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J Mehler

Publications and source records attributed to J Mehler.

At least 37 records · Page 2Linked to original sources
PubMed1994

Cross-linguistic approaches to speech processing.

Recent advances in the field of speech processing indicate that speakers of differing languages process speech relying on units that are appropriate to the rhythmical properties of their maternal tongue. Studies with young infants suggest that the acquisition of these processing routines takes place before the end of the first year of life. Further evidence shows that the left hemisphere initially processes any language and gradually becomes specialized for the maternal language.

Adult↗
PubMed1994

Do infants perceive word boundaries? An empirical study of the bootstrapping of lexical acquisition.

Babies, like adults, hear mostly continuous speech. Unlike adults, however, they are not acquainted with the words that constitute the utterances; yet in order to construct representations for words, they have to retrieve them from the speech wave. Given the apparent lack of obvious cues to word boundaries (such as pauses between words), this is not a trivial problem. Among the several mechanisms that could be explored to solve this bootstrapping problem for lexical acquisition, a tentative but reasonable one posits the existence of some cues (other than silence) that signal word boundaries. In order to test this hypothesis, infants were used as informants in our experiments. It was hypothesized that if word boundary cues exist, and if infants are to use them in the course of language acquisition, then they should at least perceive these cues. As a consequence, infants should be able to discriminate sequences that contain a word boundary from those that do not. A number of bisyllabic stimuli were extracted either from within French words (e.g., mati in mathématicien), or from between words (e.g., mati in panorama typique). Three-day-old infants were tested with a non-nutritive sucking paradigm, and the results of two experiments suggest that infants can discriminate between items that contain a word boundary and items that do not. It is therefore conceivable that newborns are already sensitive to cues that correlate with word boundaries. This result lends plausibility to the hypothesis that infants might use word boundary cues during lexical acquisition.

Arousal↗
PubMed1992

Cross-linguistic regularities in the frequency of number words.

We examine the frequency of numerals and ordinals in seven different languages and/or cultures. Many cross-cultural and cross-linguistic patterns are identified. The most striking is a decrease of frequency with numerical magnitude, with local increases for reference numerals such as 10, 12, 15, 20, 50 or 100. Four explanations are considered for this effect: sampling artifacts, notational regularities, environmental biases and psychological limitations on number representations. The psychological explanation, which appeals to a Fechnerian encoding of numerical magnitudes and to the existence of numerical points of reference, accounts for most of the data. Our finding also has practical importance since it reveals the frequent confound of two experimental variables: numerical magnitude and numeral frequency.

Adult↗
PubMed1992

The monolingual nature of speech segmentation by bilinguals.

Monolingual French speakers employ a syllable-based procedure in speech segmentation; monolingual English speakers use a stress-based segmentation procedure and do not use the syllable-based procedure. In the present study French-English bilinguals participated in segmentation experiments with English and French materials. Their results as a group did not simply mimic the performance of English monolinguals with English language materials and of French monolinguals with French language materials. Instead, the bilinguals formed two groups, defined by forced choice of a dominant language. Only the French-dominant groups showed syllabic segmentation and only with French language materials. The English-dominant group showed no syllabic segmentation in either language. However, the English-dominant group showed stress-based segmentation with English language materials; the French-dominant group did not. We argue that rhythmically based segmentation procedures are mutually exclusive, as a consequence of which speech segmentation by bilinguals is, in one respect at least, functionally monolingual.

Adult↗
PubMed1991

[Cardiac arrest during anesthesia induction with halothane and succinylcholine in an infant. Massive hyperkalemia and rhabdomyolysis in suspected myopathy and/or malignant hyperthermia].

This report describes a cardiac arrest that occurred in a 4-month-old infant during induction of anesthesia. During the administration of N2O/O2 and halothane via a face mask tachycardia was noted and rigor followed the application of succinylcholine for intubation. Shortly thereafter cardiac arrest occurred; 15 min later we found a profound metabolic acidosis as well as signs of rhabdomyolysis with a serum potassium level of 10.3 mmol/l and an increase in serum creatine kinase (CK). While performing cardiopulmonary resuscitation (CPR) and treating the acid-base imbalance and hyperkalemia, we administered--suspecting malignant hyperthermia (MH)--dantrolene. Approximately 60 min post-arrest we achieved stabilization of the vital signs. During the following hours the CK level rose to 99, 600 IU/l and myoglobinuria of 360,000 micrograms/l confirmed the extent of the rhabdomyolysis. The infant was discharged home without detectable sequelae after 2 1/2 weeks. Comparisons with corresponding case reports in the literature lead to the supposition that our patient suffered from a myopathy thus far undiagnosed. To what extent a MH episode may have contributed to the clinical picture cannot be determined at present. The spectrum of adverse reactions to volatile anesthetics and succinylcholine in patients with myopathic disorders is presented and discussed. As in other case reports, the dramatic course described here also demonstrates that in addition to CPR and treatment of the acid-base and electrolyte imbalances, administration of dantrolene should be considered at an early stage.

Anesthesia, Inhalation↗
PubMed1990

Is numerical comparison digital? Analogical and symbolic effects in two-digit number comparison.

