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D B Rosenfield

Publications and source records attributed to D B Rosenfield.

At least 19 recordsLinked to original sources
PubMed2003

Modulation of theta/alpha frequency profiles of slow auditory-evoked responses in the songbird zebra finch.

Spatiotemporal patterns of forebrain neural activity associated with auditory perception of biologically relevant complex acoustic stimuli can be conveniently studied in the songbird zebra finch. Here we present a time-frequency analysis of averaged slow auditory-evoked potentials (sAEPs) obtained at electrode locations overlying the main song control nucleus, high vocal center. Gabor spectrograms of these sAEPs show a prolonged response time course consisting of unimodal frequency peaks in the theta/alpha range (4-17 Hz). There is a stimulus-dependent modulation of the duration of the response and of the total number of its constituent frequency peaks, an effect that is bilateral in 75% of the birds and lateralized to the left side in the remaining 25%. Since the state of alertness of birds modulates these parameters along a similar continuum, these findings suggest that modulation of sAEP frequency profile may be dependent on attentional mechanisms. The presence and modulation of neurobiologically ubiquitous dominant frequency components also implicate the possible role of induced cerebral neuronal circuit oscillations in songbird auditory perception.

Acoustic Stimulation↗
PubMed2003

Development and adult phase plasticity of syllable repetitions in the birdsong of captive zebra finches (Taeniopygia guttata).

Oscines learn their birdsongs from tutors. The authors found that a small fraction (approximately 7%) of captive male zebra finches (Taeniopygia guttata) produce variant acoustic birdsong profiles consisting of repetitions of single song syllables at high frequencies. Juvenile offspring of nonrepeaters can selectively learn the syntactic rule or habit of repeating syllables from repeaters. Adult tutored syllable repeaters, unlike spontaneous repeaters, undergo a form of song plasticity involving progressive reduction of the mean number and variance of repeated syllables as a function of long-term exposure to nonrepeater songs without altering the number or sequence of syllables within motifs. These findings suggest that aspects of song syntax or temporal frame can be acquired independently of song syllable or spectral content, and plasticity involving restorative alteration of acquired variant temporal frames can occur after the closure of the critical period for song learning.

Animals↗
PubMed2001

Reduction of female-directed song motifs induced by repeated singing in laboratory-bred zebra finches.

Songbirds such as zebra finches show a remarkable degree of neural plasticity associated with the motor act of singing. Here we show that in adult male zebra finches repeated female-directed singing episodes are associated with a change in subsequent singing behavior involving a progressive long-lasting decline in the number of song motifs sung. This reduction in song motif production cannot be completely explained by the circadian rhythm, declining motivation or neuromuscular exhaustion. Paired song induction sessions reveal that the time course of motif reduction during repeated singing can be best explained by the cumulative effect of reduction produced by each singing episode. These results suggest that song production in zebra finches is prone to a form of rapid behavioral adaptation.

Adaptation, Physiological↗
PubMed2000

Transient speech compromise following sublabial transsphenoidal surgery: a case report and findings of a small preliminary study.

Sublabial transsphenoidal surgical removal of pituitary tumors is a common procedure with minimal complications. Although many investigators have reported oral sensory compromises following surgery, none has reported any postoperative compromise in speaking ability. In this article, we describe the case of a 33-year-old woman who developed transient but severe speech symptoms after she underwent sublabial transsphenoidal surgery. This case prompted us to undertake a brief retrospective analysis of our experience with this procedure in other patients, which revealed that speech compromise is far more common than heretofore realized.

Adult↗
PubMed1994

Stuttering induced by theophylline.

We retrospectively evaluated three fluent asthmatic children who developed speech dysfluency following administration of theophylline. The dysfluency ceased in all three, following discontinuation of the medication. The medication was re-instituted in two patients, prompting return of dysfluency. It is unknown whether the patients had characteristics of "acquired stuttering" or "developmental stuttering." We urge appropriate testing should this complication again occur. This might then provide pharmacologic information regarding stuttering.

Asthma↗
PubMed1992

A model of the phonatory response time of stutterers and fluent speakers to frequency-modulated tones.

Stutterers and fluent speakers tracked frequency-modulated tones by humming. The response time (RT) to the first corrective change in fundamental frequency in response to linear ramps of increasing and decreasing frequency was measured. The results demonstrate that RT is a function of the stimulus ramp velocity. A model of this dependency is provided which consists of parameters of threshold frequency and a fixed time delay. The estimated threshold frequency for the fluent speakers is 2.029 Hz with 95% confidence interval: (1.70 Hz, 2.35 Hz) whereas that of the stutterers is 3.937 Hz (3.28 Hz, 4.60 Hz). These threshold frequencies are significantly different (p < 0.0001). This implies that stutterers are slower to respond to changes in frequency than are fluent speakers. The fixed time delays for the two groups are not significantly different. This means that it is possible for the stutterers to respond as fast as the fluent speakers (i.e., their basic "reflexes" are the same); however, they spend more time in the detection of the change in a tracking signal. This supports the model of the stuttered event as being triggered by an instability in a multiloop speech motor control system.

Adult↗
PubMed1990

Neurologic aspects of spasmodic dysphonia.

We discuss the etiology of 100 spasmodic dysphonia patients. Seventy-one patients had underlying essential tremor, 25 had Meige's syndrome, 12 were hypothyroid, and 27 had either a functional disturbance or focal dystonia. Six patients had intermittent breathy dysphonia. A large corpus of spasmodic dysphonia patients have organic neurolaryngeal disease.

Adolescent↗
PubMed1990

Physician referral patterns for stutterers.

Many children who stutter initially seek guidance from their pediatricians. Pediatricians often do not refer stutterers for speech therapy. We present a brief analysis of pediatricians' views regarding stuttering, as well as their exposure to patients who stutter. We present a practical approach to children who stutter.

Cross-Sectional Studies↗
PubMed1989

Stuttering.

Explore the source record for details and available documents.

Attitude↗
PubMed1984

The role of electromyography in clinical laryngology.

Laryngeal electromyography (EMG) has been used primarily as a research tool with only limited application to clinical practice. We have performed laryngeal EMG in a clinical research setting for over 2 years and have found it a valuable adjunct in selected situations. The electrophysiology and technique of laryngeal EMG are reviewed. Laryngeal EMG is the most accurate method of determining compromise of the superior laryngeal nerve. It is valuable in evaluating patients with mechanical fixation of the vocal cords. The eventual outcome of recurrent laryngeal nerve paralysis may also be predicted in certain patients. Laryngeal EMG is safe, easy to perform, and should be considered when evaluating the patient with laryngeal dysfunction.

Aged↗