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How may the basal ganglia contribute to auditory categorization and speech perception?

Lim SJ, Fiez JA, Holt LL - Front Neurosci (2014)

Bottom Line: Although neurobiological models of speech perception have mainly focused on cerebral cortex, research outside the speech domain is consistent with the possibility of significant subcortical contributions in category learning.We also present emerging evidence for a direct role for basal ganglia in learning auditory categories in a complex, naturalistic task intended to model the incidental manner in which speech categories are acquired.To conclude, we highlight new research questions that arise in incorporating the broader neuroscience research literature in modeling speech perception, and suggest how understanding contributions of the basal ganglia can inform attempts to optimize training protocols for learning non-native speech categories in adulthood.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology, Carnegie Mellon University Pittsburgh, PA, USA ; Department of Neuroscience, Center for the Neural Basis of Cognition, University of Pittsburgh Pittsburgh, PA, USA.

ABSTRACT
Listeners must accomplish two complementary perceptual feats in extracting a message from speech. They must discriminate linguistically-relevant acoustic variability and generalize across irrelevant variability. Said another way, they must categorize speech. Since the mapping of acoustic variability is language-specific, these categories must be learned from experience. Thus, understanding how, in general, the auditory system acquires and represents categories can inform us about the toolbox of mechanisms available to speech perception. This perspective invites consideration of findings from cognitive neuroscience literatures outside of the speech domain as a means of constraining models of speech perception. Although neurobiological models of speech perception have mainly focused on cerebral cortex, research outside the speech domain is consistent with the possibility of significant subcortical contributions in category learning. Here, we review the functional role of one such structure, the basal ganglia. We examine research from animal electrophysiology, human neuroimaging, and behavior to consider characteristics of basal ganglia processing that may be advantageous for speech category learning. We also present emerging evidence for a direct role for basal ganglia in learning auditory categories in a complex, naturalistic task intended to model the incidental manner in which speech categories are acquired. To conclude, we highlight new research questions that arise in incorporating the broader neuroscience research literature in modeling speech perception, and suggest how understanding contributions of the basal ganglia can inform attempts to optimize training protocols for learning non-native speech categories in adulthood.

No MeSH data available.


Related in: MedlinePlus

The direct pathway circuitry of the basal ganglia via the dorsal striatum. SNc, substantia nigra pars compacta; SNr, substantia nigra pars reticulata; GPi, globus pallidus, internal portion.
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Figure 2: The direct pathway circuitry of the basal ganglia via the dorsal striatum. SNc, substantia nigra pars compacta; SNr, substantia nigra pars reticulata; GPi, globus pallidus, internal portion.

Mentions: The basal ganglia are a collection of subcortical nuclei with a complex circuitry. The input nuclei of the basal ganglia consist of the caudate nucleus and putamen (together referred to as the dorsal striatum) and the nucleus accumbens (considered part of the ventral striatum). The dorsal and ventral striatum receive input from the cerebral cortex and send projections to the output nuclei of the basal ganglia, which include the globus pallidus and the substantia nigra pars reticulata (see Figure 1). The output signals from these nuclei ultimately project back to the cerebral cortex via the thalamus (see Figure 2). This basal ganglia-thalamo-cortical circuitry forms “closed loops,” whereby cortical regions projecting to the basal ganglia receive recurrent feedback projections from the basal ganglia (Alexander et al., 1986) and also “open loops,” whereby cortical regions projecting to the basal ganglia terminate in different cortical regions via the basal ganglia (Joel and Weiner, 1994). In addition to these structures, neurons in the substantia nigra pars compacta and ventral tegmental area play a crucial role in mediating basal ganglia's functions. Dopamingeric projections from these neurons modulate activity of the dorsal and ventral striatum, which ultimately modulate plasticity among the synapses within basal ganglia-thalamo-cortical loops (Reynolds and Wickens, 2002).


How may the basal ganglia contribute to auditory categorization and speech perception?

Lim SJ, Fiez JA, Holt LL - Front Neurosci (2014)

The direct pathway circuitry of the basal ganglia via the dorsal striatum. SNc, substantia nigra pars compacta; SNr, substantia nigra pars reticulata; GPi, globus pallidus, internal portion.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4117994&req=5

Figure 2: The direct pathway circuitry of the basal ganglia via the dorsal striatum. SNc, substantia nigra pars compacta; SNr, substantia nigra pars reticulata; GPi, globus pallidus, internal portion.
Mentions: The basal ganglia are a collection of subcortical nuclei with a complex circuitry. The input nuclei of the basal ganglia consist of the caudate nucleus and putamen (together referred to as the dorsal striatum) and the nucleus accumbens (considered part of the ventral striatum). The dorsal and ventral striatum receive input from the cerebral cortex and send projections to the output nuclei of the basal ganglia, which include the globus pallidus and the substantia nigra pars reticulata (see Figure 1). The output signals from these nuclei ultimately project back to the cerebral cortex via the thalamus (see Figure 2). This basal ganglia-thalamo-cortical circuitry forms “closed loops,” whereby cortical regions projecting to the basal ganglia receive recurrent feedback projections from the basal ganglia (Alexander et al., 1986) and also “open loops,” whereby cortical regions projecting to the basal ganglia terminate in different cortical regions via the basal ganglia (Joel and Weiner, 1994). In addition to these structures, neurons in the substantia nigra pars compacta and ventral tegmental area play a crucial role in mediating basal ganglia's functions. Dopamingeric projections from these neurons modulate activity of the dorsal and ventral striatum, which ultimately modulate plasticity among the synapses within basal ganglia-thalamo-cortical loops (Reynolds and Wickens, 2002).

Bottom Line: Although neurobiological models of speech perception have mainly focused on cerebral cortex, research outside the speech domain is consistent with the possibility of significant subcortical contributions in category learning.We also present emerging evidence for a direct role for basal ganglia in learning auditory categories in a complex, naturalistic task intended to model the incidental manner in which speech categories are acquired.To conclude, we highlight new research questions that arise in incorporating the broader neuroscience research literature in modeling speech perception, and suggest how understanding contributions of the basal ganglia can inform attempts to optimize training protocols for learning non-native speech categories in adulthood.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology, Carnegie Mellon University Pittsburgh, PA, USA ; Department of Neuroscience, Center for the Neural Basis of Cognition, University of Pittsburgh Pittsburgh, PA, USA.

ABSTRACT
Listeners must accomplish two complementary perceptual feats in extracting a message from speech. They must discriminate linguistically-relevant acoustic variability and generalize across irrelevant variability. Said another way, they must categorize speech. Since the mapping of acoustic variability is language-specific, these categories must be learned from experience. Thus, understanding how, in general, the auditory system acquires and represents categories can inform us about the toolbox of mechanisms available to speech perception. This perspective invites consideration of findings from cognitive neuroscience literatures outside of the speech domain as a means of constraining models of speech perception. Although neurobiological models of speech perception have mainly focused on cerebral cortex, research outside the speech domain is consistent with the possibility of significant subcortical contributions in category learning. Here, we review the functional role of one such structure, the basal ganglia. We examine research from animal electrophysiology, human neuroimaging, and behavior to consider characteristics of basal ganglia processing that may be advantageous for speech category learning. We also present emerging evidence for a direct role for basal ganglia in learning auditory categories in a complex, naturalistic task intended to model the incidental manner in which speech categories are acquired. To conclude, we highlight new research questions that arise in incorporating the broader neuroscience research literature in modeling speech perception, and suggest how understanding contributions of the basal ganglia can inform attempts to optimize training protocols for learning non-native speech categories in adulthood.

No MeSH data available.


Related in: MedlinePlus