Contribution of auditory cortex to sound localization by the ferret (Mustela putorius)

1987 ◽  
Vol 57 (6) ◽  
pp. 1746-1766 ◽  
Author(s):  
G. L. Kavanagh ◽  
J. B. Kelly
Keyword(s):  
Auditory Cortex ◽  
Sound Localization ◽  
Horizontal Plane ◽  
Primary Auditory Cortex ◽  
Cortical Lesions ◽  
Mustela Putorius ◽  
Complete Destruction ◽  
Left And Right ◽  
The Right ◽  
Bilateral Lesions

Ferrets were tested in a semicircular apparatus to determine the effects of auditory cortical lesions on their ability to localize sounds in space. They were trained to initiate trials while facing forward in the apparatus, and sounds were presented from one of two loudspeakers located in the horizontal plane. Minimum audible angles were obtained for three different positions, viz., the left hemifield, with loudspeakers centered around -60 degrees azimuth; the right hemifield, with loudspeakers centered around +60 degrees azimuth; and the midline with loudspeakers centered around 0 degrees azimuth. Animals with large bilateral lesions had severe impairments in localizing a single click in the midline test. Following complete destruction of the auditory cortex performance was only marginally above the level expected by chance even at large angles of speaker separation. Severe impairments were also found in localization of single clicks in both left and right lateral fields. In contrast, bilateral lesions restricted to the primary auditory cortex resulted in minimal impairments in midline localization. The same lesions, however, produced severe impairments in localization of single clicks in both left and right lateral fields. Large unilateral lesions that destroyed auditory cortex in one hemisphere resulted in an inability to localize single clicks in the contralateral hemifield. In contrast, no impairments were found in the midline test or in the ipsilateral hemifield. Unilateral lesions of the primary auditory cortex resulted in severe contralateral field deficits equivalent to those seen following complete unilateral destruction of auditory cortex. No deficits were seen in either the midline or the ipsilateral tests.

Music Perception and Cognition Following Bilateral Lesions of Auditory Cortex

1990 ◽  
Vol 2 (3) ◽  
pp. 195-212 ◽  
Author(s):  
Mark Jude Tramo ◽  
Jamshed J. Bharucha ◽  
Frank E. Musiek
Keyword(s):  
Auditory Cortex ◽  
Cognitive Functions ◽  
Music Perception ◽  
Primary Auditory Cortex ◽  
Planum Temporale ◽  
Temporoparietal Junction ◽  
Inferior Parietal Cortex ◽  
Harmonic Context ◽  
The Right ◽  
Bilateral Lesions

We present experimental and anatomical data from a case study of impaired auditory perception following bilateral hemispheric strokes. To consider the cortical representation of sensory, perceptual, and cognitive functions mediating tonal information processing in music, pure tone sensation thresholds, spectral intonation judgments, and the associative priming of spectral intonation judgments by harmonic context were examined, and lesion localization was analyzed quantitatively using straight-line two-dimensional maps of the cortical surface reconstructed from magnetic resonance images. Despite normal pure tone sensation thresholds at 250–8000 Hz, the perception of tonal spectra was severely impaired, such that harmonic structures (major triads) were almost uniformly judged to sound dissonant; yet, the associative priming of spectral intonation judgments by harmonic context was preserved, indicating that cognitive representations of tonal hierarchies in music remained intact and accessible. Brainprints demonstrated complete bilateral lesions of the transverse gyri of Heschl and partial lesions of the right and left superior temporal gyri involving 98 and 20% of their surface areas, respectively. In the right hemisphere, there was partial sparing of the planum temporale, temporoparietal junction, and inferior parietal cortex. In the left hemisphere, all of the superior temporal region anterior to the transverse gyrus and parts of the planum temporale, temporoparietal junction, inferior parietal cortex, and insula were spared. These observations suggest that (1) sensory, perceptual, and cognitive functions mediating tonal information processing in music are neurologically dissociable; (2) complete bilateral lesions of primary auditory cortex combined with partial bilateral lesions of auditory association cortex chronically impair tonal consonance perception; (3) cognitive functions that hierarchically structure pitch information and generate harmonic expectancies during music perception do not rely on the integrity of primary auditory cortex; and (4) musical priming may be mediated by broadly tuned subcomponents of the thala-mocortical auditory system.

