The shape of the human language-ready brain

Area of Science:

• Neuroscience
• Evolutionary Biology
• Genetics

Background:

• Human brain evolution involved significant morphological and connectivity changes after divergence from Neanderthals-Denisovans.
• These changes, including a more globular braincase, may have subcortical implications impacting cognition.
• The thalamus, crucial for fronto-parietal activity, is implicated in language and human cognition.

Purpose of the Study:

• To investigate the neurobiological basis of human language capacity, focusing on the thalamus.
• To explore the molecular underpinnings of thalamic development and connectivity related to language evolution.
• To identify candidate genes associated with thalamic function, human head evolution, and language disorders.

Main Methods:

• Comparative analysis of brain morphology and neural connectivity changes in human evolution.
• Focus on subcortical structures, specifically the thalamus, and its role in cognitive functions.
• Construction of a candidate gene set based on thalamic development, head evolution, and known language-associated disorders.

Main Results:

• Hypothesized significant subcortical changes, particularly in the thalamus, accompanying the shift to a globular braincase.
• Identified a candidate gene set potentially underlying the genetic basis of human linguistic capacity.
• Proposed a neurobiological framework linking thalamic function to language evolution.

Conclusions:

• The evolution of the human brain, including subcortical structures like the thalamus, is central to understanding the emergence of language.
• Candidate genes involved in thalamic development and connectivity offer new insights into the genetic architecture of language.
• This research provides a foundation for further investigation into the ontogeny and phylogeny of human linguistic abilities.