Signal Detection Theory and Recognition Memory

Cognition: Week 4

• The course covers the retrieval process and factors affecting it, retrieval tasks, the role of contextual cues, and recognition memory.

• Semantic memory was discussed last week.

Overview

• Retrieval process and factors affecting it
• Retrieval Tasks
• The role of contextual cues
• Recognition memory

The retrieval process

• Retrieval is a progression from cues to a target memory trace.
• The aim is to find the target memory.
• Retrieval cues are bits of information guiding the search.
• Associations connect items in memory. Association strength varies.
• A stronger association makes retrieval easier. A weaker one hinders retrieval.

Retrieval Process

• Retrieval involves a progression from one or more cues to a target memory trace through associative connections.
• The goal is to make the target memory available.
• The target memory trace is the specific memory being searched for.
• Retrieval cues are bits of information about the target memory that guide the search.
• Associations are bonds linking items in memory, with varying strength.
• Stronger associations facilitate retrieval; weaker ones hinder it.

Spreading Activation

• Activation level reflects the excitement level of a memory.
• Activation level affects accessibility.
• Activation increases when something related to the memory is encountered.
• Activation persists for some time.
• Spreading activation is the automatic transfer of energy from one memory to related items through associations.
• The strength of connections between memories affects the spread of activation.

Spreading Activation & Pattern Completion

• Cues, like "Dinner," activate related activities and memories.
• Spreading activation connects related concepts (e.g., peas, wife, mashed potatoes).
• Pattern completion is the process where spreading activation fills in missing components of a memory.
• This process helps reinstate the entire memory.

Pattern Completion

• Retrieval involves reinstating the features representing a memory.
• Cues trigger spreading activation to other features, completing missing components.
• Pattern completion describes how spreading activation brings a memory back.
• This is thought to be a role of the hippocampus.

Pattern Completion and "the memory of the dinner event"

• The diagram shows connections between elements of the dinner event memory.

Retrieval Factors

• Factors determining retrieval success relate to the relationship between cues and the target.
• These factors are attention to cues, relevance of cues, strength of cue-target association, number of cues, strength of target memory, retrieval strategy, and retrieval mode.

1. Attention to Cues

• Reduced attention to cues impairs retrieval guidance.
• Dividing attention reduces memory performance when the secondary task is related to the primary one.
• Attention-demanding secondary tasks hinder recall.

2. Relevance of Cues

• Retrieval cues are most effective when connected to the target, especially present at encoding.
• The effectiveness of retrieval cues is enhanced when they are similar to the initial encoding cue.
• The encoding specificity principle is key in retrieval.

3. Cue-target Associative Strength

• Retrieval success relies on the strength of cue-target association, which depends on encoding time and attention spent on connecting the cue and target.
• Separate encoding of the cue and target is ineffective for retrieval.

4. Number of Cues

• Access to multiple relevant cues facilitates retrieval because cues spread activation to the target.
• Dual cuing strengthens retrieval by utilizing more retrieval routes.

5. Strength of Target Memory

• The more deeply encoded a target memory, the easier it is to retrieve.
• Frequent target words start with a higher activation level.
• Familiar targets are easier to retrieve.

6. Retrieval Strategy

• Efficient memory search strategies, and reorganization of material used for encoding improve retrieval.
• Strategy changes (new perspective) can improve recollection of formerly forgotten items.

7. Retrieval Mode

• Frame of mind impacts how environmental cues trigger retrieval.
• Multiple episodic tasks in succession improve memory, likely due to different brain region involvement.
• Involuntary retrieval (e.g., something "springs to mind") happens without conscious intent.

Retrieval Tasks

• Direct/Explicit memory tests require conscious recall of experiences, usually requiring a contextual cue.
• Impaired performance in amnesia often results from these explicit memory tests.
• Indirect/Implicit memory tests gauge the unconscious influence of experiences without explicit recall.
• Priming, where recent experiences improve performance, is an example.

Retrieval Tasks: Tests

• Free Recall
• Cued Recall
• Yes/No Recognition
• Forced-Choice Recognition
• Stem Completion
• Fragment Completion
• Conceptual Fluency

Contextual Cues

• External contextual cues include location, time, and mood.
• Internal contextual cues include physiological state and cognitive factors like concepts.

Context-Dependent Memory

• Memory retrieval is improved when the retrieval context matches the encoding context.
• This is based on encoding specificity: information is encoded with its context.

Context-Dependent Memory: Environmental Factors

• Memory tests (cued recall) have shown better performance when the encoding and retrieval environments match.
• Retrieval is typically better in the same environment the learning occurred.

Cognitive Context-Dependent Memory

• Retrieval efficacy is improved when encoding and retrieval cognitive contexts match.
• The same concepts that occupied attention at encoding will be more easily retrieved.

Recognition Memory

• Recognition memory involves discerning old stimuli (learned) from new stimuli (unfamiliar).
• Signal detection theory (SDT) explains the decision process involved in recognition judgments.
• SDT analyzes the decision process in terms of hits, misses, false alarms, and correct rejections.
• The familiarity of items plays a role in recognizing items.

Signal Detection Theory (SDT) in Recognition Memory

• SDT describes how recognition decisions are made when presented with stimuli.
• Memory traces each have strength as opposed to one single recognition threshold.
• Memories with strong traces overlap.
• SDT analyzes hits, misses, and false alarms to understand factors influencing recognition.

Dual-Process Theory in Recognition Memory

• Recognition memory involves two processes: familiarity and recollection.
• Familiarity is a fast, automatic sense of knowing.
• Recollection is a slower, more demanding process of actively retrieving details from episodic memory.
• Measuring recognition involves the remember/know procedure.

Recognition Memory: Measuring

• Using the Remember/Know procedure, participants decide if they recollect context details of previously seen items or if the item seems familiar.

Summary

• Retrieval failure can cause memory failure.
• Retrieval success depends on the relationship between cues and memory traces.
• Context greatly impacts memory retrieval.
• Recognition memory is a crucial aspect of memory.
• Both signal detection and dual-process theories describe recognition memory.