Marc Ettlinger

Implicit memory in music and language

Research on music and language in recent decades has focused on their overlapping neurophysiological, perceptual, and cognitive underpinnings, ranging from the mechanism for encoding basic auditory cues to the mechanism for detecting violations in phrase structure. These overlaps have most often been identified in musicians with musical knowledge that was acquired explicitly, through formal training. In this paper, we review independent bodies of work in music and language that suggest an important role for implicitly acquired knowledge, implicit memory, and their associated neural structures in the acquisition of linguistic or musical grammar. These findings motivate potential new work that examines music and language comparatively in the context of the implicit memory system.

The Relationship Between Artificial and Second Language Learning

Artificial language learning (ALL) experiments have become an important tool in exploring principles of language and language learning. A persistent question in all of this work, however, is whether ALL engages the linguistic system and whether ALL studies are ecologically valid assessments of natural language ability. In the present study, we considered these questions by examining the relationship between performance in an ALL task and second language learning ability. Participants enrolled in a Spanish language class were evaluated using a number of different measures of Spanish ability and classroom performance, which was compared to IQ and a number of different measures of ALL performance. The results show that success in ALL experiments, particularly more complex artificial languages, correlates positively with indices of L2 learning even after controlling for IQ. These findings provide a key link between studies involving ALL and our understanding of second language learning in the classroom.

The bilingual advantage in phonetic learning

Numerous factors are thought to be advantageous for non-native language learning although they are typically investigated in isolation, and the interaction between them is not understood. Firstly, bilinguals are claimed to acquire a third language easier than monolinguals acquire a second. Secondly, closely related languages may be easier to learn. Thirdly, certain phonetic features could be universally more difficult to acquire. We tested these hypotheses used as explanations by having adults learn vocabularies that differentiated words using foreign phonetic contrasts. In Experiment 1, Mandarin–English bilinguals outlearned English monolinguals, and the Mandarin-like (retroflex) artificial language was better learned than the English-like (fricative voicing). In Experiment 2, bilinguals again outlearned English monolinguals for the Mandarin-like artificial language. However, only Korean–English bilinguals showed an advantage for the more difficult Korean-like (lenition) language. Bilinguals, relative to monolinguals, show a general advantage when learning ‘easy’ contrasts, but phonetic similarity to the native language is useful for learning universally ‘difficult’ contrasts.

Linguistic grammar learning and DRD2-TAQ-IA polymorphism.

As research into the neurobiology of language has focused primarily on the systems level, fewer studies have examined the link between molecular genetics and normal variations in language functions. Because the ability to learn a language varies in adults and our genetic codes also vary, research linking the two provides a unique window into the molecular neurobiology of language. We consider a candidate association between the dopamine receptor D2 gene (DRD2) and linguistic grammar learning. DRD2-TAQ-IA polymorphism (rs1800497) is associated with dopamine receptor D2 distribution and dopamine impact in the human striatum, such that A1 allele carriers show reduction in D2 receptor binding relative to carriers who are homozygous for the A2 allele. The individual differences in grammatical rule learning that are particularly prevalent in adulthood are also associated with striatal function and its role in domain-general procedural memory. Therefore, we reasoned that procedurally-based grammar learning could be associated with DRD2-TAQ-IA polymorphism. Here, English-speaking adults learned artificial concatenative and analogical grammars, which have been respectively associated with procedural and declarative memory. Language learning capabilities were tested while learners’ neural hemodynamic responses were simultaneously measured by fMRI. Behavioral learning and brain activation data were subsequently compared with the learners’ DRD2 (rs1800497) genotype. Learners who were homozygous for the A2 allele were better at concatenative (but not analogical) grammar learning and had higher striatal responses relative to those who have at least one A1 allele. These results provide preliminary evidence for the neurogenetic basis of normal variations in linguistic grammar learning and its link to domain-general functions.

Vowel Discrimination by English, French and Turkish Speakers: Evidence for an Exemplar-Based Approach to Speech Perception

Recent studies of speech perception have shown that speakers retain significant amounts of the phonetic detail of heard speech providing strong evidence for an exemplar-based model of the representation of speech sounds. This does not preclude the existence of a feature-based model as well; indeed many theories of speech perception advocate a feature- or contrast-based model for the discrimination of speech sounds. In this study, we provide evidence that an exemplar-based model of speech perception makes more accurate predictions for the performance of English, French and Turkish speakers in a vowel discrimination task. Participants were asked to discriminate the four high front vowels of German, which differ by both the rounding and tense/lax contrasts. Crucially, English has only the tense/lax contrast, while Turkish and French have only rounding. The results show that having one of the vowels in one’s language facilitates discrimination more than having the featural contrast supporting an exemplar-based model. Furthermore, different discrimination tasks were used showing that the effects of native language on vowel discrimination are mediated by task and by psychoacoustic similarity.

