Memory
Chapter Outline
8.1 How Memory Functions
8.2 Parts of the Brain Involved with Memory
8.3 Problems with Memory
8.4 Ways to Enhance Memory
Introduction
We may be top-notch learners, but if we don't have a way to store what we've learned, what good is the knowledge we've gained?
Imagine a day without memory—it is chaotic and confusing. We rely on memory for everyday tasks such as getting dressed, eating, or even identifying people.
This chapter explores how memory works, the types of memory, the retrieval process, and the reasons behind forgetting.
8.1 How Memory Functions
Learning Objectives
By the end of this section, you will be able to:
Discuss the three basic functions of memory
Describe the three stages of memory storage
Describe and distinguish between procedural and declarative memory and semantic and episodic memory
Memory is an information processing system, often compared to a computer. It consists of processes used to encode, store, and retrieve information over differing time spans.
These processes are elaborated through the understanding of:
Encoding
Storage
Retrieval
Encoding
Encoding is the process of inputting information into the memory system.
Once sensory information is received, our brains label or code it, organizing it with similar information and connecting new concepts to existing ones.
This process occurs through two types:
Automatic Processing: Involves effortless encoding of details such as time, space, or frequency; it typically occurs without conscious awareness (e.g., recalling what you had for lunch).
Effortful Processing: Requires more attention and effort to encode information; typically used for study materials or new skills (e.g., learning to drive).
The effectiveness of encoding can be improved when information is made meaningful.
Types of Encoding
Semantic Encoding: Focuses on the meaning of words, shown through research by William Bousfield in 1935 where participants recalled words in categories based on meaning.
Visual Encoding: Involves mental images; concrete words are easier to recall due to clear imagery as compared to abstract concepts.
Acoustic Encoding: Involves the sound of words and is effective for learning through song or rhyme, which is particularly useful for children.
Factors Affecting Encoding
A study by Fergus Craik and Endel Tulving found that semantic encoding leads to better recall than visual or acoustic encoding due to deeper processing.
Self-Reference Effect: Information relating to oneself is better remembered than less personal material.
Storage
After encoding, the information must be retained as a permanent record.
Richard Atkinson and Richard Shiffrin proposed that memory passes through three stages:
Sensory Memory: Brief storage of sensory information (up to a few seconds).
Short-Term Memory (STM): Temporary storage lasting 15-30 seconds, where information is either consolidated into long-term memory or discarded.
Long-Term Memory (LTM): Potentially unlimited storage encompassing everything remembered longer than a few minutes.
Active Rehearsal is key for transferring information from STM to LTM, through repetition or linking new information to existing knowledge (Elaborative Rehearsal).
These stages conceptually mirror computer processing, as illustrated by the Atkinson-Shiffrin model.
Short-Term Memory Capacity
The capacity of short-term memory typically allows retaining 7 (± 2) items (George Miller, 1956) and more recent studies suggest it may be closer to 4 (± 1) (Cowan, 2010).
Factors affecting retention include Memory Trace Decay, where information fades with time, and Proactive Interference, where old information hinders the recall of new information.
Long-Term Memory Types
Explicit Memory: Consciously recalled (includes episodic and semantic memory).
Episodic Memory: Personal experiences and events (e.g., significant life events).
Semantic Memory: Facts and concepts (e.g., definitions or historical dates).
Implicit Memory: Unconscious habits and skills (includes procedural memory).
Procedural Memory: Skills and tasks (e.g., riding a bike).
Priming: Exposure to one stimulus affecting response to another.
Emotional Conditioning: Memories associated with emotional responses.
Memory Organization
Long-term memories are organized in semantic networks, which consist of linked concepts. Activation of one concept can trigger related concepts through a process called spreading activation.
This interconnected organization aids in retrieval such that activating one related concept may facilitate recalling others.
8.2 Parts of the Brain Involved with Memory
Learning Objectives
By the end of this section, you will be able to:
Explain the brain functions involved in memory
Recognize the roles of the hippocampus, amygdala, and cerebellum
Mark Lashley, through experiments in the 1950s, sought the engram (physical representation of memory) but did not find definitive locales in the brain associated with memory, leading to the hypothesis of equipotentiality instead.
