Unit 1 A.P. Psych Review

Unit 1: Biological Bases of Behavior

Mod 1.1 Interaction of Heredity and Environment

• Heredity: The genetic transmission of characteristics from parents to offspring.
  Example: An inherited trait like eye color from parents to children.

• Nature vs Nurture: The debate regarding the relative importance of genetic inheritance (nature) and environmental factors (nurture) in determining behavior.
  Example: A person’s athletic ability can be influenced by both genetic factors and the environment in which they were raised.

• Genetic Predisposition: A biological tendency to develop certain traits or behaviors based on genetic makeup.
  Example: An individual with a family history of depression may have a genetic predisposition to the condition.

• Evolutionary Perspective: The viewpoint that behavior can be understood in the context of evolutionary theory, emphasizing adaptation and survival.
  Example: A fear of snakes may be understood as an adaptation for survival from potentially dangerous creatures.

• Natural Selection: The process through which advantageous traits increase in a population over time, leading to evolution.
  Example: The development of antibiotic resistance in bacteria due to natural selection.

• Epigenetic Interaction: How environmental factors can influence gene expression and thus behavior.
  Example: Exposure to stress in early life can lead to changes in gene expression affecting stress responses later in life.

• Eugenics: A controversial social philosophy advocating for the improvement of the human race through selective breeding.
  Example: Historical practices in the early 20th century where individuals deemed 'unfit' were sterilized.

• Twin Studies: Research comparing traits and behaviors in identical and fraternal twins to understand genetic and environmental influences.
  Example: Studies showing that identical twins raised apart often have similar personalities and life paths, supporting genetic influences.

• Family Studies: Investigating family members to assess the influence of genetics on behavior.
  Example: Research indicating that children of alcoholics are more likely to become alcoholics themselves, suggesting a genetic link.

• Adoption Studies: Analyzing children raised in different environments from their biological parents to evaluate the effects of environment versus heredity.
  Example: Studies showing adopted children often show behavioral similarities to their biological parents rather than their adoptive parents, highlighting genetic influences.

• Biological Approach: A perspective that stresses the importance of biological factors in influencing behavior.
  Example: The use of medications to manage mental health disorders based on biological research.

Mod 1.2 Overview of the Nervous System

• Central Nervous System (CNS): Comprises the brain and spinal cord, controlling most functions of the body and mind.
  Example: Damage to the spinal cord can result in paralysis.

• Peripheral Nervous System (PNS): Connects the CNS to the rest of the body and is responsible for transmitting information to and from the CNS.
  Example: The role of peripheral nerves in sensing pain from a pinprick.

• Autonomic Nervous System (ANS): Manages involuntary functions like heart rate and digestion.
      - Sympathetic Nervous System: Activates the fight-or-flight response during stressful situations.
  Example: Increased heart rate and adrenaline release when encountering a bear in the woods.
      - Parasympathetic Nervous System: Promotes the rest-and-digest response when the body is at rest.
  Example: Decreased heart rate and increased digestive activity after eating.

• Somatic Nervous System: Controls voluntary movements and transmits sensory information to the CNS.
  Example: Moving your arm to wave at a friend.

• Interneurons: Neurons that connect sensory and motor pathways within the CNS.
  Example: Interneurons in the spinal cord that allow reflex actions without involving the brain.

Mod 1.3a The Neuron and Neural Firing: Neural Communication & Endocrine System

• Structure of a Neuron: The cell body, dendrites (receive signals), axon (sends signals), and synaptic terminals (release neurotransmitters).
  Example: Dendrites receiving signals from other neurons during communication.

• Neural Transmission Process: Involves the firing of action potentials and communication across synapses via neurotransmitters.
  Example: The transmission of pain signals through neurons when touching something hot.

• Action Potential: A rapid rise and fall in voltage (membrane potential) across a cellular membrane, allowing transmission of signals.
  Example: The generation of an action potential during a reflex reaction.

• All-or-Nothing Principle: The principle that a neuron either fires completely or not at all; there is no in-between.
  Example: A neuron firing fully in response to a strong enough stimulus, like stepping on a nail.

• Depolarization: A decrease in membrane potential where the inside of the neuron becomes less negative.
  Example: The change in voltage when a neuron is activated by a neurotransmitter.

• Refractory Period: The time following an action potential during which a neuron is unable to fire again.
  Example: A neuron cannot fire a second action potential until it returns to its resting state after the first.

• Resting Potential: The stable, negative charge of a neuron when it is not firing (approximately -70 mV).
  Example: The condition of a neuron before it is stimulated.

• Reuptake: The process by which neurotransmitters are reabsorbed by the presynaptic neuron after transmission.
  Example: The reabsorption of serotonin in the brain, which can affect mood.

• Threshold: The level of depolarization required to trigger an action potential.
  Example: A neuron that reaches the threshold level will fire an action potential.

• Neurotransmitters: Chemical messengers that transmit signals across a synapse from one neuron to another.
    - Excitatory Neurotransmitters (Agonist): Promote action potentials; examples include Acetylcholine, Epinephrine/Adrenaline, Dopamine, Glutamate, etc.
  Example: Dopamine release during pleasurable activities enhances motivation.
    - Inhibitory Neurotransmitters (Antagonist): Prevent action potentials; include GABA, Serotonin, etc.
  Example: GABA’s role in lowering anxiety levels by inhibiting neuronal firing.

• Diseases and Disorders:
    - Myasthenia Gravis: An autoimmune disorder affecting transmission at the neuromuscular junction.
  Example: Muscle weakness and fatigue in individuals with this condition.
    - Multiple Sclerosis: A disease affecting the myelin sheath of neurons, leading to disrupted communication in the nervous system.
  Example: Symptoms like numbness and impaired coordination in patients.
    - Alzheimer's Disease: A progressive neurological disease affecting memory and cognitive function.
  Example: Memory loss and confusion in individuals diagnosed with the disease.

