Monthly Archives: April 2011
Measures of Vocal Attack Time for Healthy Young Adults
Conclusions
Normative data are presented for a new measure of the duration of vocal initiation, VAT. Acquiring this measure requires very little intervention by the user and, thereby, eliminates the influence of subjective decision making. Although beyond the scope of this article, we suggest several factors that might underlie VAT as a function of speaker sex and age.
from the Journal of Voice
Sir Felix Semon (1849–1921): Pioneer in Neurolaryngology
This article will attempt to review the historical and scientific literature pertaining to the life and work of Felix Semon (1849–1921). Sir Felix Semon was one of the most distinguished figures in the early development of laryngology. He was an astute researcher of laryngeal pathophysiology and an active participant in laryngological scientific societies. Felix Semon was a talented doctor and was one of the most esteemed laryngologists in London for 35 years (1875–1910). Primarily, his scientific interests included complications after thyroid surgery, laryngeal cancer, tuberculosis and motor innervation of the larynx, and movement disorders of the larynx. Semon formulated the law regarding the sequence of occurrence of the laryngeal muscle paralysis—abduction before adduction. The 132 articles he had published over the years have had a significant impact on contemporary medical knowledge. At the 160th anniversary of Semon’s birth, we attempt to summarize his invaluable contribution to laryngology.
from the Journal of Voice
Psychiatric comorbidity in young adults with a clinical diagnosis of Asperger syndrome
In children with autism spectrum disorders, previous studies have shown high rates of psychiatric comorbidity. To date, studies on adults have been scarce. The aim of the present study was to investigate psychiatric comorbidity in young adults with Asperger syndrome. Participants were 26 men and 28 women (mean age 27 years) with a clinical diagnosis of Asperger syndrome. Psychiatric comorbidity was assessed by the Structured Clinical Interview for DSM-IV Axis I Disorders. IQ was measured using the Wechsler Adult Intelligence Scale, Third Edition. Autism spectrum diagnoses were confirmed using the DIagnostic Interview for Social and Communication Disorders. In our study group, 70% had experienced at least one episode of major depression, and 50% had suffered from recurrent depressive episodes. Anxiety disorders were seen in about 50%. Psychotic disorders and substance-induced disorders were uncommon. In conclusion, young adults with autism spectrum disorders are at high risk for mood and anxiety disorders. To identify these conditions and offer treatment, elevated vigilance is needed in clinical practice.
Mindfulness Training in Stuttering Therapy: A Tutorial for Speech-Language Pathologists
The use of mindfulness training for increasing psychological well-being in a variety of clinical and nonclinical populations has exploded over the last decade. In the area of stuttering, it has been widely recognized that effective long term management often necessitates treatment of cognitive and affective dimensions of the disorder in addition to behavioral components. Yet, mindfulness based strategies and their possible usefulness in stuttering management have not been described in detail in the literature. This article seeks to engage professionals who treat stuttering in a conversation about the possible usefulness of incorporating mindfulness training into stuttering management. A review of the literature reveals that there is a substantial overlap between what is required for effective stuttering management and the benefits provided by mindfulness practices. Mindfulness practice results in decreased avoidance, increased emotional regulation, and acceptance in addition to improved sensory-perceptual processing and attentional regulation skills. These skills are important for successful long term stuttering management on both psychosocial and sensory-motor levels. It is concluded that the integration of mindfulness training and stuttering treatment appears practical and worthy of exploration. Mindfulness strategies adapted for people who stutter may help in the management of cognitive, affective, and behavioral challenges associated with stuttering.
Ion Flow In Cochlear Hair Cells And The Regulation Of Hearing Sensitivity
This paper discusses how ion transport proteins in the hair cells of the mammalian cochlea work to produce a sensitive but stable hearing organ. The transport proteins in the inner and outer hair cells are summarized (including their current voltage characteristics), and the roles of these proteins in determining intracellular Ca2+, membrane potential, and ultimately cochlear sensitivity are discussed. The paper also discusses the role of the Ca2+ sequestration sacs in outer hair cells in the autoregulation of hair cell membrane potential and cochlear gain, and how the underdamped control of Ca2+ within these sacs may produce the observed slow oscillations in cochlear sensitivity and otoacoustic emissions after cochlear perturbations, including perilymphatic perfusions and prolonged low-frequency tones. The relative insensitivity of cochlear gain to short-term changes in the endocochlear potential is also discussed.
from Hearing Research
Neural Processing of Emotional Pictures and Words: A Comparison of Young and Older Adults
Recent findings have revealed age-related changes in neural recruitment during the processing of emotional information. The present study examined whether these age-related changes would be more pronounced for words, thought to be processed in a controlled manner versus relatively automatically processed pictures. Compared to young adults, older adults showed less amygdala activation, and more medial prefrontal cortex (PFC) activation, for negative than positive pictures. The opposite pattern was observed for words. Older adults showed a positivity effect in memory for words, but not for pictures, suggesting that their positivity effect may stem from age-related changes in medial PFC engagement during encoding.
