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Journal of the Association For Research... Jun 2021The ability to process and perceive sensory stimuli is an essential function for animals. Among the sensory modalities, audition is crucial for communication, pleasure,... (Review)
Review
The ability to process and perceive sensory stimuli is an essential function for animals. Among the sensory modalities, audition is crucial for communication, pleasure, care for the young, and perceiving threats. The auditory cortex (ACtx) is a key sound processing region that combines ascending signals from the auditory periphery and inputs from other sensory and non-sensory regions. The development of ACtx is a protracted process starting prenatally and requires the complex interplay of molecular programs, spontaneous activity, and sensory experience. Here, we review the development of thalamic and cortical auditory circuits during pre- and early post-natal periods.
Topics: Animals; Auditory Cortex; Auditory Perception; Sound; Thalamus
PubMed: 33909161
DOI: 10.1007/s10162-021-00794-3 -
Neuroscience and Biobehavioral Reviews Jan 2022The auditory system provides us with extremely rich and precise information about the outside world. Once a sound reaches our ears, the acoustic information it carries... (Review)
Review
The auditory system provides us with extremely rich and precise information about the outside world. Once a sound reaches our ears, the acoustic information it carries travels from the cochlea all the way to the auditory cortex, where its complexity and nuances are integrated. In the auditory cortex, functional circuits are formed by subpopulations of intermingled excitatory and inhibitory cells. In this review, we discuss recent evidence of the specific contributions of inhibitory neurons in sound processing and integration. We first examine intrinsic properties of three main classes of inhibitory interneurons in the auditory cortex. Then, we describe how inhibition shapes the responsiveness of the auditory cortex to sound. Finally, we discuss how inhibitory interneurons contribute to the sensation and perception of sounds. Altogether, this review points out the crucial role of cortical inhibitory interneurons in integrating information about the context, history, or meaning of a sound. It also highlights open questions to be addressed for increasing our understanding of the staggering complexity leading to the subtlest auditory perception.
Topics: Acoustic Stimulation; Auditory Cortex; Auditory Perception; Interneurons
PubMed: 34822879
DOI: 10.1016/j.neubiorev.2021.11.021 -
Neuron Aug 2023The brain can combine auditory and visual information to localize objects. However, the cortical substrates underlying audiovisual integration remain uncertain. Here, we...
The brain can combine auditory and visual information to localize objects. However, the cortical substrates underlying audiovisual integration remain uncertain. Here, we show that mouse frontal cortex combines auditory and visual evidence; that this combination is additive, mirroring behavior; and that it evolves with learning. We trained mice in an audiovisual localization task. Inactivating frontal cortex impaired responses to either sensory modality, while inactivating visual or parietal cortex affected only visual stimuli. Recordings from >14,000 neurons indicated that after task learning, activity in the anterior part of frontal area MOs (secondary motor cortex) additively encodes visual and auditory signals, consistent with the mice's behavioral strategy. An accumulator model applied to these sensory representations reproduced the observed choices and reaction times. These results suggest that frontal cortex adapts through learning to combine evidence across sensory cortices, providing a signal that is transformed into a binary decision by a downstream accumulator.
Topics: Animals; Mice; Visual Perception; Acoustic Stimulation; Auditory Perception; Photic Stimulation; Frontal Lobe; Auditory Cortex
PubMed: 37295419
DOI: 10.1016/j.neuron.2023.05.008 -
Cerebral Cortex (New York, N.Y. : 1991) May 2023To understand auditory cortical processing, the effective connectivity between 15 auditory cortical regions and 360 cortical regions was measured in 171 Human Connectome...
To understand auditory cortical processing, the effective connectivity between 15 auditory cortical regions and 360 cortical regions was measured in 171 Human Connectome Project participants, and complemented with functional connectivity and diffusion tractography. 1. A hierarchy of auditory cortical processing was identified from Core regions (including A1) to Belt regions LBelt, MBelt, and 52; then to PBelt; and then to HCP A4. 2. A4 has connectivity to anterior temporal lobe TA2, and to HCP A5, which connects to dorsal-bank superior temporal sulcus (STS) regions STGa, STSda, and STSdp. These STS regions also receive visual inputs about moving faces and objects, which are combined with auditory information to help implement multimodal object identification, such as who is speaking, and what is being said. Consistent with this being a "what" ventral auditory stream, these STS regions then have effective connectivity to TPOJ1, STV, PSL, TGv, TGd, and PGi, which are language-related semantic regions connecting to Broca's area, especially BA45. 3. A4 and A5 also have effective connectivity to MT and MST, which connect to superior parietal regions forming a dorsal auditory "where" stream involved in actions in space. Connections of PBelt, A4, and A5 with BA44 may form a language-related dorsal stream.
Topics: Humans; Auditory Cortex; Temporal Lobe; Parietal Lobe; Semantics; Language
PubMed: 36573464
DOI: 10.1093/cercor/bhac496 -
Nature Reviews. Neuroscience Oct 2013The fundamental perceptual unit in hearing is the 'auditory object'. Similar to visual objects, auditory objects are the computational result of the auditory system's... (Review)
Review
The fundamental perceptual unit in hearing is the 'auditory object'. Similar to visual objects, auditory objects are the computational result of the auditory system's capacity to detect, extract, segregate and group spectrotemporal regularities in the acoustic environment; the multitude of acoustic stimuli around us together form the auditory scene. However, unlike the visual scene, resolving the component objects within the auditory scene crucially depends on their temporal structure. Neural correlates of auditory objects are found throughout the auditory system. However, neural responses do not become correlated with a listener's perceptual reports until the level of the cortex. The roles of different neural structures and the contribution of different cognitive states to the perception of auditory objects are not yet fully understood.
