Faculty Opinions recommendation of Ultra-fine frequency tuning revealed in single neurons of human auditory cortex.

The frequency resolution of neurons throughout the ascending auditory pathway is important for understanding how sounds are processed. In many animal studies, the frequency tuning widths are about 1/5th octave wide in auditory nerve fibers and much wider in auditory cortex neurons. Psychophysical studies show that humans are capable of discriminating far finer frequency differences. A recent study suggested that this is perhaps attributable to fine frequency tuning of neurons in human auditory cortex (Bitterman Y, Mukamel R, Malach R, Fried I, Nelken I. Nature 451: 197–201, 2008). We investigated whether such fine frequency tuning was restricted to human auditory cortex by examining the frequency tuning width in the awake common marmoset monkey. We show that 27% of neurons in the primary auditory cortex exhibit frequency tuning that is finer than the typical frequency tuning of the auditory nerve and substantially finer than previously reported cortical data obtained from anesthetized animals. Fine frequency tuning is also present in 76% of neurons of the auditory thalamus in awake marmosets. Frequency tuning was narrower during the sustained response compared to the onset response in auditory cortex neurons but not in thalamic neurons, suggesting that thalamocortical or intracortical dynamics shape time-dependent frequency tuning in cortex. These findings challenge the notion that the fine frequency tuning of auditory cortex is unique to human auditory cortex and that it is a de novo cortical property, suggesting that the broader tuning observed in previous animal studies may arise from the use of anesthesia during physiological recordings or from species differences.

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Attention Improves Population-Level Frequency Tuning in Human Auditory Cortex

Journal of Neuroscience ◽

10.1523/jneurosci.2963-07.2007 ◽

2007 ◽

Vol 27 (39) ◽

pp. 10383-10390 ◽

Cited By ~ 65

Author(s):

H. Okamoto ◽

H. Stracke ◽

C. H. Wolters ◽

F. Schmael ◽

C. Pantev

Keyword(s):

Auditory Cortex ◽

Frequency Tuning ◽

Population Level ◽

Human Auditory Cortex

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Frequency-specific modulation of population-level frequency tuning in human auditory cortex

BMC Neuroscience ◽

10.1186/1471-2202-10-1 ◽

2009 ◽

Vol 10 (1) ◽

Cited By ~ 47

Author(s):

Hidehiko Okamoto ◽

Henning Stracke ◽

Pienie Zwitserlood ◽

Larry E Roberts ◽

Christo Pantev

Keyword(s):

Auditory Cortex ◽

Frequency Tuning ◽

Population Level ◽

Human Auditory Cortex

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Combining ultra-high-field fMRI adaptation and computational modelling to estimate neuronal frequency selectivity in human auditory cortex

10.1101/2022.01.06.475208 ◽

2022 ◽

Author(s):

Julien Besle ◽

Rosa-Maria Sánchez-Panchuelo ◽

Susan Francis ◽

Katrin Krumbholz

Keyword(s):

Auditory Cortex ◽

Frequency Tuning ◽

Computational Modelling ◽

Frequency Selectivity ◽

Bold Response ◽

Specific Adaptation ◽

Tuning Curves ◽

Frequency Independent ◽

Human Auditory Cortex ◽

Fmri Adaptation

Frequency selectivity is a ubiquitous property of auditory neurons. Measuring it in human auditory cortex may be crucial for understanding common auditory deficits, but current non-invasive neuroimaging techniques can only measure the aggregate response of large populations of cells, thereby overestimating tuning width. Here we attempted to estimate neuronal frequency tuning in human auditory cortex using a combination of fMRI-adaptation paradigm at 7T and computational modelling. We measured the BOLD response in the auditory cortex of eleven participants to a high frequency (3.8 kHz) probe presented alone or preceded by adaptors at different frequencies (0.5 to 3.8 kHz). From these data, we derived both the response tuning curves (the BOLD response to adaptors alone as a function of adaptor frequency) and adaptation tuning curves (the degree of response suppression to the probe as a function of adaptor frequency, assumed to reflect neuronal tuning) in primary and secondary auditory cortical areas, delineated in each participant. Results suggested the existence of both frequency-independent and frequency-specific adaptation components, with the latter being more frequency-tuned than response tuning curves. Using a computational model of neuronal adaptation and BOLD non-linearity in topographically-organized cortex, we demonstrate both that the frequency-specific adaptation component overestimates the underlying neuronal frequency tuning and that frequency-specific and frequency-independent adaptation component cannot easily be disentangled from the adaptation tuning curve. By fitting our model directly to the response and adaptation tuning curves, we derive a range of plausible values for neuronal frequency tuning. Our results suggest that fMRI adaptation is suitable for measuring neuronal frequency tuning properties in human auditory cortex, provided population effects and the non-linearity of BOLD response are taken into account.

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Responses of single neurons in posterior field of cat auditory cortex to tonal stimulation

Journal of Neurophysiology ◽

10.1152/jn.1984.51.1.147 ◽

1984 ◽

Vol 51 (1) ◽

pp. 147-163 ◽

Cited By ~ 89

Author(s):

D. P. Phillips ◽

S. S. Orman

Keyword(s):

Auditory Cortex ◽

Sound Pressure Level ◽

Sound Pressure ◽

Frequency Tuning ◽

Tuning Curve ◽

Pressure Level ◽

Spike Count ◽

Single Neurons ◽

High Stimulus ◽

Posterior Field

In the auditory cortex of barbiturate-anesthetized cats, the posterior auditory field (field P) was identified by its tonotopic organization, and single neurons in that field were studied quantitatively for their sensitivity to the frequency and intensity of tonal stimuli presented via calibrated, sealed stimulating systems. Field P neurons had narrow, V-shaped, threshold frequency tuning curves. At suprathreshold levels, spike counts were generally greatest at frequencies at or close to the neuron's threshold best frequency (BF). Eighty-six percent of posterior-field neurons displayed spike counts that were a nonmonotonic function of the intensity of a BF tone. Of these, over 90% showed at least a 50% reduction in spike count at high stimulus levels, and almost 20% of nonmonotonic cells ceased responding entirely at high stimulus intensities. The nonmonotonic shape of spike count-versus-intensity profiles was typically preserved across the range of frequencies to which any given neuron was responsive. For some neurons, this had the consequence of generating a completely circumscribed frequency-intensity response area. That is, these neurons responded to a tonal stimulus only if the stimulus was within a restricted range of both frequency and intensity. These response areas showed internal organizations that appeared to reflect one or both of two processes. For some neurons, the optimal sound pressure level for spike counts varied with tone frequency, roughly paralleling the threshold tuning curve. For other neurons, the optimal sound pressure level tended to be constant across frequency despite threshold variations of up to 20 dB. The minimum response latencies of posterior-field neurons were generally in the range of 20-50 ms, while cells in the primary auditory cortex (AI) in the same animals generally had minimum latent periods of less than 20 ms. Comparison of these data with those previously presented for neurons in two other cortical auditory fields suggests that the cat's auditory cortex might show an interfield segregation of neurons according to their coding properties.

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