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Short, high frequency stimulation bursts (4 pulses at 100 Hz) were applied to Schaffer/commissural projections to the CA1 field of rat hippocampal slices at 0.1, 0.2, 1.0 or 2.0-s intervals to assess their efficacy in eliciting long-term potentiation (LTP). Bursts repeated at 2-s intervals induced very little LTP; shorter repetition intervals reliably(More)
In studies of pitch processing, a fundamental question is whether shared neural mechanisms at higher cortical levels are engaged for pitch perception of linguistic and nonlinguistic auditory stimuli. Positron emission tomography (PET) was used in a crosslinguistic study to compare pitch processing in native speakers of two tone languages (that is, languages(More)
Speech prosody is processed in neither a single region nor a specific hemisphere, but engages multiple areas comprising a large-scale spatially distributed network in both hemispheres. It remains to be elucidated whether hemispheric lateralization is based on higher-level prosodic representations or lower-level encoding of acoustic cues, or both. A(More)
Differences in hemispheric functions underlying speech perception may be related to the size of temporal integration windows over which prosodic features (e.g., pitch) span in the speech signal. Chinese tone and intonation, both signaled by variations in pitch contours, span over shorter (local) and longer (global) temporal domains, respectively. This(More)
Functional neuroimaging with positron emission tomography (PET) was used to compare the brain activation patterns of normal-hearing (NH) with postlingually deaf, cochlear-implant (CI) subjects listening to speech and nonspeech signals. The speech stimuli were derived from test batteries for assessing speech-perception performance of hearing-impaired(More)
Conflicting data from neurobehavioral studies of the perception of intonation (linguistic) and emotion (affective) in spoken language highlight the need to further examine how functional attributes of prosodic stimuli are related to hemispheric differences in processing capacity. Because of similarities in their acoustic profiles, intonation and emotion(More)
The mechanisms by which polymorphonuclear leukocytes (PMN) cross the human blood-brain barrier have not been fully elucidated. Using a well characterized in vitro model of the human BBB, we examined the role of endothelial cell adhesion molecules on the adhesion and transendothelial migration of PMN across primary cultures of human brain microvessel(More)
This study investigates the neural substrates underlying the perception of two sentence-level prosodic phenomena in Mandarin Chinese: contrastive stress (initial vs. final emphasis position) and intonation (declarative vs. interrogative modality). In an fMRI experiment, Chinese and English listeners were asked to selectively attend to either stress or(More)
It remains a matter of controversy precisely what kind of neural mechanisms underlie functional asymmetries in speech processing. Whereas some studies support speech-specific circuits, others suggest that lateralization is dictated by relative computational demands of complex auditory signals in the spectral or time domains. To examine how the brain(More)