Biomedical subjects

L Gerken

Publications and source records attributed to L Gerken.

10 recordsLinked to original sources

PubMed2000

Infant artificial language learning and language acquisition.

The rapidity with which children acquire language is one of the mysteries of human cognition. A view held widely for the past 30 years is that children master language by means of a language-specific learning device. An earlier proposal, which has generated renewed interest, is that children make use of domain-general, associative learning mechanisms. However, our current lack of knowledge of the actual learning mechanisms involved during infancy makes it difficult to determine the relative contributions of innate and acquired knowledge. A recent approach to studying this problem exposes infants to artificial languages and assesses the resulting learning. In this article, we review studies using this paradigm that have led to a number of exciting discoveries regarding the learning mechanisms available during infancy. These studies raise important issues with respect to whether such mechanisms are general or specific to language, the extent to which they reflect statistical learning versus symbol manipulation, and the extent to which such mechanisms change with development. The fine-grained characterizations of infant learning mechanisms that this approach permits should result in a better understanding of the relative contributions of, and the dynamic between, innate and learned factors in language acquisition.

Journal Article↗

PubMed2000

The basis of transfer in artificial grammar learning.

In two experiments, we examined the extent to which knowledge of sequential dependencies and/or patterns of repeating elements is used during transfer in artificial grammar learning. According to one view of transfer, learners abstract the grammar's sequential dependencies and then learn a mapping to new vocabulary at test (Dienes, Altmann, & Gao, 1999). Elements that are repeated have no special status on this view, and so a logical prediction is that learners should transfer as well after exposure to a grammar without repetitions as after exposure to a grammar with them. On another view, repetition structure is the very basis of transfer (Brooks & Vokey, 1991; Mathews & Roussel, 1997). Learners were trained on grammars with or without repeating elements to test these competing views. Learners demonstrated considerable knowledge of sequential dependencies in their training vocabulary but did not use such knowledge to transfer to a new vocabulary. Transfer only occurred in the presence of repetition structure, demonstrating this to be the basis of transfer.

Humans↗

PubMed1999

Artificial grammar learning by 1-year-olds leads to specific and abstract knowledge.

Four experiments used the head-turn preference procedure to assess whether infants could extract and remember information from auditory strings produced by a miniature artificial grammar. In all four experiments, infants generalized to new structure by discriminating new grammatical strings from ungrammatical ones after less than 2 min exposure to the grammar. Infants acquired specific information about the grammar as demonstrated by the ability to discriminate new grammatical strings from those with illegal endpoints (Experiment 1). Infants also discriminated new grammatical strings from those with string-internal pairwise violations (Experiments 2 and 3). Infants in Experiment 4 abstracted beyond specific word order as demonstrated by the ability to discriminate new strings produced by their training grammar from strings produced by another grammar despite a change in vocabulary between training and test. We discuss the implications of these findings for the study of language acquisition.

Analysis of Variance↗

PubMed1999

Grammatical and caregiver cues in early sentence comprehension.

In order to begin to learn a language, young children must be able to locate and distinguish linguistic units in the speech they hear. A number of cues in the speech stream may aid them in this task. Some cues, such as frequently occurring grammatical morphemes and prosodic changes at linguistic boundaries are inherent in the language. Other cues, such as short utterance length and placement of key words in utterance-final position, are not integral to the grammar of the language but are characteristically provided by caregivers. Although previous studies suggest that even infants are sensitive to many of these cues, it is not clear that young listeners actually use them in assigning structure to sentences. The experiments reported here asked whether 60 children aged 2;0 to 2;2 used grammatical and caregiver cues in sentence comprehension and how different types of cues interacted. Two findings are of note: children used all of the cues tested, and the presence of one type of cue did not diminish use of another.

Age Factors↗

PubMed1998

An electrophysiological study of infants' sensitivity to the sound patterns of English speech.

The study explores 10- to 11-month-old infants' sensitivity to the phonological characteristics of their native language. Event-related potentials (ERPs) were obtained for tones that were superimposed on two versions of a story: an Unmodified version containing normal English function morphemes, and a Modified version in which the prosodic and segmental properties of a subset of function morphemes were changed to make them atypical. The 11-month-olds exhibited significantly lower amplitude ERPs to the tones during the Modified story than to the Unmodified story, whereas the 10-month-olds showed no differences. These results suggest that the 11-month-olds discriminated the two versions of the story based on their representations of the phonological properties of English. Further, the tone-probe ERP method can successfully be used to study the development of speech perception in the pre-linguistic infant.

Child Development↗

PubMed1996

Prosody's role in language acquisition and adult parsing.

There has been recent interest in the role of prosody in language acquisition as well as in adult sentence processing. Although the specific questions about prosody asked in these two domains may appear to differ, there are at least three basic issues that they have in common. These include the role of prosody in segmentation (i.e., deciding whether two adjacent sections of speech belong to the same or to different linguistic units), structural bracketing (i.e., discerning structural relations among linguistic units), and the reliability of prosodic cues. Data from both language acquisition and adult parsing research suggest that, although prosody almost certainly plays a role in segmentation, it probably does not aid in bracketing. Research on the reliability of prosodic cues suggest that these are probably more reliable and robust in child-directed than in adult-directed speech registers, raising questions about how child and adult listeners interpret the presence vs. absence of prosodic cues.

