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Song X, Guo Y, Chen C, Lee JH, Wang X. Tonotopic organization of auditory cortex in awake marmosets revealed by multi-modal wide-field optical imaging. CURRENT RESEARCH IN NEUROBIOLOGY 2024; 6:100132. [PMID: 38799765 PMCID: PMC11127206 DOI: 10.1016/j.crneur.2024.100132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2023] [Revised: 05/06/2024] [Accepted: 05/08/2024] [Indexed: 05/29/2024] Open
Abstract
Tonotopic organization of the auditory cortex has been extensively studied in many mammalian species using various methodologies and physiological preparations. Tonotopy mapping in primates, however, is more limited due to constraints such as cortical folding, use of anesthetized subjects, and mapping methodology. Here we applied a combination of through-skull and through-window intrinsic optical signal imaging, wide-field calcium imaging, and neural probe recording techniques in awake marmosets (Callithrix jacchus), a New World monkey with most of its auditory cortex located on a flat brain surface. Coarse tonotopic gradients, including a recently described rostral-temporal (RT) to parabelt gradient, were revealed by the through-skull imaging of intrinsic optical signals and were subsequently validated by single-unit recording. Furthermore, these tonotopic gradients were observed with more detail through chronically implanted cranial windows with additional verifications on the experimental design. Moreover, the tonotopy mapped by the intrinsic-signal imaging methods was verified by wide-field calcium imaging in an AAV-GCaMP labeled subject. After these validations and with further effort to expand the field of view more rostrally in both windowed and through-skull subjects, an additional putative tonotopic gradient was observed more rostrally to the area RT, which has not been previously described by the standard model of tonotopic organization of the primate auditory cortex. Together, these results provide the most comprehensive data of tonotopy mapping in an awake primate species with unprecedented coverage and details in the rostral proportion and support a caudal-rostrally arranged mesoscale organization of at least three repeats of functional gradients in the primate auditory cortex, similar to the ventral stream of primate visual cortex.
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Affiliation(s)
- Xindong Song
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
- Institute of Automation, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
- Key Laboratory of Brain Cognition and Brain-inspired Intelligence Technology, Chinese Academy of Sciences, China
| | - Yueqi Guo
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Chenggang Chen
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Jong Hoon Lee
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
- Department of Biological Sciences, KAIST, Daejeon, 34141, South Korea
| | - Xiaoqin Wang
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
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2
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Souffi S, Varnet L, Zaidi M, Bathellier B, Huetz C, Edeline JM. Reduction in sound discrimination in noise is related to envelope similarity and not to a decrease in envelope tracking abilities. J Physiol 2023; 601:123-149. [PMID: 36373184 DOI: 10.1113/jp283526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 11/08/2022] [Indexed: 11/15/2022] Open
Abstract
Humans and animals constantly face challenging acoustic environments, such as various background noises, that impair the detection, discrimination and identification of behaviourally relevant sounds. Here, we disentangled the role of temporal envelope tracking in the reduction in neuronal and behavioural discrimination between communication sounds in situations of acoustic degradations. By collecting neuronal activity from six different levels of the auditory system, from the auditory nerve up to the secondary auditory cortex, in anaesthetized guinea-pigs, we found that tracking of slow changes of the temporal envelope is a general functional property of auditory neurons for encoding communication sounds in quiet conditions and in adverse, challenging conditions. Results from a go/no-go sound discrimination task in mice support the idea that the loss of distinct slow envelope cues in noisy conditions impacted the discrimination performance. Together, these results suggest that envelope tracking is potentially a universal mechanism operating in the central auditory system, which allows the detection of any between-stimulus difference in the slow envelope and thus copes with degraded conditions. KEY POINTS: In quiet conditions, envelope tracking in the low amplitude modulation range (<20 Hz) is correlated with the neuronal discrimination between communication sounds as quantified by mutual information from the cochlear nucleus up to the auditory cortex. At each level of the auditory system, auditory neurons retain their abilities to track the communication sound envelopes in situations of acoustic degradation, such as vocoding and the addition of masking noises up to a signal-to-noise ratio of -10 dB. In noisy conditions, the increase in between-stimulus envelope similarity explains the reduction in both behavioural and neuronal discrimination in the auditory system. Envelope tracking can be viewed as a universal mechanism that allows neural and behavioural discrimination as long as the temporal envelope of communication sounds displays some differences.
