Forgetting: Retrieval Failure

While interference theory explains forgetting as a result of memories disrupting each other, retrieval failure theory offers a different explanation. It proposes that forgetting occurs not because the memory has been lost, but because the right cue (trigger) is not available to access it. The memory is still stored in LTM but cannot be retrieved.

---

What is Retrieval Failure?

Retrieval failure is the failure to recall information that is stored in memory, due to the absence of appropriate cues. A cue is any stimulus that is associated with the memory and can trigger its recall.

Think of it like a filing cabinet: the information is filed away correctly, but you have lost the label that tells you which drawer to look in. The memory is there, but you cannot find it without the right cue.

This is why you might forget something in one situation but remember it perfectly in another — the cues present in the second situation trigger the memory.

---

The Encoding Specificity Principle

Tulving (1983) proposed the encoding specificity principle, which states that a cue will be effective in triggering recall only if it was present at the time of encoding (learning) and at the time of retrieval (remembering).

In other words, if you encoded a memory while listening to a particular song, hearing that song again later will help you recall the memory. If different cues are present at encoding and retrieval, recall will be worse.

flowchart LR
    A["Event encoded with<br/>context + state cues"] --> B[Memory stored in LTM]
    B --> C{"Cues at<br/>retrieval?"}
    C -->|Match cues present| D[Successful recall]
    C -->|No match / cues missing| E["Retrieval failure<br/>memory still stored"]
    E --> F[Re-introduce cue] --> D

---

Types of Cues

There are two main types of cues that can trigger retrieval:

1. Context-Dependent Forgetting

Context-dependent forgetting occurs when the external environment (the physical setting) at the time of recall is different from the environment at the time of encoding. The physical context acts as a cue.

Godden and Baddeley (1975) tested this using deep-sea divers:

Condition	Encoding Location	Retrieval Location	Recall
1	On land	On land	Good
2	Underwater	Underwater	Good
3	On land	Underwater	Poor
4	Underwater	On land	Poor

Key finding: Recall was significantly better when the encoding and retrieval environments matched (conditions 1 and 2) compared to when they did not match (conditions 3 and 4). This demonstrates that the external context acts as a retrieval cue.

2. State-Dependent Forgetting

State-dependent forgetting occurs when a person's internal state (mood, physiological state, level of arousal) at the time of recall is different from their internal state at the time of encoding.

Carter and Cassaday (1998) investigated this using an antihistamine drug that causes a mild sedative effect (a slightly drowsy internal state):

Condition	Internal State at Encoding	Internal State at Retrieval	Recall
1	Drug	Drug	Good
2	No drug	No drug	Good
3	Drug	No drug	Poor
4	No drug	Drug	Poor

Key finding: Recall was better when the internal states at encoding and retrieval matched. When there was a mismatch (e.g. participants learned while drowsy but recalled while alert), recall was significantly worse.

---

Summary: Context vs State

Type	What Mismatches?	Example
Context-dependent	External environment	Revising at home but taking the exam in a hall
State-dependent	Internal physiological state	Learning while happy but trying to recall while sad

---

Evaluation of Retrieval Failure Theory

Strengths

• Supported by strong research evidence (e.g. Godden and Baddeley, Carter and Cassaday)
• It explains everyday experiences of forgetting, such as going into a room and forgetting why, then remembering when you return to the original room — this has high ecological validity as a concept
• Tulving (1983) argued that retrieval failure is the main reason for forgetting from LTM, making it a comprehensive explanation
• It has practical applications — for example, students may recall more if they revise in conditions similar to the exam environment

Weaknesses

• Godden and Baddeley's study was a laboratory-style experiment (despite the natural setting), so the learning task (word lists) was artificial
• Context effects may only apply to recall tasks, not recognition tasks — Godden and Baddeley (1980) found no context effect when participants used recognition rather than recall
• State-dependent effects can be difficult to test because it is hard to control a person's internal state precisely
• The theory does not explain forgetting in situations where cues are available but recall still fails

---

Retrieval Failure in Everyday Life

• Tip-of-the-tongue phenomenon — you know you know something but cannot quite retrieve it, often until a cue triggers the memory
• Returning to a room — going to a room to get something, forgetting why, then remembering when you return to the original room
• Studying in the same place as the exam — students may benefit from revising in conditions similar to their exam environment
• Music and smells — hearing a song or smelling a particular scent can suddenly trigger vivid memories from the past

---

Key Points

• Retrieval failure occurs when appropriate cues are not available to access stored memories.
• Tulving's encoding specificity principle states that cues must be present at both encoding and retrieval.
• Context-dependent forgetting: external environment mismatch (Godden and Baddeley, 1975).
• State-dependent forgetting: internal state mismatch (Carter and Cassaday, 1998).
• Retrieval failure is considered the main explanation for forgetting from LTM.
• Criticisms include the artificial nature of some research and effects being limited to recall tasks.

---

Study case: Godden and Baddeley (1975) — Deep-Sea Divers