Monthly Archives: September 2009

Age dependence of otoacoustic emissions: the loss of amplitude is primarily caused by age-related hearing loss and not by aging alone

The amplitude of otoacoustic emissions (OAE) is known to decrease with increasing age, but it is still unclear whether this is due to aging alone or to age-related hearing loss. This study describes the exploration of a large database (5,142 patients from 0.4 to 89.8 years) collected in a routine clinical testing. Reliable pure tone audiograms, transitory evoked otoacoustic emissions (TEOAE) and distortion product otoacoustic emissions (DPOAE) recordings were available from 5,424 ears without conductive loss, acute sudden deafness or retrocochlear disorder. From this database, group 1 with behavioral thresholds of 10 dB HL or better at all frequencies from 1 to 4 kHz and group 2 with age-accordant thresholds after ISO 7029 were formed. In both groups, the OAE amplitude decreased with increasing age, but in group 1, the effect was significant only for DPOAE recorded at 3 and 4 kHz. In group 2, the loss of amplitude was steeper and highly significant for TEOAE as well as DPOAE at all frequencies, but most pronounced at high frequencies. These findings support the hypothesis that the reduction of OAE amplitude with increasing age is primarily caused by age-linked hearing loss and not by aging alone.

from ORL -Journal for Oto-Rhino-Laryngology and Its Related Specialties

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Differences in task demands influence the hemispheric lateralization and neural correlates of metaphor

This study investigated metaphor comprehension in the broader context of task-difference effects and manipulation of processing difficulty. We predicted that right hemisphere recruitment would show greater specificity to processing difficulty rather than metaphor comprehension. Previous metaphor processing studies have established that the left inferior frontal gyrus strongly correlates with metaphor comprehension but there has been controversy about whether right hemisphere (RH) involvement is specific for metaphor comprehension. Functional MRI data were recorded from healthy subjects who read novel metaphors, conventional metaphors, definition-like sentences, or literal sentences. We investigated metaphor processing in contexts where semantic judgment or imagery modulates linguistic judgment. Our findings support the position that the type of task rather than figurative language processing per se modulates the left inferior gyrus (LIFG). RH involvement was more influenced by processing difficulty and less by the novelty or figurativity of linguistic expressions. Our results suggest that figurative language processing depends upon the effects of task-type and processing difficulty on imaging results.

from Brain and Language

Neural development of networks for audiovisual speech comprehension

Everyday conversation is both an auditory and a visual phenomenon. While visual speech information enhances comprehension for the listener, evidence suggests that the ability to benefit from this information improves with development. A number of brain regions have been implicated in audiovisual speech comprehension, but the extent to which the neurobiological substrate in the child compares to the adult is unknown. In particular, developmental differences in the network for audiovisual speech comprehension could manifest through the incorporation of additional brain regions, or through different patterns of effective connectivity. In the present study we used functional magnetic resonance imaging and structural equation modeling (SEM) to characterize the developmental changes in network interactions for audiovisual speech comprehension. The brain response was recorded while children 8- to 11-years-old and adults passively listened to stories under audiovisual (AV) and auditory-only (A) conditions. Results showed that in children and adults, AV comprehension activated the same fronto-temporo-parietal network of regions known for their contribution to speech production and perception. However, the SEM network analysis revealed age-related differences in the functional interactions among these regions. In particular, the influence of the posterior inferior frontal gyrus/ventral premotor cortex on supramarginal gyrus differed across age groups during AV, but not A speech. This functional pathway might be important for relating motor and sensory information used by the listener to identify speech sounds. Further, its development might reflect changes in the mechanisms that relate visual speech information to articulatory speech representations through experience producing and perceiving speech.

from Brain and Language

Wave-ering: An ERP study of syntactic and semantic context effects on ambiguity resolution for noun/verb homographs

Two event-related potential experiments investigated the effects of syntactic and semantic context information on the processing of noun/verb (NV) homographs (e.g., park). Experiment 1 embedded NV-homographs and matched unambiguous words in contexts that provided only syntactic cues or both syntactic and semantic constraints. Replicating prior work, when only syntactic information was available NV-homographs elicited sustained frontal negativity relative to unambiguous words. Semantic constraints eliminated this frontal ambiguity effect. Semantic constraints also reduced N400 amplitudes, but less so for homographs than unambiguous words. Experiment 2 showed that this reduced N400 facilitation was limited to cases in which the semantic context picks out a non-dominant meaning, likely reflecting the semantic mismatch between the context and residual, automatic activation of the contextually-inappropriate dominant sense. Overall, the findings suggest that ambiguity resolution in context involves the interplay between multiple neural networks, some involving more automatic semantic processing mechanisms and others involving top-down control mechanisms.

from the Journal of Memory and Language

Wave-ering: An ERP study of syntactic and semantic context effects on ambiguity resolution for noun/verb homographs

