122 research outputs found
Stuttered swallowing: Electric stimulation of the right insula interferes with water swallowing. A case report
<p>Abstract</p> <p>Background</p> <p>Various functional resonance imaging, magnetoencephalographic and lesion studies suggest the involvement of the insular cortex in the control of swallowing. However, the exact location of insular activation during swallowing and its functional significance remain unclear.</p> <p>Case presentation</p> <p>Invasive electroencephalographic monitoring was performed in a 24-year-old man with medically intractable stereotyped nocturnal hypermotor seizures due to a ganglioglioma. During stimulation of the right inferior posterior insular cortex with depth electrodes the patient spontaneously reported a perception of a "stutter in swallowing". Stimulation of the inferior posterior insular cortex at highest intensity (4 mA) was also associated with irregular and delayed swallows. Swallowing was not impaired during stimulation of the superior posterior insular cortex, regardless of stimulation intensity.</p> <p>Conclusions</p> <p>These results indicate that the right inferior posterior insular cortex is involved in the neural circuitry underlying the control of swallowing.</p
Language experience impacts brain activation for spoken and signed language in infancy: Insights from unimodal and bimodal bilinguals
Recent neuroimaging studies suggest that monolingual infants activate a left lateralised fronto-temporal brain network in response to spoken language, which is similar to the network involved in processing spoken and signed language in adulthood. However, it is unclear how brain activation to language is influenced by early experience in infancy. To address this question, we present functional near infrared spectroscopy (fNIRS) data from 60 hearing infants (4-to-8 months): 19 monolingual infants exposed to English, 20 unimodal bilingual infants exposed to two spoken languages, and 21 bimodal bilingual infants exposed to English and British Sign Language (BSL). Across all infants, spoken language elicited activation in a bilateral brain network including the inferior frontal and posterior temporal areas, while sign language elicited activation in the right temporo-parietal area. A significant difference in brain lateralisation was observed between groups. Activation in the posterior temporal region was not lateralised in monolinguals and bimodal bilinguals, but right lateralised in response to both language modalities in unimodal bilinguals. This suggests that experience of two spoken languages influences brain activation for sign language when experienced for the first time. Multivariate pattern analyses (MVPA) could classify distributed patterns of activation within the left hemisphere for spoken and signed language in monolinguals (proportion correct = 0.68; p = 0.039) but not in unimodal or bimodal bilinguals. These results suggest that bilingual experience in infancy influences brain activation for language, and that unimodal bilingual experience has greater impact on early brain lateralisation than bimodal bilingual experience
Functional MRI of working memory and selective attention in vibrotactile frequency discrimination
Acquired and congenital disorders of sung performance: A review.
Many believe that the majority of people are unable to carry a tune. Yet, this
widespread idea underestimates the singing abilities of the layman. Most
occasional singers can sing in tune and in time, provided that they perform at a
slow tempo. Here we characterize proficient singing in the general population
and identify its neuronal underpinnings by reviewing behavioral and neuroimaging
studies. In addition, poor singing resulting from a brain injury or neurogenetic
disorder (i.e., tone deafness or congenital amusia) is examined. Different lines
of evidence converge in indicating that poor singing is not a monolithic
deficit. A variety of poor-singing "phenotypes" are described,
with or without concurrent perceptual deficits. In addition, particular
attention is paid to the dissociations between specific abilities in poor
singers (e.g., production of absolute vs. relative pitch, pitch vs. time
accuracy). Such diversity of impairments in poor singers can be traced to
different faulty mechanisms within the vocal sensorimotor loop, such as pitch
perception and sensorimotor integration
Impairment of Auditory-Motor Timing and Compensatory Reorganization after Ventral Premotor Cortex Stimulation
Integrating auditory and motor information often requires precise timing as in speech and music. In humans, the position of the ventral premotor cortex (PMv) in the dorsal auditory stream renders this area a node for auditory-motor integration. Yet, it remains unknown whether the PMv is critical for auditory-motor timing and which activity increases help to preserve task performance following its disruption. 16 healthy volunteers participated in two sessions with fMRI measured at baseline and following rTMS (rTMS) of either the left PMv or a control region. Subjects synchronized left or right finger tapping to sub-second beat rates of auditory rhythms in the experimental task, and produced self-paced tapping during spectrally matched auditory stimuli in the control task. Left PMv rTMS impaired auditory-motor synchronization accuracy in the first sub-block following stimulation (p<0.01, Bonferroni corrected), but spared motor timing and attention to task. Task-related activity increased in the homologue right PMv, but did not predict the behavioral effect of rTMS. In contrast, anterior midline cerebellum revealed most pronounced activity increase in less impaired subjects. The present findings suggest a critical role of the left PMv in feed-forward computations enabling accurate auditory-motor timing, which can be compensated by activity modulations in the cerebellum, but not in the homologue region contralateral to stimulation
Ultra-fast speech comprehension in blind subjects engages primary visual cortex, fusiform gyrus, and pulvinar – a functional magnetic resonance imaging (fMRI) study
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Basic research needed for the development of geothermal energy
Basic research needed to facilitate development of geothermal energy is identified. An attempt has been made to make the report representative of the ideas of productive workers in the field. The present state of knowledge of geothermal energy is presented and then specific recommendations for further research, with status and priorities, are listed. Discussion is limited to a small number of applicable concepts, namely: origin of geothermal flux; transport of geothermal energy; geothermal reservoirs; rock-water interactions, and geophysical and geochemical exploration
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