Coding Of Vocalizations Research Articles

Characterization of the superior olivary complex of Canis lupus domesticus

The superior olivary complex (SOC) is a collection of brainstem auditory nuclei which play essential roles in the localization of sound sources, temporal coding of vocalizations and descending modulation of the cochlea. Notwithstanding, the SOC nuclei vary considerably between species in accordance with the auditory needs of the animal. The canine SOC was subjected to anatomical and physiological examination nearly 50 years ago and was then virtually forgotten. Herein, we aimed to characterize the nuclei of the canine SOC using quantitative morphometrics, estimation of neuronal number, histochemistry for perineuronal nets and immunofluorescence for the calcium binding proteins calbindin and calretinin. We found the principal nuclei to be extremely well developed: the lateral superior olive (LSO) contained over 20,000 neurons and the medial superior olive (MSO) contained over 15,000 neurons. In nearly all non-chiropterian terrestrial mammals, the MSO exists as a thin, vertical column of neurons. The canine MSO was folded into a U-shaped contour and had associated with the ventromedial tip a small, round collection of neurons we termed the tail nucleus of the MSO. Further, we found evidence within the LSO, MSO and medial nucleus of the trapezoid body (MNTB) for significant morphological variations along the mediolateral or rostrocaudal axes. Finally, the majority of MNTB neurons were calbindin-immunopositive and associated with calretinin-immunopositive calyceal terminals. Together, these observations suggest the canine SOC complies with the basic plan of the mammalian SOC but possesses a number of unique anatomical features.

A critique and empirical assessment of Alexandra Horowitz and Julie Hecht's "Examining dog-human play: the characteristics, affect, and vocalizations of a unique interspecific interaction".

Horowitz and Hecht (Anim Cog 19:779-788, 2016) presented data about activities and vocalizations during brief videotaped dog-owner play provided by owners, examined these in relation to human affect during play, and made comparisons from their results to other research on activities and vocalizations during dog-human play. In this critique, I describe problems with Horowitz and Hecht's methodology, analyses, and evidence; in their interpretations of the data, evidence, and categorizations provided in other research, particularly my own studies of dog-human play; and in their claims of novelty for their findings. I argue that, to support their ideas about vocalizations and play types during dog-human play and their comparisons to other studies, their study requires fuller descriptions and reliability for their coding of vocalizations and play types, appropriate statistical analyses, and accurate descriptions of prior research. I also argue that their methodology provides results strikingly similar in many aspects to those of other researchers studying dog-human play, contrary to their claims of novel findings. Finally, I examine their suggestions about relationships between human affect and types of play activities and vocalizations using the videos of dog-human play I discussed in earlier publications, discovering minimal, if any, relationship.

Differential Coding of Conspecific Vocalizations in the Ventral Auditory Cortical Stream

The mammalian auditory cortex integrates spectral and temporal acoustic features to support the perception of complex sounds, including conspecific vocalizations. Here we investigate coding of vocal stimuli in different subfields in macaque auditory cortex. We simultaneously measured auditory evoked potentials over a large swath of primary and higher order auditory cortex along the supratemporal plane in three animals chronically using high-density microelectrocorticographic arrays. To evaluate the capacity of neural activity to discriminate individual stimuli in these high-dimensional datasets, we applied a regularized multivariate classifier to evoked potentials to conspecific vocalizations. We found a gradual decrease in the level of overall classification performance along the caudal to rostral axis. Furthermore, the performance in the caudal sectors was similar across individual stimuli, whereas the performance in the rostral sectors significantly differed for different stimuli. Moreover, the information about vocalizations in the caudal sectors was similar to the information about synthetic stimuli that contained only the spectral or temporal features of the original vocalizations. In the rostral sectors, however, the classification for vocalizations was significantly better than that for the synthetic stimuli, suggesting that conjoined spectral and temporal features were necessary to explain differential coding of vocalizations in the rostral areas. We also found that this coding in the rostral sector was carried primarily in the theta frequency band of the response. These findings illustrate a progression in neural coding of conspecific vocalizations along the ventral auditory pathway.