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Affiliation(s)
- Samira Souffi
- Paris-Saclay Institute of Neuroscience (Neuro-PSI, UMR 9197), CNRS - Université Paris-Saclay, Saclay, France
| | - Léo Varnet
- Laboratoire des systèmes perceptifs, UMR CNRS 8248, Département d'Etudes Cognitives, Ecole Normale Supérieure, Université Paris Sciences & Lettres, Paris, France
| | - Meryem Zaidi
- Paris-Saclay Institute of Neuroscience (Neuro-PSI, UMR 9197), CNRS - Université Paris-Saclay, Saclay, France
| | - Brice Bathellier
- Institut de l'Audition, Institut Pasteur, Université de Paris, INSERM, Paris, France
| | - Chloé Huetz
- Paris-Saclay Institute of Neuroscience (Neuro-PSI, UMR 9197), CNRS - Université Paris-Saclay, Saclay, France
| | - Jean-Marc Edeline
- Paris-Saclay Institute of Neuroscience (Neuro-PSI, UMR 9197), CNRS - Université Paris-Saclay, Saclay, France
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3
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Sohoglu E, Kumar S, Chait M, Griffiths TD. Multivoxel codes for representing and integrating acoustic features in human cortex. Neuroimage 2020; 217:116661. [PMID: 32081785 PMCID: PMC7339141 DOI: 10.1016/j.neuroimage.2020.116661] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 02/13/2020] [Accepted: 02/15/2020] [Indexed: 10/25/2022] Open
Abstract
Using fMRI and multivariate pattern analysis, we determined whether spectral and temporal acoustic features are represented by independent or integrated multivoxel codes in human cortex. Listeners heard band-pass noise varying in frequency (spectral) and amplitude-modulation (AM) rate (temporal) features. In the superior temporal plane, changes in multivoxel activity due to frequency were largely invariant with respect to AM rate (and vice versa), consistent with an independent representation. In contrast, in posterior parietal cortex, multivoxel representation was exclusively integrated and tuned to specific conjunctions of frequency and AM features (albeit weakly). Direct between-region comparisons show that whereas independent coding of frequency weakened with increasing levels of the hierarchy, such a progression for AM and integrated coding was less fine-grained and only evident in the higher hierarchical levels from non-core to parietal cortex (with AM coding weakening and integrated coding strengthening). Our findings support the notion that primary auditory cortex can represent spectral and temporal acoustic features in an independent fashion and suggest a role for parietal cortex in feature integration and the structuring of sensory input.
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Affiliation(s)
- Ediz Sohoglu
- School of Psychology, University of Sussex, Brighton, BN1 9QH, United Kingdom.
| | - Sukhbinder Kumar
- Institute of Neurobiology, Medical School, Newcastle University, Newcastle Upon Tyne, NE2 4HH, United Kingdom; Wellcome Trust Centre for Human Neuroimaging, University College London, London, WC1N 3BG, United Kingdom
| | - Maria Chait
- Ear Institute, University College London, London, United Kingdom
| | - Timothy D Griffiths
- Institute of Neurobiology, Medical School, Newcastle University, Newcastle Upon Tyne, NE2 4HH, United Kingdom; Wellcome Trust Centre for Human Neuroimaging, University College London, London, WC1N 3BG, United Kingdom
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4
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The rhythm of attention: Perceptual modulation via rhythmic entrainment is lowpass and attention mediated. Atten Percept Psychophys 2020; 82:3558-3570. [PMID: 32686065 DOI: 10.3758/s13414-020-02095-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Modulation patterns are known to carry critical predictive cues to signal detection in complex acoustic environments. The current study investigated the persistence of masker modulation effects on postmodulation detection of probe signals. Hickok, Farahbod, and Saberi (Psychological Science, 26, 1006-1013, 2015) demonstrated that thresholds for a tone pulse in stationary noise follow a predictable periodic pattern when preceded by a 3-Hz amplitude modulated masker. They found entrainment of detection patterns to the modulation envelope lasting for approximately two cycles after termination of modulation. The current study extends these results to a wide range of modulation rates by mapping the temporal modulation transfer function for persistent modulatory effects. We found significant entrainment to modulation rates of 2 and 3 Hz, a weaker effect at 5 Hz, and no entrainment at higher rates (8 to 32 Hz). The effect seems critically dependent on attentional mechanisms, requiring temporal and level uncertainty of the probe signal. Our findings suggest that the persistence of modulatory effects on signal detection is lowpass in nature and attention based.