scholarly journals Lesions of the Auditory Cortex Impair Azimuthal Sound Localization and Its Recalibration in Ferrets

2010 ◽  
Vol 103 (3) ◽  
pp. 1209-1225 ◽  
Author(s):  
Fernando R. Nodal ◽  
Oliver Kacelnik ◽  
Victoria M. Bajo ◽  
Jennifer K. Bizley ◽  
David R. Moore ◽  
...  
Keyword(s):  
Auditory Cortex ◽  
Sound Localization ◽  
Primary Auditory Cortex ◽  
Spatial Cues ◽  
Target Behavior ◽  
Long Duration ◽  
Orienting Behavior ◽  
Before And After ◽  
Bilateral Lesions

The role of auditory cortex in sound localization and its recalibration by experience was explored by measuring the accuracy with which ferrets turned toward and approached the source of broadband sounds in the horizontal plane. In one group, large bilateral lesions were made of the middle ectosylvian gyrus, where the primary auditory cortical fields are located, and part of the anterior and/or posterior ectosylvian gyrus, which contain higher-level fields. In the second group, the lesions were intended to be confined to primary auditory cortex (A1). The ability of the animals to localize noise bursts of different duration and level was measured before and after the lesions were made. A1 lesions produced a modest disruption of approach-to-target responses to short-duration stimuli (<500 ms) on both sides of space, whereas head orienting accuracy was unaffected. More extensive lesions produced much greater auditory localization deficits, again primarily for shorter sounds. In these ferrets, the accuracy of both the approach-to-target behavior and the orienting responses was impaired, and they could do little more than correctly lateralize the stimuli. Although both groups of ferrets were still able to localize long-duration sounds accurately, they were, in contrast to ferrets with an intact auditory cortex, unable to relearn to localize these stimuli after altering the spatial cues available by reversibly plugging one ear. These results indicate that both primary and nonprimary cortical areas are necessary for normal sound localization, although only higher auditory areas seem to contribute to accurate head orienting behavior. They also show that the auditory cortex, and A1 in particular, plays an essential role in training-induced plasticity in adult ferrets, and that this is the case for both head orienting responses and approach-to-target behavior.

Correlation Between the Activity of Single Auditory Cortical Neurons and Sound-Localization Behavior in the Macaque Monkey

2000 ◽  
Vol 83 (5) ◽  
pp. 2723-2739 ◽  
Author(s):  
Gregg H. Recanzone ◽  
Darren C. Guard ◽  
Mimi L. Phan ◽  
Tien-I K. Su
Keyword(s):  
Auditory Cortex ◽  
Sound Localization ◽  
Cortical Neurons ◽  
Primary Auditory Cortex ◽  
Macaque Monkey ◽  
Auditory Space ◽  
Spatial Sensitivity ◽  
Acoustic Space ◽  
Localization Ability ◽  
Primate Cerebral Cortex

Lesion studies have indicated that the auditory cortex is crucial for the perception of acoustic space, yet it remains unclear how these neurons participate in this perception. To investigate this, we studied the responses of single neurons in the primary auditory cortex (AI) and the caudomedial field (CM) of two monkeys while they performed a sound-localization task. Regression analysis indicated that the responses of ∼80% of neurons in both cortical areas were significantly correlated with the azimuth or elevation of the stimulus, or both, which we term “spatially sensitive.” The proportion of spatially sensitive neurons was greater for stimulus azimuth compared with stimulus elevation, and elevation sensitivity was primarily restricted to neurons that were tested using stimuli that the monkeys also could localize in elevation. Most neurons responded best to contralateral speaker locations, but we also encountered neurons that responded best to ipsilateral locations and neurons that had their greatest responses restricted to a circumscribed region within the central 60° of frontal space. Comparing the spatially sensitive neurons with those that were not spatially sensitive indicated that these two populations could not be distinguished based on either the firing rate, the rate/level functions, or on their topographic location within AI. Direct comparisons between the responses of individual neurons and the behaviorally measured sound-localization ability indicated that proportionally more neurons in CM had spatial sensitivity that was consistent with the behavioral performance compared with AI neurons. Pooling the responses across neurons strengthened the relationship between the neuronal and psychophysical data and indicated that the responses pooled across relatively few CM neurons contain enough information to account for sound-localization ability. These data support the hypothesis that auditory space is processed in a serial manner from AI to CM in the primate cerebral cortex.

