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

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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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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Temporal Encoding of the Voice Onset Time Phonetic Parameter by Field Potentials Recorded Directly From Human Auditory Cortex

Journal of Neurophysiology ◽

10.1152/jn.1999.82.5.2346 ◽

1999 ◽

Vol 82 (5) ◽

pp. 2346-2357 ◽

Cited By ~ 120

Author(s):

Mitchell Steinschneider ◽

Igor O. Volkov ◽

M. Daniel Noh ◽

P. Charles Garell ◽

Matthew A. Howard

Keyword(s):

Auditory Cortex ◽

Voice Onset Time ◽

Onset Time ◽

Stop Consonant ◽

Superior Temporal Gyrus ◽

Response Patterns ◽

Stop Consonants ◽

Field Potentials ◽

Heschl’S Gyrus ◽

Heschl's Gyrus

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

2008 30th Annual International Conference of the IEEE Engineering in Medicine and Biology Society ◽

10.1109/iembs.2008.4650067 ◽

2008 ◽

Author(s):

Amir M. Tahmasebi ◽

I.S. Johnsrude ◽

C. Wild ◽

M. H. Moghari ◽

P. Abolmaesumi

Keyword(s):

Auditory Cortex ◽

Automatic Segmentation ◽

Mr Images ◽

Heschl’S Gyrus ◽

Heschl's Gyrus ◽

Human Auditory Cortex ◽

Statistical Atlas

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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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Tone Profiles of Isolated Musical Chords: Psychoacoustic Versus Cognitive Models

Music Perception An Interdisciplinary Journal ◽

10.1525/mp.2019.36.4.406 ◽

2019 ◽

Vol 36 (4) ◽

pp. 406-430

Author(s):

Richard Parncutt ◽

Sabrina Sattmann ◽

Andreas Gaich ◽

Annemarie Seither-Preisler

Keyword(s):

Effect Size ◽

Historical Development ◽

Cognitive Models ◽

Statistical Properties ◽

Musical Structure ◽

Harmonic Complex ◽

Complex Tones ◽

Musical Chords ◽

Lower Tone

We investigated perception of virtual pitches at missing fundamentals (MFs) in musical chords of three chromas (simultaneous trichords). Tone profiles for major, minor, diminished, augmented, suspended, and four other trichords of octave-complex tones were determined. In Experiment 1, 40 musicians rated how well a tone went with a preceding chord; in Experiment 2, whether the tone was in the chord. Mean ratings for nine non-chord tones were compared with predictions of four models: MFs, diatonicity, 5th-interval relations, and tones that complete familiar tetrachords (e.g., 7th chords). Profiles were accounted for by all four models in Experiment 1, and two (MFs, 5th relations) in Experiment 2. Overall, effect size was largest for MFs. In Experiment 3, listeners heard a chord and chose a matching tone from 12 possibilities. Profile peaks were predicted by pitch models (usually, the lower tone of a perfect 5th). Participants who more likely attended to MFs in isolated harmonic complex tones (fundamental listeners) were not more sensitive to MFs in chords, suggesting their responses instead depended on statistical properties of familiar music. We propose a speculative, psychohistoric explanation: MFs influenced the historical development of musical structure, which in turn influenced the perception of enculturated modern listeners.

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Spectral response patterns of auditory cortex neurons to harmonic complex tones in alert monkey (Macaca mulatta)

Journal of Neurophysiology ◽

10.1152/jn.1990.64.1.282 ◽

1990 ◽

Vol 64 (1) ◽

pp. 282-298 ◽

Cited By ~ 51

Author(s):

D. W. Schwarz ◽

R. W. Tomlinson

Keyword(s):

Receptive Field ◽

Auditory Cortex ◽

Pure Tone ◽

Response Pattern ◽

Response Patterns ◽

Neuronal Responses ◽

Harmonic Complex ◽

Tuning Curves ◽

Complex Tones ◽

Pure Tones

1. The auditory cortex in the superior temporal region of the alert rhesus monkey was explored for neuronal responses to pure and harmonic complex tones and noise. The monkeys had been previously trained to recognize the similarity between harmonic complex tones with and without fundamentals. Because this suggested that they could preceive the pitch of the lacking fundamental similarly to humans, we searched for neuronal responses relevant to this perception. 2. Combination-sensitive neurons that might explain pitch perception were not found in the surveyed cortical regions. Such neurons would exhibit similar responses to stimuli with similar periodicities but differing spectral compositions. The fact that no neuron with responses to a fundamental frequency responded also to a corresponding harmonic complex missing the fundamental indicates that cochlear distortion products at the fundamental may not have been responsible for missing fundamental-pitch perception in these monkeys. 3. Neuronal responses can be expressed as relatively simple filter functions. Neurons with excitatory response areas (tuning curves) displayed various inhibitory sidebands at lower and/or higher frequencies. Thus responses varied along a continuum of combined excitatory and inhibitory filter functions. 4. Five elementary response classes along this continuum are presented to illustrate the range of response patterns. 5. “Filter (F) neurons” had little or no inhibitory sidebands and responded well when any component of a complex tone entered its pure-tone receptive field. Bandwidths increased with intensity. Filter functions of these neurons were thus similar to cochlear nerve-fiber tuning curves. 6. ”High-resolution filter (HRF) neurons” displayed narrow tuning curves with narrowband widths that displayed little growth with intensity. Such cells were able to resolve up to the lowest seven components of harmonic complex tones as distinct responses. They also responded well to wideband stimuli. 7. “Fundamental (F0) neurons” displayed similar tuning bandwidths for pure tones and corresponding fundamentals of harmonic complexes. This response pattern was due to lower harmonic complexes. This response pattern was due to lower inhibitory sidebands. Thus these cells cannot respond to missing fundamentals of harmonic complexes. Only physically present components in the pure-tone receptive field would excite such neurons. 8. Cells with no or very weak responses to pure tones or other narrowband stimuli responded well to harmonic complexes or wideband noise.(ABSTRACT TRUNCATED AT 400 WORDS)

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