To extract the temporal structure of sensory inputs is of great significance to our adaptive functioning in the dynamic environment. Here we characterize three types of temporal structure information, and review behavioral and neural evidence bearing on the encoding and utilization of such information in visual and auditory perception. The evidence together supports a functional view that the brain not only tracks but also makes use of temporal structure from diverse sources for a broad range of cognitive processes, such as perception, attention, and unconscious information processing. These functions are implemented by brain mechanisms including neural entrainment, predictive coding, as well as more specific mechanisms that vary with the type of temporal regularity and sensory modality. This framework enriches our understanding of how the human brain promotes dynamic information processing by exploiting regularities in ubiquitous temporal structures.
Attention ; Auditory Perception ; Brain ; physiology ; Humans ; Time Perception ; Visual Perception

In order to explore the possible mechanisms by which ethologically relevant sounds can be extracted from complex auditory environments, this study examined the effects of weak noise on the rate-intensity functions (RIFs) of neurons responding to tone burst in the inferior colliculus (IC) of nine mice (Mus musculus Km). Under free field stimuli conditions, a total of 112 IC neurons were recorded. RIFs with and without simultaneous presentation of weak noise, of which the intensity was relative to 5 dB below minimum threshold of tone burst, were measured in 44 IC neurons. By means of evaluating the changes of dynamic range (DR), slope of RIFs, and percent inhibition at different tone burst intensities evoked by the weak noise, three types of variations in RIFs were observed, i. e., inhibition (39/44, 88.6%), facilitation (2/44, 4.6%), and no effectiveness (3/44, 6.8%). Statistical analysis indicated that only inhibitory effect of weak noise was significant (P< 0.001, n = 39). The inhibitory effect of weak noise was greater at lower stimulus intensity of tone burst but decreased significantly with increased stimulus intensity (P< 0.0001, n = 39). In addition, the DR and slope of RIFs became narrower and steeper with weak noise presentation, respectively (P< 0.01, n = 31). The results from the present study suggest that weak noise exerts a dynamic modulatory action on acoustical intensity sensitivity of IC neurons, which possibly leads to a better understanding of neural mechanisms underlying the extraction of sound signals from natural auditory scenes.
Acoustic Stimulation ; Animals ; Auditory Perception ; physiology ; Auditory Threshold ; physiology ; Inferior Colliculi ; physiology ; Mice ; Neurons ; physiology ; Noise

Integrating multisensory inputs to generate accurate perception and guide behavior is among the most critical functions of the brain. Subcortical regions such as the amygdala are involved in sensory processing including vision and audition, yet their roles in multisensory integration remain unclear. In this study, we systematically investigated the function of neurons in the amygdala and adjacent regions in integrating audiovisual sensory inputs using a semi-chronic multi-electrode array and multiple combinations of audiovisual stimuli. From a sample of 332 neurons, we showed the diverse response patterns to audiovisual stimuli and the neural characteristics of bimodal over unimodal modulation, which could be classified into four types with differentiated regional origins. Using the hierarchical clustering method, neurons were further clustered into five groups and associated with different integrating functions and sub-regions. Finally, regions distinguishing congruent and incongruent bimodal sensory inputs were identified. Overall, visual processing dominates audiovisual integration in the amygdala and adjacent regions. Our findings shed new light on the neural mechanisms of multisensory integration in the primate brain.
Animals ; Macaca ; Acoustic Stimulation ; Auditory Perception/physiology* ; Visual Perception/physiology* ; Amygdala/physiology* ; Photic Stimulation

The anterior auditory field (AAF) is a core region of the auditory cortex and plays a vital role in discrimination tasks. However, the role of the AAF corticostriatal neurons in frequency discrimination remains unclear. Here, we used c-Fos staining, fiber photometry recording, and pharmacogenetic manipulation to investigate the function of the AAF corticostriatal neurons in a frequency discrimination task. c-Fos staining and fiber photometry recording revealed that the activity of AAF pyramidal neurons was significantly elevated during the frequency discrimination task. Pharmacogenetic inhibition of AAF pyramidal neurons significantly impaired frequency discrimination. In addition, histological results revealed that AAF pyramidal neurons send strong projections to the striatum. Moreover, pharmacogenetic suppression of the striatal projections from pyramidal neurons in the AAF significantly disrupted the frequency discrimination. Collectively, our findings show that AAF pyramidal neurons, particularly the AAF-striatum projections, play a crucial role in frequency discrimination behavior.
Acoustic Stimulation/methods* ; Neurons/physiology* ; Auditory Cortex/physiology* ; Auditory Perception ; Pyramidal Cells

Sound duration plays important role in acoustic communication. Information of acoustic signal is mainly encoded in the amplitude and frequency spectrum of different durations. Duration selective neurons exist in the central auditory system including inferior colliculus (IC) of frog, bat, mouse and chinchilla, etc., and they are important in signal recognition and feature detection. Two generally accepted models, which are "coincidence detector model" and "anti-coincidence detector model", have been raised to explain the mechanism of neural selective responses to sound durations based on the study of IC neurons in bats. Although they are different in details, they both emphasize the importance of synaptic integration of excitatory and inhibitory inputs, and are able to explain the responses of most duration-selective neurons. However, both of the hypotheses need to be improved since other sound parameters, such as spectral pattern, amplitude and repetition rate, could affect the duration selectivity of the neurons. The dynamic changes of sound parameters are believed to enable the animal to effectively perform recognition of behavior related acoustic signals. Under free field sound stimulation, we analyzed the neural responses in the IC and auditory cortex of mouse and bat to sounds with different duration, frequency and amplitude, using intracellular or extracellular recording techniques. Based on our work and previous studies, this article reviews the properties of duration selectivity in central auditory system and discusses the mechanisms of duration selectivity and the effect of other sound parameters on the duration coding of auditory neurons.
Acoustic Stimulation ; Animals ; Auditory Perception ; physiology ; Echolocation ; physiology ; Evoked Potentials, Auditory ; physiology ; Humans ; Inferior Colliculi ; physiology ; Mesencephalon ; physiology ; Sound Localization ; physiology ; Time Perception ; physiology

