A statistical atlas-based technique for automatic segmentation of the first Heschl's gyrus in human auditory cortex from MR images

Voice onset time (VOT) is an important parameter of speech that denotes the time interval between consonant onset and the onset of low-frequency periodicity generated by rhythmic vocal cord vibration. Voiced stop consonants (/b/, /g/, and /d/) in syllable initial position are characterized by short VOTs, whereas unvoiced stop consonants (/p/, /k/, and t/) contain prolonged VOTs. As the VOT is increased in incremental steps, perception rapidly changes from a voiced stop consonant to an unvoiced consonant at an interval of 20–40 ms. This abrupt change in consonant identification is an example of categorical speech perception and is a central feature of phonetic discrimination. This study tested the hypothesis that VOT is represented within auditory cortex by transient responses time-locked to consonant and voicing onset. Auditory evoked potentials (AEPs) elicited by stop consonant-vowel (CV) syllables were recorded directly from Heschl's gyrus, the planum temporale, and the superior temporal gyrus in three patients undergoing evaluation for surgical remediation of medically intractable epilepsy. Voiced CV syllables elicited a triphasic sequence of field potentials within Heschl's gyrus. AEPs evoked by unvoiced CV syllables contained additional response components time-locked to voicing onset. Syllables with a VOT of 40, 60, or 80 ms evoked components time-locked to consonant release and voicing onset. In contrast, the syllable with a VOT of 20 ms evoked a markedly diminished response to voicing onset and elicited an AEP very similar in morphology to that evoked by the syllable with a 0-ms VOT. Similar response features were observed in the AEPs evoked by click trains. In this case, there was a marked decrease in amplitude of the transient response to the second click in trains with interpulse intervals of 20–25 ms. Speech-evoked AEPs recorded from the posterior superior temporal gyrus lateral to Heschl's gyrus displayed comparable response features, whereas field potentials recorded from three locations in the planum temporale did not contain components time-locked to voicing onset. This study demonstrates that VOT at least partially is represented in primary and specific secondary auditory cortical fields by synchronized activity time-locked to consonant release and voicing onset. Furthermore, AEPs exhibit features that may facilitate categorical perception of stop consonants, and these response patterns appear to be based on temporal processing limitations within auditory cortex. Demonstrations of similar speech-evoked response patterns in animals support a role for these experimental models in clarifying selected features of speech encoding.

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Consonance and Dissonance of Musical Chords: Neural Correlates in Auditory Cortex of Monkeys and Humans

Journal of Neurophysiology ◽

10.1152/jn.2001.86.6.2761 ◽

2001 ◽

Vol 86 (6) ◽

pp. 2761-2788 ◽

Cited By ~ 106

Author(s):

Yonatan I. Fishman ◽

Igor O. Volkov ◽

M. Daniel Noh ◽

P. Charles Garell ◽

Hans Bakken ◽

...

Keyword(s):

Auditory Cortex ◽

Current Source ◽

Intractable Epilepsy ◽

Auditory Evoked Potential ◽

Harmonic Complex ◽

Heschl’S Gyrus ◽

Complex Tones ◽

Heschl's Gyrus ◽

Musical Chords ◽

Consonance And Dissonance

Some musical chords sound pleasant, or consonant, while others sound unpleasant, or dissonant. Helmholtz's psychoacoustic theory of consonance and dissonance attributes the perception of dissonance to the sensation of “beats” and “roughness” caused by interactions in the auditory periphery between adjacent partials of complex tones comprising a musical chord. Conversely, consonance is characterized by the relative absence of beats and roughness. Physiological studies in monkeys suggest that roughness may be represented in primary auditory cortex (A1) by oscillatory neuronal ensemble responses phase-locked to the amplitude-modulated temporal envelope of complex sounds. However, it remains unknown whether phase-locked responses also underlie the representation of dissonance in auditory cortex. In the present study, responses evoked by musical chords with varying degrees of consonance and dissonance were recorded in A1 of awake macaques and evaluated using auditory-evoked potential (AEP), multiunit activity (MUA), and current-source density (CSD) techniques. In parallel studies, intracranial AEPs evoked by the same musical chords were recorded directly from the auditory cortex of two human subjects undergoing surgical evaluation for medically intractable epilepsy. Chords were composed of two simultaneous harmonic complex tones. The magnitude of oscillatory phase-locked activity in A1 of the monkey correlates with the perceived dissonance of the musical chords. Responses evoked by dissonant chords, such as minor and major seconds, display oscillations phase-locked to the predicted difference frequencies, whereas responses evoked by consonant chords, such as octaves and perfect fifths, display little or no phase-locked activity. AEPs recorded in Heschl's gyrus display strikingly similar oscillatory patterns to those observed in monkey A1, with dissonant chords eliciting greater phase-locked activity than consonant chords. In contrast to recordings in Heschl's gyrus, AEPs recorded in the planum temporale do not display significant phase-locked activity, suggesting functional differentiation of auditory cortical regions in humans. These findings support the relevance of synchronous phase-locked neural ensemble activity in A1 for the physiological representation of sensory dissonance in humans and highlight the merits of complementary monkey/human studies in the investigation of neural substrates underlying auditory perception.

