Bifurcation in space: Emergence of functional modularity in the neocortex

Area of Science:

• Computational Neuroscience
• Systems Neuroscience
• Cognitive Neuroscience

Background:

• The emergence of functional modularity within the cortex, despite its repetitive local circuit structure, remains a key question.
• Understanding how distributed neural processes lead to specialized cognitive functions is crucial.

Purpose of the Study:

• To investigate the emergence of functional modularity in the cortex using computational models.
• To explore the role of "bifurcation in space" in organizing cortical function, particularly during working memory.

Main Methods:

• Developed and analyzed connectome-based models of monkey cortex.
• Utilized generative and multi-regional cortex models for both macaque monkey and mouse.
• Examined neuronal timescales across the cortical hierarchy during simulated working memory tasks.

Main Results:

• Demonstrated that "bifurcation in space" describes the emergence of modularity in cortical models.
• Observed this phenomenon during decision-making and working memory simulations.
• Identified an inverted-U-shaped profile of neuronal timescales across the cortical hierarchy, predicting modular organization.

Conclusions:

• "Bifurcation in space" is proposed as a fundamental principle governing the brain's modular organization.
• Distributed neural processes, driven by connectivity and neurobiological gradients, underlie functional specificity.
• The findings offer an experimentally testable prediction for cortical modularity.