Encoding specificity principle

The encoding specificity principle provides a framework for understanding how the conditions present while encoding information relate to memory and recall of that information.^[1] Memory researchers Thomson and Tulving suggest that recall is most effective when the conditions at the time of encoding match the conditions at the time of retrieval. These conditions may refer to the context in which the information was encoded, the physical location or surroundings, as well as the mental or physical state of the individual at the time of encoding. This principle plays a significant role in both the concept of context-dependent memory and the concept of state-dependent memory.

Consider the debate on whether taking an exam in the same classroom in which the material for the exam was encoded positively correlates with performance on said exam. The encoding specificity principle suggests that it does. In this example, the context refers to the physical location in which the exam takes place. Another example could correspond to the state an individual is in at the time of encoding; studies show that a person who is intoxicated at the time of encoding has a better time retrieving information if later the person is also intoxicated.^[2] State can also refer to the emotional state the individual is in at the time of encoding and at the time of retrieval; if these states match, the individual is more likely to recall the encoded information.

In a laboratory study, a subject presented with an unrelated word pair is able to recall a target word with much more accuracy when prompted with the unrelated word it was matched with at the time of encoding, than if presented with a semantically related word that was not available during the time of encoding.^[3] During a recall task, people benefit equally from a weakly related cue word as from a strongly related cue word, provided the weakly related word was present at encoding.^[4]

Specific results

Role of semantics

Semantics does not always play a role in encoding specificity; memory, rather, depends upon the context at encoding and retrieval.^[3] Early research has shown that semantically related cues should be effective in retrieving a word provided the semantic cue was encoded along with the target word. If the semantically related word is not present at the time of encoding, it will not be efficient at cuing recall for the target word.^[5]

Regardless of semantic relatedness of the paired words, participants more effectively recalled target words that had been primed when prompted for recall.^[1] Many of the following experiments employed a method modeled off of Thomson and Tulving's. All, however, had slight variations which allowed the researchers to discover their own individual findings. The following table shows the importance of priming through word pairs to achieve enhanced recall of words encoded together.^[6]

Modeled after Table 1 Bahrick^[6] (1970)

Immediate environment

Multiple studies have shown a dependence on context of one's environment as an aid to recall specific items and events.

Physical environment

The location and environment in which you learn something readily affects how you can freely recall it.^[7] Lists of words were presented to participants both underwater and on the beach. When recall was tested in the environment of original encoding, free recall was far superior to recall when tested in an altered environment.^[8] Memory tested through recognition, however, was not affected. This phenomenon is explained by what is termed the outshining hypothesis: context can be a useful cue for memory but only when it is needed. One will only turn to context as a cue when better cues are unavailable. In recognition tests, cues other than the immediate encoding context and environment are superior, whereas in free-recall tests, the immediate environment serves as the only cue to trigger memory.^[8]

Auditory environment

The level and kind of noise in any given encoding environment will affect the ability to recall the information encoded in a different auditory environment.^[9] Students receive higher scores on tests when they study for and take examinations in environments that have similar auditory background distractions, thus proving that the context-dependency effect applies to meaningful scenarios in addition to unrelated word lists. While a typical college student's study environment often includes background noise, test environments are typically quieter.^[9] In line with the encoding specificity principle, this mismatch at encoding and retrieval is detrimental to test performance.^[10] Students who study with background noise recall just as much information as students studying in silence, provided they are tested in the same type of environment as which the information was encoded.^[9]

Voluntary retrieval of autobiographical memory

Autobiographical memories are more accessible when the language at encoding and recall match.^[11] Researchers conducted interviews with Russian and English speaking bilingual students in both languages and asked participants to retrieve the first memory that comes to mind when hearing a generic word in either language. They found that when presented with Russian-language cues, participants recalled memories that occurred in a Russian-speaking environment and when presented with English-language cues, they easily recalled memories from English-speaking contexts.^[11] This is first because the cue words may have been spoken during the original event that the participant was remembering; hearing the word at encoding and again at retrieval may have been a sufficient cue to bring the memory to mind. Second, this phenomenon may be due to the general language-created ambiance of the situation in which participants were tested rather than the specific associations to individual cue words.^[11]

Diagnosis of disease

Patients with Alzheimer's disease (AD) are unable to effectively process the semantic relationship between two words at encoding to assist in the retrieval process.^[12] The general population benefits equally from a weakly related cue word as from a strongly related cue word during a recall task, provided the weakly related word was present at encoding. Patients with AD, however, were unable to benefit from the weakly related cue even if it was present at both encoding and retrieval.^[12] Instead of relying upon semantic encoding, those with AD presented their most dominant associations to the cue words during recall test. This explains why all AD patients performed well when two strong words were matched together but very poorly when a strong and weak pairs were presented during recall(10). Deficits in episodic memory are now widely accepted as a characteristic symptom of Alzheimer's disease.^[4]

Alcohol

Information encoded and stored while intoxicated is retrieved more effectively when later recall tests are performed while intoxicated as compared to recall while sober.^[2] This finding is a variation of the context-dependency effect of the encoding specificity principle and is much more apparent with low-imagery words than high-imagery words. Both high and low imagery words, however, are less likely to be recalled while intoxicated due to the inherent nature of intoxication.^[2]

Advertising

The emotional nature of advertisements affects the rate of recall for the advertised product.^[13] When the nature of the advertisement was emotional, an encoding focus on episodic memory (trying to carefully remember the visual content of the commercial) led to a much higher rate of recall for emotional advertisements. Conversely, when advertisements were neutral in emotional nature, a semantic encoding of memory (how advertisement shapes personal perceptions, preferences of given object advertised) led to a much higher recall of specific advertisements.^[13] Empirical evidence regarding the nature of emotional advertising provides the advertising industry with data as to how to contour their ads to maximize recall of advertisements. Political advertising displays this emotional nature of content. A political advertisement^[14] from Lyndon B. Johnson's 1964 presidential campaign is inherently emotional in nature and therefore very easily remembered. If this advertisement were viewed and encoded in an episodic mode, due to its emotional nature, it would be easily recalled because of the mode of memory during the encoding process. This advertisement is a lasting example of emotional advertisements being easily recalled: it aired only once on September 7, 1964 yet is one of the most remembered and famous campaign advertisements to date.

Criticism

James S. Nairne of Purdue University is the primary opponent of Thomson and Tulving's encoding specificity principle.^[10] He argues that the encoding-retrieval match is correlational rather than causal and states that many cognitive psychologists consider the principle to be "sacrosanct".^[15] Nairne suggests that what determines successful memory is cue distinctiveness. He says that good memory may be produced even if there is almost no encoding-retrieval overlap, provided the minimal overlap is highly distinctive.^[15] He characterizes memory as an "active process of discrimination"^[15] and proposes that we use cues to choose between several retrieval candidates. Increasing the encoding-retrieval match improves memory performance, he believes, but only because it increases the probability that distinctive features will come into play.^[15]

References