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Biomedical subjects

A Fernald

Publications and source records attributed to A Fernald.

12 recordsLinked to original sources
PubMed1999

Continuous processing in word recognition at 24 months.

Speech processing in adults in continuous: as acoustic-phonetic information is heard, listeners' interpretation of the speech is updated incrementally. The present studies used a visual fixation technique to examine whether young children also interpret speech continuously. In Experiments 1 and 2, 24-month-old children looked at visual displays while hearing sentences. Sentences each contained a target word labeling one of the two displayed pictures. Children's latency to fixate the labeled picture was measured. Children's responses were delayed when the competing distractor picture's label overlapped phonetically with the target at onset (dog-doll), but not when the pictures' labels rhymed (ball-doll), showing that children monitored the speech stream incrementally for acoustic-phonetic information specifying the correct picture. In Experiment 3, adults' responses in the same task were found to be very similar to those of the 24-month-olds. This research shows that by 24 months, children can interpret speech continuously.

Adult↗
PubMed1998

Therapeutic advances of new fluoroquinolones.

Fluoroquinolone antimicrobials have been available for over 10 years. Recent modifications to nuclear side-chains have enhanced both the antimicrobial and pharmacokinetic profiles of this class. Rapidly increasing antimicrobial resistance among community and hospital bacterial pathogens has diminished therapeutic options. Infections caused by such pathogens, including drug-resistant Streptococcus pneumoniae and multi-resistant Enterobacteriaceae are now treatable by few classes of antibacterials, one of these being the fluoroquinolones. Ciprofloxacin was one of the first effective agents available in both iv. and oral formulations for the treatment of Gram-negative infection, resistant to other antibiotics. More recent developments, such as sparfloxacin and grepafloxacin, are more effective in vitro against Gram-positive pathogens, although their safety profile may be less promising. Fluoroquinolones not yet in widespread clinical use, including trovafloxacin, clinafloxacin and moxifloxacin, hold considerable promise as community 'respiratory antimicrobials' and the results of clinical trials are awaited with anticipation. In this review, the three generations of fluoroquinolone development are examined and the relative antimicrobial, pharmacokinetic, clinical and safety profiles of available and developmental quinolones are compared.

Journal Article↗
PubMed1996

Infants' responses to facial and vocal emotional signals in a social referencing paradigm.

The independent effects of facial and vocal emotional signals and of positive and negative signals on infant behavior were investigated in a novel toy social referencing paradigm. 90 12-month-old infants and their mothers were assigned to an expression condition (neutral, happy, or fear) nested within a modality condition (face-only or voice-only). Each infant participated in 3 trials: a baseline trial, an expression trial, and a final positive trial. We found that fearful vocal emotional signals, when presented without facial signals, were sufficient to elicit appropriate behavior regulation. Infants in the fear-voice condition looked at their mothers longer, showed less toy proximity, and tended to show more negative affect than infants in the neutral-voice condition. Happy vocal signals did not elicit differential responding. The infants' sex was a factor in the few effects that were found for infants' responses to facial emotional signals.

Affect↗
PubMed1993

Common themes and cultural variations in Japanese and American mothers' speech to infants.

This study explored both universal features and cultural variation in maternal speech. Japanese and American mothers' speech to infants at 6, 12, and 19 months was compared in a cross-sectional study of 60 dyads observed playing with toys at home. Mothers' speech in both cultures shared common characteristics, such as linguistic simplification and frequent repetition, and mothers made similar adjustments in their speech to infants of different ages. American mothers labeled objects more frequently and consistently than did Japanese mothers, while Japanese mothers used objects to engage infants in social routines more often than did American mothers. American infants had larger noun vocabularies than did Japanese infants, according to maternal report. The greater emphasis on object nouns in American mothers' speech is only partially attributable to structural differences between Japanese and English. Cultural differences in interactional style and beliefs about child rearing strongly influence the structure and content of speech to infants.

Adolescent↗
PubMed1993

Approval and disapproval: infant responsiveness to vocal affect in familiar and unfamiliar languages.

