Memory: Foundations, Processes, and Applications in Psychology

Memory in Psychological Science

Introduction to Human Memory

Memory is the process by which we encode, store, and retrieve information. It is not a static system; rather, it is dynamic and subject to change over time. Human memory is reconstructive, meaning we often "fill in the gaps" to make sense of the world, which can lead to errors.

• Definition: Memory refers to the mental processes involved in acquiring, storing, and later retrieving information.

• Reconstructive Nature: Memory is not like a recording device; it can be altered by ourselves and others (Loftus).

• Adaptive Function: Filling in gaps is generally adaptive but can make us prone to error.

Foundations of Memory

Basic Processes

Memory involves three fundamental processes: encoding, storage, and retrieval.

• Encoding: Initial recording of information.

• Storage: Information is saved for future use.

• Retrieval: Recovery of stored information.

Three-Stage Model of Memory

Stages and Flow of Information

Information must pass through three distinct stages to be remembered: sensory memory, short-term memory (STM), and long-term memory (LTM).

• Sensory Memory: Brief storage of sensory events (sights, sounds, tastes).

• Short-Term Memory: Limited capacity system, retains information for up to 30 seconds.

• Long-Term Memory: Continuous, potentially lifelong storage of information.

Flow: SENSORY → STM → LTM

Sensory Memory

Characteristics and Types

Sensory memory stores brief sensory events with high precision. Each sense has its own sensory memory.

• Iconic Memory: Visual system, duration < 1 second.

• Echoic Memory: Auditory system, duration 2-3 seconds.

• Loss: Unless transferred, sensory information is quickly lost.

Short-Term Memory (STM)

Capacity and Duration

STM is a limited capacity system where information is retained for only a short period unless actively maintained.

• Capacity: 7 ± 2 items (the "magic number 7").

• Duration: Up to 30 seconds without rehearsal.

• Fate: Information is either discarded or transferred to LTM.

Extending STM Capacity

• Chunking: Organizing information into smaller, meaningful groups to increase STM span.

• Example: Grouping random letters into familiar acronyms or words.

Transferring Information: Rehearsal

Types of Rehearsal

• Maintenance Rehearsal: Repeating information in its original form.

• Elaborative Rehearsal: Organizing and linking information in meaningful ways; more effective for transferring to LTM.

• Memory Consolidation: The process by which rehearsal leads to stable long-term memories.

Working Memory

Active Processing

Working memory is a set of temporary memory stores that actively manipulate and rehearse information. It includes a central executive processor involved in reasoning and decision-making.

• Mental Whiteboard: Used for holding and processing information in real time.

Long-Term Memory (LTM)

Characteristics

• Continuous Storage: Information may last decades or a lifetime.

• No Limit: Comparable to a computer's hard drive.

• Amnesia Evidence: Anterograde vs. retrograde amnesia shows distinction from STM.

Types of Long-Term Memory

Type	Description	Example
Explicit (Declarative)	Conscious recollection of facts/events	Semantic: Knowing the prime minister; Episodic: First day of university
Implicit (Non-declarative)	Unconscious memory affecting behavior	Procedural: Tying shoes; Priming: Identifying a car faster after seeing similar images

The Serial Position Effect

Primacy and Recency Effects

• Primacy Effect: Better recall for items presented first.

• Recency Effect: Better recall for items presented last.

• Odd/Unique Stimuli: Remembered regardless of position.

Case Studies in Memory

Henry Molaison (HM)

• Hippocampus removed to treat seizures.

• Could not form new explicit memories; had retrograde amnesia.

• Could learn new skills (mirror tracing), showing distinction between explicit and implicit memory.

Clive Wearing

• Severe anterograde and retrograde amnesia after viral encephalitis.

• Retained ability to play piano (procedural memory).

Neuroscience of Memory

Brain Structures

• Engram: Memory traces distributed throughout the brain (Karl Lashley).

• Hippocampus: Essential for memory consolidation and encoding new declarative memories.

