ERP evidence for Slavic and German word stress cue sensitivity in English

Abstract

Word stress is demanding for non-native learners of English, partly because speakers from different backgrounds weight perceptual cues to stress like pitch, intensity, and duration differently. Slavic learners of English and particularly those with a fixed stress language background like Czech and Polish have been shown to be less sensitive to stress in their native and non-native languages. In contrast, German English learners are rarely discussed in a word stress context. A comparison of these varieties can reveal differences in the foreign language processing of speakers from two language families. We use electroencephalography (EEG) to explore group differences in word stress cue perception between Slavic and German learners of English. Slavic and German advanced English speakers were examined in passive multi-feature oddball experiments, where they were exposed to the word impact as an unstressed standard and as deviants stressed on the first or second syllable through higher pitch, intensity, or duration. The results revealed a robust Mismatch Negativity (MMN) component of the event-related potential (ERP) in both language groups in response to all conditions, demonstrating sensitivity to stress changes in a non-native language. While both groups showed higher MMN responses to stress changes to the second than the first syllable, this effect was more pronounced for German than for Slavic participants. Such group differences in non-native English word stress perception from the current and previous studies are argued to speak in favor of customizable language technologies and diversified English curricula compensating for non-native perceptual variation.

Keywords: Electroencephalography (EEG); Mismatch Negativity (MMN); cue weighting; non-native English; word stress perception.

Figure 1

Sound waveforms and spectrograms of the standard and deviant stimuli employed in the current study.

Figure 2

Visualization of the multi-feature oddball paradigm applied in this study. At least one unstressed standard is enforced before each of the deviants. Inter-stimulus interval is jittered within a range of 330 and 630 ms.

Figure 3

Grand-average topographies with nose reference and ERP waveforms at FCz referenced against average mastoids for each word stress condition. The results from running t-tests with FDR correction are presented below the ERP waves with blue regions indicating significant negativity. MMN windows are highlighted with grey rectangles. Arrows point at the beginning of the syllable containing the deviation.

Figure 4

(A) Grand-average ERP difference waves at FCz referenced against average mastoids for each word stress condition. MMN windows are highlighted with grey rectangles. Arrows point at the beginning of the syllable containing the deviation. (B) Mean and single-subject MMN amplitudes per language group and word stress condition. Each cross indicates one participant; group mean is plotted with error bars reflecting standard deviation across participants.

Figure 5

Comparison between mean MMN amplitudes for first and second syllable position (A) per stress cue and (B) per language group. Each cross indicates one participant; group mean is plotted with error bars reflecting standard deviation across participants. The statistical significance of the difference between the groups is indicated above the respective groups: n.s. p > 0.05, * p < 0.05, *** p < 0.001.