In a series of 5 auditory preference experiments, 120 5-month-old infants were presented with Approval and Prohibition vocalizations in infant-directed (ID) and adult-directed (AD) English, and in ID speech in nonsense English and 3 unfamiliar languages, German, Italian, and Japanese. Dependent measures were looking-time to the side of stimulus presentation, and positive and negative facial affect. No consistent differences in looking-time were found. However, infants showed small but significant differences in facial affect in response to ID vocalizations in every language except Japanese. Infants smiled more to Approvals, and when they showed negative affect, it was more likely to occur in response to Prohibitions. Infants did not show differential affect in response to Approvals and Prohibitions in AD speech. The results indicate that young infants can discriminate affective vocal expressions in ID speech in several languages and that ID speech is more effective than AD speech in eliciting infant affect.

Acoustic Stimulation↗
PubMed1992

Fluorescence in situ hybridization: a sensitive method for trisomy 8 detection in bone marrow specimens.

Trisomy 8 is a common anomaly in bone marrow (BM) cells of patients with myeloproliferative disorders (MPD), myelodysplastic syndromes (MDS), or acute nonlymphocytic leukemia (ANLL). We studied the efficacy of fluorescence in situ hybridization (FISH) detection of trisomy 8 in patients with MPD, MDS, or ANLL using directly labeled fluorescent alpha-satellite and whole chromosome paint (WCP) DNA probes specific for chromosome 8. Using FISH, we analyzed interphase nuclei and metaphase spreads from randomized series of BM specimens from normal individuals and patients with varying proportions of trisomy 8 as determined by conventional cytogenetic analysis. The BM of all normal donors contained less than or equal to 2.0% nuclei with 3 interphase FISH signals and less than or equal to 1 metaphase with 3 WCP FISH signals. Ninety-five percent and 98% of BM specimens with at least two metaphase cells with trisomy 8 by cytogenetic analysis contained greater than 2.0% nuclei with 3 interphase FISH and greater than 2 metaphases with 3 WCP FISH signals, respectively. Thirteen patients had 1 in 20 or 1 in 30 metaphase cells with trisomy 8 by conventional cytogenetic studies. Of these patients, four had greater than 2.0% nuclei with 3 interphase FISH signals. The BM of all four patients contained positive metaphase FISH results. We then studied the usefulness of FISH analysis to detect occult trisomy 8 by analyzing BM nuclei from 144 patients who had MPD, MDS, or ANLL and either 20 normal metaphase cells or an abnormal karyotype without trisomy 8. Seven patients had greater than 2.0% nuclei with 3 interphase FISH signals (range, 2.10% to 3.40%) and six patients had 2 or more cells with trisomy 8 upon metaphase FISH or extensive conventional cytogenetic analysis. Our results show that interphase and metaphase FISH analyses are useful methods to detect trisomy 8 cells in BM specimens, especially for specimens with normal or uncertain conventional cytogenetic results.

Bone Marrow↗
PubMed1989

A cross-language study of prosodic modifications in mothers' and fathers' speech to preverbal infants.

This study compares the prosodic modifications in mothers' and fathers' speech to preverbal infants in French, Italian, German, Japanese, British English, and American English. At every stage of data collection and analysis, standardized procedures were used to enhance the comparability across data sets that is essential for valid cross-language comparison of the prosodic features of parental speech. In each of the six language groups, five mothers and five fathers were recorded in semi-structured home observations while speaking to their infant aged 0;10-1;2 and to an adult. Speech samples were instrumentally analysed to measure seven prosodic parameters: mean fundamental frequency (f0), f0-minimum, f0-maximum, f0-range, f0-variability, utterance duration, and pause duration. Results showed cross-language consistency in the patterns of prosodic modification used in parental speech to infants. Across languages, both mothers and fathers used higher mean-f0, f0-minimum, and f0-maximum, greater f0-variability, shorter utterances, and longer pauses in infant-directed speech than in adult-directed speech. Mothers, but not fathers, used a wider f0-range in speech to infants. American English parents showed the most extreme prosodic modifications, differing from the other language groups in the extent of intonational exaggeration in speech to infants. These results reveal common patterns in caretaker's use of intonation across languages, which may function developmentally to regulate infant arousal and attention, to communicate affect, and to facilitate speech perception and language comprehension. In addition to providing evidence for possibly universal prosodic features of speech to infants, these results suggest that language-specific variations are also important, and that the findings of the numerous studies of early language input based on American English are not necessarily generalisable to other cultures.

