Effect of stimulus onset delay on auditory cortex neural responses to voice pitch feedback perturbation.

2009 ◽  
Vol 125 (4) ◽  
pp. 2719-2719
Author(s):  
Roozbeh Behroozmand ◽  
Charles R. Larson
2008 ◽  
Vol 99 (5) ◽  
pp. 2305-2319 ◽  
Author(s):  
Ling Qin ◽  
Jing Yu Wang ◽  
Yu Sato

Previous investigation of neural responses to cat meows in the primary auditory cortex (A1) of the anesthetized cat revealed a preponderance of phasic responses aligned to stimulus onset, offset, or envelope peaks. Sustained responses during stationary components of the stimulus were rarely seen. This observation motivates further investigation into how stationary components of naturalistic auditory stimuli are encoded by A1 neurons. We therefore explored neuronal response patterns in A1 of the awake cat using natural meows, time-reversed meows, and human vowels as stimuli. We found heterogeneous response types: ∼2/3 of units classified as “phasic cells” responding only to amplitude envelope variations and the remaining 1/3 were “phasic-tonic cells” with continuous responses during the stationary components. The classification was upheld across all stimuli tested for a given cell. The differences of phasic responses were correlated with amplitude-envelope differences in the early stimulus portion (<100 ms), whereas the differences between tonic responses were correlated with ongoing spectral differences in the later stimulus portion. Phasic-tonic cells usually had a characteristic frequency (CF) <5 kHz, which corresponded to the dominant spectral range of vocalizations, suggesting that the cells encode spectral information. Phasic cells had CFs across the tested frequency range (<16 kHz). Instantaneous firing rates for natural and time-reversed meows were different, but mean rates for different categories of stimuli were similar. Evidence for cat's A1 preferring conspecific meows was not found. These functionally heterogeneous responses may serve to encode ongoing changes in sound spectra or amplitude envelope occurring throughout the entirety of the sound stimulus.


2013 ◽  
Vol 25 (2) ◽  
pp. 175-187 ◽  
Author(s):  
Jihoon Oh ◽  
Jae Hyung Kwon ◽  
Po Song Yang ◽  
Jaeseung Jeong

Neural responses in early sensory areas are influenced by top–down processing. In the visual system, early visual areas have been shown to actively participate in top–down processing based on their topographical properties. Although it has been suggested that the auditory cortex is involved in top–down control, functional evidence of topographic modulation is still lacking. Here, we show that mental auditory imagery for familiar melodies induces significant activation in the frequency-responsive areas of the primary auditory cortex (PAC). This activation is related to the characteristics of the imagery: when subjects were asked to imagine high-frequency melodies, we observed increased activation in the high- versus low-frequency response area; when the subjects were asked to imagine low-frequency melodies, the opposite was observed. Furthermore, we found that A1 is more closely related to the observed frequency-related modulation than R in tonotopic subfields of the PAC. Our findings suggest that top–down processing in the auditory cortex relies on a mechanism similar to that used in the perception of external auditory stimuli, which is comparable to early visual systems.


2000 ◽  
Vol 84 (3) ◽  
pp. 1453-1463 ◽  
Author(s):  
Jos J. Eggermont

Responses of single- and multi-units in primary auditory cortex were recorded for gap-in-noise stimuli for different durations of the leading noise burst. Both firing rate and inter-spike interval representations were evaluated. The minimum detectable gap decreased in exponential fashion with the duration of the leading burst to reach an asymptote for durations of 100 ms. Despite the fact that leading and trailing noise bursts had the same frequency content, the dependence on leading burst duration was correlated with psychophysical estimates of across frequency channel (different frequency content of leading and trailing burst) gap thresholds in humans. The duration of the leading burst plus that of the gap was represented in the all-order inter-spike interval histograms for cortical neurons. The recovery functions for cortical neurons could be modeled on basis of fast synaptic depression and after-hyperpolarization produced by the onset response to the leading noise burst. This suggests that the minimum gap representation in the firing pattern of neurons in primary auditory cortex, and minimum gap detection in behavioral tasks is largely determined by properties intrinsic to those, or potentially subcortical, cells.


