Towards a functional neuroanatomy of speech perception

Area of Science:

• Neuroscience
• Cognitive Science
• Psycholinguistics

Background:

• Characterizing the functional neuroanatomy of speech perception is challenging.
• Neural systems for speech perception differ between laboratory tasks and natural language comprehension.
• Existing models do not fully account for task-dependent neural network variations.

Purpose of the Study:

• To review and synthesize current understanding of the neural basis of speech perception.
• To propose a framework where task demands shape the recruitment of neural systems for speech processing.
• To differentiate neural substrates for auditory-based representations versus task-specific processing.

Main Methods:

• Literature review and synthesis of neuroimaging and cognitive neuroscience studies.
• Analysis of task-dependent variations in neural activation patterns during speech perception.
• Conceptual integration of findings from auditory, cognitive, and language neuroscience.

Main Results:

• Cortical fields in the posterior-superior temporal lobe (bilaterally) are key for constructing sound-based speech representations.
• These representations interface with distinct supramodal systems based on task demands.
• Auditory-to-meaning systems near the left temporal-parietal-occipital junction support lexical access.
• Auditory-motor interface systems in the left frontal and parietal lobes are crucial for explicit speech segment access and phonological working memory.

Conclusions:

• Speech perception neuroanatomy is not monolithic but dynamically configured by task demands.
• The posterior-superior temporal lobe provides a foundational auditory speech representation.
• Task-specific interactions with frontal and temporoparietal regions enable diverse speech comprehension functions.