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Chien VSC, Maess B, Knösche TR. A generic deviance detection principle for cortical On/Off responses, omission response, and mismatch negativity. BIOLOGICAL CYBERNETICS 2019; 113:475-494. [PMID: 31428855 PMCID: PMC6848254 DOI: 10.1007/s00422-019-00804-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 08/07/2019] [Indexed: 05/04/2023]
Abstract
Neural responses to sudden changes can be observed in many parts of the sensory pathways at different organizational levels. For example, deviants that violate regularity at various levels of abstraction can be observed as simple On/Off responses of individual neurons or as cumulative responses of neural populations. The cortical deviance-related responses supporting different functionalities (e.g., gap detection, chunking, etc.) seem unlikely to arise from different function-specific neural circuits, given the relatively uniform and self-similar wiring patterns across cortical areas and spatial scales. Additionally, reciprocal wiring patterns (with heterogeneous combinations of excitatory and inhibitory connections) in the cortex naturally speak in favor of a generic deviance detection principle. Based on this concept, we propose a network model consisting of reciprocally coupled neural masses as a blueprint of a universal change detector. Simulation examples reproduce properties of cortical deviance-related responses including the On/Off responses, the omitted-stimulus response (OSR), and the mismatch negativity (MMN). We propose that the emergence of change detectors relies on the involvement of disinhibition. An analysis of network connection settings further suggests a supportive effect of synaptic adaptation and a destructive effect of N-methyl-D-aspartate receptor (NMDA-r) antagonists on change detection. We conclude that the nature of cortical reciprocal wiring gives rise to a whole range of local change detectors supporting the notion of a generic deviance detection principle. Several testable predictions are provided based on the network model. Notably, we predict that the NMDA-r antagonists would generally dampen the cortical Off response, the cortical OSR, and the MMN.
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Affiliation(s)
- Vincent S. C. Chien
- Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, Leipzig, Germany
| | - Burkhard Maess
- Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, Leipzig, Germany
| | - Thomas R. Knösche
- Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, Leipzig, Germany
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Chang KH, Thomas JM, Boynton GM, Fine I. Reconstructing Tone Sequences from Functional Magnetic Resonance Imaging Blood-Oxygen Level Dependent Responses within Human Primary Auditory Cortex. Front Psychol 2017; 8:1983. [PMID: 29184522 PMCID: PMC5694557 DOI: 10.3389/fpsyg.2017.01983] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Accepted: 10/30/2017] [Indexed: 01/12/2023] Open
Abstract
Here we show that, using functional magnetic resonance imaging (fMRI) blood-oxygen level dependent (BOLD) responses in human primary auditory cortex, it is possible to reconstruct the sequence of tones that a person has been listening to over time. First, we characterized the tonotopic organization of each subject’s auditory cortex by measuring auditory responses to randomized pure tone stimuli and modeling the frequency tuning of each fMRI voxel as a Gaussian in log frequency space. Then, we tested our model by examining its ability to work in reverse. Auditory responses were re-collected in the same subjects, except this time they listened to sequences of frequencies taken from simple songs (e.g., “Somewhere Over the Rainbow”). By finding the frequency that minimized the difference between the model’s prediction of BOLD responses and actual BOLD responses, we were able to reconstruct tone sequences, with mean frequency estimation errors of half an octave or less, and little evidence of systematic biases.
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Affiliation(s)
- Kelly H Chang
- Department of Psychology, University of Washington, Seattle, WA, United States
| | - Jessica M Thomas
- Department of Psychology, University of Washington, Seattle, WA, United States
| | - Geoffrey M Boynton
- Department of Psychology, University of Washington, Seattle, WA, United States
| | - Ione Fine
- Department of Psychology, University of Washington, Seattle, WA, United States
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7
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Cortical Activation Patterns Evoked by Temporally Asymmetric Sounds and Their Modulation by Learning. eNeuro 2017; 4:eN-NWR-0241-16. [PMID: 28451640 PMCID: PMC5399754 DOI: 10.1523/eneuro.0241-16.2017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 03/29/2017] [Accepted: 04/03/2017] [Indexed: 01/20/2023] Open
Abstract
When complex sounds are reversed in time, the original and reversed versions are perceived differently in spectral and temporal dimensions despite their identical duration and long-term spectrum-power profiles. Spatiotemporal activation patterns evoked by temporally asymmetric sound pairs demonstrate how the temporal envelope determines the readout of the spectrum. We examined the patterns of activation evoked by a temporally asymmetric sound pair in the primary auditory field (AI) of anesthetized guinea pigs and determined how discrimination training modified these patterns. Optical imaging using a voltage-sensitive dye revealed that a forward ramped-down natural sound (F) consistently evoked much stronger responses than its time-reversed, ramped-up counterpart (revF). The spatiotemporal maximum peak (maxP) of F-evoked activation was always greater than that of revF-evoked activation, and these maxPs were significantly separated within the AI. Although discrimination training did not affect the absolute magnitude of these maxPs, the revF-to-F ratio of the activation peaks calculated at the location where hemispheres were maximally activated (i.e., F-evoked maxP) was significantly smaller in the trained group. The F-evoked activation propagated across the AI along the temporal axis to the ventroanterior belt field (VA), with the local activation peak within the VA being significantly larger in the trained than in the naïve group. These results suggest that the innate network is more responsive to natural sounds of ramped-down envelopes than their time-reversed, unnatural sounds. The VA belt field activation might play an important role in emotional learning of sounds through its connections with amygdala.
