The classical auditory oddball paradigm is a commonly used experimental paradigm for evoking event related potentials (ERPs). The present study was aimed to explore the auditory cognitive processing mechanism of space perception of human brain. We employed an auditory oddball paradigm of binaural unbiased and biased sound intensity to compare and analyze the response characteristics of ERP. By focusing on the spatial lateralization characteristics of P300 and mismatch negativity (MMN) components, we analyzed their lateralization trends according to the laterality index. We found that both P300 and MMN components showed right-hemisphere lateralization phenomenon under the stimulation of asymmetric intensity of auditory acoustic. The results suggested that the right hemisphere of human brain played a key role in spatial information processing. The results also indicated that the hemispherical characteristics of the brain were not related to the actual spatial direction of the auditory stimulus, but were determined by the hemispherical functions of the brain. Furthermore, the results suggested that the MMN components induced by spatial differences were stronger in females than those in males.
Acoustic Stimulation ; Auditory Perception/physiology* ; Brain Mapping ; Electroencephalography ; Evoked Potentials ; Evoked Potentials, Auditory/physiology* ; Female ; Humans ; Male

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

OBJECTIVE: To explore whether the characteristic responses to sound stimulations of the auditory neurons in the striatum is regulated in different behavioral states. METHODS: The auditory neurons in the striatum of awake C57BL/6J mice were selected for this study. We recorded the auditory response of the striatum to noises over a long period of time by building a synchronous in vivo electrophysiological and locomotion recording system and using glass microelectrode attachment recording. By analyzing the running speed of the mice, the behavioral states of the mice were divided into the quiet state and the active state, and the spontaneous activity and evoked responses of the auditory neurons in the striatum were analyzed in these two states. RESULTS: Compared with those recorded in the quiet state, the spontaneous activity of the auditory neurons in the striatum of the mice increased significantly (37.06±12.02 vs 18.51±10.91, P < 0.001) while the auditory response of the neurons decreased significantly (noise intensity=60 dB, 3.45±2.99 vs 3.04±2.76, P < 0.001) in the active state. CONCLUSION Locomotion has a significant inhibitory effect on the auditory response of the striatum, which may importantly contribute to the decline of sound information recognition ability in the active state.
Acoustic Stimulation ; Animals ; Auditory Cortex/physiology* ; Evoked Potentials, Auditory ; Locomotion/physiology* ; Mice ; Mice, Inbred C57BL ; Neurons

OBJECTIVETo establish a model of acoustically evoked short latency negative response (ASNR) in guinea pigs, a model of profound hearing loss with normal saccular functions, and verify the correlation between ASNR and vestibular evoked myogenic potential (VEMP).

METHODSThirty-two healthy guinea pigs were employed in the experiment, which were randomly divided into control group (16 subjects) and deafened group (16 subjects). Each animal experienced auditory and vestibular tests including auditory brainstem response (ABR), VEMP and caloric test. A quick treatment was employed for deafened group consisting of a subcutaneous injection of kanamycin at a dose of 400 mg/kg followed by a jugular vein injection of ethacrynic acid at a dose of 40 mg/kg one hour later. The animals were received ABR, VEMP and caloric test 7 - 10 days following the drug administration. The deafened group was further divided into ASNR group and non-ASNR group, based on the presence of ASNR.

RESULTSIn deafened group, five subjects died postoperatively, 11 subjects (22 ears) provided full data, ASNR was elicited in eight ears (36.4%), the threshold was 120 - 130 dB SPL with mean of (124.4 ± 4.96) dB SPL. Its latency range was 1.75 - 2.60 ms with mean of (2.15 ± 0.27) ms. The mean latency of threshold was (2.34 ± 0.18) ms. All eight ASNR ears presented with VEMP. The VEMP threshold, positive and negative potential latencies proved no statistical difference (P > 0.05) between ASNR group and control group. Significant difference was detected between the VEMP presence of ASNR group and non-ASNR group (P = 0.002). There was no statistically significant correlation between VEMP and caloric test neither between ASNR and caloric test in deafened group.

