Memory and Retrieval – Study Notes

Memory Concepts and Retrieval – Comprehensive Study Notes

Memory Models Overview

• Recent cognitive theories view memory as a continuous process operating across neural networks, rather than in distinct stages.

• Stage-based models are still valuable for understanding processing and retention of information.

Classic Three-Stage Model of Memory

• Sensory Memory: Retains incoming sensory information for only a few seconds.

• Short-Term (Working) Memory: Receives information from sensory memory if attention is given.

• Long-Term Memory: Achieved by transferring information from short-term memory through elaborative rehearsal (actively connecting new info to existing knowledge).

Types of Sensory Memory

• Echoic Memory: Registers auditory information for about 2\text{–}4\text{ seconds}; enables meaningful conversation by allowing access to recent sounds, even after brief lapses in attention.

• Iconic Memory: Holds visual information for roughly 0.5\text{ seconds}; helps create seamless visual perception and allows enough time to recognize critical environmental details.

Function and Limitations of Sensory Memory

• Short duration results from constant input of new information, which replaces old data — a process called masking.

• Only the most current sensory input is retained for further processing.

• Example Demonstration: Rapidly flashing letters on a screen illustrate how quickly iconic memory turns over, emphasizing its brevity.

Key Terms

• Elaborative Rehearsal: Actively relating new information to existing knowledge to aid transfer to long-term memory.

• Masking: The overwriting of existing sensory information with new input, resulting in brief retention times.

Memory Systems in Psychology

• Sensory Memory

  • Includes senses such as touch, taste, and smell.

  • Main focus: iconic memory (visual) and echoic memory (auditory).

  • Not all sensory input is retained; only important information is transferred for further processing primarily through attention.

  • If enough attention is paid, sensory data can move into working or long-term memory.

• Working Memory / Short-Term Memory

  • Working memory: Temporarily holds and manipulates information while in use.

  • Short-term memory: Duration 15\text{–}30\,\text{seconds}; maintenance rehearsal can extend slightly but does not transfer to long-term storage; once repetition stops, information is usually forgotten.

  • Capacity traditionally estimated at 7\pm 2 items, though some studies suggest 4\pm 1 items.

  • Chunking (grouping items into meaningful units) helps maximize capacity (e.g., turning a sequence of letters into familiar acronyms or names).

• Long-Term Memory and Processing

  • Effortful processing: Connecting new knowledge with existing ideas or adding meaning improves transfer to long-term memory.

  • Shallow processing: Simple repetition is less effective for lasting retention.

  • Flashbulb memories: Highly detailed and vivid memories resulting from emotional or significant events; may form rapidly and persist over time.

Memory Formation & Encoding Strategies

• Elaborative rehearsal is a key strategy for transferring information into long-term memory; enhances encoding with deeper processing.

• Mnemonic devices enhance elaborative rehearsal:

  • Example: "Please Excuse My Dear Aunt Sally" for the order of operations.

  • Acronyms: HOMES for the Great Lakes (Huron, Ontario, Michigan, Erie, Superior).

  • Music mnemonics for scales or sequences.

• Flashbulb Memories: Created by hormonal responses to significant emotional events; deeply encoded for survival value.

  • Note: Artificially inducing this effect (e.g., via hormones) does not help with routine memorisation (like for exams).

Memory Retrieval Factors

• Context-Dependent Memory: Recall improves when learning and retrieval occur in the same physical environment.

  • Example: Scuba divers remembered words best when tested underwater if studied underwater.

• State-Dependent Memory: Internal states (mood, physiological conditions) impact recall; consistency in mental/physical state between studying and testing improves retrieval.

Neurological Damage and Memory

• Injury (e.g., strokes) can affect memory types (explicit/implicit), language production (e.g., Broca’s area), and physical function depending on affected brain regions.

Types of Memory (Neurology & Psych)

• Long-Term Memory is divided into:

  • Explicit (Declarative) Memory:

  • Semantic memory: knowledge of facts, historical dates, general information.

