Modern Concept of Cortical Fields
Modern understanding of cerebral cortex function is based on the principle of the multifunctionality of cortical fields. Science has definitively rejected the outdated idea of functional equipotentiality (equivalence and complete interchangeability of cortical areas).
It has been proven that the right and left hemispheres are not equivalent in their physiological significance and contribution to mental activity. This fundamental property of the nervous system determines the division of labor between brain regions.
Classification of Hemispheric Asymmetry
The division of functions between the left and right halves of the cortex manifests at several levels. Traditionally, three main types of hemispheric asymmetry are distinguished:
- Sensory asymmetry — inequality in the perception of sensory information from sense organs by different hemispheres.
- Motor asymmetry — differences in motor activity control (e.g., handedness).
- Psychological asymmetry — specialization of the hemispheres in various forms of thinking and emotional response.
Characteristics of the Left Hemisphere
In the vast majority of people, the left hemisphere is dominant. It assumes key analytical and management tasks.
Main functions:
- Production and comprehension of speech.
- Control of motor actions of the right hand.
- Execution of verbal and strictly logical thinking.
Psychological profile of the left-hemisphere type: Such individuals lean toward theory and possess an extensive vocabulary. They are characterized by pronounced goal-directedness, high motor activity, and excellent forecasting ability—the capacity to anticipate the development of events.
Characteristics of the Right Hemisphere
Unlike the logical left hemisphere, the right hemisphere specializes in holistic and perceptual processing of the world.
Main functions:
- Perception of object shapes and spatial relationships.
- Active participation in intuitive thinking processes.
Psychological profile of the right-hemisphere type: Activity of this hemisphere is brightly manifested in concrete (practical or creative) types of activities. These individuals are distinguished by their ability to sensitively perceive the surrounding environment and experience deep emotions.
Systemic Organization of Brain Function
Despite a clear division of functions, the brain operates as a unified whole. Both hemispheres continuously cooperate with each other. This integration is essential for achieving adaptive utility and adequate organismal responses to environmental changes.
Functional differences between the halves of the brain persist throughout life, while the dominance of one hemisphere ultimately determines the basic psychological traits of a person's personality.