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Pitch and Duration Mismatch Negativity and Heschl’s Gyrus Volume in First-Episode Schizophrenia-Spectrum Individuals

Clinical EEG and Neuroscience ◽

10.1177/1550059420914214 ◽

2020 ◽

Vol 51 (6) ◽

pp. 359-364 ◽

Cited By ~ 1

Author(s):

Dean F. Salisbury ◽

Anna R. Shafer ◽

Timothy K. Murphy ◽

Sarah M. Haigh ◽

Brian A. Coffman

Keyword(s):

Auditory Cortex ◽

Left Hemisphere ◽

Gray Matter ◽

Mismatch Negativity ◽

First Episode ◽

Disease Course ◽

Heschl’S Gyrus ◽

Schizophrenia Spectrum ◽

Heschl's Gyrus ◽

First Episode Schizophrenia

Background. The mismatch negativity (MMN) brainwave indexes novelty detection. MMN to infrequent pitch (pMMN) and duration (dMMN) deviants is reduced in long-term schizophrenia. Although not reduced at first psychosis, pMMN is inversely associated with left hemisphere Heschl’s gyrus (HG) gray matter volume within 1 year of first hospitalization for schizophrenia-spectrum psychosis, consistent with pathology of left primary auditory cortex early in disease course. We examined whether the relationship was present earlier, at first psychiatric contact for psychosis, and whether the same structural-functional association was apparent for dMMN. Method. Twenty-seven first-episode schizophrenia-spectrum (FESz) and 27 matched healthy comparison (HC) individuals were compared. EEG-derived pMMN and dMMN were measured by subtracting the standard tone waveform (80%) from the pitch- and duration-deviant waveforms (10% each). HG volumes were calculated from T1-weighted structural magnetic resonance imaging using Freesurfer. Results. In FESz, pMMN amplitudes at Fz were inversely associated with left HG (but not right) gray matter volumes, and dMMN amplitudes were associated significantly with left HG volumes and at trend-level with right HG. There were no structural-functional associations in HC. Conclusions. pMMN and dMMN index gray matter reduction in left hemisphere auditory cortex early in psychosis, with dMMN also marginally indexing right HG volumes. This suggest conjoint functional and structural pathology that affects the automatic detection of novelty with varying degrees of penetrance prior to psychosis. These brainwaves are sensitive biomarkers of pathology early in the psychotic disease course, and may serve as biomarkers of disease progression and as therapeutic outcome measures.

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Hemispheric asymmetry of primary auditory cortex and Heschl's gyrus in schizophrenia and nonpsychiatric brains

Psychiatry Research Neuroimaging ◽

10.1016/j.pscychresns.2013.08.009 ◽

2013 ◽

Vol 214 (3) ◽

pp. 435-443 ◽

Cited By ~ 6

Author(s):

John F. Smiley ◽

Troy A. Hackett ◽

Todd M. Preuss ◽

Cynthia Bleiwas ◽

Khadija Figarsky ◽

...

Keyword(s):

Auditory Cortex ◽

Hemispheric Asymmetry ◽

Primary Auditory Cortex ◽

Heschl’S Gyrus ◽

Heschl's Gyrus

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Coding of Repetitive Transients by Auditory Cortex on Heschl's Gyrus

Journal of Neurophysiology ◽

10.1152/jn.91346.2008 ◽

2009 ◽

Vol 102 (4) ◽

pp. 2358-2374 ◽

Cited By ~ 109

Author(s):

John F. Brugge ◽

Kirill V. Nourski ◽

Hiroyuki Oya ◽

Richard A. Reale ◽

Hiroto Kawasaki ◽

...

Keyword(s):

Auditory Cortex ◽

Intractable Epilepsy ◽

Primate Species ◽

Frequency Following Response ◽

Depth Electrodes ◽

Heschl’S Gyrus ◽

Long Latency ◽

Surgical Evaluation ◽

Latency Response ◽

Heschl's Gyrus

The capacity of auditory cortex on Heschl's gyrus (HG) to encode repetitive transients was studied in human patients undergoing surgical evaluation for medically intractable epilepsy. Multicontact depth electrodes were chronically implanted in gray matter of HG. Bilaterally presented stimuli were click trains varying in rate from 4 to 200 Hz. Averaged evoked potentials (AEPs) and event-related band power (ERBP), computed from responses at each of 14 recording sites, identified two auditory fields. A core field, which occupies posteromedial HG, was characterized by a robust polyphasic AEP on which could be superimposed a frequency following response (FFR). The FFR was prominent at click rates below ∼50 Hz, decreased rapidly as click rate was increased, but could reliably be detected at click rates as high as 200 Hz. These data are strikingly similar to those obtained by others in the monkey under essentially the same stimulus conditions, indicating that mechanisms underlying temporal processing in the auditory core may be highly conserved across primate species. ERBP, which reflects increases or decreases of both phase-locked and non–phase-locked power within given frequency bands, showed stimulus-related increases in gamma band frequencies as high as 250 Hz. The AEPs recorded in a belt field anterolateral to the core were typically of low amplitude, showing little or no evidence of short-latency waves or an FFR, even at the lowest click rates used. The non–phase-locked component of the response extracted from the ERBP showed a robust, long-latency response occurring here in response to the highest click rates in the series.

