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A neuronal network model for context-dependence of pitch change perception.

Huang C, Englitz B, Shamma S, Rinzel J - Front Comput Neurosci (2015)

Bottom Line: We developed a recurrent, firing-rate network model, which detects frequency-change-direction of successively played stimuli and successfully accounts for the context-dependent perception demonstrated in behavioral experiments.The model's network architecture and slow facilitating inhibition emerge as predictions of neuronal mechanisms for these perceptual dynamics.Since the model structure does not depend on the specific stimuli, we show that it generalizes to other contextual effects and stimulus types.

View Article: PubMed Central - PubMed

Affiliation: Courant Institute of Mathematical Sciences, New York University New York, NY, USA.

ABSTRACT
Many natural stimuli have perceptual ambiguities that can be cognitively resolved by the surrounding context. In audition, preceding context can bias the perception of speech and non-speech stimuli. Here, we develop a neuronal network model that can account for how context affects the perception of pitch change between a pair of successive complex tones. We focus especially on an ambiguous comparison-listeners experience opposite percepts (either ascending or descending) for an ambiguous tone pair depending on the spectral location of preceding context tones. We developed a recurrent, firing-rate network model, which detects frequency-change-direction of successively played stimuli and successfully accounts for the context-dependent perception demonstrated in behavioral experiments. The model consists of two tonotopically organized, excitatory populations, E up and E down, that respond preferentially to ascending or descending stimuli in pitch, respectively. These preferences are generated by an inhibitory population that provides inhibition asymmetric in frequency to the two populations; context dependence arises from slow facilitation of inhibition. We show that contextual influence depends on the spectral distribution of preceding tones and the tuning width of inhibitory neurons. Further, we demonstrate, using phase-space analysis, how the facilitated inhibition from previous stimuli and the waning inhibition from the just-preceding tone shape the competition between the E up and E down populations. In sum, our model accounts for contextual influences on the pitch change perception of an ambiguous tone pair by introducing a novel decoding strategy based on direction-selective units. The model's network architecture and slow facilitating inhibition emerge as predictions of neuronal mechanisms for these perceptual dynamics. Since the model structure does not depend on the specific stimuli, we show that it generalizes to other contextual effects and stimulus types.

No MeSH data available.


Related in: MedlinePlus

Idealized conceptual model for Eup and Edown units on a pitch class circle. Four tri-unit subpopulations (Eup, Edown, I) at representative PC's (0, 3, 6, 9 st), including their interactions, are shown to illustrate the mechanism of the full network model (Equation 2). I units (blue) inhibit the Eup unit below (lower CF) and the Edown unit above (higher CF). When a bias tone is presented at PC = 3, the synaptic strength of the I unit at PC = 3 is facilitated, resulting in more inhibition to the Eup unit at PC = 0 and the Edown unit at PC = 6. Hence, T1 at PC = 0 invokes a weaker response in Eup (D < 0 for T1, perceived as descending), while T2 at PC = 6 results in a weaker response in Edown (D > 0 for T2, perceived as ascending).
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Figure 10: Idealized conceptual model for Eup and Edown units on a pitch class circle. Four tri-unit subpopulations (Eup, Edown, I) at representative PC's (0, 3, 6, 9 st), including their interactions, are shown to illustrate the mechanism of the full network model (Equation 2). I units (blue) inhibit the Eup unit below (lower CF) and the Edown unit above (higher CF). When a bias tone is presented at PC = 3, the synaptic strength of the I unit at PC = 3 is facilitated, resulting in more inhibition to the Eup unit at PC = 0 and the Edown unit at PC = 6. Hence, T1 at PC = 0 invokes a weaker response in Eup (D < 0 for T1, perceived as descending), while T2 at PC = 6 results in a weaker response in Edown (D > 0 for T2, perceived as ascending).

Mentions: The essential mechanism of how our model's architecture leads to context effects can be illustrated with a conceptual model, an idealization based on our computational network model. The conceptual model consists of four tri-unit subpopulations (Eup, Edown, I) at representative PC's (0, 3, 6, 9 st) distributed around the PC circle (Figure 10). In the model, each I unit inhibits the Eup unit below (lower frequency) and the Edown unit above (higher frequency). When a context tone is presented at PC = 3 st, for example, the I unit at PC = 3 st is facilitated, which increases inhibition on the Eup unit at PC = 0 st and the Edown unit at PC = 6 st. Therefore, the pitch change percept is biased toward descending to T1 at PC = 0 st and ascending to T2 at PC = 6 st.


