Psychology: Higher Nervous Activity

Reflexes

• IP Pavlov and IM Sechenov discovered the reflex character of higher brain activity.
• Conditioned reflexes are acquired, temporary, and individual, formed during ontogenesis through the combination of an unconditional stimulus with an indifferent signal.
• Unconditioned reflexes are innate, constant, and specific, appearing during evolution and hereditarily fixed.

Reflex Classification

• Unconditioned reflexes: innate, constant, specific; examples include pupillary light reflex, ocular-cardiac reflex, and pupillary narrowing under the effect of light.
• Conditioned reflexes: acquired, temporary, individual; examples include salivary secretion in a hungry person caused by food images and the reflex of tachypnea in runners before the start.

Inhibition

• External inhibition: congenital, disappears unconditional and conditioned reflexes without preliminary development.
• Conditioned inhibition: arising in nerve centers of conditioned reflexes, demands preliminary development.
• Types of inhibition: external, conditioned, fading brake, protective, differentiating, and lagging.

Brain Function and Higher Nervous Activity

• The left part of the brain dominates in speech, writing, and calculation.
• The right part of the brain dominates in analysis and synthesis of the first signaling system.
• I.P. Pavlov distinguished four types of higher nervous activity: strong, unbalanced, impatient; strong, balanced, mobile; strong, balanced, inert; and weak.
• Hippocrates classified temperaments as choleric, sanguine, phlegmatic, and melancholic, corresponding to Pavlov's types.

Sleep and EEG Rhythms

• Sleep is a sum of functional conditions of the CNS, characterized by decreased responsiveness to external stimuli.
• EEG rhythms:
  • Beta: active wakefulness
  • Alpha: quiet wakefulness
  • Delta: deep sleep
• Biological value of fast sleep: processing and keeping of information in long-term memory, restoration of mental processes.
• Dreams occur during the phase of fast sleep.

Memory

• Short-term memory: has a small volume of 7±2 units.
• Long-term memory: provides long storage and reproduction of information.

Emotions

• Structures directly participating in emotion formation: hypothalamic structures, cerebral cortex, limbic system.