What factors underlie associative and categorical memory illusions? The roles of backward associative strength and interitem connectivity

Factors that affect categorical and associative false memory illusions were investigated in 2 experiments. In Experiment 1, backward associative strength (BAS) from the list word to the critical lure and interitem connectivity were manipulated in Deese-Roediger-McDermott (DRM) and category list types. For both recall and recognition tasks, the likelihood of producing DRM and category false memories was greater for lists with high BAS and low interitem connectivity. In Experiment 2, DRM and category lists with high BAS showed similar indirect priming effects in a word stem completion task. With low BAS, category lists, unlike DRM lists, showed no priming effect. We discuss the role of BAS, interitem connectivity, and associate-level differences in implicit and explicit measures of false memory production.     

The difference between implicit and explicit associative processes at study in creating false memory in the DRM paradigm

The effects of implicit and explicit associative processes for false recognition were examined by manipulating exposure duration of studied items; 20 ms or 2000 ms. Participants studied lists of words that were high associates to a nonpresented word (critical lure) in either condition. After learning each list, they took a recognition test and remember/know judgements immediately (Experiment 1) or 1 minute later (Experiment 2). In Experiment 1, know responses for critical lures were more in the 20 ms than in the 2000 ms conditions, while remember responses for them were more in the 2000 ms condition. Implicit associative processes create familiarity of critical lures, and explicit associative processes create details of false memories. Comparing the results of Experiment 1 with those of Experiment 2, remember responses for critical lures were increased with the prolonged time only in the 20 ms condition. Characteristics of false memory made by implicit associative processes could be changed by prolonged time.     

The difference between implicit and explicit associative processes at study in creating false memory in the DRM paradigm

The effects of implicit and explicit associative processes for false recognition were examined by manipulating exposure duration of studied items; 20 ms or 2000 ms. Participants studied lists of words that were high associates to a nonpresented word (critical lure) in either condition. After learning each list, they took a recognition test and remember/know judgements immediately (Experiment 1) or 1 minute later (Experiment 2). In Experiment 1, know responses for critical lures were more in the 20 ms than in the 2000 ms conditions, while remember responses for them were more in the 2000 ms condition. Implicit associative processes create familiarity of critical lures, and explicit associative processes create details of false memories. Comparing the results of Experiment 1 with those of Experiment 2, remember responses for critical lures were increased with the prolonged time only in the 20 ms condition. Characteristics of false memory made by implicit associative processes could be changed by prolonged time.     

A fuzzy trace analysis of categorical inferences and instantial associations as a function of retention interval

Two experiments on children's inferences and associative memory provided a test of predictions from fuzzy-trace theory. Specifically, it was expected that gist-based false recognitions would increase with age and that false recognitions would be uncorrelated with verbatim memory. In Experiment 1, children in Grades 1 through 5 heard lists of category labels, clustered instances from categories, and individual instances. On an immediate test, children indicated whether or not they had previously heard a series of individually presented test words. This list consisted of old words, new words, or words that were categorically or semantically related to the studied word clusters. Children made more false recognition errors for instances than for categories. Verbatim memory and inferences were unrelated. In Experiment 2, the effect of a test delay on categorical inferences and associated instances was examined with children in Grades 1 to 6. With delay, false recognition of associated instances declined for children at all grade levels. In contrast, categorical inferences increased with delay for older children. Verbatim memory and inferences were uncorrelated under immediate and 1-day delay conditions, but there were some low but significant correlations across grades under the 7-day delay. The results of the two experiments are interpreted as supporting fuzzy-trace theory.     

Can intentional forgetting reduce false memory? Effects of list-level and item-level forgetting

This study examined whether false memory produced by the learning of lists of categorized and associative materials could be reduced by directed forgetting. The number of items within a list that participants were asked to remember or forget was manipulated, while the length of the list remained constant. Experiment 1a used categorized lists and Experiment 1b used associative lists; the participants performed immediate free recall and cued recall tests. For both the categorized and associative lists, the rate of false recall increased upon increasing the proportion of "forget" (F) words. After removing the immediate recall test, Experiment 2 found that intentionally forgetting part of the studied list reduced false memory, whereas forgetting the whole studied list did not. The results are discussed in terms of the list-level-vs.-item-level inhibition in semantic activation and the role of monitoring in reducing false memory.     