A neuronal network model for context-dependence of pitch change perception.

Huang C, Englitz B, Shamma S, Rinzel J - Front Comput Neurosci (2015)

Idealized conceptual model for Eup and Edown units on a pitch class circle. Four tri-unit subpopulations (Eup, Edown, I) at representative PC's (0, 3, 6, 9 st), including their interactions, are shown to illustrate the mechanism of the full network model (Equation 2). I units (blue) inhibit the Eup unit below (lower CF) and the Edown unit above (higher CF). When a bias tone is presented at PC = 3, the synaptic strength of the I unit at PC = 3 is facilitated, resulting in more inhibition to the Eup unit at PC = 0 and the Edown unit at PC = 6. Hence, T1 at PC = 0 invokes a weaker response in Eup (D < 0 for T1, perceived as descending), while T2 at PC = 6 results in a weaker response in Edown (D > 0 for T2, perceived as ascending).
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4526807&req=5

Figure 10: Idealized conceptual model for Eup and Edown units on a pitch class circle. Four tri-unit subpopulations (Eup, Edown, I) at representative PC's (0, 3, 6, 9 st), including their interactions, are shown to illustrate the mechanism of the full network model (Equation 2). I units (blue) inhibit the Eup unit below (lower CF) and the Edown unit above (higher CF). When a bias tone is presented at PC = 3, the synaptic strength of the I unit at PC = 3 is facilitated, resulting in more inhibition to the Eup unit at PC = 0 and the Edown unit at PC = 6. Hence, T1 at PC = 0 invokes a weaker response in Eup (D < 0 for T1, perceived as descending), while T2 at PC = 6 results in a weaker response in Edown (D > 0 for T2, perceived as ascending).
Mentions: The essential mechanism of how our model's architecture leads to context effects can be illustrated with a conceptual model, an idealization based on our computational network model. The conceptual model consists of four tri-unit subpopulations (Eup, Edown, I) at representative PC's (0, 3, 6, 9 st) distributed around the PC circle (Figure 10). In the model, each I unit inhibits the Eup unit below (lower frequency) and the Edown unit above (higher frequency). When a context tone is presented at PC = 3 st, for example, the I unit at PC = 3 st is facilitated, which increases inhibition on the Eup unit at PC = 0 st and the Edown unit at PC = 6 st. Therefore, the pitch change percept is biased toward descending to T1 at PC = 0 st and ascending to T2 at PC = 6 st.

Bottom Line: We developed a recurrent, firing-rate network model, which detects frequency-change-direction of successively played stimuli and successfully accounts for the context-dependent perception demonstrated in behavioral experiments.The model's network architecture and slow facilitating inhibition emerge as predictions of neuronal mechanisms for these perceptual dynamics.Since the model structure does not depend on the specific stimuli, we show that it generalizes to other contextual effects and stimulus types.

View Article: PubMed Central - PubMed

Affiliation: Courant Institute of Mathematical Sciences, New York University New York, NY, USA.

ABSTRACT
Many natural stimuli have perceptual ambiguities that can be cognitively resolved by the surrounding context. In audition, preceding context can bias the perception of speech and non-speech stimuli. Here, we develop a neuronal network model that can account for how context affects the perception of pitch change between a pair of successive complex tones. We focus especially on an ambiguous comparison-listeners experience opposite percepts (either ascending or descending) for an ambiguous tone pair depending on the spectral location of preceding context tones. We developed a recurrent, firing-rate network model, which detects frequency-change-direction of successively played stimuli and successfully accounts for the context-dependent perception demonstrated in behavioral experiments. The model consists of two tonotopically organized, excitatory populations, E up and E down, that respond preferentially to ascending or descending stimuli in pitch, respectively. These preferences are generated by an inhibitory population that provides inhibition asymmetric in frequency to the two populations; context dependence arises from slow facilitation of inhibition. We show that contextual influence depends on the spectral distribution of preceding tones and the tuning width of inhibitory neurons. Further, we demonstrate, using phase-space analysis, how the facilitated inhibition from previous stimuli and the waning inhibition from the just-preceding tone shape the competition between the E up and E down populations. In sum, our model accounts for contextual influences on the pitch change perception of an ambiguous tone pair by introducing a novel decoding strategy based on direction-selective units. The model's network architecture and slow facilitating inhibition emerge as predictions of neuronal mechanisms for these perceptual dynamics. Since the model structure does not depend on the specific stimuli, we show that it generalizes to other contextual effects and stimulus types.

No MeSH data available.


Related in: MedlinePlus