Language Experience with a Native-Language Phoneme Sequence Modulates the Effects of Attention on Cortical Sensory Processing

Abstract

Auditory evoked potentials (AEP) reflect spectro-temporal feature changes within the spoken word and are sufficiently reliable to probe deficits in auditory processing. The current research assessed whether attentional modulation would alter the morphology of these AEPs and whether native-language experience with phoneme sequences would influence the effects of attention. Native-English and native-Polish adults listened to nonsense word pairs that contained the phoneme sequence onsets /st/, /sət/, /pət/ that occur in both the Polish and English languages and the phoneme sequence onset /pt/ that occurs in the Polish language, but not the English language. Participants listened to word pairs within two experimental conditions designed to modulate attention. In one condition, participants listened to word pairs and performed a behavioral task to the second word in the pairs (“with task”) and in the alternate condition participants listened to word pairs without performing a task (“without task”). Conditions were counterbalanced so that half the English and Polish subjects performed the “without task” condition as the first testing session and the “with task” condition as the second testing session. The remaining English and Polish subjects performed the tasks in the reverse order. Two or more months separated the testing sessions. Task conditions did not modulate the morphology of the AEP. Attention, however, modulated the AEP by producing a negative shift in the overall waveform. This effect of attention was modulated by experience with a native-language phoneme sequence. Thus, only Polish listeners showed an effect of attention to the native language /pt/ onset when the behavioral task occurred as the second testing session for which attention demands were reduced. This effect began at 400 ms and suggests a mechanism at intermediate stages within auditory cortex that facilitates recognition of the native language for comprehension.

Acoustic-level and language-specific processing of native and non-native phonological sequence onsets in the low gamma and theta-frequency bands

“…From the ACN1-L source a significant difference was found to the /sət/ onset with a larger amplitude for the attend compared to the passive condition at a late time interval (p = 0.015, attend mean 2.306, passive mean 0.49, latency 330–400 ms). This is consistent with our earlier work with this same participant group, in which attention for task (attend condition compared to passive condition) resulted in a negative shift of the AEP waveform, but the AEP waveform morphology that was specific for each onset sequence (/pt/, /pət/, /st/ and /sət/) and reflected sensory processing of the acoustic characteristics of the stimuli remained unchanged 30 .…”

“…The language-specific effects found here began at an early stage of cortical processing, an automatic processing stage that is modulated less by selective attention 30 , 64 , 65 . This result expands on previous AEP studies that have shown automatic patterns of native-language speech perception to be elicited during tasks for which attention to auditory stimuli was reduced 29 , 30 . Automatic processing of lexico-semantic content has also been demonstrated within a non-attend compared to an attend condition 66 .…”

“…The apparent left asymmetry for the Polish, but not the English listeners, to the /pt/ onsets is consistent with this view. In an earlier AEP study examining these same research participants, we analyzed the P1–N1–P2 complex to the onset sequences from fronto-central electrode sites (0.1–30 Hz) in counterbalanced, attend and passive conditions 30 . Current source density (CSD) maps in that study illustrated that the English compared to the Polish listeners had an increased response to the /pt/ onsets in the passive condition.…”

“…Language-specific processing in LG to native and non-native phonological sequences in two-language groups, to the best of our knowledge, has not been previously demonstrated. Therefore, we suggest that presenting an experimental context that highlights phonemic-level contrasts 54 as well as a passive-listening condition 29 , 30 may be beneficial for disentangling automatic patterns of sensory processing in LG, at least for EEG 31 , 32 .…”

Neural Mechanisms Underlying Human Auditory Evoked Responses Revealed By Human Neocortical Neurosolver

“…Brain activity evoked by auditory stimulation has been studied for many decades and remains not only commonly used in cognitive neuroscience (Wagner et al 2017 ; Parviainen et al 2019 ) but also clinically relevant (Paulraj et al 2015 ; Samatra et al 2020 ). In humans, the sequence of neural activation evoked by auditory stimulation can be measured using electroencephalography (EEG) or magnetoencephalography (MEG), and the surface-recorded responses are typically divided into three categories based on their latency.…”