Maija S. Peltola

Native and foreign vowel discrimination as indexed by the mismatch negativity (MMN) response

The development of a new vowel category was studied by measuring both automatic mismatch negativity and conscious behavioural target discrimination. Three groups, nai;ve Finns, advanced Finnish students of English, and native speakers of English, were presented with one pair of Finnish and three pairs of English synthetic vowels. The aim was to determine whether the advanced student group would show native-like responses to the unfamiliar vowel contrasts of the target language. The results suggest that learning in classroom environment may not lead to the formation of new long-term native-like memory traces.

Contralateral White Noise Masking Affects Auditory N1 and P2 Waves Differently

Abstract In this study, we examined the effect of contralateral masking on cortical auditory evoked potentials N1 (modal-specific slowly adapting component) and P2 at different masking intensities. N1 and P2 potentials were recorded from 15 subjects with normal hearing using 500Hz tone pips (intensity 65dB HL, duration 100ms, ISI 1s) presented to the right ear. Continuous white noise was delivered to the left ear at the intensities of 35, 50, 65, or 75dB effective masking level (EML), as well as a no-mask condition. The electrodes F3, Fz, F4, C3, Cz, C4, and Pz were used. The results show that N1 amplitude was significantly attenuated and, in contrast, P2 amplitude was significantly increased, with contralateral 75dB EML white noise. N1P2 peak to peak amplitude was not affected by masking, nor were the peak latencies. Thus, contralateral masking affects the exogenous cortical evoked N1 and P2 curves differently. We suggest that the effect is mediated by the efferent hearing system. The effect of ≤ 50dB EM...

Early exposure to non-native language alters preattentive vowel discrimination

The present study examined whether early exposure in language immersion would result in better pre-attentive discrimination of non-native speech sound contrasts. Mismatch negativity (MMN) responses were measured from two groups of Finnish children. The Monolingual group had no prior exposure to other languages than the native one, while the Immersion group consisted of children attending a French immersion program. The subjects were presented with two vowel contrasts in the oddball paradigm: the first pair was phonemic in the native language and the second was a within category pair in Finnish, but phonological in French. The results revealed that the Monolingual group showed a larger response to the native contrast in comparison with the non-native one, whereas both contrasts elicited a similar response in the Immersion group. These results suggest that early exposure to a new language enhances the pre-attentive discrimination ability reflected in increased MMN amplitude.

Different kinds of bilinguals: different kinds of brains: the neural organisation of two languages in one brain.

The aim of this study was to determine whether the type of bilingualism affects neural organisation. We performed identification experiments and mismatch negativity (MMN) registrations in Finnish and Swedish language settings to see, whether behavioural identification and neurophysiological discrimination of vowels depend on the linguistic context, and whether there is a difference between two kinds of bilinguals. The stimuli were two vowels, which differentiate meaning in Finnish, but not in Swedish. The results indicate that Balanced Bilinguals are inconsistent in identification performance, and they have a longer MMN latency. Moreover, their MMN amplitude is context-independent, while Dominant Bilinguals show a larger MMN in the Finnish context. These results indicate that Dominant Bilinguals inhibit the preattentive discrimination of native contrast in a context where the distinction is non-phonemic, but this is not possible for Balanced Bilinguals. This implies that Dominant Bilinguals have separate systems, while Balanced Bilinguals have one inseparable system.

Phonetic training and non-native speech perception — New memory traces evolve in just three days as indexed by the mismatch negativity (MMN) and behavioural measures

Language-specific, automatically responding memory traces form the basis for speech sound perception and new neural representations can also evolve for non-native speech categories. The aim of this study was to find out how a three-day phonetic listen-and-repeat training affects speech perception, and whether it generates new memory traces. We used behavioural identification, goodness rating, discrimination, and reaction time tasks together with mismatch negativity (MMN) brain response registrations to determine the training effects on native Finnish speakers. We trained the subjects the voicing contrast in fricative sounds. Fricatives are not differentiated by voicing in Finnish, i.e., voiced fricatives do not belong to the Finnish phonological system. Therefore, they are extremely hard for Finns to learn. However, only after three days of training, the native Finnish subjects had learned to perceive the distinction. The results show striking changes in the MMN response; it was significantly larger on the second day after two training sessions. Also, the majority of the behavioural indicators showed improvement during training. Identification altered after four sessions of training and discrimination and reaction times improved throughout training. These results suggest remarkable language-learning effects both at the perceptual and pre-attentive neural level as a result of brief listen-and-repeat training in adult participants.

Long-Term Memory Trace Activation for Vowels Depends on the Mother Tongue and the Linguistic Context

Abstract. The perception of native speech sounds is based on the automatically responding long-term memory traces. In second language (L2) learning, the perception of the target language speech sounds is filtered through the first language (L1) system, but new memory traces for L2 sounds may also evolve in cases of immigration. However, it seems that these new native-like memory traces are not formed in the context of classroom learning or early immersion. In experimental procedures, the language of the experimental setting is rarely varied systematically. We tested the effects of linguistic context on two groups of advanced Finnish students of English to see whether automatic and preattentive perception could also be affected by the linguistic context and explicit instructions. The first group was not informed as to whether the vowels were Finnish or English while the second group received explicit information in English that they were listening to English vowels. The results showed, firstly, that the la...

Brain responses reveal hardwired detection of native-language rule violations

Mismatch negativity (MMN) is a neural correlate of the preattentive detection of any change in the acoustic characteristics of sounds. Here we provide evidence that violations of a purely phonological constraint in a listeners native language can also elicit the brains automatic change-detection response. The MMN differed between Finnish and Estonian listeners, conditions being equal except for the native language of the listeners. We used two experimental conditions: synthetic vowels in isolation and the same vowels embedded in a pseudo-word context. MMN responses to isolated vowels were similar for Finns and Estonians, while the same vowels in a pseudoword context elicited different MMN patterns depending on the listeners mother tongue.

Phonological processing differences in bilinguals and monolinguals

The present study examined whether monolinguals and balanced bilinguals perceive speech sounds similarly or whether the two phonological systems in bilinguals interact so that one language is affected by the other. Two groups, monolingual native speakers of Finnish and balanced Finnish-Swedish bilinguals, were tested. We measured mismatch negativity (MMN) responses and used individually selected, native language, stimuli. The results revealed that balanced bilinguals had a significantly longer MMN latency than the monolinguals which suggests slower and weaker preattentive processing in the bilinguals. This implies that the two phonological systems are intertwined which decreases the access of exemplars.