Do Ss compare multidigit numbers digit by digit (symbolic model) or do they compute the whole magnitude of the numbers before comparing them (holistic model)? In 4 experiments of timed 2-digit number comparisons with a fixed standard, the findings of Hinrichs, Yurko, and Hu (1981) were extended with French Ss. Reaction times (RTs) decreased with target-standard distance, with discontinuities at the boundaries of the standard's decade appearing only with standards 55 and 66 but not with 65. The data are compatible with the holistic model. A symbolic interference model that posits the simultaneous comparison of decades and units can also account for the results. To separate the 2 models, the decades and units digits of target numbers were presented asynchronously in Experiment 4. Contrary to the prediction of the interference model, presenting the units before the decades did not change the influence of units on RTs. Pros and cons of the holistic model are discussed.

Adult↗
PubMed1989

Limits on bilingualism.

Speech, in any language, is continuous; speakers provide few reliable cues to the boundaries of words, phrases, or ther meaningful units. To understand speech, listeners must divide the continuous speech stream into portions that correspond to such units. This segmentation process is so basic to human language comprehension that psycholinguists long assumed that all speakers would do it in the same way. In previous research, however, we reported that segmentation routines can be language-specific: speakers of English do not. French has relatively clear syllable boundaries and syllable-based timing patterns, whereas English has relatively unclear syllable boundaries and stress-based timing; thus syllabic segmentation would work more efficiently in the comprehension of French than in the comprehension of English. Our present study suggests that at this level of language processing, there are limits to bilingualism: a bilingual speaker has one and only one basic language.

England↗
PubMed1989

Dichotic perception and laterality in neonates.

Groups of 4-day-old neonates were tested for dichotic discrimination and ear differences with the High-Amplitude-Sucking procedure. In the first experiment, dichotic speech discrimination was attested by comparison with a control group. Furthermore, among those subjects who showed a substantial recovery of sucking response at least after one of the two syllable changes, it was observed that significantly more subjects manifested a stronger reaction to a right-ear change than to a left-ear change. In the second experiment, 4-day-old neonates were tested on syllable and music timbre discrimination. The significant Stimulus Type x Ear interaction observed suggests perceptual asymmetries indicative of very precocious brain specialization.

Arousal↗
PubMed1989

[The relationship of the macrophage system to the blood vessel wall and atherogenesis].

Monocytes/macrophages are physiological cellular components of the subendothelium of greater arteries as has been shown by our studies on endothelial/intimal preparations of 9 species, including man. Differentiation is possible between species rich (pig, man, sheep) or poor in macrophages (rabbit and other small laboratory animals) according to their density of subendothelial infiltration in the aorta. Morphological, histochemical, and ultrastructural results have shown that we are mainly dealing with metabolic quiescent, resident macrophages, their number being regulated by influences depending on endothelium and intima factors. We assume that in species rich in macrophages and in man, they have physiological functions for homoeostasis of border layer and intima. The most considerable signal for subendothelial macrophage accumulation in man, pig, and rabbit is intimal deposition of lipids, independent of experimental or spontaneous induction. Short-term or long-term hypercholesterolemia is not associated with increased adhesion and emigration of monocytes in unchanged intima at venous or arterial endothelial cells of pigs and rabbits. There is no evidence to intimal lipid infiltration being preceded by subendothelial macrophage invasion. Most studies on vessel border layer have suggested that in the early high-lipid phase of atherogenesis subendothelial macrophages participate in lipid metabolic clearance. But in conditions of metabolic activation they can be an atherogenic danger due to a whole range of secretory products stimulating recruitment of blood monocytes and lymphocytes, increasing the permeability of endothelium, altering the extracellular matrix components, and causing modulation of gen expression of vessel wall cells. Therefore, metabolic activation of the subendothelial macrophage system is a new, potentially atherogenic mechanism.

Animals↗
PubMed1988

Illiteracy and brain damage. 3: A contribution to the study of speech and language disorders in illiterates with unilateral brain damage (initial testing).

This report bears on the behavior of 188 unilateral stroke subjects when administered an aphasia screening test comprising a short interview as well as naming, repetition, word-picture matching and sentence-picture matching tasks. All subjects were unilingual lusophone adult (40 yr of age or older) right-handers. Furthermore, they were either totally unschooled illiterates or they had received school education and thereafter retained writing skills and reading habits. Subjects were tested less than 2 months after a first unilateral stroke. In all tasks, global error scores were greater among left and right brain-damaged illiterate and literate subjects than among their controls. In repetition and matching, these differences were statistically significant for the left but not for the right-stroke groups, irrespective of the literacy factor. In naming, on the other hand, significant differences were found not only for the two left-stroke groups but also for the right-stroke illiterate group although not for the right-stroke literate one. Likewise, some degree of word-finding difficulty and of reduction in speech output as well as sizeable production of phonemic paraphasias were observed in the interviews of several right-stroke illiterates, clearly less in those of right-stroke literates. These findings lead us to suggest that cerebral representation of language is more ambilateral in illiterates than it is in school educated subjects although left cerebral "dominance" remains the rule in both.