Sparse and Background-Invariant Coding of Vocalizations in Auditory Scenes

Vocal communicators such as humans and songbirds readily recognize individual vocalizations, even in distracting auditory environments. This perceptual ability is likely subserved by auditory neurons whose spiking responses to individual vocalizations are minimally affected by background sounds. However, auditory neurons that produce background-invariant responses to vocalizations in auditory scenes have not been found. Here, we describe a population of neurons in the zebra finch auditory cortex that represent vocalizations with a sparse code and that maintain their vocalization-like firing patterns in levels of background sound that permit behavioral recognition. These same neurons decrease or stop spiking in levels of background sound that preclude behavioral recognition. In contrast, upstream neurons represent vocalizations with dense and background-corrupted responses. We provide experimental evidence suggesting that sparse coding is mediated by feedforward suppression. Finally, we show through simulations that feedforward inhibition can transform a dense representation of vocalizations into a sparse and background-invariant representation.

Analysis of the causes of 117 infants with persistent hoarseness

To explore the causes of persistent hoarseness in infants. One hundred and seventeen infants with persistent hoarseness treated in the department of otorhinolaryngology in Children's Hospital of Fudan University between June 2008 and July 2010 were retrospectively analyzed (all patients received antibiotic therapy for 2 weeks and the symptoms were not relieved after that). The patients were divided into three groups according to the age at first visit: 22 newborns, < 6 months old in 60 cases, < 12 months old in 35 cases. All patients had video laryngoscope examinations. Some of them received CT scan, cardiac ultrasonography and pathological examination in additional. The diagnosis was established by clinical history and imaging modalities, and the causes were analyzed subsequently. Among the 117 patients, 45 cases were vocal hypertrophy and hyperplasia (37.81%), 39 cases were vocal cord paralyses (32.78%), 7 cases were laryngeal hemangiomas (5.89%), 4 cases were laryngeal webs and cyst (3.36%), 2 cases were vocal cord polyps (1.68%), 2 cases were glottic incompetence (1.68%), 1 case was laryngeal papillomas(0.84%), 1 case was vocal code granulomas (0.84%), 1 case was glottis restricted by neck lymphangioma (0.84%); 4 cases were undetermined and 13 cases were no abnormalities. The percentage of patients with congenital heart diseases (19 cases) in vocal cord paralysis was 48.72%. The proportion of vocal cord paralysis in younger group was higher than that in elder one, their percentage were 50.00%, 36.67% and 17.14% respectively (χ(2) = 7.18, P < 0.05). A variety of causes can lead to persistent hoarseness in infants. The majority of them are vocal hypertrophy and hyperplasia, followed by vocal cord paralyze. Vocal cord paralysis is more common in younger infants than in elder ones, and the main causes are post-cardiac surgery and congenital heart disease.

The Relationship of Lyrics and Tunes in the Processing of Unfamiliar Songs: A Functional Magnetic Resonance Adaptation Study

The cognitive relationship between lyrics and tunes in song is currently under debate, with some researchers arguing that lyrics and tunes are represented as separate components, while others suggest that they are processed in integration. The present study addressed this issue by means of a functional magnetic resonance adaptation paradigm during passive listening to unfamiliar songs. The repetition and variation of lyrics and/or tunes in blocks of six songs was crossed in a 2 x 2 factorial design to induce selective adaptation for each component. Reductions of the hemodynamic response were observed along the superior temporal sulcus and gyrus (STS/STG) bilaterally. Within these regions, the left mid-STS showed an interaction of the adaptation effects for lyrics and tunes, suggesting an integrated processing of the two components at prelexical, phonemic processing levels. The degree of integration decayed toward more anterior regions of the left STS, where the lack of such an interaction and the stronger adaptation for lyrics than for tunes was suggestive of an independent processing of lyrics, perhaps resulting from the processing of meaning. Finally, evidence for an integrated representation of lyrics and tunes was found in the left dorsal precentral gyrus (PrCG), possibly relating to the build-up of a vocal code for singing in which musical and linguistic features of song are fused. Overall, these results demonstrate that lyrics and tunes are processed at varying degrees of integration (and separation) through the consecutive processing levels allocated along the posterior-anterior axis of the left STS and the left PrCG.

Three‐dimensional mechanical tongue and vocal cord models for human speech production.

