Contralateral dominance emerges from geometric transformation in bilateral control systems

Area of Science:

• Neuroscience
• Computational Biology
• Systems Biology

Background:

• Contralateral organization is a fundamental characteristic of vertebrate nervous systems.
• The functional advantages and evolutionary origins of contralateral neural pathways remain incompletely understood.
• Investigating computational models can elucidate the principles underlying neural architecture development.

Purpose of the Study:

• To determine if contralateral routing can emerge as an advantageous solution in delayed bilateral control systems.
• To explore the role of sensorimotor transformations in the development of neural organization.
• To utilize a minimal computational framework to analyze network architectures.

Main Methods:

• Abstract bilateral sensorimotor networks with varying sensory laterality, commissural coupling, and connectivity were constructed.
• One-dimensional and two-dimensional models were evaluated, incorporating a twist parameter for coordinate transformations.
• Dense parameter scanning and bootstrap analysis were employed to identify transition points and assess robustness.

Main Results:

• Contralateral configurations were viable in 1D models but sensitive to objective functions.
• In 2D models, a twist parameter induced a shift from ipsilateral to contralateral solutions under strong transformation.
• An abrupt transition to contralateral dominance was observed at a specific threshold (θ_c ≈ 0.483), stable across delays.

Conclusions:

• Contralateral routing can become advantageous in abstract dynamical systems with transformed sensorimotor relationships and delays.
• The findings suggest that specific transformations in sensory-motor mapping can drive the evolution of contralateral neural organization.
• This computational approach provides a framework for understanding the emergence of fundamental neural architectures.