ABSTRACT
OBJECTIVE: Sensory intelligence in the brain helps listeners automatically extract abstract auditory rules formed by invariant acoustic features from complex speech sound streams, presumably serving as the neural basis for speech comprehension. However, whether this intelligence is deficient in children with cochlear implants (CIs) remains unclear. METHODS: Mandarin Chinese monosyllables shared a flat lexical tone contour to form an abstract auditory rule but differed in other acoustic features to construct a complex speech sound stream. The abstract rule was occasionally violated by monosyllables with a rising or falling lexical tone. RESULTS: In normal hearing (NH) children, the abstract auditory rule could be extracted, as revealed by a mismatch negativity (MMN) and a late discriminative negativity (LDN). However, the MMN and LDN were only evoked in CI children with good hearing and speech performance. NH children with a higher speech perception or spatial hearing score had a greater MMN. The LDN was attenuated with increasing age in NH children. CONCLUSIONS: The sensory intelligence for extraction of auditory abstract rules, associated with speech perception, is deficient in CI children. This intelligence may gradually develop during childhood and adolescence. SIGNIFICANCE: Deficient sensory intelligence in CI children may aid in understanding poor speech comprehension in complex environments.
ABSTRACT
Anxiety is a remarkably common condition among patients with pharyngitis, but the relationship between these disorders has received little research attention, and the underlying neural mechanisms remain unknown. Here, we show that the densely innervated pharynx transmits signals induced by pharyngeal inflammation to glossopharyngeal and vagal sensory neurons of the nodose/jugular/petrosal (NJP) superganglia in mice. Specifically, the NJP superganglia project to norepinephrinergic neurons in the nucleus of the solitary tract (NTSNE). These NTSNE neurons project to the ventral bed nucleus of the stria terminalis (vBNST) that induces anxiety-like behaviors in a murine model of pharyngeal inflammation. Inhibiting this pharynxâNJPâNTSNEâvBNST circuit can alleviate anxiety-like behaviors associated with pharyngeal inflammation. This study thus defines a pharynx-to-brain axis that mechanistically links pharyngeal inflammation and emotional response.
Subject(s)
Pharyngitis , Pharynx , Humans , Animals , Mice , Anxiety , Brain , Sensory Receptor Cells , InflammationABSTRACT
Predictions, the bridge between the internal and external worlds, are established by prior experience and updated by sensory stimuli. Responses to omitted but unexpected stimuli, known as omission responses, can break the one-to-one mapping of stimulus-response and can expose predictions established by the preceding stimulus built up. While research into exogenous predictions (driven by external stimuli) is often reported, that into endogenous predictions (driven by internal percepts) is rarely available in the literature. Here, we report evidence for endogenous predictions established by the Zwicker tone illusion, a phantom pure-tone-like auditory percept following notch noises. We found that MMN, P300, and theta oscillations could be recorded using an omission paradigm in subjects who can perceive Zwicker tone illusions, but could not in those who cannot. The MMN and P300 responses relied on attention, but theta oscillations did not. In-depth analysis shows that an increase in single-trial theta power, including total and induced theta, with the endogenous prediction, is lateralized to the left frontal brain areas. Our study depicts that the brain automatically analyzes internal perception, progressively establishes predictions and yields prediction errors in the left frontal region when a violation occurs.
Subject(s)
Illusions , Humans , Illusions/physiology , Sound , Attention/physiology , Cerebral Cortex/physiology , Frontal Lobe/physiology , Acoustic Stimulation , Auditory Perception/physiology , Electroencephalography , Evoked Potentials, Auditory/physiologyABSTRACT
Background: While a cochlear implant (CI) can restore access to audibility in deaf children, implanted children may still have difficulty in concentrating. Previous studies have revealed a close relationship between sensory gating and attention. However, whether CI children have deficient auditory sensory gating remains unclear. Methods: To address this issue, we measured the event-related potentials (ERPs), including P50, N100, and P200, evoked by paired tone bursts (S1 and S2) in CI children and normal-hearing (NH) controls. Suppressed amplitudes for S2 compared with S1 in these three ERPs reflected sensory gating during early and later phases, respectively. A Swanson, Nolan, and Pelham IV (SNAP-IV) scale was performed to assess the attentional performance. Results: Significant amplitude differences between S1 and S2 in N100 and P200 were observed in both NH and CI children, indicating the presence of sensory gating in the two groups. However, the P50 suppression was only found in NH children and not in CI children. Furthermore, the duration of deafness was significantly positively correlated with the score of inattention in CI children. Conclusion: Auditory sensory gating can develop but is deficient during the early phase in CI children. Long-term auditory deprivation has a negative effect on sensory gating and attentional performance.
ABSTRACT
Compared with children having normal hearing (NH), those with cochlear implants (CIs) perform poorly in spoken language comprehension which involves both low-level acoustic encoding and higher-level cognitive processing. Here, we performed an electroencephalography study to portray this brain dynamics of speech perception in CI children. We presented a Mandarin Chinese monosyllable or four-syllable idiom to CI and NH children, and infrequently varied its lexical tone to form a novel monosyllable or pseudo-idiom in an oddball paradigm. The tone contrast embedded in the monosyllables evoked similar mismatch negativities (MMNs) in CI and NH children at an early stage (~200 ms). However, the amplitude of the MMN evoked by the tone contrast in the idiom context was significantly lower in CI children than in NH children. Furthermore, robust late discriminative negativity (LDN) at a late stage (~500 ms) was found only in NH children, but not in CI children. The MMN and LDN findings indicate deficits of low-level acoustic encoding in a complex context (such as an idiom) and higher-level cognitive processing in CI children, respectively. Both deficient sensory and cognitive processing may contribute to the speech perception difficulties in CI children.