Training Humans to Categorize Monkey Calls: Auditory Feature- and Category-Selective Neural Tuning Changes

Area of Science:

• Neuroscience
• Cognitive Science
• Auditory Perception

Background:

• Categorizing auditory stimuli, such as speech, is crucial for recognition.
• Understanding the neural mechanisms of auditory category learning is essential.

Purpose of the Study:

• To investigate the neural changes associated with learning to categorize novel auditory stimuli.
• To explore the role of auditory cortex and prefrontal cortex in auditory category learning.

Main Methods:

• Human participants were trained to categorize morphed monkey vocalizations.
• Functional magnetic resonance imaging with rapid adaptation (fMRI-RA) was employed.
• Multi-voxel pattern analysis (MVPA) was used to analyze brain activity patterns.

Main Results:

• Categorization training led to sharpened tuning to vocalization features in the left auditory cortex.
• Category selectivity for different call types emerged in the lateral prefrontal cortex.
• Neural selectivity sharpness predicted categorical boundary steepness, and judgment correlated with adaptation release in the left inferior frontal gyrus.

Conclusions:

• Auditory category learning involves distinct neural changes in auditory and prefrontal cortices.
• Findings support a two-stage model of auditory category learning, similar to visual learning.
• Suggests generalizable principles of perceptual category learning across sensory domains in the human brain.