6: Learning, Memory, and Amnesia

Memory

is the brain's ability to store, retain, and recall information

Learning

happens when experiences change your behavior or understanding.

Stages of Learning

ACQUIRING

RETAINING

REMEMBERING

Acquiring:

Gaining new knowledge or skills (e.g., learning to play the piano).

Retaining

Holding onto what you've learned over time (e.g., remembering piano notes).

Remembering

Being able to recall and apply the knowledge later (e.g., playing a song from memory).

Memory Processes

encoding

storage

retrieval

forgetting

Encoding

Changing sensory input into a form your brain can store.

Storage

Keeping the information in your brain.

Retrieval

Accessing stored information when needed

Forgetting

Failing to remember due to decay or interference.

Types of Memory

sensory memory

iconic memory

echoic memory

short term memory

long term memory

declarative memory

Sensory Memory:

Briefly stores information from senses (sight, sound).

Iconic memory

Visual info (e.g., briefly remembering a flashed image).

Echoic memory

Auditory info (e.g., recalling a sound you just heard).

Short-Term Memory

Holds information for about 30 seconds.

Long-Term Memory:

Declarative Memory (Explicit)

Facts and events you can describe.

Declarative Memory (Explicit) types:

SEMANTIC AND EPISODIC

Semantic:

Facts and knowledge (e.g., capital cities).

Episodic:

Personal experiences (e.g., your last birthday).

long term memory types:

declarative memory

procedural memory

Procedural Memory (Implicit)

Skills you do automatically (e.g., riding a bike).

Brain Areas Involved in Memory

• Hippocampus

• Amygdala

• Prefrontal Cortex

• Cerebellum

• Striatum

• Hippocampus

Helps form and retrieve memories, especially spatial ones.

Amygdala: .

Stores emotional memories

Prefrontal Cortex: .

Organizes events in time

Cerebellum:

Controls motor memory (e.g., playing sports).

Striatum

links motivation and motor movement.

AMNESIA

• A condition where someone loses memories, can’t form new ones, or both.

Types of Amnesia

RETROGRADE AND ANTEROGADE

Retrograde Amnesia:

• Can’t remember past events.

Anterograde Amnesia:

Can’t form new memories after an event.

Other Types of amnesia

• Dissociative Amnesia

• Post-Traumatic Amnesia (PTA)

• Infantile Amnesia

Dissociative Amnesia:

Forgetting personal information due to trauma.

Post-Traumatic Amnesia (PTA):

Temporary memory loss after a brain injury.

Infantile Amnesia:

Adults’ inability to remember early childhood.

Korsakoff’s Syndrome

Caused by Vitamin B1 deficiency, often linked to alcohol abuse

Symptoms of Korsakoff’s Syndrome

• Anterograde and retrograde amnesia

• Confabulation

• Lack of motivation and insight

Confabulation

Making up false memories unknowingly

Alzheimer’s Disease

• A progressive brain disorder that slowly destroys memory and thinking skills.

Key Symptoms of Alzheimer’s Disease

• Memory loss affecting daily life

• Difficulty completing familiar tasks

• Confusion about time or place

• Mood swings and social withdrawal

Brain Changes in Alzheimer’s:

• Plaques

• Tangles

Plaques:

Clumps of a protein called amyloid-beta that damage brain cells.

Tangles:

Twisted fibers inside neurons made from tau protein.

Important Surgeries Related to Memory

• Lobectomy

• Lobotomy

• Bilateral Medial Temporal Lobectomy

Lobectomy:

Removing a lobe of the brain to stop seizures (common for epilepsy).

Lobotomy:

Severing brain connections to treat severe mental health disorders (rarely used today).

Bilateral Medial Temporal Lobectomy:

Removal of hippocampus and nearby areas, which can stop seizures but may cause permanent memory loss.