2021 ◽  
Author(s):  
Tao Yu ◽  
Shihui Han

Perceived cues signaling others' pain induce empathy that in turn motivates altruistic behavior toward those who appear suffering. This perception-emotion-behavior reactivity is the core of human altruism but does not always occur in real life situations. Here, by integrating behavioral and multimodal neuroimaging measures, we investigate neural mechanisms underlying the functional role of beliefs of others' pain in modulating empathy and altruism. We show evidence that decreasing (or enhancing) beliefs of others' pain reduces (or increases) subjective estimation of others' painful emotional states and monetary donations to those who show pain expressions. Moreover, decreasing beliefs of others' pain attenuates neural responses to perceived cues signaling others' pain within 200 ms after stimulus onset and modulate neural responses to others' pain in the frontal cortices and temporoparietal junction. Our findings highlight beliefs of others' pain as a fundamental cognitive basis of human empathy and altruism and unravel the intermediate neural architecture.


2020 ◽  
Vol 123 (4) ◽  
pp. 1320-1331 ◽  
Author(s):  
Martin Andermann ◽  
Roy D. Patterson ◽  
André Rupp

In recent years, electroencephalography and magnetoencephalography (MEG) have both been used to investigate the response in human auditory cortex to musical sounds that are perceived as consonant or dissonant. These studies have typically focused on the transient components of the physiological activity at sound onset, specifically, the N1 wave of the auditory evoked potential and the auditory evoked field, respectively. Unfortunately, the morphology of the N1 wave is confounded by the prominent neural response to energy onset at stimulus onset. It is also the case that the perception of pitch is not limited to sound onset; the perception lasts as long as the note producing it. This suggests that consonance studies should also consider the sustained activity that appears after the transient components die away. The current MEG study shows how energy-balanced sounds can focus the response waves on the consonance-dissonance distinction rather than energy changes and how source modeling techniques can be used to measure the sustained field associated with extended consonant and dissonant sounds. The study shows that musical dyads evoke distinct transient and sustained neuromagnetic responses in auditory cortex. The form of the response depends on both whether the dyads are consonant or dissonant and whether the listeners are musical or nonmusical. The results also show that auditory cortex requires more time for the early transient processing of dissonant dyads than it does for consonant dyads and that the continuous representation of temporal regularity in auditory cortex might be modulated by processes beyond auditory cortex. NEW & NOTEWORTHY We report a magnetoencephalography (MEG) study on transient and sustained cortical consonance processing. Stimuli were long-duration, energy-balanced, musical dyads that were either consonant or dissonant. Spatiotemporal source analysis revealed specific transient and sustained neuromagnetic activity in response to the dyads; in particular, the morphology of the responses was shaped by the dyad’s consonance and the listener’s musicality. Our results also suggest that the sustained representation of stimulus regularity might be modulated by processes beyond auditory cortex.


2000 ◽  
Vol 83 (5) ◽  
pp. 2708-2722 ◽  
Author(s):  
Jos J. Eggermont

Neural synchrony within and between auditory cortical fields is evaluated with respect to its potential role in feature binding and in the coding of tone and noise sound pressure level. Simultaneous recordings were made in 24 cats with either two electrodes in primary auditory cortex (AI) and one in anterior auditory field (AAF) or one electrode each in AI, AAF, and secondary auditory cortex. Cross-correlograms (CCHs) for 1-ms binwidth were calculated for tone pips, noise bursts, and silence (i.e., poststimulus) as a function of intensity level. Across stimuli and intensity levels the total percentage of significant stimulus onset CCHs was 62% and that of significant poststimulus CCHs was 58% of 1,868 pairs calculated for each condition. The cross-correlation coefficient to stimulus onsets was higher for single-electrode pairs than for dual-electrode pairs and higher for noise bursts compared with tone pips. The onset correlation for single-electrode pairs was only marginally larger than the poststimulus correlation. For pairs from electrodes across area boundaries, the onset correlations were a factor 3–4 higher than the poststimulus correlations. The within-AI dual-electrode peak correlation was higher than that across areas, especially for spontaneous conditions. Correlation strengths for between area pairs were independent of the difference in characteristic frequency (CF), thereby providing a mechanism of feature binding for broadband sounds. For noise-burst stimulation, the onset correlation for between area pairs was independent of stimulus intensity regardless the difference in CF. In contrast, for tone-pip stimulation a significant dependence on intensity level of the peak correlation strength was found for pairs involving AI and/or AAF with CF difference less than one octave. Across all areas, driven rate, between-area peak correlation strength, or a combination of the two did not predict stimulus intensity. However, between-area peak correlation strength performs better than firing rate to decide if a stimulus is present or absent.


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