The ontogeny of phonological categories and the primacy of lexical learning in linguistic development.

In this paper, we draw on recent developments in several areas of cognitive science that suggest that the lexicon is at the core of grammatical generalizations at several different levels of representation. Evidence comes from many sources, including recent studies on language processing in adults and on language acquisition in children. Phonological behavior is influenced very early by pattern frequency in the lexicon of the ambient language, and we propose that phonological acquisition might provide the initial bootstrapping into grammatical generalization in general. The phonological categories over which pattern frequencies are calculated, however, are neither transparently available in the audiovisual signal nor deterministically fixed by the physiological and perceptual capacities of the species. Therefore, we need several age-appropriate models of how the lexicon can influence a child's interactions with the ambient language over the course of phonological acquisition.

Characterizing knowledge deficits in phonological disorders.

To aid the development of finer-grained measures of phonological competence within a representation-based approach to phonology, two aspects of nonsymbolic phonological knowledge (knowledge of the acoustic/perceptual space and of the articulatory/production space) were examined in 6 preschool-age children with phonological disorders and 6 typically developing age peers. To evaluate perceptual knowledge, gating and noise-center tasks were used. Children with phonological disorders recognized significantly fewer words than age peers on both tasks. To evaluate production knowledge, spectral and temporal measures were obtained for CV sequences involving both lingual and labial stop consonants. Group differences on this task (such as larger transition slope values from lingual consonants to vowels for children with phonological disorders) were also observed. These differerences were interpreted as indicating that the children with phonological disorders were less able to maneuver jaw and tongue body separately or that they used "ballistic" (i.e., less controlled) gestures from lingual consonants to vowels than their age peers. These results suggest that phonological knowledge is multifaceted, and that seemingly categorical deficits at one level can be linked to less robust representations at other levels.

Primary craniofacial chordoma: case report.

A 37-year-old man presented with right facial pain and a nonpalpable mass over the malar eminence. An incisional biopsy via the intraoral route was performed and interpreted as a vascular malformation with degenerative changes. His symptoms persisted, and a repeat biopsy was suggestive of an epithelioid nerve sheath tumor. Total resection of the tumor was planned to include the infraorbital and malar regions, the infratemporal fossa, and the pterygopalatine fossa. At surgery, the tumor was removed with tumor-free margins obtained along the course of the maxillary nerve just before its entrance into the cavernous sinus. The pathological findings and the immunohistochemistry demonstrated a typical chordoma with no chondroid or sarcomatous dedifferentiation. We think that with greater use of immunohistochemical markers and electron microscopy, patients with chordoma in this location may be diagnosed promptly and accurately.

The interplay between prosodic structure and coarticulation.

In this paper we draw on a linguistic model of prosodic structure and a task-dynamic model of speech gestures to account for the interplay of coarticulation and stress in English. We reinterpret results from two experiments in which articulator movements were recorded for utterances varying in pitch accept placement. In the first experiment, jaw kinematics were studied in post-nuclear unaccented and nuclear accented [pap] syllables. The kinematic patterns suggested that gestures in syllables with greater stress (nuclear accented) show less coarticulatory overlap. By contrast, the vowel's low jaw target is undershot in unaccented syllables. Two hypotheses are possible. Either the jaw is lower in stressed syllables so more energy can radiate from the mouth ("sonority expansion") or the jaw is lower to help distinguish the low vowel from other vowels ("hyperarticulation"). Another experiment differentiates the two hypotheses by examining tongue point positions in [put] preceding a [th]. In the more stressed syllables, the tongue dorsum retracts more, likely to make a more distinct back vowel. Also, the amount of assimilation of the alveolar stop to the following dental is reduced. Both results suggest hyperarticulation rather than sonority expansion. Thus, it seems that coarticulation is reduced in stressed syllables, because stressed syllables are hyperarticulated.

The interaction of coarticulation and prosody in sound change.

Ohala (1974, 1981a) has proposed that sound changes can originate in hearers' misinterpretations of synchronic phonetic patterns. This paper applies this idea to sound changes that are conditioned by the prosodic environment, such as the voicing of voiceless fricatives in unstressed syllables in Proto-Germanic. Browman and Goldstein's (1989, 1990) "gestural score" suggests a representation of synchronic patterns in which extreme overlap between gestures of neighboring phoneme segments in casual speech can produce the appearance of a feature change or a segment deletion. Many of the sound changes that are conditioned by prosodic environment can be viewed as a diachronic reinterpretation of just such synchronic fast-speech processes. For example, vowel reduction in unstressed syllables can be viewed as a reinterpretation of undershoot that occurs when the vowel is overlapped to a great extent by the oral gestures for neighboring consonants. Phonetic data are reviewed that support analogous accounts of stop spirantization, voiceless obstruent voicing, and even the insertion of an intrusive stop in clusters such as /ns/ in some prosodic environments.

Intramedullary connections of the rostral nucleus of the solitary tract in the hamster.

The rostral nucleus of the solitary tract (NST) figures prominently in the gustatory system, giving rise to ascending taste pathways that are well documented. Less is known of the local connections of the rostral NST with sites in the medulla. This study defines the intramedullary connections of the rostral NST in the hamster. Small iontophoretic injections of horseradish peroxidase (HRP), confined to the rostral NST, resulted in Golgi-like filling of axons that exited the NST or that interconnected cytoarchitectonic subdivisions within the NST complex. The NST efferent axons terminated sparsely in the trigeminal, facial and hypoglossal motor nuclei, but axons and endings were heavily distributed in the parvicellular reticular formation ventral to the NST. HRP injections centered in this part of the reticular formation resulted in heavy projections to the orofacial motor nuclei. Intranuclear connections, labelled after NST injections, linked NST subdivisions that receive primary afferent taste inputs to subdivisions involved in (1) projections to the preoromotor reticular formation, (2) projections to swallowing motor neurons, (3) activation of preganglionic parasympathetic neurons, and (4) general viscerosensation. In general, the connections defined in the present study provide anatomical details about the substrate for gustatory-motor and gustatory-visceral interactions.

The articulatory kinematics of final lengthening.

In order to understand better the phonetic control of final lengthening, the articulation of phrase-final syllables was compared with that of two other contexts known to increase syllable duration: accent and slow tempo. The kinematics of jaw movements in [pap] sequences and of lower lip movements in [pe] sequences for four subjects were interpreted in terms of a task-dynamic model. There was evidence of two different control strategies: decreasing intragestural stiffness to slow down some part of the syllable, and changing intergestural phasing to decrease overlap of the vowel gesture by the consonant. The first was used in slowing down tempo, whereas the second was used to increase the duration of accented syllables over unaccented syllables. Both strategies were implicated in phrase-final lengthening. In accented syllables, final closing gestures generally were longer and slower, but not more displaced. The two slowest subjects, however, used the other strategy in their slow-tempo final syllables. Final lengthening in reduced syllables was more difficult to interpret. The relationship between peak velocity and displacement suggested that a lesser stiffness is obscured by an increased gestural amplitude. Thus, by comparison to lengthening for accent, final lengthening is like a localized change in speaking tempo, although it cannot be equated directly with the specification of stiffness.