Updating functional brain units: Insights far beyond Luria.

Area of Science:

• Neuroscience
• Neurobiology
• Cognitive Science

Background:

• Alexander Luria's model of three functional brain units is a foundational concept in neuroscience.
• Understanding brain organization requires integrating functional systems theory with phylogenetic and embryogenetic principles.
• Existing models often struggle to reconcile basic needs with complex behaviors and hierarchical brain structures.

Purpose of the Study:

• To review and critically analyze Luria's model of functional brain units.
• To propose an updated model of brain organization based on phylogenetic, embryogenetic, and systemic perspectives.
• To delineate five functional units within two integrated complexes.

Main Methods:

• Review of existing literature on functional systems theory, phylogenesis, and embryogenesis.
• Analysis of the relationship between homeostatic needs and complex behaviors.
• Integration of multi-scale hierarchical and distributed brain organization principles.

Main Results:

• The brain exhibits multi-scale hierarchical and distributed organization with complex cell-system interactions.
• Phylogenesis, particularly exaptation in basal ganglia and cerebellum, significantly impacts brain expansion.
• A new model proposes two integrated complexes: primordial-limbic and telencephalic-cortical, comprising five functional units.

Conclusions:

• Luria's original tripartite model is challenged by principles of brain organization.
• The proposed five functional units (brainstem, limbic/paralimbic, telencephalic-cortical, basal ganglia, cerebellar) offer a more integrated view.
• Functional brain organization is dynamic, involving overlapping processes that transcend strict anatomical boundaries.