We have developed talking robot Waseda Talker series, which mimicked human speech production mechanism. This robot is consisted of mechanical vocal cords, tongue, lips, and nasal cavity. The current version, WT‐7R (Waseda Talker No. 7 Refined), has 16 DOF (7 DOF in tongue, 1 DOF in jaw, 4 DOF in lips, 1 DOF in velum, 2 DOF in vocal cords, and 1 DOF in lung), having same vocal tract length as average adult male. The mechanical vocal cord model is made of styrene based thermoplastic elastomer “Septon” and the shape is mimicking vocal folds of human with three dimensions. The vocal code model has pitch control mechanism by adjusting the cord tension and glottal opening‐closing mechanism, and it could reproduce the vocal cord vibration of the vocal fry (double pitched) and the breathy voice (unclose in one cycle) as well as the modal voice with variable pitch. The three‐dimensional tongue model is constructed by the rigid link mechanism covered by the Septon soft rubber. The tongue model could be controlled so as to configure the tongue shape in a three‐dimensional way. We will describe the details of the mechanism of talking robot by showing some demonstration videos.

Marginal zone B‐cell lymphoma of minor salivary gland representing tumor‐forming amyloidosis of the oral cavity. A case report

We report here a case of mucosa-associated lymphoid tissue (MALT)-type lymphoma arising from the minor salivary gland of the oral cavity exhibiting tumor-forming amyloidosis. The patient was a 64-year-old Japanese woman who presented with 4-year history of a left soft palate mass. Despite multiple and multifocal recurrences including the lip, soft palate, tongue, oral base and vocal code and soft palate, the tumor remained localized in the upper aerodigestive tract, and the patient did not develop multiple myeloma during the course of disease. Histologically, the majority of the lesion was occupied by amyloid deposition. Only the periphery of the lesion contained numerous plasmacytoid cells, along with occasional centrocyte-like cells. In addition, lymphoepithelial lesion and follicular colonization were noted. The present case indicates that primary minor salivary gland MALT-type lymphoma appears to be the cause of tumor-forming amyloidosis of the upper aerodigestive tract including the larynx.

Stimulus-Dependent Auditory Tuning Results in Synchronous Population Coding of Vocalizations in the Songbird Midbrain

Physiological studies in vocal animals such as songbirds indicate that vocalizations drive auditory neurons particularly well. But the neural mechanisms whereby vocalizations are encoded differently from other sounds in the auditory system are unknown. We used spectrotemporal receptive fields (STRFs) to study the neural encoding of song versus the encoding of a generic sound, modulation-limited noise, by single neurons and the neuronal population in the zebra finch auditory midbrain. The noise was designed to match song in frequency, spectrotemporal modulation boundaries, and power. STRF calculations were balanced between the two stimulus types by forcing a common stimulus subspace. We found that 91% of midbrain neurons showed significant differences in spectral and temporal tuning properties when birds heard song and when birds heard modulation-limited noise. During the processing of noise, spectrotemporal tuning was highly variable across cells. During song processing, the tuning of individual cells became more similar; frequency tuning bandwidth increased, best temporal modulation frequency increased, and spike timing became more precise. The outcome was a population response to song that encoded rapidly changing sounds with power and precision, resulting in a faithful neural representation of the temporal pattern of a song. Modeling responses to song using the tuning to modulation-limited noise showed that the population response would not encode song as precisely or robustly. We conclude that stimulus-dependent changes in auditory tuning during song processing facilitate the high-fidelity encoding of the temporal pattern of a song.

The Vocal Repertoire of the Red Junglefowl: A Spectrographic Classification and the Code of Communication

This report attempts to describe objectively the complete vocal repertoire and the vocal code of the Red Junglefowl (Gallus gallus), most probable wild ancestor of the domestic fowl. An unconfined color-banded flock was watched over a period of 6 years at the San Diego Zoo. The general behavior and vocalizations are essentially the same in Red Junglefowl and the domestic fowl. Different vocal signals can be recognized by their sonograms and by the common element in the various situations in which a signal is given. Twenty-four vocal signals are described but because of intergradation between some signals and between different situations no absolute size of vocal repertoire can be fixed. A spectrographic (structural) key to the vocal signals of the Red Junglefowl is given and with the sonograms should enable one to identify the typical calls. Different elements can be combined to produce specific vocal signals, in effect a code. Brief, soft repetitive notes of low frequency are attraction calls. Loud harsh sounds with high frequencies are alarm cries. Harsh sounds emphasizing low frequencies are threat sounds. These rules hold for many other birds. Junglefowl also have special calls that appear to indicate well-being, or mild disturbance and frustration. The evolution of the vocal signals of the Red Junglefowl is discussed in relation to Darwin's (1872) three principles of communication and to modern ethology.