How Context-Dependent Memory Works

Context-dependent memory refers to improved recall when the context during encoding is the same as the context during retrieval. For example, when an event is stored in one's memory, contextual information surrounding the event is stored too. Therefore, returning to or recreating that context can help trigger the memory of the event.

For example, consider people's tendency to retrace their steps when they've misplaced an item like their wallet or mobile phone. If they can return to the right context, they can usually easily find the lost item because the context helps them remember where they put it.

Types of Context-Dependent Memory

Context-dependent memory may be cued by both external contexts based on some aspect of the environment or internal contexts such as mood or motivation.

Environmental Context

Experiments on the impact of environmental context date back at least to the 1920s. Much of this work has focused on the physical setting, but environmental context can also refer to other environment features, such as background noise or smell.

Reinstatement Effect

In one influential experiment about the impact of a novel environmental context on memory, divers learned a list of words either underwater or on dry land. Later, when the divers were asked to recall the words they learned, they remembered best in the environment they learned, so those who learned the words underwater better recalled them underwater than on dry land. This demonstrated that physical context could have an impact on recall.

This study is an example of an investigation of the reinstatement effect, the most researched area of environmental context-dependent memory. However, research has found that it's not necessary to physically reinstate the environment in order for memory to benefit from context cues. Instead, simply imagining the original context can be just as effective for recall as returning physically to the context.

Studies on the impact of environmental context have shown variable results. However, a meta-analysis of environmental context-dependent memory found that the effects were reliable but less likely when the environment was suppressed. Two explanations have been offered for the suppression of environmental context: the overshadowing hypothesis and the outshining hypothesis.

• The overshadowing hypothesis posits that environmental context is suppressed during learning—say because the way information is learned takes up more cognitive resources or attention is focused on something else—environmental context will not be encoded. It will therefore reduce or eliminate the effects of context on recall.
• The outshining hypothesis suggests that a person won't use environmental cues during recall if better cues are available. For example, if someone learned word definitions from listening to a catchy song, they are more likely to rely on that cue during recall because it was more deeply encoded in their memory.

State-Dependent Learning

People can more easily recall information if they are in the same physical or emotional state they were when they learned the information. This is called state-dependent learning.

Many studies have examined this phenomenon in people in intoxicated states. For example, one study, conducted by J.E. Eich et al., had participants learn a list of words while smoking marijuana or a placebo.

Like studies on environmental context, studies on state-dependent memories have not consistently shown strong results. Consequently, some researchers have come to regard state-dependent memory as untrustworthy.

However, according to Eich, who has done extensive research on state-dependent memory, studies that have shown weak or negative results have failed to remove other memory cues from the research environment, thus making it impossible to accurately determine which cues impact recall.

Mood-Dependence and Mood-Congruence

Mood is another context that can impact memory. Mood has been found to impact memory in two ways.

Mood-Dependence

In mood-dependent memory, mood is the same at encoding and recall. For example, one study showed that people were better able to recall autobiographical memories of events two to three days after they originally generated them if they were in the same mood at both times. One key to finding mood-dependent effects, however, is that the moods at encoding and recall must be authentic. Simulated moods will not demonstrate mood-dependent memory recall.

Mood-Congruence

In mood-congruent memory, people are more likely to recall memories when they are in the same mood as the memory itself. This is a product of the content of the memory rather than the mood of the individual during encoding such that people who are happy are more likely to recall happy memories and people who are sad are more likely to recall sad memories.

For instance, after research subjects learned personality trait words in a neutral mood, a happy or depressed mood was induced. Those in a happy mood recalled more positive trait words and those in a depressed mood recalled more negative trait words. Meanwhile, those whose mood was unaffected by the mood induction procedure and therefore maintained a neutral mood didn't show these effects.

Cognitive Context

Cognitive state can impact memory recall as well. In the research literature, this has primarily been studied in the context of language and motivation. However, numerous studies have demonstrated that those who speak multiple languages remember information best when recall happens in the language the information was encoded.

For instance, over two studies, people who spoke both Russian and English were shown to recall more autobiographical memories from the Russian-speaking period of their lives if they were interviewed and provided with word prompts in Russian. Researchers saw this same outcome when conducting the same test but in English.

Research has also shown that matching motivational states at encoding and recall can impact memory. In one study, word pairs were better remembered if they were associated with achievement cues when they were learned.

Using Context to Improve Recall

Clearly, context can have a powerful impact on our memories. While many other factors influence our recall of information, context can be used to help us remember. The key is to match the context in which information will be recalled to the context in which it is learned. Matching environmental contexts is the best way to use context-dependent memories to our advantage, given it can be more difficult to control things like your mood or your motivational state.

However, remember that if other cues pull your attention away from the encoding context, matching context at encoding and recall ultimately may not improve memory. Therefore, to ensure you can rely on context-specific memory, make sure the context you choose, whether it involves physical space, sound, smell, taste, or something else, will not be disrupted.