Biological Bases of Behavior

Biological Bases of Behavior

• Brain Structure & Function: Phrenology, an outdated concept, explored the correlation between skull shape and personality. This early attempt sparked interest in brain mapping. Critical thinking is crucial in psychology.

• Genetics and Behavior: Chromosomes (23 pairs) carry genes (DNA segments) contributing to our traits. The genome is the complete genetic blueprint. Heritability describes the extent of trait variation due to genes. Gene-environment interactions are significant (environment influences gene expression).

• Evolutionary Psychology: Natural selection explains traits like fear of heights and taste preferences. Gender differences in mate preferences are explained by evolutionary theory: men prioritize indicators of fertility; women prioritize resources. This approach faces criticism about balancing biological and social learning explanations.

Nervous and Endocrine Systems

• Nervous System: The central nervous system (CNS) consists of the brain and spinal cord. The peripheral nervous system (PNS) contains nerves outside the CNS, including somatic (voluntary movement) and autonomic (involuntary processes) divisions, further categorized into sympathetic (fight-or-flight) and parasympathetic (rest-and-digest) systems.

• Neurons and Neurotransmitters: Neurons are the basic units transmitting signals. Types include sensory (send info to brain), motor (transmit commands from brain), and interneurons (process signals). Key neurotransmitters include acetylcholine (muscle movement, memory), dopamine (reward, learning, emotion), serotonin (mood, hunger, sleep), and endorphins (natural pain killers).

• Endocrine System: Hormones influence bodily functions more slowly and for longer durations than neurotransmitters. The hypothalamus regulates homeostasis, the pituitary is the "master gland" controlling other glands, the adrenal produces adrenaline for stress response, and the pineal gland secretes melatonin (sleep).

Sleep, Drugs, and Sensation

• Sleep: Sleep cycles repeat approximately every 90 minutes. Sleep stages include NREM-1 (light sleep), NREM-2 (moderate sleep), NREM-3 (deep sleep), and REM (dreaming). Sleep is vital for memory consolidation, problem-solving, growth, and overall health.

• Psychoactive Drugs: Categories include depressants (alcohol), stimulants (nicotine, cocaine), and hallucinogens (LSD, marijuana). Tolerance, withdrawal, and addiction are key concepts.

• Sensation and Perception: Thresholds determine detection levels (absolute threshold for smallest detectable signal; difference threshold for minimum change detectable). Visual perception involves rods for low light and cones for color. Auditory perception relies on hair cells in the ear. Chemical sensations include taste (five basic types) and smell (linked to memory). Touch involves pressure, temperature, and pain receptors. Balance relies on the vestibular system in the inner ear.

Brain Functionality

• Brainstem Components: The medulla controls heartbeat and breathing; the pons links brain and body communication; the reticular formation regulates alertness.

• Cerebral Cortex: The cerebral cortex is divided into four lobes (frontal, parietal, occipital, temporal). Association areas manage complex tasks. Brain plasticity demonstrates the ability to adapt and rewire. Split-brain studies are crucial in revealing hemisphere specialization.

Explore the intricate relationships between brain structure, genetics, and behaviors in this quiz. Delve into concepts like the influence of genes on traits, evolutionary psychology, and the nervous system's role in behavior. This is essential for understanding psychological principles.