Variability in the learning of complex morphophonology

This paper explores how theories on the relationship between language and domain-general cognitive capabilities might account for individual variation in second language learning. We investigated the acquisition of a morphophonological grammar paired with standardized tests of memory function. The language learned had simple and complex morphophonological patterns of word formation, which are hypothesized to correlate with standardized measures of procedural and declarative memory, respectively. The results show a significant amount of variation in learning success is accounted for by these measures of memory in accordance with the hypothesis. These findings help explain why some adults are able to learn a second language more easily than others while also advancing a model of second language learning motivated by linguistic theory.

Hemispheric asymmetries in cortical and subcortical anatomy

Previous research studies have reported many hemispherical asymmetries in cortical and subcortical anatomy, but only a subset of findings is consistent across studies. Here, we used improved Freesurfer-based automated methods to analyse the properties of the cortex and seven subcortical structures in 138 young adult subjects. Male and female subjects showed similar hemispheric asymmetries in gyral and sulcal structures, with many areas associated with language processing enlarged in the left hemisphere (LH) and a number of areas associated with visuospatial processing enlarged in the right hemisphere (RH). In addition, we found greater (non-directional) cortical asymmetries in subjects with larger brains. Asymmetries in subcortical structures included larger LH volumes of thalamus, putamen and globus pallidus and larger RH volumes of the cerebellum and the amygdala. We also found significant correlations between the subcortical structural volumes, particularly of the thalamus and cerebellum, with cortical area. These results help to resolve some of the inconsistencies in previous studies of hemispheric asymmetries in brain anatomy.

The Role of Phonology in Children's Acquisition of the Plural

The correct use of an affix, such as the English plural suffix, may reflect mastery of a morphological process, but it may also depend on childrens syntactic, semantic, and phonological abilities. The present article reports a set of experiments in support of this latter view, specifically focusing on the importance of the phonological make-up of plural forms for both production and comprehension. In Experiments 1 and 2, plural productions were elicited from 80 two-year-old children for nouns with codas with varying phonological properties. The results provide evidence that production of the plural morpheme is partly governed by the complexity of the coda and its sonority. Experiments 3 and 4 show that these constraints on codas hold for comprehension as well, suggesting that this effect is not simply articulatory, but also impacts the morphophonology of the plural.

Bilingual speech perception and learning: A review of recent trends

Over the past several years, the field of bilingual speech perception has seen a substantial increase in both the number of publications and in the amount of interest directed at its findings. Consequently, the time is ripe to assess the state of the field, what we have accomplished and where we have yet to go. Although we cannot capture the full state of the field in the space of this paper, we hope to summarize the major trends that have led to the current state and take stock of its future directions. To that end, we focus our review on the relative merits of single phonemes versus whole words and phrases when investigating bilingual speech, the efficacy of the different training paradigms that have been attempted and we focus, in particular, on the role of individual differences in predicting learning outcomes. We conclude our review by highlighting recent developments demonstrating that identifying individual differences in ability pre-training can result in more efficacious training paradigms. Goals for future research are also discussed.

Predictors of spoken language learning

UNLABELLED We report two sets of experiments showing that the large individual variability in language learning success in adults can be attributed to neurophysiological, neuroanatomical, cognitive, and perceptual factors. In the first set of experiments, native English-speaking adults learned to incorporate lexically meaningfully pitch patterns in words. We found those who were successful to have higher activation in bilateral auditory cortex, larger volume in Heschls Gyrus, and more accurate pitch pattern perception. All of these measures were performed before training began. In the second set of experiments, native English-speaking adults learned a phonological grammatical system governing the formation of words of an artificial language. Again, neurophysiological, neuroanatomical, and cognitive factors predicted to an extent how well these adults learned. Taken together, these experiments suggest that neural and behavioral factors can be used to predict spoken language learning. These predictors can inform the redesign of existing training paradigms to maximize learning for learners with different learning profiles. LEARNING OUTCOMES Readers will be able to: (a) understand the linguistic concepts of lexical tone and phonological grammar, (b) identify the brain regions associated with learning lexical tone and phonological grammar, and (c) identify the cognitive predictors for successful learning of a tone language and phonological rules.