The role of associative strength in children's false memory illusions

The effects of associative strength on rates of 7- and 11-year-old children's true and false memories were examined when category and Deese-Roediger-McDermott (DRM) lists were used to cue the same critical lure. Backward associative strength (BAS) was varied such that the category and DRM lists had the same strength (DRM=category), DRM lists had more BAS (DRM>category), or category lists had more BAS (DRM<category). If BAS drives children's false memories then BAS, not the type of relation across items in a list, should determine false memory production. The results confirmed this prediction using both recall and recognition measures: (1) both true and false memories increased with age, (2) true memory was better for category than DRM lists but there were no differences for false memory, and (3) at all ages, false memories varied predictably with changes in BAS but were unaffected by list-type manipulations. These findings are discussed in the context of models of false memory development.     

Negativity bias in false memory: moderation by neuroticism after a delay

The negativity bias is the tendency for individuals to give greater weight, and often exhibit more rapid and extreme responses, to negative than positive information. Using the Deese-Roediger-McDermott illusory memory paradigm, the current study sought to examine how the negativity bias might affect both correct recognition for negative and positive words and false recognition for associated critical lures, as well as how trait neuroticism might moderate these effects. In two experiments, participants studied lists of words composed of semantic associates of an unpresented word (the critical lure). Half of the lists were comprised of positive words and half were comprised of negative words. As expected, individuals remembered negative list words better than positive list words, consistent with a negativity bias in correct recognition. When tested immediately (Experiment 1), individuals also exhibited greater false memory for negative versus positive critical lures. When tested after a 24-hr delay (Experiment 2), individuals higher in neuroticism maintained greater false memory for negative versus positive critical lures, but those lower in neuroticism showed no difference in false memory between negative and positive critical lures. Possible mechanisms and implications for mental health disorders are discussed.     

Word frequency influences on the list length effect and associative memory in young and older adults

Many studies show that age deficits in memory are smaller for information supported by pre-experimental experience. Many studies also find dissociations in memory tasks between words that occur with high and low frequencies in language, but the literature is mixed regarding the extent of word frequency effects in normal ageing. We examined whether age deficits in episodic memory could be influenced by manipulations of word frequency. In Experiment 1, young and older adults studied short and long lists of high- and low-frequency words for free recall. The list length effect (the drop in proportion recalled for longer lists) was larger in young compared to older adults and for high- compared to low-frequency words. In Experiment 2, young and older adults completed item and associative recognition memory tests with high- and low-frequency words. Age deficits were greater for associative memory than for item memory, demonstrating an age-related associative deficit. High-frequency words led to better associative memory performance whilst low-frequency words resulted in better item memory performance. In neither experiment was there any evidence for age deficits to be smaller for high- relative to low-frequency words, suggesting that word frequency effects on memory operate independently from effects due to cognitive ageing.     

A gender difference in the false recall of negative words: women DRM more than men

Gender differences in susceptibility to associative memory illusions in the Deese/Roediger-McDermott paradigm were investigated using negative and neutral word lists. Women (n=50) and men (n=50) studied 20 lists of 12 words that were associates of a non-presented critical lure. Ten lists were associates of negatively valenced lures (e.g., cry, evil) and ten were associates of neutral lures (e.g., chair, slow). When asked to recall the words after each list, women falsely recalled more negative lures than men, but there was no gender difference in the false recall of neutral lures. These findings suggest that women reflect on associations within negative lists to a greater degree than men and are thereby more likely to generate the negative critical lures.     

Association and categorisation effects on free recall

Lists of 18 words which varied in mean associative strength, the category membership of the associations and in word frequency were presented to subjects 3 times with recall required after each presentation. Recall efficiency increased with association level and with similarly categorised associates. In lists of High mean associative strength which consisted of similarly categorised words, the recall of high frequency word lists was facilitated but at low levels of associative strength, with similarly categorised words, recall was facilitated at both levels of word frequency used. Clustering and errors which were associatively related to the items being learned were greater in lists which contained sets of similarly categorised associates.     