The Women who Heard Folk Portuguese Music in the Right Ear: A Case of Unilateral Musical Hallucinosis

2009 ◽  
Vol 24 (S1) ◽  
pp. 1-1
Author(s):  
P. Ferreira ◽  
S. Simões ◽  
J. Cerqueira ◽  
J. Soares-Fernandes ◽  
Á. Machado
Keyword(s):  
Auditory Cortex ◽  
Classical Music ◽  
Mild Hypertension ◽  
Sensory Deprivation ◽  
Primary Auditory Cortex ◽  
Pet Scan ◽  
Charles Bonnet Syndrome ◽  
History Of ◽  
The Right ◽  
Portuguese Music

Introduction:Although probably undereported, musical hallucinosis is very rare and usually bilateral. It refers to auditory complex hallucinations, for which the patient has full insight, and includes melodies, tunes, rhythms and timbres.Clinical case:A 71-year-old women was seen for a history of hearing music in the right ear. She had mild hypertension and auricular fibrillation, being chronically medicated with aspirine, bisoprolol and hydroclorothiazide. Three months previously she started hearing some popular folk Portuguese songs in the right ear. She could identify the lyrics and sing the songs she heard. Weeks later fado and classical music were added to the repertoire, and later on she started hearing less well-formed sounds like “dlam... dlam” or “uhh... uhh”. There were no other auditory or visual hallucinations. She was seen by an otorhinolaryngologist, and made an audiogram showing bilateral, right-predominant, pre-coclear deafness with normal evoked brainstem auditory potentials. An MRI showed small deep subcortical lacunar lesions. EEG was normal. PET scan showed left temporal hypometabolism. On benzodiazepines she had discrete improvement.Conclusion:Musical hallucinosis has been found mainly in deaf patients, and a similar mechanism to that of Charles-Bonnet syndrome has been proposed. Sensory deprivation of primary auditory cortex would “release” the secondary auditory cortex, to produce complex auditory hallucinations with full insight. In our patient we were able to demonstrate the integrity of the brainstem pathway, supporting a direct link between diminished right ear sound transmission and left temporal lobe diminished activation as ascertained by the pet scan.

scholarly journals Functional Topography of Auditory Areas Derived From the Combination of Electrophysiological Recordings and Cortical Electrical Stimulation

2021 ◽  
Vol 15 ◽  
Author(s):  
Agnès Trébuchon ◽  
F.-Xavier Alario ◽  
Catherine Liégeois-Chauvel
Keyword(s):  
Auditory Cortex ◽  
Language Processing ◽  
Hemispheric Specialization ◽  
Posterior Part ◽  
Primary Auditory Cortex ◽  
Epileptic Seizures ◽  
Superior Temporal Gyrus ◽  
Depth Electrodes ◽  
Electrophysiological Recordings ◽  
The Right

The posterior part of the superior temporal gyrus (STG) has long been known to be a crucial hub for auditory and language processing, at the crossroad of the functionally defined ventral and dorsal pathways. Anatomical studies have shown that this “auditory cortex” is composed of several cytoarchitectonic areas whose limits do not consistently match macro-anatomic landmarks like gyral and sulcal borders. The only method to record and accurately distinguish neuronal activity from the different auditory sub-fields of primary auditory cortex, located in the tip of Heschl and deeply buried in the Sylvian fissure, is to use stereotaxically implanted depth electrodes (Stereo-EEG) for pre-surgical evaluation of patients with epilepsy. In this prospective, we focused on how anatomo-functional delineation in Heschl’s gyrus (HG), Planum Temporale (PT), the posterior part of the STG anterior to HG, the posterior superior temporal sulcus (STS), and the region at the parietal-temporal boundary commonly labeled “SPT” can be achieved using data from electrical cortical stimulation combined with electrophysiological recordings during listening to pure tones and syllables. We show the differences in functional roles between the primary and non-primary auditory areas, in the left and the right hemispheres. We discuss how these findings help understanding the auditory semiology of certain epileptic seizures and, more generally, the neural substrate of hemispheric specialization for language.

scholarly journals Specific connectivity with Operculum 3 (OP3) brain region in acoustic trauma tinnitus: a seed-based resting state fMRI study

