Lecture_7_-'_Long_Term_Memory_Encoding_Consolidation_and_Retrieval_Spring_2025

Chapter 7: Long-Term Memory: Encoding, Consolidation, and Retrieval

Questions to Consider

• What is the best way to store information in long-term memory (LTM)?

• How can we effectively retrieve information from long-term memory?

• How is a lifetime of experiences stored in neurons?

• How can memory research inform effective study techniques?

Getting Information Into LTM

• Encoding: The process of acquiring and transforming incoming information into memory.

• Retrieval: The process of transferring information from long-term memory back into working memory.

• Maintenance Rehearsal: Repetition of information that keeps it active but doesn't effectively transfer it to LTM.

• Elaborative Rehearsal: Involves using meanings and connections to enhance the transfer of information to LTM.

Levels of Processing Theory

Shallow Processing

• Little attention paid to meaning, focused on physical features.

• Leads to poor memory retention.

Deep Processing

• Close attention paid to meaning.

• Results in better memory retention.

Study Outcomes of Levels of Processing Theory

• Craik and Tulving (1975): Demonstrated that deeper processing (like fill-in-the-blanks) correlates with improved memory performance.

Factors That Aid Encoding

• Visual Imagery: Enhances memory by creating mental images.

• Self-Reference Effect: Relating information to oneself improves retention.

• Generation Effect: Actively generating information (e.g., through practice) reinforces memory.

• Information Organization: Structuring information can aid recall.

• Survival Value: Relating words to survival scenarios increases memory relevance.

• Retrieval Practice: Actively recalling information strengthens memory.

Research Study: Organization, Comprehension, and Memory

• Bransford & Johnson (1972): Experiment showed that creating a mental framework (like a picture) before reading improved memory of difficult information.

Retrieval Practice Effect

• Karpicke and Roediger (2008): Examined the effectiveness of study-and-test procedures:

  • Group 1: Studied and tested all words.

  • Group 2: Studied only missed words and tested on all.

  • Group 3: Studied all words but tested only on missed ones.

• Conclusion: Testing enhances retrieval and memory performance.

Retrieving Information from LTM

• Cued Recall: Uses cues to aid in recalling information. More effective than free recall.

• Mantyla’s Experiment (1986): Showed better recall when retrieval cues were personally generated.

Encoding Specificity

• Information is remembered better when the context at encoding matches the retrieval context.

• Baddeley’s Diving Experiment (1975): Best recall was in the same location for both encoding and retrieval.

State-Dependent Learning

• Better memory occurs when a person’s mood during encoding matches the mood during retrieval.

Matching the Cognitive Task

• Transfer-Appropriate Processing: Improved memory occurs when the processing type at encoding aligns with retrieval task.

• Morris et al. (1977): Showed that a rhyming-based encoding task led to better performance in a matching test.

Consolidation

Overview

• Transforms new memories from a fragile state to a more stable one.

  • Synaptic Consolidation: Fast, occurs at synapses.

  • Systems Consolidation: Slow, involves gradual reorganization of neural circuits.

Research Insights on Consolidation

• Müller and Pilzecker (1900): Participants who experienced a delay before learning a second list had better recall of the first; this demonstrated the significance of consolidation time.

Synaptic Consolidation

• Hebb (1948): Proposed that memories are recorded through physiological changes at synapses.

• Long-term Potentiation (LTP): Enhanced neuron firing following repeated stimulation.

Systems Consolidation Explained

• Standard Model: Postulates that hippocampal activity decreases over time after encoding, while cortical connections strengthen.

Memory Loss and Injury

• Retrograde Amnesia: Memory loss of events prior to trauma.

• Graded Amnesia: Recent memories are more fragile compared to older memories.

Systems Consolidation Mechanism

• Multiple Trace Model: Suggests that the hippocampus is activated during the retrieval of both recent and remote memories and that its involvement can change over time.

The Role of Sleep in Memory Consolidation

• Sleep enhances memory consolidation by minimizing interference.

• Certain memories are reinforced more than others post-sleep.

Reconsolidation: Memory Updating

• Retrieved memories can become fragile and need re-consolidation.

• Studies demonstrate that memories are continually modified based on experiences and context.

Reconsolidation and PTSD

• Brunet et al. (2008): Used a drug during reconsolidation of a traumatic memory to reduce stress responses in future activations.

Effective Studying Techniques

• Elaboration: Connect new knowledge with prior knowledge.

• Self-testing: Generate questions and test oneself regularly.

• Breaks and Spacing Effect: Use short, spaced sessions for better retention.

• Sleep: Facilitates memory consolidation.

• Avoid Familiarity Cues: Understanding doesn’t equate to just recognizing information.