scholarly journals Context-dependent plasticity in the subcortical encoding of linguistic pitch patterns

2017 ◽  
Vol 117 (2) ◽  
pp. 594-603 ◽  
Author(s):  
Joseph C. Y. Lau ◽  
Patrick C. M. Wong ◽  
Bharath Chandrasekaran
Keyword(s):  
Auditory System ◽  
Fine Tuning ◽  
Pitch Contour ◽  
Dependent Plasticity ◽  
Pitch Tracking ◽  
Neural Ensembles ◽  
Pitch Pattern ◽  
Online Experience ◽  
Context Dependent ◽  
Pitch Patterns

We examined the mechanics of online experience-dependent auditory plasticity by assessing the influence of prior context on the frequency-following responses (FFRs), which reflect phase-locked responses from neural ensembles within the subcortical auditory system. FFRs were elicited to a Cantonese falling lexical pitch pattern from 24 native speakers of Cantonese in a variable context, wherein the falling pitch pattern randomly occurred in the context of two other linguistic pitch patterns; in a patterned context, wherein, the falling pitch pattern was presented in a predictable sequence along with two other pitch patterns, and in a repetitive context, wherein the falling pitch pattern was presented with 100% probability. We found that neural tracking of the stimulus pitch contour was most faithful and accurate when listening context was patterned and least faithful when the listening context was variable. The patterned context elicited more robust pitch tracking relative to the repetitive context, suggesting that context-dependent plasticity is most robust when the context is predictable but not repetitive. Our study demonstrates a robust influence of prior listening context that works to enhance online neural encoding of linguistic pitch patterns. We interpret these results as indicative of an interplay between contextual processes that are responsive to predictability as well as novelty in the presentation context. NEW & NOTEWORTHY Human auditory perception in dynamic listening environments requires fine-tuning of sensory signal based on behaviorally relevant regularities in listening context, i.e., online experience-dependent plasticity. Our finding suggests what partly underlie online experience-dependent plasticity are interplaying contextual processes in the subcortical auditory system that are responsive to predictability as well as novelty in listening context. These findings add to the literature that looks to establish the neurophysiological bases of auditory system plasticity, a central issue in auditory neuroscience.

scholarly journals Plasticity in the Adult Human Auditory Brainstem following Short-term Linguistic Training

2008 ◽  
Vol 20 (10) ◽  
pp. 1892-1902 ◽  
Author(s):  
Judy H. Song ◽  
Erika Skoe ◽  
Patrick C. M. Wong ◽  
Nina Kraus
Keyword(s):  
Language Learning ◽  
Auditory Pathway ◽  
Auditory Brainstem ◽  
Pitch Contour ◽  
Tracking Accuracy ◽  
Subcortical Structures ◽  
Complex Sounds ◽  
Pitch Tracking ◽  
English Speaking ◽  
Pitch Patterns

Peripheral and central structures along the auditory pathway contribute to speech processing and learning. However, because speech requires the use of functionally and acoustically complex sounds which necessitates high sensory and cognitive demands, long-term exposure and experience using these sounds is often attributed to the neocortex with little emphasis placed on subcortical structures. The present study examines changes in the auditory brainstem, specifically the frequency following response (FFR), as native English-speaking adults learn to incorporate foreign speech sounds (lexical pitch patterns) in word identification. The FFR presumably originates from the auditory midbrain and can be elicited preattentively. We measured FFRs to the trained pitch patterns before and after training. Measures of pitch tracking were then derived from the FFR signals. We found increased accuracy in pitch tracking after training, including a decrease in the number of pitch-tracking errors and a refinement in the energy devoted to encoding pitch. Most interestingly, this change in pitch-tracking accuracy only occurred in the most acoustically complex pitch contour (dipping contour), which is also the least familiar to our English-speaking subjects. These results not only demonstrate the contribution of the brainstem in language learning and its plasticity in adulthood but also demonstrate the specificity of this contribution (i.e., changes in encoding only occur in specific, least familiar stimuli, not all stimuli). Our findings complement existing data showing cortical changes after second-language learning, and are consistent with models suggesting that brainstem changes resulting from perceptual learning are most apparent when acuity in encoding is most needed.

scholarly journals On Older Listeners' Ability to Perceive Dynamic Pitch

2016 ◽  
Vol 59 (3) ◽  
pp. 572-582 ◽  
Author(s):  
Jing Shen ◽  
Richard Wright ◽  
Pamela E. Souza
Keyword(s):  
Speech Recognition ◽  
Interindividual Variability ◽  
Pitch Perception ◽  
Natural Speech ◽  
Pitch Contour ◽  
Older Individuals ◽  
Pitch Contours ◽  
Pitch Patterns ◽  
Better Than

