Mechanisms of short-term false memory formation (original) (raw)
Related papers
2014
Summary False memories are the erroneous recollection of events that did not actually occur. False memories have been broadly investigated within the domain of long-term memory, while studies involving short-term memory are less common and provide a far less detailed ‘picture’ of this phenomenon. We tested participants in a short-term memory task involving lists of four semantically related words that had to be matched with a probe word. Crucially, the probe word could be one of the four words of the list, it could be semantically related to them, or it could be semantically unrelated to the list. Participants had to decide whether the probe was in the list. To this task we added articulatory suppression to impair rehearsal, concurrent material to remember, and changes to the visual appearance of the probes to assess the mechanism involved in short-term memory retrieval. The results showed that, similarly to the studies on longterm memory, false memories emerged more frequently for ...
False Memory in a Short-Term Memory Task
Experimental Psychology, 2007
The Deese/Roediger-McDermott (DRM; Roediger & McDermott, 1995 ) paradigm reliably elicits false memories for critical nonpresented words in recognition tasks. The present studies used a Sternberg (1966) task with DRM lists to determine whether false memories occur in short-term memory tasks and to assess the contribution of latency data in the measurement of false memories. Subjects studied three, five, or seven items from DRM lists and responded to a single probe (studied or nonstudied). In both experiments, critical lures were falsely recognized more often than nonpresented weak associates. Latency data indicated that correct rejections of critical lures were slower than correct rejections of weakly related items at all set sizes. False alarms to critical lures were slower than hits to list items. Latency data can distinguish veridical and false memories in a short-term memory task. Results are discussed in terms of activation-monitoring models of false memory.
Distortions of short -term memory: False memory, semantic interference, and familiarity
2009
Decades of research have demonstrated that episodic memory is vulnerable to significant semantic distortion (Gallo, 2006). Recent findings suggest that short-term memory is susceptible to similar distortions of meaning. The present investigations explore the cognitive and neural mechanisms of memory distortions that emerge within a few seconds of encoding. Findings demonstrate false recall and recognition of unstudied lure items only 3-4 seconds following encoding of a short, 4-item memory set, and show that correct rejections of lures are associated with considerable semantic interference (SI). An fMRI investigation of these effects suggests a distinction between the left midventrolateral prefrontal cortex (L VLPFC), which shows increased activity changes associated with increased SI, and the right posterior parietal cortex (R PPC) which shows increased activity associated with declines in SI. An investigation of interactions between SI and proactive interference (PI) in short-term memory shows that vulnerability to PI is mediated by the semantic relationship between recently studied items and current memoranda. Taken together, findings are consistent with unitary, activation-based models of memory (Nairne, 2002), and reveal the considerable vulnerability of verbatim memory processes, even over very short retention intervals. Chapter I Chapter II FALSE WORKING MEMORIES: SEMANTIC DISTORTION IN A MERE 4 SECONDS.
False memories seconds later: The rapid and compelling onset of illusory recognition
Journal of Experimental Psychology: Learning, Memory, and Cognition, 2010
Distortions of long-term memory (LTM) in the converging associates task are thought to arise from semantic associative processes and monitoring failures due to degraded verbatim and/or contextual memory. Traditionally, sensory-based coding is considered more prevalent than meaning-based coding in short-term memory (STM), whereas the converse characterizes LTM, leading to the expectation that false memory phenomena should be less robust in a canonical STM task. These expectations were violated in two experiments in which participants viewed lists of four semanticallyrelated words and were probed immediately following a filled 3-4 second retention interval or approximately 20 minutes later in a surprise recognition test. Corrected false recognition rates, confidence ratings, and Remember/Know judgments reveal similar false memory effects across STM and LTM conditions. These results indicate that compelling false memory illusions can be rapidly instantiated, and originate from processes that are not specific to LTM tasks, consistent with unitary models of memory.
Memory & Cognition, 2014
Gist-based processing has been proposed to account for robust false memories in the converging associates task. The deep encoding processes known to enhance verbatim memory also strengthen gist memory and increase distortions of long-term memory (LTM). Recent research demonstrates that compelling false memory illusions are relatively delay-invariant, also occurring under canonical short-term memory (STM) conditions. To investigate the contribution of gist to false memory at short and long delays, processing depth was manipulated as participants encoded lists of four semantically-related words and were probed immediately following a filled 3-4 second retention interval or approximately 20 minutes later in a surprise recognition test. In two experiments, the encoding manipulation dissociated STM and LTM on the frequency, but not the phenomenology, of false memory. Deep encoding at STM increases false recognition rates at LTM, but confidence ratings and Remember/Know judgments are similar across delay and do not differ as a function of processing depth. These results suggest that some shared and some unique processes underlie false memory illusions at short and long delays.