  • Episodic memory: personal experiences and specific life events (e.g., recalling your first-grade teacher).

  • Implicit (Procedural) Memory: unconscious skills and routines (e.g., riding a bicycle, tying a tie).

Memory Encoding Strategies (Detailed)

• Elaborative rehearsal: linking new material to existing knowledge; enhanced by mnemonic devices.

• Flashbulb memories: emotionally charged events; include recall of event details and personal experiences.

• Deep vs. shallow encoding: deep encoding yields better long-term retention than repetition alone.

Factors Influencing Memory Retrieval (Expanded)

• Context-Dependent Memory: environment-as-cue effects.

• State-Dependent Memory: internal states as retrieval cues.

Neurological Concepts in Memory Formation

• Amygdala: located at the front of the brain; central to processing anxiety and fear responses and creating flashbulb memories; when activated during high-emotion experiences, releases hormones that enhance memory retention for these events.

• Cerebellum: key role in forming procedural (implicit) memories; damage can impair learned motor skills (e.g., temporarily forgetting how to tie a tie).

• Broca’s Area: critical for speech production; damage (e.g., due to stroke) affects language abilities.

Types of Amnesia (Overview)

• Anterograde amnesia: inability to form new long-term memories after brain injury (e.g., HM could not remember events after surgery).

• Retrograde amnesia: loss of memories formed before the injury.

• Anterograde amnesia is particularly disruptive because recent events are quickly forgotten while older memories remain intact.

Research Methodologies – Study Notes

1) Naturalistic Observation

• Definition: Observing subjects in their natural environment without interference to understand behaviors and mental processes.

• Key Issues:

  • Reactivity: participants may alter behavior when they know they are being observed.

  • Observer Bias: researchers’ expectations can influence recording/interpreting.

• Mitigation Strategies:

  • Use blind or naive observers who do not know the hypothesis.

  • Train observers to record only directly observed behaviors without assumptions.

• Applications: Applies to both human and animal studies; observers should minimize presence, using camouflage or discrete observation techniques.

2) Case Studies

• Definition: Detailed examination of a single individual or a small group, especially in rare/unusual situations.

• Example: Phineas Gage, whose personality changed after a brain injury, providing insight into brain function and behavior.

• Limitations: Findings from one case cannot be broadly generalized due to unique circumstances.

3) Surveys

• Purpose: Collect data on attitudes or behaviors within large populations.

• Sampling Methods:

  • Random Sampling: Ensures every member of the population has an equal chance of selection, leading to representative samples.

  • Implementation: Assign numbers to potential participants and use a random number generator to select participants.

• Advantages: Provides fairness and statistical reliability by mirroring key characteristics of the broader population.

4) Summary

• Understanding strengths and weaknesses of naturalistic observation, case studies, and surveys is crucial for designing research that yields reliable and valid psychological data.

Survey and Correlational Research – Key Concepts

• Polling Errors & Sampling Methodology:

  • Premature election predictions can occur due to flawed sampling.

  • Sampling bias: Telephonic directories excluded people without phones, skewing projections.

  • Key Principle: Every member of the target population must have an equal chance of selection for a survey to be valid.

• Purposes of Survey Research: Studying specific behaviors (e.g., drinking habits among university students).

• Correlational Research: Measures two or more variables to assess how they are associated.

  • Examples: Drinking behavior vs. age/GPA; Depression levels vs. time spent on Facebook.

  • Data Representation: Scatterplots showing hours online vs. depression score.

• Types of Correlation:

  • Positive correlation: Both variables increase together (e.g., more Facebook use correlates with higher depression scores).

  • Negative correlation: One variable increases while the other decreases.

  • No correlation: No apparent pattern.

• Media Misrepresentation: Headlines often misreport correlations as causation; e.g., claiming Facebook causes depression.