Cross-modal stochastic resonance is a ubiquitous phenomenon, that is, a weak signal from one sensory pathway can be enhanced by the noise from a different sensory pathway. It is a special multisensory integration (MI) that can not be explained by the inverse-effectiveness rule. According to cross-modal stochastic resonance, the detection of signal is an inverted U-like function of the intensity of noise at different levels. In this paper, we reviewed the research of cross-modal stochastic resonance and put forward some possible explanations for it. These efforts raise a new idea for neural encoding and information processing of the brain.
Acoustic Stimulation ; Auditory Perception ; physiology ; Brain ; physiology ; Humans ; Mental Processes ; physiology ; Sensory Thresholds ; physiology ; Stochastic Processes ; Visual Perception ; physiology

OBJECTIVE: To analyze the short monosyllabic list of Mandarin speech test materials (MSTMs) which have been evaluated the equivalence of difficulty, and to establish the performance-intensity function (P-I function) for people with normal hearing as clinical reference of hearing recovery and individuals ability to perceive and process speech. METHOD: Thirty-seven subjects (the age ranged from 18 to 26 years old) who speak Mandarin well in their daily lives with normal hearing participated in this study. Eight lists of the Short Mandarin Monosyllabic materials (20 words per list) with equal difficulty were utilized. The results were analyzed by Statistical Package for the Social Sciences (SPSS) software version 17.0. RESULT: P-I function for short monosyllabic word list was x = 98.557/(1 + 12.243 exp (-0.17(P-15, x(max) = 98.557. And the sound pressure level of speech corresponding to a 50% recognition score was 29.6 dB SPL or 9.6 dB HL. The results showed P-I function of 3.1 per dB for Mandarin materials. CONCLUSION The study established the P-I function of the Mandarin short monosyllabic word list materials with equal difficulty, which provides the normative data for identifying the normal hearing in a clinical setting.
Adult ; Auditory Perception ; Female ; Hearing Tests ; methods ; Humans ; Male ; Speech ; Speech Perception ; physiology

This is a review of the progress in the study on auditory event-related potentials (ERP) of novel events. Several cognitive problems about the novelty ERP response on brain and the experiment methods are introduced. The mismatch negative potential (MMN) reflects the detection of deviant events, and MMN is related with the novelty P3. Familiarity and attention influence the novelty ERP response. Experiments results showed that the amplitude of ERPs in the frontal area was reduced with the enhancement of familiarity, while that in the parietal area had little change. Attention was helpful in increasing the amplitude of ERPs, and could make the corresponding brain area active. The functional significance of the response of ERP was discussed also.
Auditory Perception ; physiology ; Brain ; physiology ; Electroencephalography ; Environment ; Event-Related Potentials, P300 ; physiology ; Evoked Potentials, Auditory ; physiology ; Humans

Similar to the visual dual-pathway model, neurophysiological studies in non-human primates have suggested that the dual-pathway model is also applicable for explaining auditory cortical processing, including the ventral "what" pathway for object identification and the dorsal "where" pathway for spatial localization. This review summarizes evidence from human neuroimaging studies supporting the dual-pathway model for auditory cortical processing in humans.
Animals ; Auditory Cortex ; anatomy & histology ; physiology ; Auditory Pathways ; anatomy & histology ; physiology ; Auditory Perception ; physiology ; Humans ; Macaca ; anatomy & histology ; physiology ; Models, Neurological ; Neurons ; physiology ; Pitch Discrimination ; physiology ; Sound Localization ; physiology ; Space Perception ; physiology

OBJECTIVETo study the value of the integrated visual and auditory continuous performance test (IVA-CPT) in the diagnosis of childhood attention deficit hyperactivity disorder (ADHD).

METHODSIVA-CPT was performed in 153 children (6-15 years old) with suspected ADHD. The "gold standard" for the diagnosis of ADHD was based on the Chinese Classification and Diagnostic Criteria of Mental Disease (3rd version) (CCMD-3) or the Diagnostic and Statistical Manual of Mental Disorders (4th version, USA) (DSM-IV).

RESULTSWhen CCMD-3 was used as the "gold standard", the sensitivity and specificity of IVA-CPT for the diagnosis of ADHD were 72.7% and 46.0% respectively. There were no significant differences in the diagnostic positive detection rate between the two diagnostic ways. When DSM-IV was used as the "gold standard", the sensitivity and specificity of IVA-CPT for the diagnosis of ADHD were 71.6% and 56.5% respectively. There were no significant differences in the diagnostic positive detection rate between the two diagnostic ways. There were similar results in the identification of subtypes of ADHD by the two diagnostic ways. The sensitivity and specificity of IVA-CPT for the diagnosis of ADHD in the 10-15 years old group were lower than those in the 6-9 years old group when either CCMD-3 or DSM-IV was used as the "gold standard".

CONCLUSIONSIVA-CPT can be used as an assisted tool for the diagnosis of ADHD. It is more effective for the diagnosis of ADHD in younger children.

Adolescent ; Attention Deficit Disorder with Hyperactivity ; diagnosis ; Auditory Perception ; physiology ; Child ; Female ; Humans ; Male ; Neuropsychological Tests ; Sensitivity and Specificity ; Visual Perception ; physiology