Lombard reflex during PAG-induced vocalization in decerebrate cats

Nonaka, Satoshi; Takahashi, Ryuji; Enomoto, Keiichi; Katada, Akihiro; Unno, Tokuji

doi:10.1016/s0168-0102(97)00097-7

Cited by 72 publications

(50 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This extremely fast latency for both parameters suggests that the underlying neuronal network can function without direct auditory feedback from the bat's own voice, which indicates a direct connection between the auditory and vocal-motor systems at the brainstem level. Earlier studies showed that auditory stimulation with clicks, pure tones, or noise evoked rapid reflex responses in the recurrent laryngeal nerve and the spinal ventral root with latencies between 6 and 25 ms (15,(32)(33)(34)(35)(36). Considering that call durations are typically between 40 and 50 ms, and calls are repeated every 50-150 ms, these studies suggest that auditory inputs originating from centers early within the ascending auditory pathway could directly affect laryngeal and expiratory muscles.…”

Section: Discussionmentioning

confidence: 90%

“…One of the most efficient mechanisms is the socalled Lombard effect, i.e., the involuntary rise in call amplitude in response to masking ambient noise (1). This effect was first described in human communication a century ago (2) and has since been found in several species of birds (3)(4)(5)(6)(7)(8)(9)(10)(11) and various mammals (12)(13)(14)(15)(16)(17), including bats (18). In human speech, several vocal changes, such as a rise in fundamental frequency (19) or lengthening in word duration (20), are often accompanied with the Lombard effect; combined, these changes are referred to as Lombard speech (21).…”

mentioning

confidence: 99%

See 1 more Smart Citation

Ambient noise induces independent shifts in call frequency and amplitude within the Lombard effect in echolocating bats

Hage

Jiang

Berquist

et al. 2013

Proc. Natl. Acad. Sci. U.S.A.

127

View full text Add to dashboard Cite

The Lombard effect, an involuntary rise in call amplitude in response to masking ambient noise, represents one of the most efficient mechanisms to optimize signal-to-noise ratio. The Lombard effect occurs in birds and mammals, including humans, and is often associated with several other vocal changes, such as call frequency and duration. Most studies, however, have focused on noisedependent changes in call amplitude. It is therefore still largely unknown how the adaptive changes in call amplitude relate to associated vocal changes such as frequency shifts, how the underlying mechanisms are linked, and if auditory feedback from the changing vocal output is needed. Here, we examined the Lombard effect and the associated changes in call frequency in a highly vocal mammal, echolocating horseshoe bats. We analyzed how bandpassfiltered noise (BFN; bandwidth 20 kHz) affected their echolocation behavior when BFN was centered on different frequencies within their hearing range. Call amplitudes increased only when BFN was centered on the dominant frequency component of the bats' calls. In contrast, call frequencies increased for all but one BFN center frequency tested. Both amplitude and frequency rises were extremely fast and occurred in the first call uttered after noise onset, suggesting that no auditory feedback was required. The different effects that varying the BFN center frequency had on amplitude and frequency rises indicate different neural circuits and/or mechanisms underlying these changes.A ny transmission of signals between sender and receiver faces the challenge of being subjected to masking by noise. For acoustic signals, for example, animals have evolved several strategies that aid in increasing the signal-to-noise ratio, thus facilitating signal transmission. One of the most efficient mechanisms is the socalled Lombard effect, i.e., the involuntary rise in call amplitude in response to masking ambient noise (1). This effect was first described in human communication a century ago (2) and has since been found in several species of birds (3-11) and various mammals (12-17), including bats (18). In human speech, several vocal changes, such as a rise in fundamental frequency (19) or lengthening in word duration (20), are often accompanied with the Lombard effect; combined, these changes are referred to as Lombard speech (21). Vocal changes associated with the Lombard effect have rarely been analyzed in animal species. So far, noisedependent changes in call frequency have been observed in birds (8,11,22), and changes in call duration in birds and monkeys (8,12).Most animal studies, however, have focused on noise-dependent changes in call amplitude and do not examine other possible vocal changes (2-5, 7, 9, 10, 15-17). It is therefore still largely unknown how the adaptive changes in call amplitude relate to frequency shifts or call elongation and how the underlying mechanisms are linked. It is also unknown if auditory feedback from the changing vocal output is needed to drive the Lombard effect in general.Over...

show abstract

Section: Discussionmentioning

confidence: 90%

mentioning

confidence: 99%

Ambient noise induces independent shifts in call frequency and amplitude within the Lombard effect in echolocating bats

Hage

Jiang

Berquist

et al. 2013

Proc. Natl. Acad. Sci. U.S.A.