• Amygdala: Involved in emotional memories (e.g., phobias, trauma).

Long-Term Potentiation

• Neural pathways become more easily excited as new responses are learned.

• "Neurons that fire together, wire together."

• Synapses between neurons increase, dendrites branch out.

Why Do We Forget?

Encoding Failures

• Failure to attend to information prevents encoding.

• Most events are never encoded.

• Self-reference Effect: Better memory for information related to oneself.

• Stress: Reduces accuracy of recall and identification; can focus attention but also impair encoding.

• Own Age Bias & Cross Race Effect: People are better at recognizing faces of their own age/race.

Retrieval Failures

• Decay: Information fades over time.

• Interference: Competition with new information.

• Proactive Interference: Old information interferes with new learning.

• Retroactive Interference: New information overshadows older memories.

Amnesia

Types of Amnesia

• Anterograde Amnesia: Inability to remember new information after trauma; often involves hippocampal damage.

• Retrograde Amnesia: Loss of memory for events prior to trauma.

Retrieving Memories

Recall and Recognition

• Recall: Accessing information without cues (e.g., essay questions).

• Recognition: Identifying previously learned information (e.g., multiple-choice questions).

• Tip-of-the-Tongue Phenomenon: Knowing information but being unable to retrieve it; sometimes aided by cues.

Levels of Processing Theory

Depth of Processing

• Shallow Processing: Focus on physical/sensory aspects (e.g., memorizing terms).

• Deep Processing: Analyzing meaning and connections to existing knowledge.

• The greater the depth, the better the retention.

Encoding Specificity

Context and State-Dependent Learning

• Context-Dependent: Better recall when retrieval context matches encoding context (e.g., classroom).

• State-Dependent: Better recall when internal state matches encoding state (e.g., mood, intoxication).

Flashbulb Memory

Emotionally Charged Memories

• Records of atypical, emotionally significant events.

• Often vivid and easily retrieved, but not always accurate.

• Examples: Assassinations, Moon landing, 9/11 attacks.

Memory is Reconstructive

Influences on Memory

• Memories change over time and can be influenced by stereotypes, schemas, scripts, and post-event information.

• Important implications for legal settings (e.g., eyewitness testimony).

Schemas & Scripts

Organized Knowledge Structures

• Schemas/Scripts: Mental models used to "fill in the gap" in memory.

• Memory may be distorted to conform with schema/script (e.g., robbery script study).

• Stereotypes can also influence memory.

Suggestibility and False Memories

Effects of Misinformation

• Suggestibility: External misinformation can create false memories.

• Memories are fragile and vulnerable to suggestion.

• Critical area for eyewitness testimony research.

The Misinformation Effect

• Post-event information alters original memory (Loftus, 1974).

• Leading questions can change what is remembered.

False Memories

• Studies show that people can be led to remember events that never happened (Loftus, 1997; Hyman et al., 1997).

• Laboratory induction of false childhood memories is possible (e.g., meeting Bugs Bunny at Disneyland).

• Mandela Effect: Collective false memories shared by groups.

Memory Hacker Study (Shaw & Porter, 2015)

• Controversial study: 70% of participants convinced they committed a crime after repeated interviews.

Eyewitness Misidentification

Implications for Justice

• Eyewitness misidentification is the leading cause of wrongful convictions.

• Line-up procedures involve identifying a suspect among foils or distractors.

• Case study: Ronald Cotton, a case of wrongful conviction due to eyewitness error.

Summary Table: Types of Memory

Memory Type	Duration	Capacity	Example
Sensory	Milliseconds to seconds	Large	Seeing a sparkler's trail
Short-Term	Up to 30 seconds	7 ± 2 items	Remembering a phone number briefly
Long-Term	Years to lifetime	Unlimited	Remembering your first day at university

Additional info: These notes expand on the original slides and text, providing definitions, examples, and context for key psychological concepts in memory. All major subtopics from the provided materials are covered and organized for exam preparation.