Two event-related potential experiments investigated the effects of syntactic and semantic context information on the processing of noun/verb (NV) homographs (e.g., park). Experiment 1 embedded NV-homographs and matched unambiguous words in contexts that provided only syntactic cues or both syntactic and semantic constraints. Replicating prior work, when only syntactic information was available NV-homographs elicited sustained frontal negativity relative to unambiguous words. Semantic constraints eliminated this frontal ambiguity effect. Semantic constraints also reduced N400 amplitudes, but less so for homographs than unambiguous words. Experiment 2 showed that this reduced N400 facilitation was limited to cases in which the semantic context picks out a non-dominant meaning, likely reflecting the semantic mismatch between the context and residual, automatic activation of the contextually-inappropriate dominant sense. Overall, the findings suggest that ambiguity resolution in context involves the interplay between multiple neural networks, some involving more automatic semantic processing mechanisms and others involving top-down control mechanisms.

from the Journal of Memory and Language

The menopause triggers hearing decline in healthy women

Epidemiological studies have shown that women have better high-frequency thresholds than men in virtually all age groups, and that age-related hearing decline starts after 30 in men but not until after the age of 50 in women. This coincides with the menopausal transition in most women, thus leading us to hypothesize that the menopause triggers auditory deterioration, possibly due to reduced levels of endogenous estrogens, which are known to have protective effects on the auditory system. Methods: 104 women with a mean age 51.2 at baseline, were tested with pure tone audiometry twice with an average interval of 7.5 years. The age at the final menstrual period (FMP) was reported by all women. Hearing decline at individual frequencies was calculated. Results: Women with a FMP 0-4 years ago, had a rate of high frequency hearing decline of 0.9-1.5 dB/year in the left ear, those with 5-7 years since the FMP had a corresponding rate of 1.1-1.5 dB/year in the right ear, and 8-13 years after the FMP the decline was more subtle, 0.7-1.1 dB/year in both ears. Conclusion: The menopause appears to act as a trigger of a relatively rapid age-related hearing decline in healthy women, starting in the left ear.

from Hearing Research

University Students’ Perceptions of the Life Effects of Stuttering

An open-ended, written survey was administered to 146 university students who did not stutter to obtain their impressions of the effects of stuttering on the lives of people who stutter (PWS). Participants first wrote about the general effects of stuttering and then considered how their lives would be different if they stuttered. Both types of responses, while not qualitatively different, indicated that participants were more likely to focus on negative listener reactions and barriers to social, academic, and occupational success when they imagined themselves as PWS. Fewer participants indicated that PWS may positively cope with their stuttering through acceptance of stuttering, motivation and determination, and support systems. Quantitative differences based on gender and familiarity with PWS were not observed. The findings suggest that while university students are generally sensitive to the issues which can affect PWS, they may also tend to exaggerate the limitations placed on PWS by their stuttering.

from the Journal of Communication Disorders

Acoustic and Electroglottographic Analyses of Nonpathological, Nonmodal Phonation

Languages where phonation type and tone are contrastive make use of extremely fine and controlled actions of laryngeal structures; hence, there is little opportunity to variation in either phonation or pitch. Nonetheless, many American Indian languages have contrastive nonmodal phonation, which, moreover, is subject to a great deal of variation. There are a few studies addressing the phonetics of nonmodal phonation in American Indian languages, and little is known about the phonetics/phonology interface of laryngeal features within the sound patterns of these languages. This article aims to contribute to the knowledge of nonmodal phonation through the detailed study of the phenomenon in Yalálag Zapotec (YZ) and American Indian language. A series of spectral and electrophysiological analyses contribute to the description of YZ nonmodal phonation and its variability across gender. It is argued that the temporal patterns in realization of laryngealization are a property of YZ speaker’s grammar.

from Journal of Fluency Disorders

Speech-induced blepharospasm

Abstract Primary blepharospasm is an adult-onset dystonia typically present at rest and exacerbated by bright light, stress and voluntary movements of eyes and eyelids. Inconsistency or inducibility by activities involving muscles other than orbicularis oculi muscles are considered incongruous with typical primary blepharospasm, heralding the suspicion of psychogenicity. We report the clinical vignette of two patients manifesting an unusual presentation of primary blepharospasm, specifically triggered by voiced speech and associated with an otherwise ‘typical’ presentation of primary adult-onset dystonia in the lower face, larynx or upper limb. Speech-induced primary blepharospasm seems a rare occurrence, representing 1.3% of our clinic-based series of 149 patients with primary adult-onset primary blepharospasm. In these atypical patients, the feature of speech inducibility suggests that the abnormal surrounding inhibition between cortical subregions representing laryngeal and orbicularis oculi muscles might underlie dystonic overflow to the orbicularis oculi muscles following the voiced speech.

from Neurological Sciences

Neural response telemetry in patients with the double-array cochlear implant

Abstract This study aimed to evaluate the neural response in double-array cochlear implant as well as to describe the refractory recovery and the spread of excitation functions. In a prospective study 11 patients were implanted with the double-array cochlear implant. Neural response telemetry (NRT) was performed intra-operatively. NRT threshold could be registered in 6 of the 11 patients, at least in one electrode. The remaining five patients did not show measurable neural response intra-operatively. It was noted that although recovery and spread of excitation functions could be recorded in all the tested electrodes with measurable neural responses, the responses were shown to be different from the usual register in patients with other etiologies.