2019 ◽  
Author(s):  
Agnès Job ◽  
Anne Kavounoudias ◽  
Chloé Jaroszynski ◽  
Assia Jaillard ◽  
Chantal Delon-Martin
Keyword(s):  
Hearing Loss ◽  
Auditory Cortex ◽  
Functional Mri ◽  
Resting State ◽  
Primary Auditory Cortex ◽  
Acoustic Trauma ◽  
Control Group ◽  
New Model ◽  
The Veil ◽  
The Right

ABSTRACTTinnitus mechanisms remain poorly understood. Our previous functional MRI (fMRI) studies demonstrated an abnormal hyperactivity in the right parietal operculum 3 (OP3) in acoustic trauma tinnitus and during provoked phantom sound perceptions without hearing loss, which lead us to propose a new model of tinnitus. This new model is not directly linked with hearing loss and primary auditory cortex abnormalities, but with a proprioceptive disturbance related to middle-ear muscles. In the present study, a seed-based resting-state functional MRI method was used to explore the potential abnormal connectivity of this opercular region between an acoustic trauma tinnitus group presenting slight to mild tinnitus and a control group. Primary auditory cortex seeds were also explored because they were thought to be directly involved in tinnitus in most current models. In such a model, hearing loss and tinnitus handicap were confounding factors and were therefore regressed in our analysis. Between-groups comparisons showed a significant specific connectivity between the right OP3 seeds and the potential human homologue of the premotor ear-eye field (H-PEEF) bilaterally and the inferior parietal lobule (IPL) in the tinnitus group. Our findings suggest the existence of a simultaneous premotor ear-eye disturbance in tinnitus that could lift the veil on unexplained subclinical abnormalities in oculomotor tests found in tinnitus patients with normal vestibular responses. The present work confirms the involvement of the OP3 subregion in acoustic trauma tinnitus and provides some new clues to explain its putative mechanisms.

scholarly journals Network-based asymmetry of the human auditory system

2018 ◽  
Author(s):  
Bratislav Mišić ◽  
Richard F. Betzel ◽  
Alessandra Griffa ◽  
Marcel A. de Reus ◽  
Ye He ◽  
...  
Keyword(s):  
Auditory Cortex ◽  
Shortest Paths ◽  
Network Configuration ◽  
Brain Areas ◽  
Opposite Hemisphere ◽  
Efficient Communication ◽  
Functional Lateralization ◽  
Left And Right ◽  
Auditory Cortices ◽  
The Right

Converging evidence from activation, connectivity and stimulation studies suggests that auditory brain networks are lateralized. Here we show that these findings can be at least partly explained by the asymmetric network embedding of the primary auditory cortices. Using diffusion-weighted imaging in three independent datasets, we investigate the propensity for left and right auditory cortex to communicate with other brain areas by quantifying the centrality of the auditory network across a spectrum of communication mechanisms, from shortest path communication to diffusive spreading. Across all datasets, we find that the right auditory cortex is better integrated in the connectome, facilitating more efficient communication with other areas, with much of the asymmetry driven by differences in communication pathways to the opposite hemisphere. Critically, the primacy of the right auditory cortex emerges only when communication is conceptualized as a diffusive process, taking advantage of more than just the topologically shortest paths in the network. Altogether, these results highlight how the network configuration and embedding of a particular region may contribute to its functional lateralization.

Sound Localization Deficits During Reversible Deactivation of Primary Auditory Cortex and/or the Dorsal Zone

2008 ◽  
Vol 99 (4) ◽  
pp. 1628-1642 ◽  
Author(s):  
Shveta Malhotra ◽  
G. Christopher Stecker ◽  
John C. Middlebrooks ◽  
Stephen G. Lomber
Keyword(s):  
Auditory Cortex ◽  
Sound Localization ◽  
Primary Auditory Cortex ◽  
Noise Burst ◽  
Orienting Response ◽  
Error Rates ◽  
Broadband Noise ◽  
Physiological Data ◽  
Anterior Ectosylvian Sulcus ◽  
Auditory Field