Adult↗

PubMed1994

When prosody fails to cue syntactic structure: 9-month-olds' sensitivity to phonological versus syntactic phrases.

According to prosodic bootstrapping accounts of syntax acquisition, language learners use the correlation between syntactic boundaries and prosodic changes (e.g., pausing, vowel lengthening, large increases or decreases in fundamental frequency) to cue the presence and arrangement of syntactic constituents. However, recent linguistic accounts suggest that prosody does not directly reflect syntactic structure but rather is governed by independent prosodic units such as phonological phrases. To examine the implications of this view for the prosodic bootstrapping hypothesis, infants in Experiment 1 were presented with sentences in which pauses were inserted either between the subject noun phrase (NP) and verb or after the verb. Half of the infants heard sentences with lexical NP subjects, in which prosodic structure is consistent with syntactic structure. The other half heard sentences with pronoun subjects, in which prosodic structure does not mirror syntactic structure. In a preferential listening paradigm, infants in the lexical NP condition listened longer to materials containing pauses between the subject and verb, the main syntactic constituents. However, in the pronoun NP condition, infants showed no difference in listening times for the two pause locations. To determine if other sentence types containing pronoun subjects potentially provide information about the syntactic constituency of these elements, infants in Experiment 2 heard yes-no questions with pronoun subjects, in which the prosodic structure reflects the constituency of the subject. Infants listened longer when pauses were inserted between the subject and verb than after the verb. Taken together, our results suggest that the prosodic information in an individual sentence is not always sufficient to assign a syntactic structure. Rather, learners must engage in active inferential processes, using cross-sentence comparisons and other types of information to arrive at the correct syntactic representation.

Arousal↗

PubMed1994

A metrical template account of children's weak syllable omissions from multisyllabic words.

Young children learning English as well as many other languages frequently omit weakly stressed syllables from multisyllabic words. In particular, they are more likely to omit weak syllables from word-initial positions than from word-internal or -final positions. For example, the weak syllable of a weak-strong (WS) word like giraffe is much more likely to be omitted than the weak syllable of a SW word like tiger. Three hypotheses for this omission pattern have been offered. In two, children's weak syllable omissions reflect innate perceptual biases either to ignore initial weak syllables or to encode word-final syllables. In contrast, the SW Production Template Hypothesis states that children have a template for producing a strong syllable followed by an optional weak syllable. When they apply a series of SW templates to their intended utterances, weak syllables that do not fit the templates are more likely to be omitted than those that do. To compare the three hypotheses, young two-year-olds were asked to say four-syllable SWWS and WSWS nonsense words. Children's pattern of weak syllable preservations was highly consistent with the SW production template hypothesis, but not with the perception-based hypotheses. Implications of this research for children's function morpheme omissions and for the relation of metrical and segmental production templates are discussed.

Child Development↗

PubMed1990

Relationships between independent living centers and medical rehabilitation programs.

A survey of independent living centers (ILCs) and medical rehabilitation programs (MRPs) with cooperative relationships was conducted to (1) document the extent and kinds of relationships that exist and (2) identify factors that are reported to impede or facilitate those relationships. A questionnaire was mailed to 83 ILCs that are listed in the ILRU Registry of Independent Living Programs and that reported having a relationship with one or more MRPs. Subsequently, another questionnaire was sent to the MRPs with which each ILC reported having a relationship. Usable questionnaires were received from 46 ILCs. In descending order, the most frequently reported relationships were (1) making referrals to or supplying information about MRPs, (2) providing peer counseling services, and (3) conducting training in daily living skills for medical rehabilitation patients. Mean ratings of satisfaction with the various kinds of relationships were relatively high. The three most frequently endorsed barriers to stronger relationships were conflicting approaches or styles of service delivery, funding of services, and conflicting program philosophies. Using information from a database describing ILCs, it was found that ILCs with MRP relationships served significantly more consumers than centers not having such relationships. According to results provided by 25 MRPs, patients with spinal cord injury most frequently received services by staff members of ILCs, with peer counseling being the most frequently provided service.

Activities of Daily Living↗

PubMedDate not supplied

Do English-learning infants use syllable weight to determine stress?

A linguistic factor governing the assignment of English lexical stress is syllable weight. Heavy syllables which have either a long (tense) vowel or are closed with a consonant are heavy and automatically bear stress. Are infants sensitive to this aspect of the English stress system? Previous research by Jusczyk, Cutler, and Redanz (1993) showed that nine-month-olds listened longer to words exhibiting Strong-Weak than Weak-Strong stress pattern. However, they did not investigate the role of syllable weight in this preference. A series of three experiments explored infants' preference for Strong-Weak versus Weak-Strong lists, but systematically manipulated the syllable weight of Strong syllables. The results suggest that syllable weight is not a necessary component of the Strong-Weak preference observed in previous studies. Rather it appears that infants prefer both words that begin with a Strong syllable and Strong syllables that are heavy. Thus, the results suggest that sensitivity to surface linguistic patterns and the principles that underlie them may be independent in early language acquisition.

Child Language↗