from the European Archives of Oto-Rhino-Laryngologyl

Further Empirical Data on the Psychoeducational Profile-Revised (PEP-R): Reliability and Validation with the Vineland Adaptive Behavior Scales

Abstract The PEP-R (psychoeducational profile revised) is an instrument that has been used in many countries to assess abilities and formulate treatment programs for children with autism and related developmental disorders. To the end to provide further information on the PEP-R’s psychometric properties, a large sample (N = 137) of children presenting Autistic Disorder symptoms under the age of 12 years, including low-functioning individuals, was examined. Results yielded data of interest especially in terms of: Cronbach’s alpha, interrater reliability, and validation with the Vineland Adaptive Behavior Scales. These findings help complete the instrument’s statistical description and augment its usefulness, not only in designing treatment programs for these individuals, but also as an instrument for verifying the efficacy of intervention.

from the Journal of Autism and Developmental Di

Primary and multisensory cortical activity is correlated with audiovisual percepts

Incongruent auditory and visual stimuli can elicit audiovisual illusions such as the McGurk effect where visual /ka/ and auditory /pa/ fuse into another percept such as/ta/. In the present study, human brain activity was measured with adaptation functional magnetic resonance imaging to investigate which brain areas support such audiovisual illusions. Subjects viewed trains of four movies beginning with three congruent /pa/ stimuli to induce adaptation. The fourth stimulus could be (i) another congruent /pa/, (ii) a congruent /ka/, (iii) an incongruent stimulus that evokes the McGurk effect in susceptible individuals (lips /ka/ voice /pa/), or (iv) the converse combination that does not cause the McGurk effect (lips /pa/ voice/ ka/). This paradigm was predicted to show increased release from adaptation (i.e. stronger brain activation) when the fourth movie and the related percept was increasingly different from the three previous movies. A stimulus change in either the auditory or the visual stimulus from /pa/ to /ka/ (iii, iv) produced within-modality and cross-modal responses in primary auditory and visual areas. A greater release from adaptation was observed for incongruent non-McGurk (iv) compared to incongruent McGurk (iii) trials. A network including the primary auditory and visual cortices, nonprimary auditory cortex, and several multisensory areas (superior temporal sulcus, intraparietal sulcus, insula, and pre-central cortex) showed a correlation between perceiving the McGurk effect and the fMRI signal, suggesting that these areas support the audiovisual illusion. Hum Brain Mapp, 2009. © 2009 Wiley-Liss, Inc.

from Human Brain Mapping

Sensory-motor brain network connectivity for speech comprehension

Abstract
The act of listening to speech activates a large network of brain areas. In the present work, a novel data-driven technique (the combination of independent component analysis and Granger causality) was used to extract brain network dynamics from an fMRI study of passive listening to Words, Pseudo-Words, and Reverse-played words. Using this method we show the functional connectivity modulations among classical language regions (Broca’s and Wernicke’s areas) and inferior parietal, somatosensory, and motor areas and right cerebellum. Word listening elicited a compact pattern of connectivity within a parieto-somato-motor network and between the superior temporal and inferior frontal gyri. Pseudo-Word stimuli induced activities similar to the Word condition, which were characterized by a highly recurrent connectivity pattern, mostly driven by the temporal lobe activity. Also the Reversed-Word condition revealed an important influence of temporal cortices, but no integrated activity of the parieto-somato-motor network. In parallel, the right cerebellum lost its functional connection with motor areas, present in both Word and Pseudo-Word listening. The inability of the participant to produce the Reversed-Word stimuli also evidenced two separate networks: the first was driven by frontal areas and the right cerebellum toward somatosensory cortices; the second was triggered by temporal and parietal sites towards motor areas. Summing up, our results suggest that semantic content modulates the general compactness of network dynamics as well as the balance between frontal and temporal language areas in driving those dynamics. The degree of reproducibility of auditory speech material modulates the connectivity pattern within and toward somatosensory and motor areas. Hum Brain Mapp, 2009. © 2009 Wiley-Liss, Inc.

from Human Brain Mapping

Respiratory-swallow phase patterns and their relationship to swallowing impairment in patients treated for oropharyngeal cancer

Conclusions.
We suggest nonexpiratory bracketed respiratory-swallowing phase patterns in patients with oropharyngeal cancer may place patients at greater risk of airway penetration or aspiration during swallowing. © 2009 Wiley Periodicals, Inc. Head Neck, 2009

from Head and Neck

Magnetic resonance imaging of facial nerve schwannoma

Conclusions:
This study highlights the morphologic heterogeneity and typical multisegment involvement of FNS. Enhanced MR is the imaging modality of choice for FNS. The neuroradiologist must accurately diagnose and characterize this lesion, and thus facilitate optimal preoperative planning and counseling. Laryngoscope, 2009

from The Laryngoscope