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Abstract
UNLABELLED Functional and anatomical studies have clearly demonstrated that auditory cortex is populated by multiple subfields. However, functional characterization of those fields has been largely the domain of animal electrophysiology, limiting the extent to which human and animal research can inform each other. In this study, we used high-resolution functional magnetic resonance imaging to characterize human auditory cortical subfields using a variety of low-level acoustic features in the spectral and temporal domains. Specifically, we show that topographic gradients of frequency preference, or tonotopy, extend along two axes in human auditory cortex, thus reconciling historical accounts of a tonotopic axis oriented medial to lateral along Heschl's gyrus and more recent findings emphasizing tonotopic organization along the anterior-posterior axis. Contradictory findings regarding topographic organization according to temporal modulation rate in acoustic stimuli, or "periodotopy," are also addressed. Although isolated subregions show a preference for high rates of amplitude-modulated white noise (AMWN) in our data, large-scale "periodotopic" organization was not found. Organization by AM rate was correlated with dominant pitch percepts in AMWN in many regions. In short, our data expose early auditory cortex chiefly as a frequency analyzer, and spectral frequency, as imposed by the sensory receptor surface in the cochlea, seems to be the dominant feature governing large-scale topographic organization across human auditory cortex. SIGNIFICANCE STATEMENT In this study, we examine the nature of topographic organization in human auditory cortex with fMRI. Topographic organization by spectral frequency (tonotopy) extended in two directions: medial to lateral, consistent with early neuroimaging studies, and anterior to posterior, consistent with more recent reports. Large-scale organization by rates of temporal modulation (periodotopy) was correlated with confounding spectral content of amplitude-modulated white-noise stimuli. Together, our results suggest that the organization of human auditory cortex is driven primarily by its response to spectral acoustic features, and large-scale periodotopy spanning across multiple regions is not supported. This fundamental information regarding the functional organization of early auditory cortex will inform our growing understanding of speech perception and the processing of other complex sounds.
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9
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Abstract
One of the fundamental properties of the mammalian brain is that sensory regions of cortex are formed of multiple, functionally specialized cortical field maps (CFMs). Each CFM comprises two orthogonal topographical representations, reflecting two essential aspects of sensory space. In auditory cortex, auditory field maps (AFMs) are defined by the combination of tonotopic gradients, representing the spectral aspects of sound (i.e., tones), with orthogonal periodotopic gradients, representing the temporal aspects of sound (i.e., period or temporal envelope). Converging evidence from cytoarchitectural and neuroimaging measurements underlies the definition of 11 AFMs across core and belt regions of human auditory cortex, with likely homology to those of macaque. On a macrostructural level, AFMs are grouped into cloverleaf clusters, an organizational structure also seen in visual cortex. Future research can now use these AFMs to investigate specific stages of auditory processing, key for understanding behaviors such as speech perception and multimodal sensory integration.
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Affiliation(s)
- Alyssa A Brewer
- Department of Cognitive Sciences and Center for Hearing Research, University of California, Irvine, California 92697; ,
| | - Brian Barton
- Department of Cognitive Sciences and Center for Hearing Research, University of California, Irvine, California 92697; ,
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10
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Abstract
The perception of pitch is a widely studied and hotly debated topic in human hearing. Many of these studies combine functional imaging techniques with stimuli designed to disambiguate the percept of pitch from frequency information present in the stimulus. While useful in identifying potential “pitch centres” in cortex, the existence of truly pitch-responsive neurons requires single neuron-level measures that can only be undertaken in animal models. While a number of animals have been shown to be sensitive to pitch, few studies have addressed the location of cortical generators of pitch percepts in non-human models. The current study uses high-field functional magnetic resonance imaging (fMRI) of the feline brain in an attempt to identify regions of cortex that show increased activity in response to pitch-evoking stimuli. Cats were presented with iterated rippled noise (IRN) stimuli, narrowband noise stimuli with the same spectral profile but no perceivable pitch, and a processed IRN stimulus in which phase components were randomized to preserve slowly changing modulations in the absence of pitch (IRNo). Pitch-related activity was not observed to occur in either primary auditory cortex (A1) or the anterior auditory field (AAF) which comprise the core auditory cortex in cats. Rather, cortical areas surrounding the posterior ectosylvian sulcus responded preferentially to the IRN stimulus when compared to narrowband noise, with group analyses revealing bilateral activity centred in the posterior auditory field (PAF). This study demonstrates that fMRI is useful for identifying pitch-related processing in cat cortex, and identifies cortical areas that warrant further investigation. Moreover, we have taken the first steps in identifying a useful animal model for the study of pitch perception.
