Auditory perceptual learning and changes in the conceptualization of auditory cortex.

Area of Science:

• Neuroscience
• Auditory Perception
• Sensory Plasticity

Background:

• Perceptual learning, a form of sensory plasticity, significantly alters our understanding of sensory cortical function.
• Auditory perceptual learning is characterized by task-specific changes, suggesting nuanced underlying neural mechanisms.
• Conflicting findings exist regarding neural substrates, with some studies suggesting neuronal recruitment and others reduced response variability.

Purpose of the Study:

• To reconcile conflicting findings on the neural substrates of auditory perceptual learning.
• To explore the transient nature of neural changes, such as cortical area expansion, during perceptual learning.
• To investigate the role of reduced response variability as a potential long-term substrate for improved auditory performance.

Main Methods:

• Review of psychophysical and neurophysiological studies on auditory perceptual learning.
• Analysis of animal studies investigating neuronal recruitment and cortical representation changes.
• Examination of human neuroimaging studies and auditory brainstem response data.
• Consideration of evidence from motor skill learning and musical training models.

Main Results:

• Evidence supports the expansion-renormalization hypothesis, where changes in cortical representation are transient.
• Reduced response variability is proposed as a potential stable neural substrate for enhanced performance.
• Long-term changes in auditory cortical function and auditory brainstem responses are observed in humans following training.
• Auditory perceptual learning is crucial for language acquisition and speech perception in cochlear implant users.

Conclusions:

• Auditory perceptual learning involves complex neural changes, potentially including transient expansion and stable reductions in variability.
• The multiplexing model, involving strengthened neuronal inputs and top-down gating, offers a framework for understanding context specificity.
• Auditory cortex functions within distributed networks integrating sensory information with attention, decision-making, and reward processes.