Interaction of Heredity and Environment

### **Module 1.1: Interaction of Heredity and Environment** **Key Concepts:** - **Nature vs. Nurture Debate**: Examines whether genetics or environment plays a larger role in human behavior. Today, psychologists agree that both factors interact in complex ways. - **Plato**: Supported the idea that behaviors and traits are innate. - **Aristotle**: Believed that knowledge comes from experience. - **Behavior Genetics**: The study of genetic and environmental influences on behavior. - **Twin Studies**: Compare identical twins (100% shared genes) and fraternal twins (50% shared genes) to determine the heritability of traits. - **Adoption Studies**: Examine whether adopted children are more similar to their biological or adoptive families in traits like intelligence, personality, and behavior. **Important Terms:** 1. **Heritability**: The proportion of variation among individuals that can be attributed to genes. 2. **Gene–Environment Interaction**: How the environment can trigger genetic predispositions (e.g., epigenetics). **Evolutionary Psychology**: - Focuses on how natural selection has shaped behaviors and mental processes that enhance survival and reproduction. --### **Module 1.2: Overview of the Nervous System** **Key Concepts:** - **Central Nervous System (CNS)**: Comprises the brain and spinal cord, controlling most functions of the body and mind. - **Peripheral Nervous System (PNS)**: Composed of sensory and motor neurons connecting the CNS to the rest of the body. - **Somatic Nervous System**: Controls voluntary movements (e.g., walking). - **Autonomic Nervous System**: Regulates involuntary functions (e.g., heart rate). It is divided into: - **Sympathetic Nervous System**: Activates the body's fight-or-flight response. - **Parasympathetic Nervous System**: Calms the body, restoring it to a restful state. **Neurotransmitters**: Chemicals that transmit signals across synapses. - **Dopamine**: Influences movement, learning, and emotion. - **Serotonin**: Affects mood, hunger, and sleep. - **GABA**: Major inhibitory neurotransmitter in the brain, reducing neural activity. - **Glutamate**: Major excitatory neurotransmitter, involved in memory. --### **Module 1.3a: The Neuron and Neural Firing** **Key Concepts:** - **Neurons**: The basic building blocks of the nervous system. - **Dendrites**: Receive messages from other neurons. - **Axon**: Sends electrical signals away from the neuron’s cell body. - **Myelin Sheath**: Speeds up neural impulses. - **Synapse**: The gap between neurons where neurotransmitters cross. **Neural Firing**: - **Action Potential**: An electrical charge that travels down the axon. - **Neurotransmitter Release**: When an action potential reaches the axon terminals, neurotransmitters are released into the synapse. **The Endocrine System**: - **Hormones**: Chemical messengers that travel through the bloodstream, affecting tissues, including the brain. The **pituitary gland** is the master gland controlling other endocrine glands. --### **Module 1.3b: Neural Firing and Psychoactive Drugs** **Key Concepts:** - **Psychoactive Drugs**: Substances that alter mood, perception, and behavior by affecting neurotransmitter activity. - **Agonists**: Drugs that increase a neurotransmitter's action. - **Antagonists**: Drugs that inhibit or block a neurotransmitter’s action. **Addiction**: A compulsive craving for drugs or certain behaviors (such as gambling) despite adverse consequences. - **Tolerance**: The need for larger doses of a drug to experience the same effect. - **Withdrawal**: The discomfort and distress following discontinuing the use of an addictive substance. --### **Module 1.4a: Neuroplasticity and Tools of Discovery** **Neuroplasticity**: - The brain’s ability to reorganize itself by forming new neural connections, allowing for adaptation following injury, experience, or learning. - **Experience-Based Plasticity**: The environment influences neural development. - **Damage-Induced Plasticity**: The brain can adapt to injury by rerouting functions to other areas. **Brain Imaging Tools**: 1. **EEG (Electroencephalogram)**: Measures brainwave activity, often used in sleep studies and diagnosing epilepsy. 2. **MRI (Magnetic Resonance Imaging)**: Provides detailed images of brain structures. 3. **fMRI (Functional MRI)**: Reveals brain activity by measuring blood flow to different brain regions. 4. **PET (Positron Emission Tomography)**: Tracks the movement of glucose in the brain, showing which areas are active during tasks. --### **Module 1.4b: Brain Regions and Structures** **Key Brain Structures**: 1. **Brainstem**: Responsible for automatic survival functions. - **Medulla**: Controls heartbeat and breathing. - **Pons**: Helps coordinate movement and control sleep. 2. **Thalamus**: Relays sensory messages to the cerebral cortex. 3. **Cerebellum**: Coordinates voluntary movement and balance. 4. **Limbic System**: - **Amygdala**: Linked to emotion, especially fear and aggression. - **Hippocampus**: Processes memories for storage. - **Hypothalamus**: Regulates bodily functions such as hunger and thirst and helps govern the endocrine system. **Cerebral Cortex**: The outer layer of the brain, involved in higher cognitive functions like reasoning and decision-making. - **Frontal Lobes**: Involved in speaking, muscle movements, and decision-making. - **Parietal Lobes**: Processes sensory input related to touch and body position. - **Temporal Lobes**: Involved in auditory processing and memory. - **Occipital Lobes**: Processes visual information. --### **Module 1.4c: Brain Damage Response and Hemispheres** **Responses to Brain Damage**: - The brain exhibits **neuroplasticity** and can reorganize after injury. For example, after a stroke, nearby regions may take over the functions of damaged areas. **The Divided Brain**: - The brain is divided into the **left** and **right hemispheres**, each responsible for different tasks. - **Left Hemisphere**: Language, logic, and analytical thinking. - **Right Hemisphere**: Spatial abilities, facial recognition, and creativity. **Split-Brain Research**: - Studies on patients with severed **corpus callosum** (which connects the two hemispheres) have provided insight into how the brain’s hemispheres operate independently. --This detailed breakdown covers important concepts, terms, and theories for each module to help you prepare for quizzes and exams. Let me know if you'd like additional details or clarifications on any specific sections!