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Affiliation(s)
- Blake E. Butler
- Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada
- Brain and Mind Institute, University of Western Ontario, London, Ontario, Canada
- * E-mail:
| | - Amee J. Hall
- Department of Anatomy and Cell Biology, University of Western Ontario, London, Ontario, Canada
| | - Stephen G. Lomber
- Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada
- Brain and Mind Institute, University of Western Ontario, London, Ontario, Canada
- Department of Psychology, University of Western Ontario, London, Ontario, Canada
- National Centre for Audiology, University of Western Ontario, London, Ontario, Canada
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11
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Hickok G, Farahbod H, Saberi K. The Rhythm of Perception: Entrainment to Acoustic Rhythms Induces Subsequent Perceptual Oscillation. Psychol Sci 2015; 26:1006-13. [PMID: 25968248 DOI: 10.1177/0956797615576533] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 02/17/2015] [Indexed: 11/15/2022] Open
Abstract
Acoustic rhythms are pervasive in speech, music, and environmental sounds. Recent evidence for neural codes representing periodic information suggests that they may be a neural basis for the ability to detect rhythm. Further, rhythmic information has been found to modulate auditory-system excitability, which provides a potential mechanism for parsing the acoustic stream. Here, we explored the effects of a rhythmic stimulus on subsequent auditory perception. We found that a low-frequency (3 Hz), amplitude-modulated signal induces a subsequent oscillation of the perceptual detectability of a brief nonperiodic acoustic stimulus (1-kHz tone); the frequency but not the phase of the perceptual oscillation matches the entrained stimulus-driven rhythmic oscillation. This provides evidence that rhythmic contexts have a direct influence on subsequent auditory perception of discrete acoustic events. Rhythm coding is likely a fundamental feature of auditory-system design that predates the development of explicit human enjoyment of rhythm in music or poetry.
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Affiliation(s)
- Gregory Hickok
- Department of Cognitive Sciences, University of California, Irvine
| | - Haleh Farahbod
- Department of Cognitive Sciences, University of California, Irvine
| | - Kourosh Saberi
- Department of Cognitive Sciences, University of California, Irvine
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12
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Gao X, Wehr M. A coding transformation for temporally structured sounds within auditory cortical neurons. Neuron 2015; 86:292-303. [PMID: 25819614 DOI: 10.1016/j.neuron.2015.03.004] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Revised: 12/11/2014] [Accepted: 02/17/2015] [Indexed: 12/01/2022]
Abstract
Although the coding transformation between visual thalamus and cortex has been known for over 50 years, whether a similar transformation occurs between auditory thalamus and cortex has remained elusive. Such a transformation may occur for time-varying sounds, such as music or speech. Most subcortical neurons explicitly encode the temporal structure of sounds with the temporal structure of their activity, but many auditory cortical neurons instead use a rate code. The mechanisms for this transformation from temporal code to rate code have remained unknown. Here we report that the membrane potential of rat auditory cortical neurons can show stimulus synchronization to rates up to 500 Hz, even when the spiking output does not. Synaptic inputs to rate-coding neurons arose in part from temporal-coding neurons but were transformed by voltage-dependent properties and push-pull excitatory-inhibitory interactions. This suggests that the transformation from temporal to rate code can be observed within individual cortical neurons.
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Affiliation(s)
- Xiang Gao
- Institute of Neuroscience and Department of Psychology, University of Oregon, Eugene, OR 97405, USA
| | - Michael Wehr
- Institute of Neuroscience and Department of Psychology, University of Oregon, Eugene, OR 97405, USA.
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13
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Baumann S, Joly O, Rees A, Petkov CI, Sun L, Thiele A, Griffiths TD. The topography of frequency and time representation in primate auditory cortices. eLife 2015; 4. [PMID: 25590651 PMCID: PMC4398946 DOI: 10.7554/elife.03256] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2014] [Accepted: 01/14/2015] [Indexed: 11/13/2022] Open
Abstract
Natural sounds can be characterised by their spectral content and temporal modulation, but how the brain is organized to analyse these two critical sound dimensions remains uncertain. Using functional magnetic resonance imaging, we demonstrate a topographical representation of amplitude modulation rate in the auditory cortex of awake macaques. The representation of this temporal dimension is organized in approximately concentric bands of equal rates across the superior temporal plane in both hemispheres, progressing from high rates in the posterior core to low rates in the anterior core and lateral belt cortex. In A1 the resulting gradient of modulation rate runs approximately perpendicular to the axis of the tonotopic gradient, suggesting an orthogonal organisation of spectral and temporal sound dimensions. In auditory belt areas this relationship is more complex. The data suggest a continuous representation of modulation rate across several physiological areas, in contradistinction to a separate representation of frequency within each area.
