PSYC100 Lecture Notes Review: The Brain and Neurons

Welcome and Retrieval Practice Prompts

• Welcome to PSYC100!

• Challenge Yourself: Retrieval Practice (without notes)

  • Describe the advantages and disadvantages of case studies.

  • Explain the two reasons why correlation does not equal causation.

• After attempting the challenge, check your notes for accuracy.

• Note: Jackson Wang & Internet Money ‘Drive You Home’ was playing. No PollEv was conducted.

Today's Learning Objectives

Today's session aims to cover the following topics:

• Review experimental methods.

• Discuss how the brain is conceptualized.

• Identify the locations and functions of the various parts of a neuron.

• Identify the main lobes of the brain.

• Begin identifying different basic sub-cortical structures of the brain.

Experimental Methods Review: Brain Games Exercise

• Exercise: Watch a clip from a Brain Games episode.

• Important Note: This clip shows what was done in a study. However, because it's a TV show, it might not be as carefully controlled or precise as a real scientific experiment should be.

• Questions to Answer while watching the clip:

  • What is the Independent Variable (IV)? This is the thing the experimenter changes or manipulates.

  • How was the IV manipulated? (How did they change it?)

  • What is the Dependent Variable (DV)? This is the thing that is measured to see if the IV had an effect.

  • How was the DV measured? (How did they measure the outcome?)

  • What are some potential confounds present in this demonstration? These are extra factors that might unknowingly influence the results.

  • What kind of validity is most affected by the presence of these confounds? (Does it make the results less believable or generalizable?)

Conceptualizing the Brain

• The brain is understood as:

  • A complex network of neurons (like tiny interconnected computers).

  • A sophisticated communication system (always sending and receiving messages).

  • An "expensive" organ, meaning it uses a lot of the body's energy and is incredibly important for survival.

The Neuron: Structure and Function

• The neuron is the basic building block of the nervous system, responsible for sending information.

• Key parts of a neuron include:

  • Dendrites: These are like tree branches that receive nerve impulses (signals) from other neurons. Example: The antenna of a radio.

  • Cell body (Soma): This is the main part of the neuron, like its brain. It contains the nucleus and keeps the cell alive. integrates and packages information that is being received by the dendrites

  • Axon: This is a long, thin cable that sends nerve impulses away from the cell body to other neurons, muscles, or glands. Example: A long electrical wire.

  • Myelin sheath: A fatty wrapping around the axon (made of glial cells). It acts like insulation on an electrical wire, making the signals travel much faster. Example: The plastic coating on an electrical cord.

  • Node of Ranvier: These are small gaps in the myelin sheath along the axon. They help the electrical signal regenerate and jump along the axon.

  • Terminal buttons (Axon terminals): Small knobs at the end of the axon that release chemical messengers (neurotransmitters) into the space between neurons. Example: The 'send' button.

  • Synapse: This is the tiny gap or junction where chemical communication happens between one neuron's terminal button and another neuron's dendrite or cell body. Example: A handshake between two people where information is exchanged.

• Direction of Nerve Impulse: Signals typically flow in one direction: from dendrites to the cell body, then down the axon, and finally across the synapse to the next neuron.

Brain Imaging Techniques

• Structural MRI Imaging: A technique that uses powerful magnets and radio waves to create very detailed pictures of the brain's physical structure (like bones, tissues, etc.). It helps doctors and researchers see different brain parts.

• Gray matter = brain cells (neurons) where thinking, memory, emotions, and decisions happen.

• White matter = wiring (axon connections) that link gray matter areas so signals can travel.

Lobes of the Brain: Location and Function

• The cerebral cortex (the brain's outer layer) is divided into four main sections, each with specific jobs:

  • Frontal Lobe: Located at the very front of the brain, behind your forehead.

    • Associated with thinking, planning, making decisions, and voluntary movements. Example: Deciding what to eat for dinner or planning your day.

  • Parietal Lobe: Located behind the frontal lobe, at the top of your head.

    • Involved in processing touch, temperature, pain, and understanding where things are in space. Example: Feeling the texture of a fabric or knowing where your hand is without looking.

  • Temporal Lobe: Located beneath the parietal and frontal lobes, near your temples.

    • Crucial for hearing, understanding language, and forming memories. Face obj recognition Example: Listening to music or remembering a friend's voice.

  • Occipital Lobe: Located at the very back of the brain.

    • Primarily responsible for processing all visual information. Example: Seeing colors, shapes, and movement.

Basic Sub-Cortical Structures of the Brain

Below the cerebral cortex (the outer wrinkly part) are several important structures:

• Brain Stem: Located at the base of the brain, connecting the brain to the spinal cord. It controls vital involuntary functions essential for life. Example: Regulating your breathing, heart rate, and digestion automatically.

• Cerebellum: Located at the back of the brain, underneath the occipital and temporal lobes.

  • Plays a key role in motor control, coordination, balance, and precision. Example: Helping you walk smoothly, ride a bike, or play a sport.

• Hippocampus: A seahorse-shaped structure located deep inside the temporal lobe.

  • Primarily involved in forming new memories. Example: Remembering what you had for breakfast or learning a new fact.

• Thalamus: Located deep in the brain, above the brain stem.

  • Often described as the "sensory gateway" because it relays almost all sensory and motor signals to the cerebral cortex. It also helps regulate sleep, alertness, and wakefulness. Example: Like a busy switchboard operator, directing incoming phone calls (sensory information) to the correct department (brain areas).

• Basal Ganglia: A group of deep brain structures.

  • Crucial for controlling voluntary movements, creating habits, and learning procedures (like riding a bike without thinking). It also plays a role in how we experience rewards. Example: Learning to tie your shoes or playing a musical instrument.

  • Includes structures like the Nucleus Accumbens, which is strongly associated with feeling good, pleasure, and motivation. Example: The feeling of satisfaction you get from achieving a goal or eating a delicious meal.

• Hypothalamus: Located below the thalamus.

  • Regulates various body functions, including hunger, thirst, sleep, body temperature, and releasing hormones from the pituitary gland. Example: Telling you when you're hungry or thirsty, or helping you cool down when you're hot.

• Amygdala: An almond-shaped structure located within the temporal lobe.

  • Primarily involved in processing emotions, especially fear and aggression, and plays a role in creating emotional memories. Example: The feeling of fear you get when you see a spider if you're afraid of them, or the strong emotional memory of a significant event.