PurposeNatural speech comes with variation in pitch, which serves as an important cue for speech recognition. The present study investigated older listeners' dynamic pitch perception with a focus on interindividual variability. In particular, we asked whether some of the older listeners' inability to perceive dynamic pitch stems from the higher susceptibility to the interference from formant changes.MethodA total of 22 older listeners and 21 younger controls with at least near-typical hearing were tested on dynamic pitch identification and discrimination tasks using synthetic monophthong and diphthong vowels.ResultsThe older listeners' ability to detect changes in pitch varied substantially, even when musical and linguistic experiences were controlled. The influence of formant patterns on dynamic pitch perception was evident in both groups of listeners. Overall, strong pitch contours (i.e., more dynamic) were perceived better than weak pitch contours (i.e., more monotonic), particularly with rising pitch patterns.ConclusionsThe findings are in accordance with the literature demonstrating some older individuals' difficulty perceiving dynamic pitch cues in speech. Moreover, they suggest that this problem may be prominent when the dynamic pitch is carried by natural speech and when the pitch contour is not strong.

scholarly journals Robust Rhythmogenesis in the Gamma Band via Spike Timing Dependent Plasticity

2020 ◽  
Author(s):  
Gabi Socolovsky ◽  
Maoz Shamir
Keyword(s):  
Mean Field ◽  
Rhythmic Activity ◽  
Gamma Oscillations ◽  
Underlying Mechanism ◽  
Spike Timing ◽  
Gamma Band ◽  
Fine Tuning ◽  
Spike Timing Dependent Plasticity ◽  
Dependent Plasticity ◽  
Wide Range

Rhythmic activity in the gamma band (30-100Hz) has been observed in numerous animal species ranging from insects to humans, and in relation to a wide range of cognitive tasks. Various experimental and theoretical studies have investigated this rhythmic activity. The theoretical efforts have mainly been focused on the neuronal dynamics, under the assumption that network connectivity satisfies certain fine-tuning conditions required to generate gamma oscillations. However, it remains unclear how this fine tuning is achieved.Here we investigated the hypothesis that spike timing dependent plasticity (STDP) can provide the underlying mechanism for tuning synaptic connectivity to generate rhythmic activity in the gamma band. We addressed this question in a modeling study. We examined STDP dynamics in the framework of a network of excitatory and inhibitory neuronal populations that has been suggested to underlie the generation of gamma. Mean field Fokker Planck equations for the synaptic weights dynamics are derived in the limit of slow learning. We drew on this approximation to determine which types of STDP rules drive the system to exhibit gamma oscillations, and demonstrate how the parameters that characterize the plasticity rule govern the rhythmic activity. Finally, we propose a novel mechanism that can ensure the robustness of self-developing processes, in general and for rhythmogenesis in particular.

scholarly journals Genetic variation in dispersal plasticity in an aquatic host-parasite model system

2020 ◽  
Author(s):  
Giacomo Zilio ◽  
Louise Solveig Noergaard ◽  
Giovanni Petrucci ◽  
Nathalie Zeballos ◽  
Claire Gougat-Barbera ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Internal State ◽  
Theoretical Models ◽  
Infection Prevalence ◽  
Main Role ◽  
Dependent Plasticity ◽  
Evolutionary Forces ◽  
State Dependent ◽  
Context Dependent ◽  
Host Parasite

Dispersal plays a main role in determining spatial dynamics, and both theory and empirical evidence indicate that evolutionary optima exist for constitutive or plastic dispersal behaviour. Plasticity in dispersal can be influenced by factors both internal (state-dependent) or external (context-dependent) to individuals. Parasitism is interesting in this context, as it can influence both types of host dispersal plasticity: individuals can disperse in response to internal infection status but might also respond to the presence of infected individuals around them. We still know little about the driving evolutionary forces of host dispersal plasticity, but a first requirement is the presence of a genetic basis on which natural selection can act. In this study, we used microcosm dispersal mazes to investigate plastic dispersal of 20 strains of the freshwater protist Paramecium caudatum in response to the bacterial parasite Holospora undulata. We additionally quantified the genetic component of the plastic responses, i.e. the heritability of state- and context-depended dispersal. We found that infection by the parasite can either increase or decrease dispersal of individual strains relative to the uninfected (state-dependent plasticity), and this to be heritable. We also found strain-specific change of dispersal of uninfected Paramecium when exposed to variable infection prevalence (context-dependent plasticity) with very low level of heritability. To our knowledge, this is the first explicit empirical demonstration and quantification of genetic variation of plastic dispersal in a host-parasite system, which could have important implications for meta-population and epidemiological dynamics. We discuss some of the underlying mechanisms of this variation and link our results to the existing theoretical models.

scholarly journals Context-dependent plasticity in a sensory circuit

2013 ◽  
Vol 16 (10) ◽  
pp. 1366-1366 ◽  
Author(s):  
Brigitta Gundersen
Keyword(s):  
Dependent Plasticity ◽  
Context Dependent

scholarly journals Stability and plasticity in neural encoding of linguistically relevant pitch patterns