CONCLUSIONSThis study evoked ASNR in an ototoxicity guinea pig model which has profound hearing loss with normal saccular functions. The presence of ASNR correlated with VEMP, however, not correlated with caloric test, suggesting that ASNR and VEMP are both originated from the saccule.

Animals ; Deafness ; physiopathology ; Disease Models, Animal ; Evoked Potentials, Auditory ; physiology ; Evoked Potentials, Auditory, Brain Stem ; Guinea Pigs ; Saccule and Utricle ; physiology ; Vestibular Evoked Myogenic Potentials ; Vestibular Function Tests

OBJECTIVES: To explore the characters and the relationship among latency response, amplitude and sound stimulus intensity of auditory long latency response（ALR）, and to investigate the significance of ALR applied in auditory threshold prediction. METHODS: Total 46 subjects （92 ears） with normal hearing were tested by ALR. The ALR waves of the subjects were elicited by 5 sound stimulus intensity according to the order of 70, 50, 30, 20 and 10 dB nHL. By making N₁ wave and P₂ wave, the values of 3 observed indexes （the latencies of N₁ wave and P₂ wave and N₁-P₂ amplitude） were obtained, and the variation trend of the observed indexes were statistically analyzed. The differences in the frequency of the indexes were observed. RESULTS: The rate of ALR waves from 46 subjects （92 ears） with normal hearing was 100%. The latencies of N₁ wave and P₂ wave delayed gradually and N₁-P₂ amplitude declined with sound stimulus intensity descending. CONCLUSIONS In suitable conditions, ALR is a stable technology for hearing thresholds prediction. The relation between sound stimulus intensity and latency of N₁ wave, latency of P₂ wave and N₁-P₂ amplitude of ALR plays an important part in auditory thresholds assessment.
Acoustic Stimulation ; Auditory Threshold/physiology* ; Evoked Potentials, Auditory ; Evoked Potentials, Auditory, Brain Stem/physiology* ; Female ; Hearing ; Humans ; Male ; Noise ; Reaction Time

Animals ; Auditory Threshold ; Cochlea ; physiology ; Ear, Middle ; surgery ; Evoked Potentials, Auditory, Brain Stem ; Female ; Male ; Rats

OBJECTIVE: To investigate the auditory characteristics of guinea pigs immunized with purified P0 protein from inner ear of guinea pigs. METHOD: Purified inner ear P0 protein was made by Preparative SDS-PAGE. To evaluate the results of Auditory Brainstem Response (ABR), Compound Action Potention (CAP), and Distortion Product Oto-acoustic Emissions (DPOAE) in guinea pigs immunized with purified guinea pigs inner ear myelin protein P0. RESULT: Seven ears of the guinea pigs immunized with purified inner ear P0 protein developed hearing loss. In the ABR study, peak latencies of wave I, III and the interpeak latency of I -III, I-IV were elevated in this group of guinea pigs compared with the control group (P < 0.01). But the interpeak latency of III-IV did not change. In the CAP study, the threshold elevated and latency prolonged (P < 0.01). No significant change of DPOAE was found in the P0-sensitized guinea pigs when compared to controls (P > 0.05). Even though the contra-lateral suppressive effect had the depressed tendency, but there was no significant different when compared with the controls (P > 0.05). CONCLUSION Purified inner ear P0 protein is an important autoimmune inner ear antigen and can develop autoimmune disease of the auditory nerve.
Animals ; Auditory Threshold ; Evoked Potentials, Auditory, Brain Stem ; physiology ; Guinea Pigs ; Immunization ; Myelin P0 Protein ; immunology

