Retrieval: How We Recall the Past from Episodic Memory

1. Retrieval: How We Recall the Past from Episodic Memory Pattern Completion and Recapitulation Episodic Retrieval and the Frontal Lobes Cues for Retrieval The Second Time Around: Recognizing Stimuli by Recollection and Familiarity Misremembering the Past

2. Pattern Completion and Recapitulation Episodic memories are encoded by binding together the various features of a stimulus or event into an integrated representation, so an episodic memory consists of a conjunction of linked features. Because in this way a whole is built from linked parts, this retrieval process is known as pattern completion. The notion that episodic retrieval depends on pattern completion has led to the additional hypothesis that retrieval entails recapitulation, a reinstatement of the pattern of activations that was present during encoding.

3. Episodic Retrieval and the Frontal Lobes Episodic retrieval involves a complex interaction between the medial temporal lobes and other cortical regions and considerable evidence indicates the importance of the frontal lobes. The frontal lobes are important when we develop a retrieval plan, which requires selecting and representing the cues that will be used to probe memory. Interference during retrieval is a significant cause of forgetting, and studies of patients with frontal lesions indicate that these patients are particularly prone to interference-based forgetting.

4. Cues for Retrieval One of the fundamental conclusions reached as a result of this approach is that retrieval is cue dependent, that is, it is stimulated by hints and clues from the external and the internal environment—from the state of the world and the state of ourselves. context-dependent effect on retrieval: retrieval is typically better when the physical environment at retrieval matches that at encoding (this is similar to the encoding specificity principle). Research has demonstrated state-dependent effects—better retrieval when internal states at retrieval match those at encoding—that parallel context-dependent effects.

5. Cues for Retrieval

6. Bias In the 1930s, Bartlett observed that participants frequently misremembered the stories in a number of ways: they noticeably shortened them; they eliminated unfamiliar interpretations; and made the stories more coherent and conventional in the storytelling tradition of their own culture. In belief bias background knowledge about the way of the world and personal beliefs unconsciously influences memory to reshape it in a form consistent with expectations. Consistency biases result from the often erroneous belief that one’s attitudes are stable over time, have been observed in personal relationships: memory for the degree of initial happiness with a relationship is typically distorted by beliefs about the current degree of happiness. In reconstructive memory, we reconstruct the past during retrieval rather than reproduce it.

7. Misattribution Misattribution, ascribing a recollection to an incorrect time, place, person, or source. False recognition occurs when we encounter a stimulus that, although not previously encountered, is semantically or perceptually similar to previously encountered stimuli. Neuropsychological studies indicate that amnesic patients show lower levels of false recognition than do neurologically healthy people. Some studies suggest that accurate recognition and false recognition activate different perceptual processes, an indication that there are subtle but perhaps important differences in the level of perceptual recapitulation underlying true and false memory.