127

View full text Add to dashboard Cite

show abstract

“…Because both envelope extraction and leaky integration can be accomplished by the peripheral auditory system (20,21), it is likely that the initiation of the Lombard effect does not require higher auditory centers. The output from the peripheral auditory system can be directly sent to the vocal-motor system of the brainstem to guide the vocal amplitude adjustments, as indicated by the finding that decerebrate cats show the Lombard effect (22).…”

Section: Discussionmentioning

confidence: 99%

Sensorimotor integration on a rapid time scale

Luo

Kothari

Moss

2017

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Sensing is fundamental to the control of movement: From grasping objects to speech production, sensing guides action. So far, most of our knowledge about sensorimotor integration comes from visually guided reaching and oculomotor integration, in which the time course and trajectories of movements can be measured at a high temporal resolution. By contrast, production of vocalizations by humans and animals involves complex and variable actions, and each syllable often lasts a few hundreds of milliseconds, making it difficult to infer underlying neural processes. Here, we measured and modeled the transfer of sensory information into motor commands for vocal amplitude control in response to background noise, also known as the Lombard effect. We exploited the brief vocalizations of echolocating bats to trace the time course of the Lombard effect on a millisecond time scale. Empirical studies revealed that the Lombard effect features a response latency of a mere 30 ms and provided the foundation for the quantitative audiomotor model of the Lombard effect. We show that the Lombard effect operates by continuously integrating the sound pressure level of background noise through temporal summation to guide the extremely rapid vocal-motor adjustments. These findings can now be extended to models and measures of audiomotor integration in other animals, including humans.S ensing plays a critical role in the control of movement. In humans, natural behaviors, from grasping a coffee mug to producing intelligible speech, all rely on the guidance of sensing. Similarly, sensory signals lie at the core of most animal behaviors. However, the brain mechanisms underlying sensorimotor integration are not well understood. This is particularly true regarding the control of vocalizations, which are used by a wide range of animal species for communication. At present, a dominant model for motor control is derived from the state feedback control (SFC) theory, which successfully accounts for a wide range of motor behaviors, such as visually guided arm movement (1) and speech production (2). SFC models posit that motor control is based on a comparison of sensory prediction generated from an internal forward model with actual sensory feedback, and sensory feedback is used to train and update the internal forward model. According to this SFC model, sensory feedback is not directly used to guide motor commands, due to its noisy and delayed characteristics, and this notion has been supported by a large body of experimental and theoretical work (1-7). These stand in contrast to motor reflexes, which are movements in direct response to sensory signals. Note, motor reflexes can be graded in response magnitude and can be modulated by cognitive processes (8, 9). One well-known example is the pupillary light reflex, an adjustment in pupil diameter in response to light intensity (10).The Lombard effect refers to an animal's increase in vocal signal amplitude in response to an increase in background noise (11). Evidence of the Lombard effect comes from s...

show abstract

“…This dynamic modulation of voice intensity allows an individual to communicate effectively under noisy conditions. The Lombard effect has been demonstrated not only in humans (Hanley and Harvey, 1965;Lane et al, 1970;Lane and Tranel, 1971;Egan, 1972;Siegel and Pick, 1974), but also in every animal species examined, including birds (Potash, 1972;Cynx et al, 1998;Manabe et al, 1998;Brumm and Todt, 2002), cats (Nonaka et al, 1997), and monkeys (Sinnott et al, 1975;Brumm et al, 2004;. The neural mechanisms underlying this important vocal behavior, however, remain largely unknown.…”

Section: Introductionmentioning

confidence: 99%

Neural Correlates of the Lombard Effect in Primate Auditory Cortex

Eliades

Wang²

2012

Journal of Neuroscience

View full text Add to dashboard Cite

Speaking is a sensory-motor process that involves constant self-monitoring to ensure accurate vocal production. Self-monitoring of vocal feedback allows rapid adjustment to correct perceived differences between intended and produced vocalizations. One important behavior in vocal feedback control is a compensatory increase in vocal intensity in response to noise masking during vocal production, commonly referred to as the Lombard effect. This behavior requires mechanisms for continuously monitoring auditory feedback during speaking. However, the underlying neural mechanisms are poorly understood. Here we show that when marmoset monkeys vocalize in the presence of masking noise that disrupts vocal feedback, the compensatory increase in vocal intensity is accompanied by a shift in auditory cortex activity toward neural response patterns seen during vocalizations under normal feedback condition. Furthermore, we show that neural activity in auditory cortex during a vocalization phrase predicts vocal intensity compensation in subsequent phrases. These observations demonstrate that the auditory cortex participates in self-monitoring during the Lombard effect, and may play a role in the compensation of noise masking during feedback-mediated vocal control.

show abstract

Lombard reflex during PAG-induced vocalization in decerebrate cats

Cited by 72 publications

References 16 publications

Ambient noise induces independent shifts in call frequency and amplitude within the Lombard effect in echolocating bats

Ambient noise induces independent shifts in call frequency and amplitude within the Lombard effect in echolocating bats

Sensorimotor integration on a rapid time scale

Neural Correlates of the Lombard Effect in Primate Auditory Cortex

Contact Info

Product

Resources

About