How Memory Formation Works

Step through the four stages of memory using the example: "Meeting Sarah at a party"

Step 1 of 4: Encoding
Stage 1 Encoding — Gathering Sensory Input
👁

Visual

  • Sarah's face
  • Red dress
  • Brown hair
👂

Auditory

  • Voice: "Hi, I'm Sarah"
  • Music playing
  • Party chatter
🎉

Context

  • Party setting
  • Friday evening
  • Feeling happy
Stage 2 Storage — Brain Processing in the Hippocampus

Sensory Input

  • Sight
  • Sound
  • Context
→

HIPPOCAMPUS

  • Pattern recognition
  • Association
  • Context tagging
  • Consolidation

The hippocampus links face to name and tags it with "party, Friday, happy"

Stage 3 Long-term Storage — Moving Memory to the Cortex

HIPPOCAMPUS

  • Temporary memory
→

CEREBRAL CORTEX

  • Permanent storage
From Hippocampus Stored in Cortex Synaptic connections form

Memory strength: Medium — strengthens with repetition and sleep

Stage 4 Retrieval — Recognizing Sarah Later

Cue

  • See Sarah again
→

HIPPOCAMPUS

  • Triggers search
→

CORTEX

  • Retrieves memory
✓ "That's Sarah from the party!"
Your senses gather information about the new person.

⚠ What Happens in Dementia

Encoding is disrupted: Hippocampus damage makes it hard to form new memories. Meeting "Sarah" at a party today may never be stored.

New memories fail first: This is why people with dementia often cannot remember what they ate for breakfast.

Old memories remain longer: Memories already in the cortex (childhood, wedding day, longtime friends) are preserved because they no longer depend on the damaged hippocampus.