visually presented stimulus represents a real or a pseudo word) and a face decision task (i.e., deciding whether a face was presented complete or with missing facial features) while their electroencephalogram was recorded from 64 scalp positions. In both tasks stronger event related potentials (ERPs) were observed for faster readers in time windows at about 200 ms. Unlike in previous studies, ERP waveforms in relevant time windows did not correspond to N170 scalp topographies. The results support the notion of visual processing ability as an orthography independent marker of reading proficiency, which advances our understanding about regular and impaired reading development.

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Related in: MedlinePlus

Grand average waveforms and scalp maps.The upper panel shows global field power (GFP) curves for words (left) and faces (right). ERP waveforms at selected electrode positions are shown in the lower panel. Grey squares indicate microstate boarders, red vertical dashes in the upper panel mark difference wave peaks, and the green squares indicate time window boarders where significant mean amplitude differences between reader groups were found. Maps in the upper panel show the scalp distribution of differences waves averaged over time points in the relevant time window. The maps below represent topographical maps at ERP peaks of the grand average computed across both reader groups.
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pone-0103139-g001: Grand average waveforms and scalp maps.The upper panel shows global field power (GFP) curves for words (left) and faces (right). ERP waveforms at selected electrode positions are shown in the lower panel. Grey squares indicate microstate boarders, red vertical dashes in the upper panel mark difference wave peaks, and the green squares indicate time window boarders where significant mean amplitude differences between reader groups were found. Maps in the upper panel show the scalp distribution of differences waves averaged over time points in the relevant time window. The maps below represent topographical maps at ERP peaks of the grand average computed across both reader groups.

Mentions: Since fixation durations during reading last on average 250 ms for adults [1], ERP analyses were restricted to a time window from stimulus onset until 250 ms afterwards. Based on visual inspection so-called microstates [27] were defined around local GFP maxima. Microstate boarders were set accordingly on local minima preceding and succeeding the maxima. Consequently, three GFP peaks indicated for both decision tasks at least three distinct microstates (see Figure 1). Topography maps show that microstate I and II correspond to the ERP components P1 and N1, respectively. Microstate III represents a large component characterized by fronto-central negative activity and positive activity in occipital regions. Waveforms on electrode positions where the N170 component is conventionally measured (i.e., P07 for words and P8 for faces) show a negative peak at 140 ms for words and at 150 ms for faces, which corresponds in terms of peak latency and topographical map more to a stimulus-unspecific N1 than to a category-specific N170 component. It rather seems that the strong amplitude of the component observed in microstate III overlaps the time window, where the N170 should occur.


Fast and slow readers of the Hebrew language show divergence in brain response ∼200 ms post stimulus: an ERP study.

Korinth SP, Breznitz Z - PLoS ONE (2014)

Grand average waveforms and scalp maps.The upper panel shows global field power (GFP) curves for words (left) and faces (right). ERP waveforms at selected electrode positions are shown in the lower panel. Grey squares indicate microstate boarders, red vertical dashes in the upper panel mark difference wave peaks, and the green squares indicate time window boarders where significant mean amplitude differences between reader groups were found. Maps in the upper panel show the scalp distribution of differences waves averaged over time points in the relevant time window. The maps below represent topographical maps at ERP peaks of the grand average computed across both reader groups.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4117504&req=5

pone-0103139-g001: Grand average waveforms and scalp maps.The upper panel shows global field power (GFP) curves for words (left) and faces (right). ERP waveforms at selected electrode positions are shown in the lower panel. Grey squares indicate microstate boarders, red vertical dashes in the upper panel mark difference wave peaks, and the green squares indicate time window boarders where significant mean amplitude differences between reader groups were found. Maps in the upper panel show the scalp distribution of differences waves averaged over time points in the relevant time window. The maps below represent topographical maps at ERP peaks of the grand average computed across both reader groups.
Mentions: Since fixation durations during reading last on average 250 ms for adults [1], ERP analyses were restricted to a time window from stimulus onset until 250 ms afterwards. Based on visual inspection so-called microstates [27] were defined around local GFP maxima. Microstate boarders were set accordingly on local minima preceding and succeeding the maxima. Consequently, three GFP peaks indicated for both decision tasks at least three distinct microstates (see Figure 1). Topography maps show that microstate I and II correspond to the ERP components P1 and N1, respectively. Microstate III represents a large component characterized by fronto-central negative activity and positive activity in occipital regions. Waveforms on electrode positions where the N170 component is conventionally measured (i.e., P07 for words and P8 for faces) show a negative peak at 140 ms for words and at 150 ms for faces, which corresponds in terms of peak latency and topographical map more to a stimulus-unspecific N1 than to a category-specific N170 component. It rather seems that the strong amplitude of the component observed in microstate III overlaps the time window, where the N170 should occur.

Bottom Line: In both tasks stronger event related potentials (ERPs) were observed for faster readers in time windows at about 200 ms.Unlike in previous studies, ERP waveforms in relevant time windows did not correspond to N170 scalp topographies.The results support the notion of visual processing ability as an orthography independent marker of reading proficiency, which advances our understanding about regular and impaired reading development.

View Article: PubMed Central - PubMed

Affiliation: Goethe University Frankfurt am Main, Department of Neurocognitive Psychology, Frankfurt am Main, Germany; Center for Individual Development and Adaptive Education of Children at Risk (IDeA), Frankfurt am Main, Germany.

ABSTRACT
Higher N170 amplitudes to words and to faces were recently reported for faster readers of German. Since the shallow German orthography allows phonological recoding of single letters, the reported speed advantages might have their origin in especially well-developed visual processing skills of faster readers. In contrast to German, adult readers of Hebrew are forced to process letter chunks up to whole words. This dependence on more complex visual processing might have created ceiling effects for this skill. Therefore, the current study examined whether also in the deep Hebrew orthography visual processing skills as reflected by N170 amplitudes explain reading speed differences. Forty university students, native speakers of Hebrew without reading impairments, accomplished a lexical decision task (i.e., deciding whether a visually presented stimulus represents a real or a pseudo word) and a face decision task (i.e., deciding whether a face was presented complete or with missing facial features) while their electroencephalogram was recorded from 64 scalp positions. In both tasks stronger event related potentials (ERPs) were observed for faster readers in time windows at about 200 ms. Unlike in previous studies, ERP waveforms in relevant time windows did not correspond to N170 scalp topographies. The results support the notion of visual processing ability as an orthography independent marker of reading proficiency, which advances our understanding about regular and impaired reading development.

Show MeSH
Related in: MedlinePlus