AP Psychology (2025) Unit 1: Biological Bases of Behavior

Overview

• Explores brain and nervous system's influence on behavior and mental processes
• Examines neuron communication and neurotransmitters' roles in behavior
• Discusses central and peripheral nervous systems
• Investigates brain disorders
• Highlights real-world applications in mental illness treatment, medication development, and learning enhancement

Key Concepts

Brain Structure and Function

• Cerebral Cortex: Higher-order cognitive functions (thinking, reasoning, decision-making); divided into four lobes.
• Limbic System: Emotional processing and memory formation; includes amygdala and hippocampus.
• Hypothalamus: Regulates biological needs (hunger, thirst); controls hormone release.
• Brainstem: Connects brain to spinal cord; regulates vital functions.
• Cerebellum: Coordinates motor movements, balance, and posture.
• Basal Ganglia: Motor control, learning, decision-making.
• Thalamus: Relays sensory and motor information.

Neurons: Building Blocks of the Nervous System

• Specialized cells transmitting electrical and chemical signals
• Composed of dendrites, cell body, axon
• Myelin: Insulates axons, speeds signal transmission
• Types: Sensory neurons, motor neurons, interneurons
• Neurons do not regenerate; brain injuries are severe

Neuron Communication

• Action Potentials: Electrical signals traveling along neurons
• Neurotransmitters: Chemicals facilitating communication between neurons
  • Examples: dopamine, serotonin, norepinephrine
• Synapse: Junction for neurotransmitter release
• Long-term Potentiation (LTP) and Depression (LTD): Facilitate learning and memory

Nervous System

• Central Nervous System (CNS): Brain and spinal cord; processes information
• Peripheral Nervous System (PNS): Nerves outside CNS
  • Somatic: Voluntary movements
  • Autonomic: Involuntary functions; includes sympathetic (fight or flight) and parasympathetic (rest and digest)

Hormones and Behavior

• Chemical messengers influencing behavior and physiological processes
• HPA Axis: Stress response system
• Hormonal imbalances linked to disorders
• Sex Hormones: Influence sexual differentiation and behavior

Brain Disorders

• Causes include genetic, environmental, injuries
• Neurodegenerative Diseases: Alzheimer's, Parkinson’s
  • Memory loss, cognitive decline, motor function impairment
• Mental Illnesses: Depression, anxiety, schizophrenia linked to neurotransmitter imbalances
• Substance Use Disorders: Changes in brain's reward system
• Traumatic Brain Injuries (TBIs): Cognitive and emotional deficits

Real-Life Applications

• Development of pharmacological treatments for mental illnesses
• Cognitive-Behavioral Therapy (CBT): Modifying thoughts and behaviors
• Neurofeedback: Regulating brain function
• Educational strategies informed by learning and memory research
• Addiction treatment development
• Advances in neuroimaging for studying brain activity
• Reducing aggression through understanding biological factors