Brief Report: Life History and Neuropathology of a Gifted Man with Asperger Syndrome
Despite recent interest in the pathogenesis of the autism spectrum disorders (pervasive developmental disorders), neuropathological descriptions of brains of individuals with well documented clinical information and without potentially confounding symptomatology are exceptionally rare. Asperger syndrome differs from classic autism by lack of cognitive impairment or delay in expressive language acquisition. We examined the 1,570 g brain of a 63 year old otherwise healthy mathematician with an Autistic Spectrum Disorder of Asperger subtype. Except for an atypical gyral pattern and megalencephaly, we detected no specific neuropathologic abnormality. Taken together, the behavioral data and pathological findings in this case are compatible with an early neurodevelopmental process affecting multiple neuroanatomic networks, but without a convincing morphologic signature detectable with routine neuropathologic technology.
Children with hearing impairment – Living with cochlear implants or hearing aids
Conclusions
Children with cochlear implants and children with hearing aids have, in some aspects, equally good functioning in everyday life situations. However, certain differences were found in dimensions of functioning, regarding neck and shoulder pain, usage of aids and sign language, and hearing problems in some activities.
from the International Journal of Pediatric Otorhinolaryngology
Functional brain activation differences in stuttering identified with a rapid fMRI sequence
The purpose of this study was to investigate whether brain activity related to the presence of stuttering can be identified with rapid functional MRI (fMRI) sequences that involved overt and covert speech processing tasks. The long-term goal is to develop sensitive fMRI approaches with developmentally appropriate tasks to identify deviant speech motor and auditory brain activity in children who stutter closer to the age at which recovery from stuttering is documented. Rapid sequences may be preferred for individuals or populations who do not tolerate long scanning sessions. In this report, we document the application of a picture naming and phoneme monitoring task in three minute fMRI sequences with adults who stutter (AWS). If relevant brain differences are found in AWS with these approaches that conform to previous reports, then these approaches can be extended to younger populations. Pairwise contrasts of brain BOLD activity between AWS and normally fluent adults indicated the AWS showed higher BOLD activity in the right inferior frontal gyrus (IFG), right temporal lobe and sensorimotor cortices during picture naming and and higher activity in the right IFG during phoneme monitoring. The right lateralized pattern of BOLD activity together with higher activity in sensorimotor cortices is consistent with previous reports, which indicates rapid fMRI sequences can be considered for investigating stuttering in younger participants.
Stuttering, Cluttering, and Phonological Complexity: Case studies
The phonological complexity of dysfluencies in those who clutter and/or stutter may help us better understand phonetic factors in these two types of fluency disorders. In this preliminary investigation, cases were three 14 year old males, diagnosed as a Stutterer, a Clutterer, and a Stutterer-Clutterer. Spontaneous speech samples were transcribed, coded for dysfluent words which were then matched to fluent words on grammatical class (i.e., function v. content), number of syllables and word familiarity. An Index of Phonological Complexity was determined per word, and word frequency, density and phonological neighborhood frequency were derived from an online database. Results showed that compared to fluent words, dysfluent words were more phonologically complex and ’sparser’, implying that they have fewer phonological neighbors or words in which a single phoneme is added, deleted or substituted. Interpretations and future directions for research regarding phonological complexity in stuttering and cluttering are offered.
Disruption of spelling-to-sound correspondence mapping during single-word reading in patients with temporal lobe epilepsy
Processing and/or hemispheric differences in the neural bases of word recognition were examined in patients with long-standing, medically-intractable epilepsy localized to the left (N = 18) or right (N = 7) temporal lobe. Participants were asked to read words that varied in the frequency of their spelling-to-sound correspondences. For the right temporal lobe group, reaction times (RTs) showed the same pattern across spelling-to-sound correspondence conditions as previously reported for normal participants. For the left temporal lobe group, however, the pattern of RTs suggested a greater relative influence of orthographic frequency than rime frequency, such that performance was worse on words whose orthographic body was less frequent in the language. We discuss these results in terms of differences in processing between the two cerebral hemispheres: the results for the right-temporal lobe patients are taken to support connectionist models of reading as described for the dominant (left) hemisphere, while results for the left-temporal lobe patients support a view of the right hemisphere as relatively less sensitive to phonology and relatively more sensitive to orthography.