ASSOCIATIVE PROCESSES IN FALSE RECALL AND FALSE RECOGNITION

Abstract— Studying a list of words associated to a critical nonpresented word results in high rates of false recall and false recognition for that nonpresented item (Roediger & McDermott, 1995) Two experiments examined the effect of manipulating the number of associates presented on false recall and later false recognition of a nonpresented item. In Experiment 1, associate lists of varying lengths were studied, in Experiment 2, list length was held constant and the number of associates within the list was manipulated. In both experiments, the rate of critical intrusions in recall increased steadily with increasing number of associates studied Most notably, the filler words used in Experiment 2 to equate the list lengths did not affect the rate of critical intrusions, although they did depress recall of studied words. False recall and false recognition appear to be tied to the total, not the mean, associative strength of items in the list.     

Associative and categorical processes in children's memory: The role of automaticity in the development of organization in free recall

Free recall performance was assessed in children in Grades 3, 5, 7, and 9 (Experiment 1) and adults (Experiment 2) on a list of categorically related words constructed so that some items within a category were highly associated with one another and interitem associations were low among other items (e.g., dog, cat, cow, lion, tiger). Associative relations were used frequently in recall by subjects of all ages, with analyses of interitem latencies and correlations between recall and clustering indicating that organization in recall was based only on associative relations for the third and fifth graders but based on both associative and nonassociative categorical relations for older subjects. Examination of the placement of high associates in recall indicated that seventh- and ninth-grade children were more apt to use associative relations to begin category clusters than were younger children or adults. These children were hypothesized to use the relatively automatic activation of associative relations to instigate categorical organization and to represent a stage in development between nonstrategic younger children and strategic adults. The results were discussed in terms of the role that the automatic activation of semantic memory relations may play in the development of strategic memory organization.     

The effects of emotional arousal and gender on the associative memory deficit of older adults

In this study we assessed the potential moderating roles of stimulus type (emotionally arousing) and participants’ characteristics (gender) in older adults’ associative memory deficit. In two experiments, young and older participants studied lists that included neutral and emotionally arousing word pairs (positive and negative) and completed recognition tests for the words and their associations. In Experiment 1, the majority of the word pairs were composed of two nouns, whereas in Experiment 2 they were composed of adjective–noun pairs. The results extend evidence for older adults’ associative deficit and suggest that older and younger adults’ item memory is improved for emotionally arousing words. However, associative memory for the word pairs did not benefit (and even showed a slight decline) from emotionally arousing words, which was the case for both younger and older adults. In addition, in these experiments, gender appeared to moderate the associative deficit of older adults, with older males but not females demonstrating this deficit.     

Similar phenomena,different mechanisms: Semantic and phonological false memories are produced by independent mechanisms

The Deese/Roediger-McDermott paradigm can produce high levels of false remembering for lists of both semantic and phonological associates. The present study investigated whether similar mechanisms mediate false memories with these two types of lists. Experiment 1 measured the relationship between levels of false memory obtained with lists of semantic and phonological associates. The results indicated little correlation between false memories generated with the two types of associates. Experiment 2 used a between-subjects design to determine whether the absence of a significant correlation in Experiment 1 was a consequence of the relatively low levels of false memory observed in that experiment. The results indicated similar proportions of false memories in Experiments 1 and 2, suggesting that the within-subjects design in Experiment 1 did not reduce the overall levels of false recall or recognition. The results are discussed in terms of their implications for the independence of the mechanisms mediating different types of false memories.     

On the dual effects of repetition on false recognition

The effects of study-list repetition on false recognition of semantic associates were examined using aging (Experiment 1) and recognition time pressure (Experiment 2). Participants studied word lists, each of which was composed of high associates to a single, unstudied word (the critical lure). Under normal testing circumstances, young adult participants (ages 19-26) falsely endorsed fewer critical lures associated with lists that had been presented multiple times than lists presented only once. However, young participants tested under time pressure and older participants (ages 67-85) endorsed a greater number of critical items associated with lists presented thrice than with lists presented once. The results suggest dual bases for the recognition decision, one of which is based on the rapid spread of activation within domains of semantic similarity and the other of which functions to attribute that activation to likely sources and set appropriate decision criteria. The latter capacity is compromised both under conditions of time pressure and in the elderly.     

