Memory

Chapter 7: Memory — Summary

Memory is the ability to store and retrieve information. Psychologists have found that memory is not just one system; different types of memory depend on different brain systems.

1. Types of Memory

The case of H.M. (Henry Molaison) helped researchers understand memory. After parts of his medial temporal lobes, including the hippocampus, were removed, H.M. could no longer form new long-term memories. However, he could still learn certain skills without remembering learning them.

Implicit memory: Memory shown through actions, skills, or reactions without conscious recall.
Explicit memory: Memory that can be consciously remembered.
Procedural memory: Implicit memory for skills and habits, such as riding a bike.
Episodic memory: Memories of personal experiences tied to a specific time and place.
Semantic memory: General knowledge and facts that are not tied to a specific personal experience.
Priming: Previous experience makes it easier to respond to a stimulus later.

2. Three Stages of Memory

All types of memory go through three basic stages:

Encoding – acquiring or transforming information into memory.
Storage – maintaining and consolidating the information.
Retrieval – bringing stored information back to mind.

3. Encoding

Encoding begins with attention. Information is more likely to be remembered when it is processed deeply and meaningfully.

Maintenance rehearsal: Repeating information over and over.
Elaborative rehearsal: Connecting information to meaning or existing knowledge.
Dual-coding: Information is remembered better when it is represented both verbally and visually.
Schemas: Existing knowledge structures that help us organize and understand new information.
Chunking: Grouping information into meaningful units.
Mnemonics: Memory strategies that use retrieval cues, such as a memory palace.

4. Memory Storage

The three major storage systems are:

Sensory memory: Very brief storage of sensory information. Visual sensory memory is iconic memory, while auditory sensory memory is echoic memory.
Working memory: Briefly holds and actively processes information. Information usually lasts about 20–30 seconds without rehearsal.
Long-term memory: Stores information from minutes to potentially a lifetime.

Working memory has a limited capacity. Miller originally suggested about 7 ± 2 items, although newer evidence suggests the limit may be closer to 4 items. Chunking can increase how much information can be remembered.

5. Consolidation and Reconsolidation

Consolidation is the gradual process of storing memories in the brain. Long-term potentiation (LTP) strengthens connections between neurons, helping information become stored.

Memory can also be changed after it is recalled. Reconsolidation occurs when a retrieved memory becomes active again and is stored again. During this process, the memory can be strengthened or modified.

6. Retrieving Memories

Retrieval cues help bring memories back.

Context-dependent memory: Recall is better when the environment during retrieval is similar to the environment where the information was learned.
State-dependent memory: Recall can improve when a person's internal state is similar during learning and retrieval.
Prospective memory: Remembering to do something in the future.
Retrieval-induced forgetting: Retrieving one memory can sometimes make it harder to remember a related memory.

For studying, the chapter recommends distributed learning, elaboration, retrieval practice, overlearning, mnemonics, and visual imagery.

7. Forgetting and Memory Mistakes

Forgetting is the inability to retrieve information from long-term memory. Ebbinghaus found that forgetting happens quickly at first and then slows down.

Important causes/types include:

Proactive interference: Old information interferes with new information.
Retroactive interference: New information interferes with old information.
Blocking: Temporary inability to remember something, such as the tip-of-the-tongue experience.
Absentmindedness: Poor or shallow encoding caused by lack of attention.
Persistence: Unwanted memories that repeatedly come back.
Memory bias: Memories change over time to fit current beliefs.
Source misattribution: Remembering information but confusing where or when it came from.
Source amnesia: Remembering information but forgetting its source.
Cryptomnesia: Believing an old idea is a new idea because its original source is forgotten.

8. False Memories

Memory is not a perfect recording of events. It can be changed by misleading information and suggestions. Elizabeth Loftus's research demonstrated that the wording of questions can influence what people remember. Suggestibility occurs when misleading information creates or changes memories.

False memories can even involve remembering events that never actually happened. The chapter also discusses the controversy surrounding repressed memories, noting that some techniques, such as hypnosis and guided recall, can contribute to false memories.

⭐ Biggest Things to Remember for a Test

Memory = Encoding → Storage → Retrieval

Implicit: skills/actions
Explicit: conscious memories
Episodic: personal experiences
Semantic: facts/knowledge
Procedural: skills/habits

Sensory → Working → Long-term

Proactive = old interferes with new
Retroactive = new interferes with old

Encoding specificity: memories are easier to retrieve when retrieval conditions resemble the conditions during encoding.

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