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.     

Memory organization of action events and its relationship to memory performance

Previous research yielded inconsistent results regarding the memory organization of self-performed actions. The authors propose that task performance changes the very basis of memory organization. Enactment during study and test (Experiment 1) yielded stronger enactive clustering (based on motor-movement similarities), whereas verbal encoding yielded stronger conceptual clustering (based on semantic-episodic similarities). Enactment enhanced memory quantity and memory accuracy. Both measures increased with enactive clustering under self-performance instructions but with conceptual clustering under verbal instructions. Enactment only during study (Experiment 2) or only during testing (Experiment 3) also enhanced enactive clustering. It is proposed that different conditions affect the relative salience of different types of memory organization and their relative contribution to recall.     

Integrative and semantic relations equally alleviate age-related associative memory deficits

Two experiments compared effects of integrative and semantic relations between pairs of words on lexical and memory processes in old age. Integrative relations occur when two dissimilar and unassociated words are linked together to form a coherent phrase (e.g., horse-doctor). In Experiment 1, older adults completed a lexical-decision task where prime and target words were related either integratively or semantically. The two types of relation both facilitated responses compared to a baseline condition, demonstrating that priming can occur in older adults with minimal preexisting associations between primes and targets. In Experiment 2, young and older adults completed a cued recall task with integrative, semantic, and unrelated word pairs. Both integrative and semantic pairs showed significantly smaller age differences in associative memory compared to unrelated pairs. Integrative relations facilitated older adults' memory to a similar extent as semantic relations despite having few preexisting associations in memory. Integratability of stimuli is therefore a new factor that reduces associative deficits in older adults, most likely by supporting encoding and retrieval mechanisms.     

Implicit associative responses influence encoding in memory

In list-learning experiments, the orienting question asked of one item may influence the processing of, and memory for, later items in the list. Four experiments demonstrated that words that are not related to their own orienting question, but that are semantically related to the question asked of a previous item, are better recalled than are words that are not related to any question in the list. Factors that influence this memory enhancement include the number of times relevant orienting questions appear during study, as well as the retention interval. Experiment 4 revealed that this effect is contingent upon conscious awareness: Item-category relations do not enhance recall if the subject is not aware of them. The results of the four experiments imply that semantic categories can be primed as implicit associative responses to words, which influence memory.     

Attention and the acquisition of new knowledge: their effects on older adults' associative memory deficit

Older adults experience a selective associative memory deficit by demonstrating intact item memory relative to impaired associative memory when compared with younger adults. Age-related deficits in associative memory have been suggested to arise from declines in attentional resources, and the role of attention during encoding and retrieval in associative memory for words and their spatial locations was investigated in the current experiment. Additionally, the tendency of younger and older adults to use knowledge acquired during encoding to improve their associative memory judgments through a strategic associative memory process was also investigated. Younger and older adults studied a list of words with each word belonging to one of four categories, which followed one of four mathematical probability structures for their presentation. Older adults exhibited intact item memory and impaired associative memory relative to full attention younger adults. In addition, both older and younger adults demonstrated an ability to engage in strategic associative memory, by learning and later using the probability structure introduced at study to guide their associative memory judgments. In contrast, dividing the attention of younger adults during encoding impaired item memory, associative memory and strategic associative memory, whereas dividing attention at retrieval did not result in similar deficits. These data add to a growing body of literature demonstrating older adults to exhibit a selective associative memory deficit that is not simulated by dividing the attention of younger adults at encoding or retrieval. Furthermore, younger and older adults maintain the ability to use new knowledge to guide their associative judgments.     