On the susceptibility of adaptive memory to false memory illusions

Previous research has shown that survival-related processing of word lists enhances retention for that material. However, the claim that survival-related memories are more accurate has only been examined when true recall and recognition of neutral material has been measured. In the current experiments, we examined the adaptive memory superiority effect for different types of processing and material, measuring accuracy more directly by comparing true and false recollection rates. Survival-related information and processing was examined using word lists containing backward associates of neutral, negative, and survival-related critical lures and type of processing (pleasantness, moving, survival) was varied using an incidental memory paradigm. Across four experiments, results showed that survival-related words were more susceptible than negative and neutral words to the false memory illusion and that processing information in terms of its relevance to survival independently increased this susceptibility to the false memory illusion. Overall, although survival-related processing and survival-related information resulted in poorer, not more accurate, memory, such inaccuracies may have adaptive significance. These findings are discussed in the context of false memory research and recent theories concerning the importance of survival processing and the nature of adaptive memory.     

False recognition without intentional learning

Asked to memorize a list of semantically related words, participants often falsely recall or recognize a highly related semantic associate that has not been presented (the critical lure). Does this false memory phenomenon depend on intentional word reading and learning? In Experiment 1, participants performed a color identification task on distractor words from typical false memory lists. In Experiment 2, participants read the same words. In both experiments, the primary task was followed by a surprise recognition test for actually presented and unpresented words, including the critical lures. False alarms to critical lures were robust and quite equivalent across the two experiments. These results are consistent with an activation/monitoring account of false memory, in which processing of semantic associates can evoke false memories even when that processing is incidental.     

The incidence of false memories in native and non-native speakers

The current study consisted of four experiments that utilised a novel approach to investigating false memories. Each of the experiments in the current study investigated individuals with varying experience with different languages. Experiment 1 tested participants in both their native and secondary languages as well as monolingual English speakers, while Experiment 2 assessed native Spanish speakers using both English and Spanish associative lists. Experiment 3 examined the illusory memories in monolingual Spanish speakers in both English and Spanish, while Experiment 4 investigated false memories in monolingual English speakers in both English and Spanish. Results indicated that memory for list items and critical lures was greatest when the lists were presented in the participants' primary language. Results can be explained by either activation-based or fuzzy-trace theories.     

The incidence of false memories in native and non-native speakers

The current study consisted of four experiments that utilised a novel approach to investigating false memories. Each of the experiments in the current study investigated individuals with varying experience with different languages. Experiment 1 tested participants in both their native and secondary languages as well as monolingual English speakers, while Experiment 2 assessed native Spanish speakers using both English and Spanish associative lists. Experiment 3 examined the illusory memories in monolingual Spanish speakers in both English and Spanish, while Experiment 4 investigated false memories in monolingual English speakers in both English and Spanish. Results indicated that memory for list items and critical lures was greatest when the lists were presented in the participants' primary language. Results can be explained by either activation-based or fuzzy-trace theories.     

False memory across languages: implicit associative response vs fuzzy trace views

We investigated false recognition across languages using the Deese-Roediger-McDermott (DRM) paradigm. A group of English-French bilinguals studied lists of converging associates, some lists in English and some in French, and then performed a recognition test containing studied list items and nonstudied critical lures whose language matched or mismatched the language at study. Participants were instructed to answer old only if the test cue was in the same language as the studied word. The results yielded a robust false memory rate both within-language and across-languages. The effect of the study-test language shift was much larger for list items than for critical lures. This finding suggests that memory representations for critical lures contain primarily semantic gist traces and little surface information, and hence is more consistent with the fuzzy trace view than with the implicit associative response view. In sum, the study demonstrates the existence of false memory across languages, and provides information about the memory traces underlying veridical and illusory recognition.