2.5 - Storing Memories

Storage: The process of retaining encoded information over time.

Atkinson-Shiffrin Model of Memory

1. Sensory Memory: Briefly holds a large amount of sensory information. If you focus on a specific stimulus, that information will enter the short-term memory. 

   1. Echoic Memory: Auditory sensory memory (lasts a few seconds).

   2. Iconic Memory: Visual sensory memory (lasts less than a second).

   3. Eidetic Imagery ("Photographic Memory"): Extremely rare ability to recall visual information in great detail.

2. Short-Term Memory (STM): Temporarily holds a small amount of information for immediate use. If elaborative rehearsal occurs, then this memory will enter the long-term memory. 

   1. Miller's Rule (7 +/- 2): The limited capacity of short-term memory (about 7 items plus or minus two).

3. Long-Term Memory (LTM): Stores information for a long time, potentially permanently.

   1. Stores information relatively permanently.

   2. Seems to have unlimited capacity.

   3. Information can be retrieved when needed.

Rehearsal

Definition: Repeating information helps keep it in short-term memory and transfer it to long-term memory.

• Elaborative Rehearsal: Linking new information to existing knowledge in long-term memory for deeper processing.

• Maintenance Rehearsal: Repeating information to keep it in short-term memory.

Impairments to Memory

• Amnesia: Partial or complete loss of memory.

  1. Anterograde Amnesia: Inability to form new memories after a brain injury or event.

  2. Retrograde Amnesia: Loss of memories from before the injury or event.

  3. Alzheimer’s Disease: Slowly destroys memory and thinking skills, and eventually, the ability to carry out the simplest tasks.

  4. Infantile Amnesia: The inability to remember events from early childhood (usually before age 3).

Brain Structures and Memory

• Prefrontal Cortex: Memory for the order of events.

• Amygdala: Emotional memories (especially fear).

• Hippocampus: Its job is to hold short-term memories and transfer them to long-term storage in our brains.

• Cerebellum: Procedural memory (skills and habits).