Neural mechanisms of semantic interference and false recognition in short-term memory
NeuroImage, 2011
Decades of research using the Deese-Roediger-McDermot (DRM) paradigm have demonstrated that episodic memory is vulnerable to semantic distortion, and neuroimaging investigations of this phenomenon have shown dissociations between the neural mechanisms subserving true and false retrieval from long-term memory. Recently, false short-term memories have also been demonstrated, with false recognition of items related in meaning to memoranda encoded less than 5 seconds earlier. Semantic interference is also evident in short-term memory, such that correct rejection of related lures is slowed relative to correct rejection of unrelated lures. The present research constitutes the first fMRI investigation of false recognition and semantic interference in short-term memory using a short-term DRM paradigm in which participants retained 4 semantic associates over a short 4 second filled retention interval. Results showed increased activation in the left mid-ventrolateral prefrontal cortex (BA45) associated with semantic interference, and significant correlations between these increases and behavioral measures of interference across subjects. Furthermore, increases in dorsolateral PFC occurred when related lures were correctly rejected versus falsely remembered. Compared with false recognition, true recognition was associated with increases in left fusiform gyrus, a finding consistent with the notion that increased perceptual processing may distinguish true from false recognition over both short and long retention intervals. Findings are discussed in relation to current models of interference resolution in short-term memory, and suggest that false short-term recognition occurs as a consequence of the failure of frontally-mediated cognitive control processes which adjudicate semantic familiarity in support of accurate mnemonic retrieval.
PsycEXTRA Dataset, 2000
People falsely endorse semantic associates and morpheme rearrangements of studied words at high rates in recognition testing. The coexistence of these results is paradoxical: Models of reading that presume automatic extraction of meaning cannot account for elevated false memory for foils that are related to studied stimuli only by their visual form; models without such a process cannot account for false memory for semantic foils. Here we show how sentence and list study contexts encourage different encoding modes and consequently lead to different patterns of memory errors. Participants studied compound words, such as tailspin and floodgate, as single words or embedded in sentences. We show that sentence contexts led subjects to be better able to discriminate conjunction lures (e.g., tailgate) from old words than did list contexts. Conversely, list contexts led to superior discrimination of semantic lures (e.g., nosedive) from old words than did sentence contexts.
Remembering words not presented in sentences: How study context changes patterns of false memories
Memory & Cognition, 2009
People falsely endorse semantic associates and morpheme rearrangements of studied words at high rates in recognition testing. The coexistence of these results is paradoxical: Models of reading that presume automatic extraction of meaning cannot account for elevated false memory for foils that are related to studied stimuli only by their visual form; models without such a process cannot account for false memory for semantic foils. Here we show how sentence and list study contexts encourage different encoding modes and consequently lead to different patterns of memory errors. Participants studied compound words, such as tailspin and floodgate, as single words or embedded in sentences. We show that sentence contexts led subjects to be better able to discriminate conjunction lures (e.g., tailgate) from old words than did list contexts. Conversely, list contexts led to superior discrimination of semantic lures (e.g., nosedive) from old words than did sentence contexts.
Test-item sequence affects false memory formation: An event-related potential study
Neuroscience Letters, 2008
False memories arise when people 'remember' experiences that have never occurred. Using the Deese-Roediger-McDermott (DRM) paradigm, researchers have demonstrated that participants tend to falsely recognize non-studied words (lures) that are associated to previously studied words. Several questions, however, remain regarding the neurocognitive basis of false memory formation. Various encoding manipulations have been shown to affect the behavioral and electrophysiological correlates of false memories, but little is known about whether false memory formation and its neurophysiological correlates are influenced by different test contexts. We recorded event-related potentials (ERPs) during the DRM paradigm, wherein the test included lures that were either preceded by semantically related words or not. Results indicated more false recognitions for lures preceded by related words than for lures that were not preceded by related words at test. Furthermore, the former elicited more positive parietal potentials at 300-600 ms relative to the latter. These findings suggest that test context critically affects behavioral and neurophysiological responses for false memory, providing further insight into the neurocognitive basis of human memory.
The role of test structure in creating false memories
Memory & Cognition, 2006
In the Deese/Roediger-McDermott (DRM) paradigm, studying lists of semantic associates results in high rates of false recognition of a nonpresented critical word. The present set of experiments was designed to measure the contribution of additional processing of list items at test to this false memory effect. The participants studied sets of lists and then performed a recognition task for each