Prepulse inhibition (PPI) refers to a decreased response to a startling stimulus when another weaker stimulus precedes it. Most PPI studies have focused on the physiological startle reflex and fewer have reported the PPI of cortical responses. We recorded local field potentials (LFPs) in four monkeys and investigated whether the PPI of auditory cortical responses (alpha, beta, and gamma oscillations and evoked potentials) can be demonstrated in the caudolateral belt of the superior temporal gyrus (STGcb). We also investigated whether the presence of a conspecific, which draws attention away from the auditory stimuli, affects the PPI of auditory cortical responses. The PPI paradigm consisted of Pulse-only and Prepulse + Pulse trials that were presented randomly while the monkey was alone (ALONE) and while another monkey was present in the same room (ACCOMP). The LFPs to the Pulse were significantly suppressed by the Prepulse thus, demonstrating PPI of cortical responses in the STGcb. The PPI-related inhibition of the N1 amplitude of the evoked responses and cortical oscillations to the Pulse were not affected by the presence of a conspecific. In contrast, gamma oscillations and the amplitude of the N1 response to Pulse-only were suppressed in the ACCOMP condition compared to the ALONE condition. These findings demonstrate PPI in the monkey STGcb and suggest that the PPI of auditory cortical responses in the monkey STGcb is a pre-attentive inhibitory process that is independent of attentional modulation.
Animals ; Auditory Cortex ; physiology ; Evoked Potentials, Auditory ; physiology ; Macaca mulatta ; Male ; Prepulse Inhibition ; physiology ; Temporal Lobe ; physiology

Long-term synaptic plasticity is considered as a key part of the neural mechanism of learning and memory. The production of learned vocalization of male zebra finches is closely related to high vocal center (HVC)-robust nucleus of the arcopallium (RA) pathway. However, the long-term plasticity of HVC-RA synapses is unclear. This study investigated the long-term plasticity of HVC-RA synapses in adult male zebra finches through in vivo field potential recording. The results showed that physiologic stimulation, i.e., δ rhythmic stimulation and low frequency stimulation could not effectively induce long-term synaptic plasticity. The former leaded to no change of the amplitudes of evoked population spikes, and the latter induced short-term depression (STD) of the amplitudes of the second evoked population spikes caused by paired pulses. But high frequency stimulation induced long-term depression (LTD) of the amplitudes of evoked population spikes to show out long-term synaptic plasticity. These results suggest that LTD represents the long-term plasticity of HVC-RA synapses in adult male zebra finches, which may be a key part of the neural mechanism of vocal learning and memory and can explain the plasticity of adult song to some degree.
Animals ; Evoked Potentials, Auditory ; Finches ; physiology ; High Vocal Center ; physiology ; Learning ; Male ; Neuronal Plasticity ; Synapses ; physiology

OBJECTIVETo explore the feasibility to evaluate objectively auditory temporal resolution using the iso-modulation depth temporal modulation transfer function (TMTF) derived from the amplitude of evoked response to sinusoidally modulated signals.

METHODSChronic electrodes were implanted in inferior colliculus and auditory cortex of guinea pigs. We recorded the evoked response to sinusoidally modulated tones with modulation frequency being varied from 20 to 400 Hz and modulation depth fixed at 100%. The response amplitude in uV was converted into relative amplitude using the fast Fourier transform (FFT) function provided by Biosig software, and then the iso-modulation depth TMTF was plotted with the relative amplitude changed with modulation frequency. Then we recorded the evoked response to the sinusoidally modulated tones with modulation depth being varied from 100% to 10% and derived the iso-amplitude TMTF comparable to conventional modulation depth threshold TMTF. The derived iso-amplitude TMTF was compared to iso-modulation depth TMTF to determine the validity of iso-modulation depth TMTF.

RESULTSThe iso-modulation-depth TMTF and iso-amplitude TMTF in inferior colliculus and auditory cortex of guinea pigs represented respectively bandpass and lowpass characteristic. The cut-off frequency calculated from the two TMTF methods didn't differ significantly and the cut-off frequency derived from auditory cortex iso-modulation depth TMTF was consistent with behavioral results.

CONCLUSIONSThe TMTF plotted with the response amplitude to sinusoidally modulated tones with the modulation depth fixed at 100% and the modulation frequency was a valid method to evaluate objectively auditory temporal resolution.

Animals ; Auditory Cortex ; physiology ; Electrodes ; Evoked Potentials, Auditory ; physiology ; Fourier Analysis ; Guinea Pigs ; Inferior Colliculi ; physiology ; Reaction Time