100_6.1_ Memory.pdf

Memory Overview

• Memory refers to the information that has been encoded, stored, and is available for retrieval in the brain.

• It serves as the basis for knowing various aspects like friends, neighbors, language, and personal history.

HM Case Study (1926-2008)

• Background: HM underwent a bilateral medial temporal lobectomy at 27 to treat epilepsy.

• Consequences: Loss of the ability to commit new explicit events to memory, but procedural memory remained intact (e.g., ability to learn new motor skills).

Stages of Memory

1. Memory Encoding

• Definition: The process of getting information into the brain.

• **Types of Encoding: **

  • Automatic Processing: e.g., remembering the route to school.

  • Effortful Processing: e.g., memorizing a friend's new phone number requires focus.

2. Memory Storage

• Definition: Retaining information in memory for later use.

• **Types of Memory: **

  • Sensory Memory: Very brief retention of sensory information (0.5 sec to a few seconds).

  • Working/Short-Term Memory: Limited capacity (7±2 items) and short duration (about 20 seconds).

  • Long-Term Memory: Unlimited capacity, can last a lifetime but may experience decay over time.

3. Memory Retrieval

• Definition: The process of recalling or recognizing stored information.

• Factors Affecting Retrieval:

  • Retrieval Cues: Stimuli that help recall information.

  • Forgetting: Memory loss over time.

  • Memory Construction: How memories can be influenced by other information (misinformation effect).

Memory Effects

• Effortful Learning: Requires rehearsal or conscious practice—Ebbinghaus’s studies showed that repeated practice leads to better recall.

• Primacy and Recency Effects: Refers to better memory for items at the beginning and end of lists, respectively.

  • Example: When memorizing a list, we tend to remember the first and last items more successfully.

• Chunking Effect: Organizing information into manageable units improves memory retention (e.g., group numbers or letters).

• Spacing Effect: Studying information over time rather than cramming enhances retention.

Types of Long-Term Memory

1. Episodic Memory:

• Involves memory for specific events in time.

2. Semantic Memory:

• Involves memory for facts, concepts, and knowledge.

3. Autobiographical Memory:

• Similar to episodic but focuses on self-relevant experiences.

4. Procedural Memory:

• Involves skills and actions (e.g., how to ride a bike).

5. Emotional Memory:

• Relates to memories tied to specific emotions.

Conclusion

• Memory involves encoding, storage, and retrieval, all governed by mechanisms that can be classified into different types.

• Understanding these concepts helps in improving memory retention and recall efficiency.