Core Postulates of the Theory
The concept is based on several key principles explaining how goal-directed behavior is formed:
- Ascending Influences: Subcortical structures exert a specific activating effect on the cerebral cortex.
- Afferent Synthesis: Behavior formation begins with information gathering, where motivation, environmental signals (triggering and situational cues), and memory play critical roles.
- Sensory-Biological Convergence: Excitations of different origins (e.g., from sensory organs and biological needs) converge on the same cortical neurons.
- Integration: Cortical neurons integrate these heterogeneous signals.
- Action Acceptor: The brain creates a specialized apparatus to predict and evaluate future results.
How a Conditioned Reflex is Formed
According to the convergent theory, the formation of a temporary connection involves several stages of interaction between various excitations on cortical neurons.
- Motivation: Motivational centers of the hypothalamus send activating influences to the cortex, forming a subjective state (e.g., food deprivation or hunger).
- Interaction: Excitation from a neutral stimulus (e.g., a flash of light) meets the pre-existing motivational state in the cortex.
- Reinforcement and Closure: When an unconditioned stimulus (food) follows the light, sensory and motivational excitations are targeted to the same neurons in the projection zone of the conditioned stimulus. The temporary connection itself is consolidated with the participation of the genetic apparatus of these cells.
Limitations of Classical Reflex Theory
I.P. Pavlov’s classical model was based on the leading role of external stimuli (the "stimulus–response" scheme) and had several methodological limitations. Experimental animals were passive (restrained in a harness), and their behavior was assessed solely through effector responses (motor or autonomic: salivation, changes in pulse and respiration).
This approach ignored active, goal-directed animal behavior in natural environments aimed at satisfying needs. The older theory could not explain numerous phenomena:
- Why a conditioned response disappears immediately after feeding (the mechanism of satiety).
- How an animal actively searches for stimuli and overcomes obstacles.
- Mechanisms of error correction.
- The role of reinforcement if viewed strictly as an unconditioned reflex.
- Complex instrumental activity (tool-making and tool-use by anthropoid apes).
Furthermore, emotions, motivations, decision-making, dynamic stereotypes, neuroses, as well as play, hunting, and herd behaviors do not fit into the structure of a simple reflex arc.