from Brain and Language
An improved cochlear implant electrode array for use in experimental studies
Experimental studies play an important role in establishing the safety and efficacy of cochlear implants and they continue to provide insight into a new generation of electrode arrays and stimulation strategies. One drawback has been the limited depth of insertion of an electrode array in experimental animals. We compared the insertion depth and trauma associated with the insertion of Cochlear Ltd’s Hybrid-L (HL) array with a standard 8 ring array in cat cochleae. Both arrays were inserted into cadaver cochleae and an X-ray recorded their anatomical location. The implanted cochlea was serially sectioned and photographed at 300μm intervals for evidence of electrode insertion trauma. Subsequently two cats were chronically implanted with HL arrays and electrically-evoked potentials recorded over a three month period. Mean insertion depth for the HL arrays was 334.8° (SD = 21°; n = 4) versus 175.5° (SD = 6°; n = 2) for the standard array. This relates to ˜10.5 mm and 6 mm respectively. A similar insertion depth was measured in a chronically implanted animal with a HL array. Histology from each cadaver cochleae showed that the electrode array was always located in the scala tympani; there was no evidence of electrode insertion trauma to the basilar membrane, the osseous spiral lamina or the spiral ligament. Finally, evoked potential data from the chronically implanted animals exhibited significantly lower thresholds compared with animals implanted with a standard 8 ring array, with electrical thresholds remaining stable over a three month observation period. Cochlear Ltd’s HL electrode array can be safely inserted ˜50% of the length of the cat scala tympani, placing the tip of the array close to the 4 kHz place. This insertion depth is considerably greater than is routinely achieved using a standard 8-ring electrode array (˜12 kHz place). The HL array evokes low thresholds that remain stable over three months of implantation. This electrode array has potential application in a broad area of cochlear implant related research.
from Hearing Research
Inhibitory Neurotransmission in Animal Models of Tinnitus: Maladaptive Plasticity
Tinnitus is a phantom auditory sensation experienced by up to 14% of the United States population with a smaller percentage experiencing decreased quality of life. A compelling hypothesis is that tinnitus results from a maladaptive plastic net down-regulation of inhibitory amino acid neurotransmission in the central auditory pathway. This loss of inhibition may be a compensatory response to loss of afferent input such as that caused by acoustic insult and/or age-related hearing loss, the most common causes of tinnitus in people. Compensatory plastic changes may result in pathologic neural activity that underpin tinnitus. The neural correlates include increased spontaneous spiking, increased bursting and decreased variance of inter-spike intervals. This review will examine evidence for chronic plastic neuropathic changes in the central auditory system of animals with psychophysically-defined tinnitus. Neurochemical studies will focus on plastic tinnitus-related changes of inhibitory glycinergic neurotransmission in the adult dorsal cochlear nucleus (DCN). Electrophysiological studies will focus on functional changes in the DCN and inferior colliculus (IC). Tinnitus was associated with increased spontaneous activity and altered response properties of fusiform cells, the major output neurons of DCN. Coincident with these physiologic alterations were changes in glycine receptor (GlyR) subunit composition, its anchoring/trafficking protein, gephyrin and the number and affinity of membrane GlyRs revealed by receptor binding. In the IC, the primary afferent target of DCN fusiform cells, multi-dimensional alterations in unit-spontaneous activity (rate, burst rate, bursting pattern) were found in animals with behavioral evidence of chronic tinnitus more than 9 months following the acoustic/cochlear insult. In contrast, immediately following an intense sound exposure, acute alterations in IC spontaneous activity resembled chronic tinnitus-related changes but were not identical. This suggests that long-term neuroplastic changes responsible for chronic tinnitus are likely to be responsible for its persistance. A clear understanding of tinnitus-related plasticity in the central auditory system and its associated neurochemistry may help define unique targets for therapeutic drug development.
from Hearing Research
The spiral ganglion: connecting the peripheral and central auditory systems
In mammals, the initial bridge between the physical world of sound and perception of that sound is established by neurons of the spiral ganglion. The cell bodies of these neurons give rise to peripheral processes that contact acoustic receptors in the organ of Corti, and the central processes collect together to form the auditory nerve that projects into the brain. In order to better understand hearing at this initial stage, we need to know the following about spiral ganglion neurons: (1) their cell biology including cytoplasmic, cytoskeletal, and membrane properties, (2) their peripheral and central connections including synaptic structure; (3) the nature of their neural signaling; and (4) their capacity for plasticity and rehabilitation. In this report, we will update the progress on these topics and indicate important issues still awaiting resolution
from Hearing Research