2017 ◽  
Vol 117 (3) ◽  
pp. 1409-1424 ◽  
Author(s):  
Zilong Xie ◽  
Rachel Reetzke ◽  
Bharath Chandrasekaran
Keyword(s):  
Auditory Processing ◽  
Developmental Differences ◽  
Language Experience ◽  
Short Term ◽  
Neural Ensembles ◽  
Adolescents And Adults ◽  
English Speaking ◽  
Pitch Patterns ◽  
The Stability ◽  
Mandarin Tones

While lifelong language experience modulates subcortical encoding of pitch patterns, there is emerging evidence that short-term training introduced in adulthood also shapes subcortical pitch encoding. Here we use a cross-language design to examine the stability of language experience-dependent subcortical plasticity over multiple days. We then examine the extent to which behavioral relevance induced by sound-to-category training leads to plastic changes in subcortical pitch encoding in adulthood relative to adolescence, a period of ongoing maturation of subcortical and cortical auditory processing. Frequency-following responses (FFRs), which reflect phase-locked activity from subcortical neural ensembles, were elicited while participants passively listened to pitch patterns reflective of Mandarin tones. In experiment 1, FFRs were recorded across three consecutive days from native Chinese-speaking ( n = 10) and English-speaking ( n = 10) adults. In experiment 2, FFRs were recorded from native English-speaking adolescents ( n = 20) and adults ( n = 15) before, during, and immediately after a session of sound-to-category training, as well as a day after training ceased. Experiment 1 demonstrated the stability of language experience-dependent subcortical plasticity in pitch encoding across multiple days of passive exposure to linguistic pitch patterns. In contrast, experiment 2 revealed an enhancement in subcortical pitch encoding that emerged a day after the sound-to-category training, with some developmental differences observed. Taken together, these findings suggest that behavioral relevance is a critical component for the observation of plasticity in the subcortical encoding of pitch.NEW & NOTEWORTHY We examine the timescale of experience-dependent auditory plasticity to linguistically relevant pitch patterns. We find extreme stability in lifelong experience-dependent plasticity. We further demonstrate that subcortical function in adolescents and adults is modulated by a single session of sound-to-category training. Our results suggest that behavioral relevance is a necessary ingredient for neural changes in pitch encoding to be observed throughout human development. These findings contribute to the neurophysiological understanding of long- and short-term experience-dependent modulation of pitch.

scholarly journals Is Relative Pitch Specific to Pitch?

2008 ◽  
Vol 19 (12) ◽  
pp. 1263-1271 ◽  
Author(s):  
Josh H. McDermott ◽  
Andriana J. Lehr ◽  
Andrew J. Oxenham
Keyword(s):  
Auditory System ◽  
General Feature ◽  
One Dimension ◽  
Contour Extraction ◽  
Relative Pitch ◽  
Melodic Contour ◽  
Pitch Level ◽  
Pitch Contours ◽  
Different Dimensions ◽  
Pitch Patterns

Melodies, speech, and other stimuli that vary in pitch are processed largely in terms of the relative pitch differences between sounds. Relative representations permit recognition of pitch patterns despite variations in overall pitch level between instruments or speakers. A key component of relative pitch is the sequence of pitch increases and decreases from note to note, known as the melodic contour. Here we report that contour representations are also produced by patterns in loudness and brightness (an aspect of timbre). The representations of contours in different dimensions evidently have much in common, as contours in one dimension can be readily recognized in other dimensions. Moreover, contours in loudness and brightness are nearly as useful as pitch contours for recognizing familiar melodies that are normally conveyed via pitch. Our results indicate that relative representations via contour extraction are a general feature of the auditory system, and may have a common central locus.

Constructing a Representation of a Melody: Transforming Melodic Segments into Reduced Pitch Patterns Operated on by Modifiers

1991 ◽  
Vol 9 (2) ◽  
pp. 251-265 ◽  
Author(s):  
Yoko Oura
Keyword(s):  
Long Term Memory ◽  
Music Majors ◽  
Harmonic Progression ◽  
Progression Model ◽  
Recall Data ◽  
Pitch Pattern ◽  
College Music ◽  
Competing Models ◽  
Pitch Patterns

A reduced-pitch-pattern model for melodic processing is proposed. The model assumes that experienced listeners divide a melody into segments, derive a reduced pitch pattern from each segment, and then try to match each pattern to one of the prototypes stored in long-term memory. As a result, the melody is memorized accurately and quickly. This model and two competing models (the contour model and the harmonic progression model) make different predictions concerning what aspects of a melody would be preserved and what types of error in recall would appear. Recall data of a tonal melody of 12 measures in length were used to examine these predictions. The data were gathered from eight college music majors. Analysis of erroneous reproductions showed that reduced pitch patterns and harmonic progressions were preserved well and that errors predicted by the reduced-pitch-pattern model occurred more often than those predicted by the two competing models. It is concluded that the reduced-pitch-pattern model is the most tenable of the three.

Sign in / Sign up

Export Citation Format

Share Document