Speeds up electrical impulses along axons.
Nervous System Overview
CNS: Brain and spinal cord; mediates behavior.
Somatic NS: Controls voluntary movement and sensation.
Autonomic NS: Regulates internal functions.
Sympathetic: Arousing (fight-or-flight).
Parasympathetic: Calming (rest-and-digest).
Neurons and Nerves
Neuron Components:
Soma (Cell Body): Information processing
Axons: Information sending
Dendrites: Collecting Information
CNS: Nuclei (cell bodies), Tracts (axons).
PNS: Ganglia (cell bodies), Nerves (axons).
Brainstem and Hindbrain
Brainstem: Connects brain to spinal cord; vital functions.
Hindbrain: Includes medulla, pons, and cerebellum.
Cerebellum: Coordinates voluntary movement, balance, motor learning.
Medulla: Autonomic survival functions like heartbeat and breathing.
Diencephalon
Thalamus: Sensory relay, except smell.
Hypothalamus: Regulates hunger, thirst, sleep, body temperature, emotions, hormones.
Telencephalon
Basal Ganglia: Movement and habit learning; disorders like Parkinson’s and Huntington’s.
Limbic System:
Amygdala: Emotions (fear, anger).
Hippocampus: Memory and navigation.
Neocortex
6 layers of gray matter; processes information.
Lobes:
Frontal: Decision-making, problem-solving, planning, voluntary movement.
Parietal: Processes touch, spatial reasoning.
Temporal: Auditory processing, memory, language.
Occipital: Visual information processing.
Corpus Callosum: Connects hemispheres.
Bottom-up processing: Driven by sensory input (e.g., recognizing a new song's melody).
Top-down processing: Shaped by prior knowledge/expectations (e.g., seeing a shape in a cloud after a suggestion).
Schemas: Mental frameworks that help organize information (e.g., a child's idea of a dog includes four legs and a tail).
Perceptual sets: Expectations that shape perception (e.g., seeing a specific shape in clouds due to a suggestion).
Definition: Neurons transmit electrical signals to communicate.
Process:
Resting Potential: Negative internal charge.
Threshold of Excitation: Minimum stimulation to trigger firing.
Action Potential: Electrical impulse along the axon.
During depolarization, sodium (Na⁺) enters the cell, making the inside of the cell more positive.
Synaptic Transmission: Neurotransmitters cross synapses to relay signals.
EPSP (Excitatory Postsynaptic Potential):
Definition: A depolarizing event that increases the likelihood of a neuron firing an action potential.
How it works: Occurs when excitatory neurotransmitters (e.g., glutamate) bind to receptors, allowing positively charged ions (e.g., Na⁺) to enter the neuron.
Result: Moves the membrane potential closer to the threshold for firing.
IPSP (Inhibitory Postsynaptic Potential):
Definition: A hyperpolarizing event that decreases the likelihood of a neuron firing an action potential.
How it works: Occurs when inhibitory neurotransmitters (e.g., GABA) bind to receptors, causing negatively charged ions (e.g., Cl⁻) to enter or positive ions (e.g., K⁺) to exit the neuron.
Result: Moves the membrane potential further away from the threshold for firing.
Explicit Memory: Conscious recall (e.g., facts, events).
Implicit Memory: Unconscious skills/habits (e.g., riding a bike).
Encoding Processes: Rehearsal, elaboration, and semantic encoding move info to long-term memory.
Sensory Memory:
Definition: The immediate, very brief recording of sensory information (e.g., sights, sounds, smells).
Duration: Lasts a fraction of a second to a few seconds.
Capacity: Very large but fleeting.
Types:
Iconic Memory: Visual sensory memory (lasting ~0.5 seconds).
Echoic Memory: Auditory sensory memory (lasting ~3-4 seconds).
Short-Term Memory (STM):
Definition: A temporary storage system for holding small amounts of information for a brief period.
Function: Passive holding of information.
Duration: About 15–30 seconds without rehearsal.
Capacity: Limited to 7 ± 2 items (e.g., a string of numbers).
Example: Remembering a phone number just long enough to dial it.
Working Memory (WM):
Definition: An active process where information is held temporarily and manipulated for cognitive tasks.
Function: Combines storage and mental manipulation to solve problems, make decisions, and perform tasks.
Duration: Information is actively maintained through rehearsal or attention but is not stored permanently.
Capacity: Similar to STM, but also depends on processing ability.
Example: Doing mental math, such as calculating 23 × 7 in your head.
Long-Term Memory:
Definition: Permanent storage of information for extended periods, ranging from minutes to a lifetime.
Capacity: Virtually unlimited.
Types:
Explicit Memory (Declarative): Conscious recall of facts and events.
Subtypes: Episodic Memory (personal experiences), Semantic Memory (facts and knowledge).
Implicit Memory (Non-Declarative): Unconscious retention of skills and conditioned responses.
Subtypes: Procedural Memory (skills like riding a bike), Classical Conditioning responses.
Key Difference Between STM and WM:
Short-Term Memory: A simple, passive storage system.
Working Memory: Dynamic, involving both storage and manipulation of information for tasks like reasoning, comprehension, and learning.
Think of short-term memory as a notepad and working memory as the notepad plus your hand actively using it to solve a problem.
Definition: Learning via association of stimuli.
Key Terms:
UCS: Triggers natural response (e.g., food).
UCR: Natural reaction (e.g., salivation to food).
CS: Neutral stimulus paired with UCS (e.g., bell).
CR: Learned response to CS (e.g., salivation to bell).
Processes: Acquisition, extinction, spontaneous recovery, generalization, discrimination.
Definition: Behavior influenced by consequences.
Reinforcement:
Positive: Add pleasant stimulus (e.g., candy for homework).
Negative: Remove unpleasant stimulus (e.g., aspirin for headache).
Punishment:
Positive: Add unpleasant stimulus (e.g., speeding ticket).
Negative: Remove pleasant stimulus (e.g., toy taken away).
Reinforcement Schedules:
Fixed/Variable Ratio: Based on number of actions.
Fixed/Variable Interval: Based on time.
Definition: Infinite word/phrase combinations for communication.
Key Features:
Syntax: Sentence structure for meaning.
Creativity: Novel word combinations.
Definition: A system of symbols governed by rules to communicate ideas.
Components:
Phonemes: Smallest sound units (e.g., /b/ in "bat").
Morphemes: Smallest meaning units (e.g., "cats" = "cat" + "s").
Semantics: Meaning of words/sentences (e.g., "bank" as riverbank or institution).
Grammar: Rules for word combination (e.g., "big house").
Morphology: Rules for forming words.
Syntax: Sentence structure and word arrangement (e.g., "The cat sat on the mat").
Significance: Enables the creation of endless sentences, supporting communication.
Cooing: Early vocalizations (e.g., “oo”).
Babbling: Repeated sounds (e.g., “ba-ba”).
One-Word Stage: Single words convey full ideas (e.g., "milk").
Telegraphic Speech: Two-word .combinations (e.g., "want cookie").
Overgeneralization: Misapplying rules (e.g., “goed” for “went”).
Other Errors:
Mispronunciations: (e.g., "wabbit" for "rabbit").
Simplifications: (e.g., "nana" for "banana").
Significance: Reflects active rule learning in children.
Sensorimotor (0–2 years): Object permanence develops.
Preoperational (2–7 years): Egocentrism, symbolic play, lacks conservation.
Concrete Operational (7–11 years): Logical thinking, concrete reasoning.
Formal Operational (12+ years): Abstract thought, problem-solving.