• Hormones: Chemical substances that regulate various bodily functions, also involved in neural communication.
  Example: The release of insulin by the pancreas to regulate blood sugar levels.
      - Examples include Leptin, Ghrelin, Melatonin, Oxytocin, and Norepinephrine.

Mod 1.3b The Neuron and Neural Firing: Substance Use Disorders & Psychoactive Drugs

• Psychoactive Drugs: Substances that alter mood, perception, and behavior; affect neurotransmitter systems.
  Example: Alcohol consumption leading to mood changes.
      - Agonists: Drugs that enhance the action of neurotransmitters (e.g., morphine for endorphins).
  Example: Morphine binding to endorphin receptors to relieve pain.
      - Antagonists: Drugs that inhibit neurotransmitter action (e.g., naloxone for opioids).
  Example: Naloxone reversing an opioid overdose by blocking opioid receptors.
      - Reuptake Inhibitors: Drugs that block the reuptake of neurotransmitters, enhancing their effects (e.g., SSRIs for serotonin).
  Example: SSRIs increasing levels of serotonin to relieve depression.

• Types of Drugs:
    - Stimulants: Increase alertness and energy (e.g., caffeine, cocaine).
  Example: People often consume caffeine to enhance alertness during work.
    - Depressants: Decrease nervous system activity (e.g., alcohol, benzodiazepines).
  Example: Alcohol's depressant effects leading to relaxation or sedation.
    - Hallucinogens: Alter perceptions (e.g., LSD, marijuana).
  Example: Experiencing visual hallucinations after consuming LSD.
    - Opioids: Prescription pain relievers that can lead to addiction (e.g., heroin).
  Example: Chronic pain patients being prescribed opioids for pain relief.

Mod 1.4a The Brain - Neuroplasticity & Tools of Discovery

• Neuroplasticity: The brain's ability to reorganize itself by forming new neural connections throughout life, a crucial element for learning and recovery from brain injuries.
  Example: A stroke patient learning to use their arm again through rehabilitation exercises.

• Tools of Discovery:
    - EEG (Electroencephalogram): Measures electrical activity in the brain.
  Example: EEGs are used to diagnose conditions like epilepsy.
    - fMRI (Functional Magnetic Resonance Imaging): Measures brain activity by detecting changes in blood flow.
  Example: Used to study brain activity patterns during cognitive tasks.
    - Lesioning: Deliberate damage to specific brain areas to study effects on behavior.
  Example: Research on animals where certain brain areas are lesioned to observe changes in behavior.

Mod 1.4b The Brain - Brain Regions & Structures

• Pituitary Gland: Known as the 'master gland,' regulates hormonal activity.
  Example: The pituitary gland's role in growth hormone release affects growth.

• Brain Stem: Responsible for automatic survival functions (includes medulla, pons).
  Example: The brain stem controlling breathing even during sleep.

• Medulla: Controls vital functions such as heartbeat and respiration.
  Example: Damage to the medulla can lead to loss of respiratory functions.

• Reticular Activating System: Plays a role in arousal and alertness.
  Example: The RAS helps in waking you up and keeping you alert throughout the day.

• Cerebellum: Coordinates movement and maintains balance.
  Example: Ensuring you can ride a bike without falling over.

• Cerebral Cortex: Involved in higher-level brain functions including thought and action.
  Example: Critical thinking and decision-making activities occur in the cerebral cortex.

• Limbic System: Associated with emotions, memory, and drives (includes amygdala, hippocampus).
  Example: The amygdala's response to emotional stimuli like fear triggers a fight-or-flight response.

• Thalamus: Relay station for sensory and motor signals.
  Example: The thalamus processes visual information before reaching the visual cortex.

• Hypothalamus: Regulates hunger, thirst, temperature, and other homeostatic systems.
  Example: The hypothalamus triggers thirst when dehydrated.

• Hippocampus: Essential for memory formation.
  Example: The hippocampus' role in forming new memories for a recent vacation.

• Amygdala: Involved in emotion regulation, notably fear and pleasure responses.
  Example: The amygdala's overactivity can lead to heightened anxiety responses.

• Corpus Callosum: Connects the left and right cerebral hemispheres for integrated function.
  Example: The corpus callosum allowing coordination between both hands during complex tasks.

• Cerebral Lobes:
    - Occipital Lobes: Responsible for vision processing.
  Example: Visual information from the environment is processed in the occipital lobe.
    - Temporal Lobes: Involved in auditory processing and memory.
  Example: The temporal lobes play a role in recognizing faces and sounds.
    - Parietal Lobes: Processes tactile information and spatial orientation.
  Example: Feeling the texture of an object is processed in the parietal lobe.
    - Frontal Lobes: Involved in reasoning, planning, movement, and problem-solving (includes prefrontal cortex for executive function).
  Example: Planning a project or making decisions about your future utilizes the frontal lobes.

• Motor Cortex: Controls voluntary movement.
  Example: The motor cortex's activation leads to movement of your legs while walking.

• Somatosensory Cortex: Processes sensory input from the body.
  Example: The somatosensory cortex allows for the feeling of pressure while holding a ball.

• Contralateral Hemispheric Organization: Each hemisphere of the brain controls the opposite side of the body.
  Example: Movement of the right arm is controlled by the left hemisphere of the brain.

• Long-term Potentiation (LTP): A process that contributes to synaptic strength and is believed to be a mechanism underlying learning and memory.
  Example: Repeated practice in a skill strengthens the neural connections involved in that skill.