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Affiliation(s)
- Simon Baumann
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Olivier Joly
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Adrian Rees
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Christopher I Petkov
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Li Sun
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Alexander Thiele
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Timothy D Griffiths
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, United Kingdom
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14
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Abstract
The auditory cortex is a network of areas in the part of the brain that receives inputs from the subcortical auditory pathways in the brainstem and thalamus. Through an elaborate network of intrinsic and extrinsic connections, the auditory cortex is thought to bring about the conscious perception of sound and provide a basis for the comprehension and production of meaningful utterances. In this chapter, the organization of auditory cortex is described with an emphasis on its anatomic features and the flow of information within the network. These features are then used to introduce key neurophysiologic concepts that are being intensively studied in humans and animal models. The discussion is presented in the context of our working model of the primate auditory cortex and extensions to humans. The material is presented in the context of six underlying principles, which reflect distinct, but related, aspects of anatomic and physiologic organization: (1) the division of auditory cortex into regions; (2) the subdivision of regions into areas; (3) tonotopic organization of areas; (4) thalamocortical connections; (5) serial and parallel organization of connections; and (6) topographic relationships between auditory and auditory-related areas. Although the functional roles of the various components of this network remain poorly defined, a more complete understanding is emerging from ongoing studies that link auditory behavior to its anatomic and physiologic substrates.
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Affiliation(s)
- Troy A Hackett
- Department of Hearing and Speech Sciences, Vanderbilt University School of Medicine and Department of Psychology, Vanderbilt University, Nashville, TN, USA.
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15
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Moerel M, De Martino F, Formisano E. An anatomical and functional topography of human auditory cortical areas. Front Neurosci 2014; 8:225. [PMID: 25120426 PMCID: PMC4114190 DOI: 10.3389/fnins.2014.00225] [Citation(s) in RCA: 147] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Accepted: 07/08/2014] [Indexed: 12/22/2022] Open
Abstract
While advances in magnetic resonance imaging (MRI) throughout the last decades have enabled the detailed anatomical and functional inspection of the human brain non-invasively, to date there is no consensus regarding the precise subdivision and topography of the areas forming the human auditory cortex. Here, we propose a topography of the human auditory areas based on insights on the anatomical and functional properties of human auditory areas as revealed by studies of cyto- and myelo-architecture and fMRI investigations at ultra-high magnetic field (7 Tesla). Importantly, we illustrate that—whereas a group-based approach to analyze functional (tonotopic) maps is appropriate to highlight the main tonotopic axis—the examination of tonotopic maps at single subject level is required to detail the topography of primary and non-primary areas that may be more variable across subjects. Furthermore, we show that considering multiple maps indicative of anatomical (i.e., myelination) as well as of functional properties (e.g., broadness of frequency tuning) is helpful in identifying auditory cortical areas in individual human brains. We propose and discuss a topography of areas that is consistent with old and recent anatomical post-mortem characterizations of the human auditory cortex and that may serve as a working model for neuroscience studies of auditory functions.
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Affiliation(s)
- Michelle Moerel
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University Maastricht, Netherlands ; Maastricht Brain Imaging Center, Maastricht University Maastricht, Netherlands ; Department of Radiology, Center for Magnetic Resonance Research, University of Minnesota Minneapolis, MN, USA
| | - Federico De Martino
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University Maastricht, Netherlands ; Maastricht Brain Imaging Center, Maastricht University Maastricht, Netherlands
| | - Elia Formisano
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University Maastricht, Netherlands ; Maastricht Brain Imaging Center, Maastricht University Maastricht, Netherlands
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16
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Kanold PO, Nelken I, Polley DB. Local versus global scales of organization in auditory cortex. Trends Neurosci 2014; 37:502-10. [PMID: 25002236 DOI: 10.1016/j.tins.2014.06.003] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2014] [Revised: 06/06/2014] [Accepted: 06/12/2014] [Indexed: 11/24/2022]
Abstract
Topographic organization is a hallmark of sensory cortical organization. Topography is robust at spatial scales ranging from hundreds of microns to centimeters, but can dissolve at the level of neighboring neurons or subcellular compartments within a neuron. This dichotomous spatial organization is especially pronounced in the mouse auditory cortex, where an orderly tonotopic map can arise from heterogeneous frequency tuning between local neurons. Here, we address a debate surrounding the robustness of tonotopic organization in the auditory cortex that has persisted in some form for over 40 years. Drawing from various cortical areas, cortical layers, recording methodologies, and species, we describe how auditory cortical circuitry can simultaneously support a globally systematic, yet locally heterogeneous representation of this fundamental sound property.
