Precursors to Natural Grammar Learning: Preliminary Evidence from 4-Month-Old Infants

When learning a new language, grammar—although difficult—is very important, as grammatical rules determine the relations between the words in a sentence. There is evidence that very young infants can detect rules determining the relation between neighbouring syllables in short syllable sequences. A critical feature of all natural languages, however, is that many grammatical rules concern the dependency relation between non-neighbouring words or elements in a sentence i.e. between an auxiliary and verb inflection as in is singing. Thus, the issue of when and how children begin to recognize such non-adjacent dependencies is fundamental to our understanding of language acquisition. Here, we use brain potential measures to demonstrate that the ability to recognize dependencies between non-adjacent elements in a novel natural language is observable by the age of 4 months. Brain responses indicate that 4-month-old German infants discriminate between grammatical and ungrammatical dependencies in auditorily presented Italian sentences after only brief exposure to correct sentences of the same type. As the grammatical dependencies are realized by phonologically distinct syllables the present data most likely reflect phonologically based implicit learning mechanisms which can serve as a precursor to later grammar learning

Syntactic learning by mere exposure - An ERP study in adult learners

<p>Abstract</p> <p>Background</p> <p>Artificial language studies have revealed the remarkable ability of humans to extract syntactic structures from a continuous sound stream by mere exposure. However, it remains unclear whether the processes acquired in such tasks are comparable to those applied during normal language processing. The present study compares the ERPs to auditory processing of simple Italian sentences in native and non-native speakers after brief exposure to Italian sentences of a similar structure. The sentences contained a non-adjacent dependency between an auxiliary and the morphologically marked suffix of the verb. Participants were presented four alternating learning and testing phases. During learning phases only correct sentences were presented while during testing phases 50 percent of the sentences contained a grammatical violation.</p> <p>Results</p> <p>The non-native speakers successfully learned the dependency and displayed an N400-like negativity and a subsequent anteriorily distributed positivity in response to rule violations. The native Italian group showed an N400 followed by a P600 effect.</p> <p>Conclusion</p> <p>The presence of the P600 suggests that native speakers applied a grammatical rule. In contrast, non-native speakers appeared to use a lexical form-based processing strategy. Thus, the processing mechanisms acquired in the language learning task were only partly comparable to those applied by competent native speakers.</p

Mass counts: ERP correlates of non-adjacent dependency learning under different exposure conditions

Miniature language learning can serve to model real language learning as high proficiency can be reached after very little exposure. In a previous study by Mueller et al. [18] German participants acquired non-adjacent syntactic dependencies by mere exposure to correct Italian sentences, but their ERP pattern differed from the one shown by native speakers. The present study follows up on that experiment using a similar design and material and is focused on two important issues: the influence of acoustic cues in the material and the impact of the learning procedure. With respect to the latter we compared alternating learning and test phases to a continuous learning and test phase. In addition, a splicing procedure eliminated prosodic cues in order to ensure that non-adjacent dependencies were learned instead of adjacent ones. Results for the continuous phase design showed a native-like biphasic ERP pattern, an N400 followed by a left-focused positivity. In the alternating design behavioural accuracy was lower and only an N400 was found. The results suggest an advantage of continuous learning phases for adult learners, possibly due to the absence of ungrammatical items present in the test phases in the alternating learning procedure. Furthermore, the replication of the earlier study with prosodically controlled material adds evidence to the general finding that syntactic non-adjacent dependencies can be learned from mere exposure to correct example

Structure and examples of Italian stimulus sentences.

<p>The figure displays the grammatical dependency between the auxiliaries (<i>sta</i>/<i>is</i> and <i>puo</i>/<i>can</i>) and the respective Italian verb inflections (-<i>ando</i> and -<i>are</i>). (A) Correct grammatical relation between <i>sta</i> and -<i>ando</i> as well as <i>puo</i> and -<i>are</i> with <i>x</i> as a place holder for the verb stem. (B) Correct example sentences for the structure represented in (A). (C) Incorrect grammatical relation between <i>sta</i> and -<i>are</i> as well as <i>puo</i> and -<i>ando</i> with <i>x</i> as a place holder for the verb stem. (D) Incorrect example sentences for the structure represented in (C). Relation between crucial non-adjacent elements is indicated by arrows. An asterisk indicates an incorrect sentence.</p

The learning effect.

<p>Grand averages of event-related potentials of 4-month-old infants (n = 34) for the processing of the verb left: grand averages for first test phase (TP1), right: grand averages for last test phase (TP4). The processing of the incorrect condition (red line) is plotted against the processing of the correct condition (blue line). The solid vertical line indicates the onset of the verb, the broken line at the scale plot indicates the onset of the suffix. Negative is plotted upwards.</p

The grammaticality effect.

<p>Top: Grand average event-related potentials of 4-month-old infants (n = 34) for the processing of the verb averaged across the four test phases. The processing of the incorrect condition (red line) is plotted against the processing of the correct condition (blue line). The solid vertical line indicates the onset of the verb, the broken vertical line at the scale plot indicates the onset of the suffix. Negative is plotted upwards. Bottom: Isovoltage map showing the scalp distribution of the effect. Positive difference is colour-coded in red.</p

Experimental procedure.

<p>The experimental procedure consisted of short learning and test phases: Learning phase approx. 3.3 minutes (containing 64 correct sentences), Test phase approx. 1.3 minutes (containing 8 correct and 8 incorrect sentences). The experiment consisted of 4 learning and 4 test phases.</p