Topics: Acoustic Stimulation; Acoustics; Animals; Auditory Cortex; Auditory Pathways; Auditory Perception; Humans
PubMed: 24052177
DOI: 10.1038/nrn3565 -
The Journal of Neuroscience : the... Apr 2019Absolute pitch (AP), the ability of some musicians to precisely identify and name musical tones in isolation, is associated with a number of gross morphological changes...
Absolute pitch (AP), the ability of some musicians to precisely identify and name musical tones in isolation, is associated with a number of gross morphological changes in the brain, but the fundamental neural mechanisms underlying this ability have not been clear. We presented a series of logarithmic frequency sweeps to age- and sex-matched groups of musicians with or without AP and controls without musical training. We used fMRI and population receptive field (pRF) modeling to measure the responses in the auditory cortex in 61 human subjects. The tuning response of each fMRI voxel was characterized as Gaussian, with independent center frequency and bandwidth parameters. We identified three distinct tonotopic maps, corresponding to primary (A1), rostral (R), and rostral-temporal (RT) regions of auditory cortex. We initially hypothesized that AP abilities might manifest in sharper tuning in the auditory cortex. However, we observed that AP subjects had larger cortical area, with the increased area primarily devoted to broader frequency tuning. We observed anatomically that A1, R and RT were significantly larger in AP musicians than in non-AP musicians or control subjects, which did not differ significantly from each other. The increased cortical area in AP in areas A1 and R were primarily low frequency and broadly tuned, whereas the distribution of responses in area RT did not differ significantly. We conclude that AP abilities are associated with increased early auditory cortical area devoted to broad-frequency tuning and likely exploit increased ensemble encoding. Absolute pitch (AP), the ability of some musicians to precisely identify and name musical tones in isolation, is associated with a number of gross morphological changes in the brain, but the fundamental neural mechanisms have not been clear. Our study shows that AP musicians have significantly larger volume in early auditory cortex than non-AP musicians and non-musician controls and that this increased volume is primarily devoted to broad-frequency tuning. We conclude that AP musicians are likely able to exploit increased ensemble representations to encode and identify frequency.
Topics: Acoustic Stimulation; Adult; Auditory Cortex; Auditory Perception; Female; Humans; Magnetic Resonance Imaging; Male; Music; Pitch Discrimination; Pitch Perception; Psychomotor Performance; Young Adult
PubMed: 30745420
DOI: 10.1523/JNEUROSCI.1532-18.2019 -
Frontiers in Neural Circuits 2017The auditory thalamus and auditory cortex (AC) are pivotal structures in the central auditory system. However, the thalamocortical mechanisms of processing sounds are... (Review)
Review
The auditory thalamus and auditory cortex (AC) are pivotal structures in the central auditory system. However, the thalamocortical mechanisms of processing sounds are largely unknown. Investigation of this process benefits greatly from the use of mice because the mouse is a powerful animal model in which various experimental techniques, especially genetic tools, can be applied. However, the use of mice has been limited in auditory research, and thus even basic anatomical knowledge of the mouse central auditory system has not been sufficiently collected. Recently, optical imaging combined with morphological analyses has enabled the elucidation of detailed anatomical properties of the mouse auditory system. These techniques have uncovered fine AC maps with multiple frequency-organized regions, each of which receives point-to-point thalamocortical projections from different origins inside the lemniscal auditory thalamus, the ventral division of the medial geniculate body (MGv). This precise anatomy now provides a platform for physiological research. In this mini review article, we summarize these recent achievements that will facilitate physiological investigations in the mouse auditory system.
Topics: Animals; Auditory Cortex; Geniculate Bodies; Mice; Neural Pathways
PubMed: 28293178
DOI: 10.3389/fncir.2017.00014 -
International Journal of... Feb 2015
Topics: Animals; Auditory Cortex; Auditory Pathways; Auditory Perception; Humans; Neurosciences
PubMed: 25645027
DOI: 10.1016/j.ijpsycho.2015.01.008 -
Hearing Research Jun 2009
Topics: Animals; Auditory Cortex; Auditory Perception; Female; Gonadal Steroid Hormones; Hearing; Humans; Male
PubMed: 19531444
DOI: 10.1016/j.heares.2009.05.005 -
Nature Communications Dec 2017An important outstanding question in auditory neuroscience is to identify the mechanisms by which specific motifs within inter-connected neural circuits affect auditory... (Review)
Review
An important outstanding question in auditory neuroscience is to identify the mechanisms by which specific motifs within inter-connected neural circuits affect auditory processing and, ultimately, behavior. In the auditory cortex, a combination of large-scale electrophysiological recordings and concurrent optogenetic manipulations are improving our understanding of the role of inhibitory-excitatory interactions. At the same time, computational approaches have grown to incorporate diverse neuronal types and connectivity patterns. However, we are still far from understanding how cortical microcircuits encode and transmit information about complex acoustic scenes. In this review, we focus on recent results identifying the special function of different cortical neurons in the auditory cortex and discuss a computational framework for future work that incorporates ideas from network science and network dynamics toward the coding of complex auditory scenes.
Topics: Animals; Auditory Cortex; Auditory Perception; Electrophysiological Phenomena; Humans; Models, Neurological; Nerve Net; Neurons
PubMed: 29255268
DOI: 10.1038/s41467-017-01755-2