Aphasia↗
PubMed1988

Agrammatism in sentence production without comprehension deficits: reduced availability of syntactic structures and/or of grammatical morphemes? A case study.

A French-speaking patient with Broca's aphasia--following a left-hemisphere lesion involving the sylvian region but sparing Broca's area--is presented. Like G. Miceli, A. Mazzuchi, L. Menn, and H. Goodglass's (1983, Brain and Language, 19, 65-97) case 2, this patient produces agrammatic speech in the absence of any comprehension deficit. Unlike Miceli's patient, though, agrammatic speech can be observed in all sentence production tasks (from spontaneous speech to repetition, oral reading, and writing) whereas production of individual words--be they open class or closed class--is almost always intact. On the basis of extensive (psycho)linguistic testing, it is argued that this patient's deficit is not central and not crucially syntactic (at least) at the level of knowledge but seems to disrupt specifically those (automatic?) processes responsible for both retrieval and production of free-standing grammatical morphemes whenever they have to be inserted into phrases and sentences.

Aphasia↗
PubMed1988

An investigation of young infants' perceptual representations of speech sounds.

The present study examined the ability of newborns and 2-month-olds to detect phonetic differences between syllables. By relying on the modified high-amplitude sucking procedure, which did not permit the infants to use a simple same-different response, the present experiments tapped the perceptual representations of the speech sounds. Infants as young as a few days old displayed some capacity to represent differences in a set of syllables varying in their phonetic composition, although there was no convincing evidence that their representations were structured in terms of phonetic segments. Finally, evidence of developmental changes in speech processing were noted for the first time with infants in this age range. The change noted was a tendency from global toward more specific representations on the part of the older infants.

Arousal↗
PubMed1987

Illiteracy and brain damage--1. Aphasia testing in culturally contrasted populations (control subjects).

One hundred neurologically healthy adults were tested for their pointing (choosing one of four or six line drawings as the match to an auditorily presented linguistic stimulus), naming (from line drawings), and repetition abilities. All subjects were unilingual adult right-handers. Fifty-seven subjects were totally unschooled illiterates and 43 were fluent readers. Statistically significant differences were found to exist between the scores of the illiterate and literate subpopulations across all tasks. With the focus being placed on these cultural differences, the discussion bears on: (a) the interaction between linguistic and iconographic factors in certain types of naming and pointing tasks currently used in clinical and research aphasiology, (b) some of the linguistic parameters which are apparently at stake in repetition behavior, and (c) the circumstances in which aphasiological research dealing with groups of patients cannot yield reliable data without reference to neurologically healthy controls. It is argued that, when testing brain-damaged patients of different cultural backgrounds, one runs the risk of over- or underestimating the frequency of aphasia if one does not refer to norms which explicitly take educational level into account.

Adult↗
PubMed1987

Illiteracy and brain damage. 2. Manifestations of unilateral neglect in testing "auditory comprehension" with iconographic materials.

This report concerns the sentence-picture matching behavior of 100 neurologically healthy and 169 brain-damaged subjects, all of whom were unilingual adult right-handers. Within this population, 144 subjects were totally unschooled illiterates and the remaining 125 had received school education and thereafter had retained writing skills and reading habits. Brain-damaged subjects were tested less than 2 months after a first left- or right-hemisphere stroke. All subjects were administered an aphasia screening battery including, among other subtests, a set of six sentence-picture matching stimuli. For each of these six stimuli, subjects heard a sentence uttered by the examiner and were then requested to match this sentence with one of four drawings presented within a single display divided into four quadrants of equal surface. Three sentences were syntactically "simple" (noun subject + verb) and three were relatively more "complex" (noun subject + verb + one or two noun complements). Evidence of unilateral neglect was found in both left- and right-brain-damaged illiterates and literates. Moreover, the right neglect of left-brain-damaged subjects was manifest mostly when target sentences were relatively "complex" whereas the left neglect of right-brain-damaged subjects was manifest irrespective of the syntactic complexity of target sentences. Our data are interpreted as indicative of an interaction between two cognitive disorders resulting from dysfunctions of asymmetrically represented cognitive mechanisms. The implications of these findings with respect to clinical and research aphasia testing are discussed.

Attention↗
PubMed1987

Discrimination in neonates of very short CVs.

The experiment reported here explores the ability of 4- to 5-day-old neonates to discriminate consonantal place of articulation and vowel quality using shortened CV syllables similar to those used by Blumstein and Stevens [J. Acoust. Soc. Am. 67, 648-662 (1980)], without vowel steady-state information. The results show that the initial 34-44 ms of CV stimuli provide infants with sufficient information to discriminate place of articulation differences in stop consonants ([ba] vs [da], [ba] vs [ga], [bi] vs [di], and [bi] vs [gi]) and following vowel quality ([ba] vs [bi], [da] vs [di], and [ga] vs [gi]). These results suggest that infants can discriminate syllables on the basis of the onset properties of CV signals. Furthermore, this experiment indicates that neonates require little or no exposure to speech to succeed in such a discrimination task.

Female↗