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A sound-sensitive source of alpha oscillations in human non-primary auditory cortex

10.1101/590323 ◽

2019 ◽

Cited By ~ 1

Author(s):

Alexander J. Billig ◽

Björn Herrmann ◽

Ariane E. Rhone ◽

Phillip E. Gander ◽

Kirill V. Nourski ◽

...

Keyword(s):

Auditory Cortex ◽

Functional Organization ◽

Temporal Cortex ◽

Alpha Activity ◽

Primary Field ◽

Alpha Oscillations ◽

Heschl’S Gyrus ◽

Superior Temporal Cortex ◽

Heschl's Gyrus ◽

And Function

AbstractThe functional organization of human auditory cortex can be probed by characterizing responses to various classes of sound at different anatomical locations. Along with histological studies this approach has revealed a primary field in posteromedial Heschl’s gyrus (HG) with pronounced induced high-frequency (70-150 Hz) activity and short-latency responses that phase-lock to rapid transient sounds. Low-frequency neural oscillations are also relevant to stimulus processing and information flow, however their distribution within auditory cortex has not been established. Alpha activity (7-14 Hz) in particular has been associated with processes that may differentially engage earlier versus later levels of the cortical hierarchy, including functional inhibition and the communication of sensory predictions. These theories derive largely from the study of occipitoparietal sources readily detectable in scalp electroencephalography. To characterize the anatomical basis and functional significance of less accessible temporal-lobe alpha activity we analyzed responses to sentences in seven human adults (four female) with epilepsy who had been implanted with electrodes in superior temporal cortex. In contrast to primary cortex in posteromedial HG, a non-primary field in anterolateral HG was characterized by high spontaneous alpha activity that was strongly suppressed during auditory stimulation. Alpha-power suppression decreased with distance from anterolateral HG throughout superior temporal cortex, and was more pronounced for clear compared to degraded speech. This suppression could not be accounted for solely by a change in the slope of the power spectrum. The differential manifestation and stimulus-sensitivity of alpha oscillations across auditory fields should be accounted for in theories of their generation and function.Significance StatementTo understand how auditory cortex is organized in support of perception, we recorded from patients implanted with electrodes for clinical reasons. This allowed measurement of activity in brain regions at different levels of sensory processing. Oscillations in the alpha range (7-14 Hz) have been associated with functions including sensory prediction and inhibition of regions handling irrelevant information, but their distribution within auditory cortex is not known. A key finding was that these oscillations dominated in one particular non-primary field, anterolateral Heschl’s gyrus, and were suppressed when subjects listened to sentences. These results build on our knowledge of the functional organization of auditory cortex and provide anatomical constraints on theories of the generation and function of alpha oscillations.

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Prediction in Human Auditory Cortex

10.1101/474718 ◽

2018 ◽

Author(s):

KJ Forseth ◽

G Hickok ◽

Patrick Rollo ◽

N Tandon

Keyword(s):

Speech Perception ◽

Auditory Cortex ◽

Low Frequency ◽

Spoken Language ◽

Heschl’S Gyrus ◽

Gamma Power ◽

Heschl's Gyrus ◽

And Function ◽

Predictive Mechanisms ◽

Speech Perception And Production

AbstractSpoken language is thought to be facilitated by an ensemble of predictive mechanisms, yet the neurobiology of prediction for both speech perception and production remains unknown. We used intracranial recordings (31 patients, 6580 electrodes) from depth probes implanted along the anteroposterior extent of the supratemporal plane during rhythm listening, speech perception, and speech production. This revealed a frequency-multiplexed encoding of sublexical features during entrainment and a traveling wave of high-frequency activity across Heschl’s gyrus. Critically, we isolated two predictive mechanisms in early auditory cortex with distinct anatomical and functional characteristics. The first mechanism, localized to bilateral Heschl’s gyrus and indexed by low-frequency phase, predicts the timing of acoustic events (“when”). The second mechanism, localized to planum temporale in the language-dominant hemisphere and indexed by gamma power, predicts the acoustic consequence of speech motor plans (“what”). This work grounds cognitive models of speech perception and production in human neurobiology, illuminating the fundamental acoustic infrastructure – both architecture and function – for spoken language.

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