• Causation vs. Correlation (Important Distinction):

  • Example: Violent video game play vs. aggression in children.

  • Positive correlation does not prove causation; other explanations include reverse causality or third variables (e.g., parental influence).

  • Limitation: Correlational studies cannot control confounding variables or establish direct causal relationships.

• Key Takeaway: "Correlation does not imply causation." Experimental controls are needed to establish direct causal links between variables.

Correlation Coefficient & Graphs

• Definition: The correlation coefficient quantifies the relationship between two variables.

• Range: r \in [-1, +1] with -1 perfect negative, +1 perfect positive, 0 no correlation.

• Interpreting Scatter Plots:

  • Positive correlation: Points trend upward; coefficient is positive.

  • Negative correlation: Points trend downward; coefficient is negative.

  • No correlation: Points scattered with coefficient near zero.

• Examples:

  • Coefficient r = +0.8: Strong positive relationship.

  • Coefficient r = -0.75: Strong negative relationship.

  • Coefficients like r = -0.02 or r = +0.02: Very weak or negligible relation.

• Key Reminders:

  • The sign indicates direction, not strength.

  • The magnitude reflects predictive strength.

• Study Tip: Practice reading scatter plots alongside their coefficients to master visual and numerical interpretation.

Experimental Design Basics

• A valid experiment requires simple ingredients and avoidance of confounding variables to accurately determine causality.

• Key Elements:

  • Independent Variable (IV): The factor manipulated by the researcher; believed to cause changes.

  • Dependent Variable (DV): The outcome measured to assess the effect of the IV.

• In a true experiment:

  • The IV is purposely changed.

  • The DV shows effects resulting from that change.

• Example: Does caffeine improve memory?

  • IV: Caffeine intake

  • DV: Memory test scores

  • Two groups: Experimental group (receives caffeine) & Control group (receives placebo, e.g., a non-caffeinated beverage such as 7UP).

  • Both groups complete the memory test after substance ingestion; scores are compared.

• True Experiments control confounding variables by:

  • Ensuring only the independent variable differs between groups.

  • Using random assignment to groups.

• Example context: When researching the impact of classical music on test performance, control factors like time of day or participant characteristics across groups to isolate the effect of the IV.

• Random Assignment: Participants are placed in groups by chance, which reduces pre-existing differences and improves validity.

• Purpose: This structure ensures outcomes can be attributed to the manipulated variable rather than unrelated factors.

Summary and Practical Takeaways

• Memory formation and recall depend on:

  • Specific brain regions (amygdala, cerebellum, Broca’s area).

  • Emotional and hormonal responses.

  • Effective encoding strategies (elaborative rehearsal, mnemonics).

  • Environmental and internal cues (context/state-dependent memory).

• Understanding these mechanisms provides practical strategies for efficient learning and effective recall.

• Long-term memory is not always perfectly reliable; it reconstructs memories and may miss or alter details.

  • Example: Forgetting details of a childhood event but recalling fragments or altered information.

• Serial position effects: Primacy (better recall of first items) and Recency (better recall of last items).

  • Example: Job interviewers may remember candidates at the beginning or end more than those in the middle.

• Misinformation effect: Memory can be altered by new information; e.g., Loftus studies showing higher speeds when cars were described as "smashed" vs. "hit" in a crash video.

• Amnesia types (recap): Anterograde vs. Retrograde memory loss and their distinct impacts on memory formation vs. retrieval.

Ethical and Practical Implications

• Recognize that memory is fallible and reconstructive; rely on robust methods when evaluating memory reliability.

• Be cautious with health/hormonal interventions claiming to induce memory changes; practical utility for exam memorization differs from real-world memory formation.

• When designing educational tools, leverage elaborative rehearsal, mnemonics, and context/state cues to enhance learning and retrieval.

These notes summarize the major and minor points across the transcript, including definitions, mechanisms, examples, and methodological considerations to support psychology study and exam preparation.