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Affiliation(s)
- Patrick O Kanold
- Department of Biology, Institute for Systems Research, University of Maryland, College Park, MD 20742, USA; Program in Neuroscience and Cognitive Science, University of Maryland, College Park, MD 20742, USA.
| | - Israel Nelken
- Department of Neurobiology, Silberman Institute of Life Sciences and the Edmond and Lily Safra Center for Brain Sciences, Hebrew University, Jerusalem 91904, Israel.
| | - Daniel B Polley
- Department of Otology and Laryngology, Harvard Medical School, Boston, MA 02114, USA; Eaton-Peabody Laboratory, Massachusetts Eye and Ear Infirmary, Boston, MA 02114, USA.
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Abstract
The functional organization of human auditory cortex has not yet been characterized beyond a rudimentary level of detail. Here, we use functional MRI to measure the microstructure of orthogonal tonotopic and periodotopic gradients forming complete auditory field maps (AFMs) in human core and belt auditory cortex. These AFMs show clear homologies to subfields of auditory cortex identified in nonhuman primates and in human cytoarchitectural studies. In addition, we present measurements of the macrostructural organization of these AFMs into "clover leaf" clusters, consistent with the macrostructural organization seen across human visual cortex. As auditory cortex is at the interface between peripheral hearing and central processes, improved understanding of the organization of this system could open the door to a better understanding of the transformation from auditory spectrotemporal signals to higher-order information such as speech categories.
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Verhey JL, Klein-Hennig H, Epp B. Masking release for sweeping masker components with correlated envelopes. J Assoc Res Otolaryngol 2012; 14:139-47. [PMID: 23053626 DOI: 10.1007/s10162-012-0351-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Accepted: 09/11/2012] [Indexed: 11/25/2022] Open
Abstract
To separate sounds from different sound sources, common properties of natural sounds are used by the auditory system, such as coherent temporal envelope fluctuations and correlated changes of frequency in different frequency regions. The present study investigates how the auditory system processes a combination of these cues using a generalized comodulation masking release (CMR) paradigm. CMR is the effect of a better signal detectability in the presence of comodulated maskers than in the presence of maskers with uncorrelated envelope fluctuations across frequencies. Using a flanking-band paradigm, the results of the first experiment of the present study show that CMR is still observed for the masker and the signal coherently sweeping up or down in frequency over time, up to a sweep rate of six octaves per second. Motivated by the successful modeling of CMR using filters sensitive to temporal modulations and recent physiological evidence of spectro-temporal modulation filters, the second experiment investigates whether CMR is also observed for spectro-temporal masker modulations generated using time-shifted versions of the masker envelope for each component. The thresholds increase as soon as the temporally coherent masker modulation is changed to a spectro-temporal masker modulation, indicating that spectro-temporal modulation filters are presumably not required in CMR models.
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Affiliation(s)
- Jesko L Verhey
- Department of Experimental Audiology, Otto von Guericke University Magdeburg, Leipziger Str. 44, 31920, Magdeburg, Germany.
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Wang X, Walker KMM. Neural mechanisms for the abstraction and use of pitch information in auditory cortex. J Neurosci 2012; 32:13339-42. [PMID: 23015423 PMCID: PMC3752151 DOI: 10.1523/jneurosci.3814-12.2012] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Revised: 07/18/2012] [Accepted: 07/23/2012] [Indexed: 11/21/2022] Open
Abstract
Experiments in animals have provided an important complement to human studies of pitch perception by revealing how the activity of individual neurons represents harmonic complex and periodic sounds. Such studies have shown that the acoustical parameters associated with pitch are represented by the spiking responses of neurons in A1 (primary auditory cortex) and various higher auditory cortical fields. The responses of these neurons are also modulated by the timbre of sounds. In marmosets, a distinct region on the low-frequency border of primary and non-primary auditory cortex may provide pitch tuning that generalizes across timbre classes.
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Affiliation(s)
- Xiaoqin Wang
- Tsinghua-Johns Hopkins Joint Center for Biomedical Engineering Research and Department of Biomedical Engineering, Tsinghua University, Beijing 100084, China.