However, modern research indicates specific brain regions do play roles in memory storage and retrieval.
Amygdala
The amygdala regulates emotions and influences how memories are stored, particularly emotional memories.
Experiments show the amygdala helps create stronger memories during emotional situations.
Hippocampus
The hippocampus is crucial for forming new declarative memories, such as the recognition and processing of spatial memory.
Neurosurgical studies (e.g., case study of H.M.) demonstrate that hippocampal damage prevents forming new memories while preserving old memories.
Cerebellum
The cerebellum is involved in processing procedural memories, evident in classical conditioning experiments where it plays a role in learning motor tasks.
Prefrontal Cortex
The left prefrontal cortex is associated with encoding, while the right regions are involved in retrieval. Brain activation patterns during memory tasks underscore differing roles of these associated areas.
Neurotransmitters in Memory
Specific neurotransmitters (e.g., acetylcholine, dopamine, serotonin) are essential for memory formation and retrieval, with heightened emotional experiences enhancing memory consolidation.
Flashbulb Memories
Strong emotional events can create exceptionally clear memories (flashbulb memories), often related to public or traumatic experiences (e.g., remembering where one was during 9/11).
8.3 Problems with Memory
Learning Objectives
By the end of this section, you will be able to:
Compare and contrast the two types of amnesia
Discuss the unreliability of eyewitness testimony
Discuss encoding failure
Discuss various memory errors
Compare and contrast the two types of interference
Amnesia
Amnesia is a loss of long-term memory impacting personal recollections (episodic) or learned information.
Anterograde Amnesia: Inability to form new memories following brain trauma, while past memories remain accessible (e.g., case of H.M.).
Retrograde Amnesia: Loss of memories for events prior to trauma, often from severe head injuries; individuals may not recognize familiar places or people.
Memory Reconstruction
Memory retrieval is subject to distortion; details can be added or altered based on new information or suggestion, leading to errors in recall.
Suggestibility and Eyewitness Testimony
Witnesses can be misled by misleading questions or suggestive cues, leading to false memories; eyewitness misidentification is a significant cause of wrongful convictions.
Memory Errors and Interference
Memory errors include:
Transience: Memory fading over time.
Absentmindedness: Attention lapses leading to forgetting.
Blocking: Temporary inability to access information (e.g., tip-of-the-tongue phenomena).
Misattribution: Confusing the source of a memory.
Suggestibility: Formation of false memories through misinformation from others.
Bias: Distortion of memories based on current beliefs or feelings.
Persistence: Difficulty forgetting undesired memories, often traumatic.
Interference occurs in two forms:Proactive Interference: Old information disturbs recall of new information.
Retroactive Interference: New information hampers recall of old information.
8.4 Ways to Enhance Memory
Learning Objectives
By the end of this section, you will be able to:
Recognize and apply memory-enhancing strategies
Recognize and apply effective study techniques
Memory failures are common, leading to the pursuit of effective methods that promote memory enhancement.
Memory-Enhancing Strategies
Rehearsal: Conscious repetition of information.
Chunking: Organizing information into manageable units.
Elaborative Rehearsal: Linking new information with existing knowledge.
Mnemonic Devices: Techniques to improve retention of information, often through acronyms or acrostics.
Expressive Writing: Aids in memory retention, particularly for traumatic experiences.
Vocalization: Saying words aloud enhances their distinctiveness.
Study Techniques
Use elaborative rehearsal to deepen understanding.
Apply the self-reference effect to create personal connections with material.
Implement distributed practice by studying over time.
Rehearse continuously through organized review sessions.
Reduce distractions during study to improve concentration.
Engage in regular aerobic exercise for enhanced cognitive functioning.
Ensure adequate sleep for memory consolidation.
Enhance memory using mnemonic techniques, such as acronyms and jingles, to facilitate recall.