Narrowed expectancies under degraded speech: Revisiting the N400 (2023)

Strauß, A., Kotz, S. A., & Obleser, J. (2013). Narrowed expectancies under degraded speech: Revisiting the N400. Journal of Cognitive Neuroscience, 25(8), 1383-1395. https://doi.org/10.1162/jocn_a_00389

Strauß, Antje ; Kotz, Sonja A. ; Obleser, Jonas. / Narrowed expectancies under degraded speech: Revisiting the N400. In: Journal of Cognitive Neuroscience. 2013 ; Vol. 25, No. 8. pp. 1383-1395.

@article{6786737cdbf140fdab007a2e9ec62e12,

title = "Narrowed expectancies under degraded speech: Revisiting the N400",

abstract = "Under adverse listening conditions, speech comprehension profits from the expectancies that listeners derive from the semantic context. However, the neurocognitive mechanisms of this semantic benefit are unclear: How are expectancies formed from context and adjusted as a sentence unfolds over time under various degrees of acoustic degradation? In an EEG study, we modified auditory signal degradation by applying noise-vocoding (severely degraded: four-band, moderately degraded: eight-band, and clear speech). Orthogonal to that, we manipulated the extent of expectancy: strong or weak semantic context (±con) and context-based typicality of the sentence-last word (high or low: ±typ). This allowed calculation of two distinct effects of expectancy on the N400 component of the evoked potential. The sentencefinal N400 effect was taken as an index of the neural effort of automatic word-into-context integration; it varied in peak amplitude and latency with signal degradation and was not reliably observed in response to severely degraded speech. Under clear speech conditions in a strong context, typical and untypical sentence completions seemed to fulfill the neural prediction, as indicated by N400 reductions. In response to moderately degraded signal quality, however, the formed expectancies appeared more specific: Only typical (+con +typ), but not the less typical (+con-typ) context-word combinations led to a decrease in the N400 amplitude. The results show that adverse listening {"}narrows,{"} rather than broadens, the expectancies about the perceived speech signal: limiting the perceptual evidence forces the neural system to rely on signal-driven expectancies, rather than more abstract expectancies, while a sentence unfolds over time. {\textcopyright} 2013 Massachusetts Institute of Technology.",

author = "Antje Strau{\ss} and Kotz, {Sonja A.} and Jonas Obleser",

year = "2013",

month = aug,

doi = "10.1162/jocn_a_00389",

language = "English",

volume = "25",

pages = "1383--1395",

journal = "Journal of Cognitive Neuroscience",

issn = "0898-929X",

publisher = "MIT Press Journals",

number = "8",

}

Strauß, A, Kotz, SA & Obleser, J 2013, 'Narrowed expectancies under degraded speech: Revisiting the N400', Journal of Cognitive Neuroscience, vol. 25, no. 8, pp. 1383-1395. https://doi.org/10.1162/jocn_a_00389

Narrowed expectancies under degraded speech: Revisiting the N400. / Strauß, Antje; Kotz, Sonja A.; Obleser, Jonas.

In: Journal of Cognitive Neuroscience, Vol. 25, No. 8, 08.2013, p. 1383-1395.

Research output: Contribution to journal › Article › peer-review

TY - JOUR

T1 - Narrowed expectancies under degraded speech: Revisiting the N400

AU - Strauß, Antje

AU - Kotz, Sonja A.

AU - Obleser, Jonas

PY - 2013/8

Y1 - 2013/8

N2 - Under adverse listening conditions, speech comprehension profits from the expectancies that listeners derive from the semantic context. However, the neurocognitive mechanisms of this semantic benefit are unclear: How are expectancies formed from context and adjusted as a sentence unfolds over time under various degrees of acoustic degradation? In an EEG study, we modified auditory signal degradation by applying noise-vocoding (severely degraded: four-band, moderately degraded: eight-band, and clear speech). Orthogonal to that, we manipulated the extent of expectancy: strong or weak semantic context (±con) and context-based typicality of the sentence-last word (high or low: ±typ). This allowed calculation of two distinct effects of expectancy on the N400 component of the evoked potential. The sentencefinal N400 effect was taken as an index of the neural effort of automatic word-into-context integration; it varied in peak amplitude and latency with signal degradation and was not reliably observed in response to severely degraded speech. Under clear speech conditions in a strong context, typical and untypical sentence completions seemed to fulfill the neural prediction, as indicated by N400 reductions. In response to moderately degraded signal quality, however, the formed expectancies appeared more specific: Only typical (+con +typ), but not the less typical (+con-typ) context-word combinations led to a decrease in the N400 amplitude. The results show that adverse listening "narrows," rather than broadens, the expectancies about the perceived speech signal: limiting the perceptual evidence forces the neural system to rely on signal-driven expectancies, rather than more abstract expectancies, while a sentence unfolds over time. © 2013 Massachusetts Institute of Technology.

AB - Under adverse listening conditions, speech comprehension profits from the expectancies that listeners derive from the semantic context. However, the neurocognitive mechanisms of this semantic benefit are unclear: How are expectancies formed from context and adjusted as a sentence unfolds over time under various degrees of acoustic degradation? In an EEG study, we modified auditory signal degradation by applying noise-vocoding (severely degraded: four-band, moderately degraded: eight-band, and clear speech). Orthogonal to that, we manipulated the extent of expectancy: strong or weak semantic context (±con) and context-based typicality of the sentence-last word (high or low: ±typ). This allowed calculation of two distinct effects of expectancy on the N400 component of the evoked potential. The sentencefinal N400 effect was taken as an index of the neural effort of automatic word-into-context integration; it varied in peak amplitude and latency with signal degradation and was not reliably observed in response to severely degraded speech. Under clear speech conditions in a strong context, typical and untypical sentence completions seemed to fulfill the neural prediction, as indicated by N400 reductions. In response to moderately degraded signal quality, however, the formed expectancies appeared more specific: Only typical (+con +typ), but not the less typical (+con-typ) context-word combinations led to a decrease in the N400 amplitude. The results show that adverse listening "narrows," rather than broadens, the expectancies about the perceived speech signal: limiting the perceptual evidence forces the neural system to rely on signal-driven expectancies, rather than more abstract expectancies, while a sentence unfolds over time. © 2013 Massachusetts Institute of Technology.

U2 - 10.1162/jocn_a_00389

DO - 10.1162/jocn_a_00389

M3 - Article

C2 - 23489145

VL - 25

SP - 1383

EP - 1395

JO - Journal of Cognitive Neuroscience

JF - Journal of Cognitive Neuroscience

SN - 0898-929X

IS - 8

ER -

Strauß A, Kotz SA, Obleser J. Narrowed expectancies under degraded speech: Revisiting the N400. Journal of Cognitive Neuroscience. 2013 Aug;25(8):1383-1395. doi: 10.1162/jocn_a_00389