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Ogawa T, Riera J, Goto T, Sumiyoshi A, Nonaka H, Jerbi K, Bertrand O, Kawashima R. Large-scale heterogeneous representation of sound attributes in rat primary auditory cortex: from unit activity to population dynamics. J Neurosci 2011; 31:14639-53. [PMID: 21994380 PMCID: PMC6703402 DOI: 10.1523/jneurosci.0086-11.2011] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2011] [Revised: 07/29/2011] [Accepted: 08/15/2011] [Indexed: 11/21/2022] Open
Abstract
Recent evidence indicates the existence of pyramidal cells (PCs) and interneurons with nontrivial tuning characteristics for sound attributes in the primary auditory cortex (A1) of mammals. These neurons are functionally distributed into layers and sparsely organized at a small scale. However, their topological locations at a large scale in A1 have not yet been investigated. Furthermore, these neurons are usually classified from fine maps of attribute-dependent spiking activity, and not much attention is paid to population postsynaptic potentials related to their activity. We used extracellular recordings obtained from multiple sites in A1 of adult rats to determine neuronal codifiers for sound attributes defined by coarse representations of the population dose-response curves. We demonstrated that these codifiers, majorly involving PCs, are heterogeneously distributed along A1. Spiking activity in these neurons during stimulation was correlated to β (12-25 Hz) and low γ (25-70 Hz) postsynaptic oscillations in the infragranular layer, whereas in the supragranular layer, better correlations were found with high γ (70-170 Hz) oscillations. The time-frequency analysis of the postsynaptic potentials showed a transient broadband power increase in all layers after the stimulus onset that was followed by a sustained high γ oscillation in the supragranular layer, fluctuations in the laminar content of the low-frequency oscillations, and a global attenuation in the low-frequency powers after the stimulus offset that happened together with a long-lasting strengthening of the β oscillations. We concluded that, for rats, sounds are codified in A1 by segregated networks of specialized PCs whose postsynaptic activity impinges on the emergence of sparse/dense spiking patterns.
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Affiliation(s)
| | | | | | | | | | - Karim Jerbi
- INSERM U1028, CNRS UMR5292, University Lyon 1, Lyon Neuroscience Research Center, Brain Dynamics and Cognition, Lyon 69500, France
| | - Olivier Bertrand
- INSERM U1028, CNRS UMR5292, University Lyon 1, Lyon Neuroscience Research Center, Brain Dynamics and Cognition, Lyon 69500, France
| | - Ryuta Kawashima
- Department of Functional Brain Imaging and
- Smart Aging International Research Center, Institute of Development, Aging, and Cancer, Tohoku University, Sendai 980-8575, Japan, and
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Imaizumi K, Priebe NJ, Cheung SW, Schreiner CE. Spatial organization of repetition rate processing in cat anterior auditory field. Hear Res 2011; 280:70-81. [PMID: 21569829 DOI: 10.1016/j.heares.2011.04.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2010] [Revised: 03/30/2011] [Accepted: 04/18/2011] [Indexed: 10/18/2022]
Abstract
Auditory cortex updates incoming information on a segment by segment basis for human speech and animal communication. Measuring repetition rate transfer functions (RRTFs) captures temporal responses to repetitive sounds. In this study, we used repetitive click trains to describe the spatial distribution of RRTF responses in cat anterior auditory field (AAF) and to discern potential variations in local temporal processing capacity. A majority of RRTF filters are band-pass. Temporal parameters estimated from RRTFs and corrected for characteristic frequency or latency dependencies are non-homogeneously distributed across AAF. Unlike the shallow global gradient observed in spectral receptive field parameters, transitions from loci with high to low temporal parameters are steep. Quantitative spatial analysis suggests non-uniform, circumscribed local organization for temporal pattern processing superimposed on global organization for spectral processing in cat AAF.
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Affiliation(s)
- Kazuo Imaizumi
- Coleman Memorial Laboratory, W.M. Keck Center for Integrative Neuroscience, University of California, San Francisco, CA 94143-0732, United States.
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Cortical encoding of pitch: recent results and open questions. Hear Res 2010; 271:74-87. [PMID: 20457240 PMCID: PMC3098378 DOI: 10.1016/j.heares.2010.04.015] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2009] [Revised: 04/30/2010] [Accepted: 04/30/2010] [Indexed: 11/16/2022]
Abstract
It is widely appreciated that the key predictor of the pitch of a sound is its periodicity. Neural structures which support pitch perception must therefore be able to reflect the repetition rate of a sound, but this alone is not sufficient. Since pitch is a psychoacoustic property, a putative cortical code for pitch must also be able to account for the relationship between the amount to which a sound is periodic (i.e. its temporal regularity) and the perceived pitch salience, as well as limits in our ability to detect pitch changes or to discriminate rising from falling pitch. Pitch codes must also be robust in the presence of nuisance variables such as loudness or timbre. Here, we review a large body of work on the cortical basis of pitch perception, which illustrates that the distribution of cortical processes that give rise to pitch perception is likely to depend on both the acoustical features and functional relevance of a sound. While previous studies have greatly advanced our understanding, we highlight several open questions regarding the neural basis of pitch perception. These questions can begin to be addressed through a cooperation of investigative efforts across species and experimental techniques, and, critically, by examining the responses of single neurons in behaving animals.
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