Child, Preschool↗
PubMed1989

Intonation and communicative intent in mothers' speech to infants: is the melody the message?

This study explores the power of intonation to convey meaningful information about the communicative intent of the speaker in speech addressed to preverbal infants and in speech addressed to adults. Natural samples of infant- and adult-directed speech were recorded from 5 mothers of 12-month-old infants, in 5 standardized interactional contexts: Attention-bid, Approval, Prohibition, Comfort, and Game/Telephone. 25 infant-directed and 25 adult-directed vocalizations were electronically filtered to eliminate linguistic content. The content-filtered speech stimuli were presented to 80 adult subjects: 40 experienced parents and 40 students inexperienced with infants. The subjects' task was to identify the communicative intent of the speaker using only prosodic information, given a 5-alternative forced choice. Listeners were able to use intonation to identify the speaker's intent with significantly higher accuracy in infant-directed speech than in adult-directed speech. These findings suggest that the prosodic patterns of speech to infants are more informative than those of adult-adult speech, and may provide the infant with reliable cues to the communicative intent of the speaker. The interpretation of these results proposed here is that the relation of prosodic form to communicative function is made uniquely salient in the melodies of mothers' speech, and that these characteristic prosodic patterns are potentially meaningful to the preverbal infant.

Adult↗
PubMed1983

Infants' discrimination of the duration of a rapid spectrum change in nonspeech signals.

Two-month-old infants discriminated complex sinusoidal patterns that varied in the duration of their initial frequency transitions. Discrimination of these nonspeech sinusoidal patterns was a function of both the duration of the transitions and the total duration of the stimulus pattern. This contextual effect was observed even though the information specifying stimulus duration occurred after the transitional information. These findings parallel those observed with infants for perception of synthetic speech stimuli. Specialized speech processing capacities are thus not required to account for infants' sensitivity to contextual effects in acoustic signals, whether speech or nonspeech.

Humans↗
PubMedDate not supplied

When half a word is enough: infants can recognize spoken words using partial phonetic information.

Adults process speech incrementally, rapidly identifying spoken words on the basis of initial phonetic information sufficient to distinguish them from alternatives. In this study, infants in the second year also made use of word-initial information to understand fluent speech. The time course of comprehension was examined by tracking infants' eye movements as they looked at pictures in response to familiar spoken words, presented both as whole words in intact form and as partial words in which only the first 300 ms of the word was heard. In Experiment 1, 21-month-old infants (N = 32) recognized partial words as quickly and reliably as they recognized whole words; in Experiment 2, these findings were replicated with 18-month-old infants (N = 32). Combining the data from both experiments, efficiency in spoken word recognition was examined in relation to level of lexical development. Infants with more than 100 words in their productive vocabulary were more accurate in identifying familiar words than were infants with less than 60 words. Grouped by response speed, infants with faster mean reaction times were more accurate in word recognition and also had larger productive vocabularies than infants with slower response latencies. These results show that infants in the second year are capable of incremental speech processing even before entering the vocabulary spurt, and that lexical growth is associated with increased speed and efficiency in understanding spoken language.

Eye Movements↗
PubMedDate not supplied

Speech to infants as hyperspeech: knowledge-driven processes in early word recognition.

The intelligibility of a word in continuous speech depends on the clarity of the word and on linguistic and nonlinguistic contextual information available to the listener. Despite limited knowledge of language and the world, infants in the first 2 years are already beginning to make use of contextual information in processing speech. Adults interacting with infants tend to modify their speech in ways that serve to maximize predictability for the immature listener by highlighting focussed words and using frequent repetition and formulaic utterances. Infant-directed speech is viewed as a form of 'hyperspeech' which facilities comprehension, not by modifying phonetic properties of individual words but rather by providing contextual support on perceptual levels accessible to infants even in the earliest stages of language learning.

Adult↗