We examined the contributions of primary auditory cortex (A1) and the dorsal zone of auditory cortex (DZ) to sound localization behavior during separate and combined unilateral and bilateral deactivation. From a central visual fixation point, cats learned to make an orienting response (head movement and approach) to a 100-ms broadband noise burst emitted from a central speaker or one of 12 peripheral sites (located in front of the animal, from left 90° to right 90°, at 15° intervals) along the horizontal plane. Following training, each cat was implanted with separate cryoloops over A1 and DZ bilaterally. Unilateral deactivation of A1 or DZ or simultaneous unilateral deactivation of A1 and DZ (A1/DZ) resulted in spatial localization deficits confined to the contralateral hemifield, whereas sound localization to positions in the ipsilateral hemifield remained unaffected. Simultaneous bilateral deactivation of both A1 and DZ resulted in sound localization performance dropping from near-perfect to chance (7.7% correct) across the entire field. Errors made during bilateral deactivation of A1/DZ tended to be confined to the same hemifield as the target. However, unlike the profound sound localization deficit that occurs when A1 and DZ are deactivated together, deactivation of either A1 or DZ alone produced partial and field-specific deficits. For A1, bilateral deactivation resulted in higher error rates (performance dropping to ∼45%) but relatively small errors (mostly within 30° of the target). In contrast, bilateral deactivation of DZ produced somewhat fewer errors (performance dropping to only ∼60% correct), but the errors tended to be larger, often into the incorrect hemifield. Therefore individual deactivation of either A1 or DZ produced specific and unique sound localization deficits. The results of the present study reveal that DZ plays a role in sound localization. Along with previous anatomical and physiological data, these behavioral data support the view that A1 and DZ are distinct cortical areas. Finally, the findings that deactivation of either A1 or DZ alone produces partial sound localization deficits, whereas deactivation of either posterior auditory field (PAF) or anterior ectosylvian sulcus (AES) produces profound sound localization deficits, suggests that PAF and AES make more significant contributions to sound localization than either A1 or DZ.

Sensitivity to Simulated Directional Sound Motion in the Rat Primary Auditory Cortex

1999 ◽  
Vol 81 (5) ◽  
pp. 2075-2087 ◽  
Author(s):  
Daryl E. Doan ◽  
James C. Saunders
Keyword(s):  
Auditory Cortex ◽  
Horizontal Plane ◽  
Tuning Curve ◽  
Primary Auditory Cortex ◽  
Neuron Activity ◽  
Sound Location ◽  
Sound Stimulation ◽  
Adult Rats ◽  
Sound Motion ◽  
Simulated Motion

Sensitivity to simulated directional sound motion in the rat primary auditory cortex. This paper examines neuron responses in rat primary auditory cortex (AI) during sound stimulation of the two ears designed to simulate sound motion in the horizontal plane. The simulated sound motion was synthesized from mathematical equations that generated dynamic changes in interaural phase, intensity, and Doppler shifts at the two ears. The simulated sounds were based on moving sources in the right frontal horizontal quadrant. Stimuli consisted of three circumferential segments between 0 and 30°, 30 and 60°, and 60 and 90° and four radial segments at 0, 30, 60, and 90°. The constant velocity portion of each segment was 0.84 m long. The circumferential segments and center of the radial segments were calculated to simulate a distance of 2 m from the head. Each segment had two trajectories that simulated motion in both directions, and each trajectory was presented at two velocities. Young adult rats were anesthetized, the left primary auditory cortex was exposed, and microelectrode recordings were obtained from sound responsive cells in AI. All testing took place at a tonal frequency that most closely approximated the best frequency of the unit at a level 20 dB above the tuning curve threshold. The results were presented on polar plots that emphasized the two directions of simulated motion for each segment rather than the location of sound in space. The trajectory exhibiting a “maximum motion response” could be identified from these plots. “Neuron discharge profiles” within these trajectories were used to demonstrate neuron activity for the two motion directions. Cells were identified that clearly responded to simulated uni- or multidirectional sound motion (39%), that were sensitive to sound location only (19%), or that were sound driven but insensitive to our location or sound motion stimuli (42%). The results demonstrated the capacity of neurons in rat auditory cortex to selectively process dynamic stimulus conditions representing simulated motion on the horizontal plane. Our data further show that some cells were responsive to location along the horizontal plane but not sensitive to motion. Cells sensitive to motion, however, also responded best to the moving sound at a particular location within the trajectory. It would seem that the mechanisms underlying sensitivity to sound location as well as direction of motion converge on the same cell.

Sign in / Sign up

Export Citation Format

Share Document