Effects of age and a divided attention task presented during encoding and retrieval on memory

The present studies were designed to examine age differences in memory when attention was divided during encoding, retrieval, or at both times. In Experiment 1, Ss studied categorized words while performing a number-monitoring task during encoding, retrieval, or at both times. Older Ss' free recall and clustering performance declined more than that of young Ss when attention was divided at encoding, but there was no similar age interaction when divided attention occurred at retrieval. In Experiment 2, the task demands at retrieval were increased by using a fast-paced, cued-recall task. The results remained unchanged from Experiment 1. Again, an age interaction occurred with divided attention at encoding but not at retrieval. These results were unexpected, given the emphasis in the memory-aging literature on increased difficulty of retrieval by older adults. The findings pose difficulties for limited processing resource views of age differences in memory.     

Factors modulating the effect of divided attention during retrieval of words

In this study, we examined variables modulating interference effects on episodic memory under divided attention conditions during retrieval for a list of unrelated words. In Experiment 1, we found that distracting tasks that required animacy or syllable decisions to visually presented words, without a memory load, produced large interference on free recall performance. In Experiment 2, a distracting task requiring phonemic decisions about nonsense words produced a far larger interference effect than one that required semantic decisions about pictures. In Experiment 3, we replicated the effect of the nonsense-word distracting task on memory and showed that an equally resource-demanding picture-based task produced significant interference with memory retrieval, although the effect was smaller in magnitude. Taken together, the results suggest that free recall is disrupted by competition for phonological or word-form representations during retrieval and, to a lesser extent, by competition for semantic representations.     

Working memory and flexibility in awareness and attention

We argue that attention and awareness form the basis of one type of working-memory storage. In contrast to models of working memory in which storage and retrieval occur effortlessly, we document that an attention-demanding goal conflict within a retrieval cue impairs recall from working memory. In a conceptual span task, semantic and color-name cues prompted recall of four consecutive words from a twelve-word list. The first-four, middle-four, and final-four words belonged to different semantic categories (e.g., body parts, animals, and tools) and were shown in different colors (e.g., red, blue, and green). In Experiment 1, the color of the cue matched that of cued items 75% of the time, and the rare mismatch impaired recall. In Experiment 2, though, the color of the cue matched that of the cued items only 25% of the time, and the now-more-frequent mismatches no longer mattered. These results are difficult to explain with passive storage alone and indicate that a processing difficulty impedes recall from working memory, presumably by distracting attention away from its storage function.     

Memory for internally generated words in Alzheimer-type dementia: breakdown in encoding and semantic memory

The "generation effect" is a phenomenon in which words that are generated by the subject are remembered better than words which are read. The present experiments examined this effect in patients with mild-to-moderate dementia of the Alzheimer type (DAT), healthy elderly adults, and young adults under a variety of different encoding and retrieval conditions. Experiment 1 employed an intentional learning task with multiple study/test trials using the same list of words. While both the young and elderly adults exhibited higher recall for internally generated words than read words, the DAT patients failed to demonstrate the effect even after repeated exposures to the same stimulus list. Experiment 2 replicated this same pattern of results using an incidental learning paradigm with both recall and recognition tests. Various explanations as to why the DAT patients failed to show the generation effect were discussed with particular emphasis placed on the role of semantic memory and encoding failure.     

Effects of correspondence between encoding and retrieval organization in social memory

Memory research has shown impaired recall performance when a subset of the studied stimuli is presented at recall (the part-list cueing effect, Slamecka, 1968) or when the recall is collaborative (collaborative-inhibition effect, Weldon & Bellinger, 1997). In two experiments we explore these effects in an impression-formation context and compare two prominent accounts (retrieval blocking versus strategy disruption) for them. We varied the correspondence between item organization at encoding and retrieval, either by manipulating the organization of part-list cues (Experiment 1) or the organization of the stimulus list that was later recalled collaboratively (Experiment 2). Results showed that when encoding and recall organizations did not correspond recall was impaired, replicating part-list cueing and collaborative-inhibition effects. However, when encoding and retrieval organization corresponded, these effects were greatly reduced. Such results support the recall strategy disruption hypothesis and challenge the retrieval blocking account. Implications for understanding memory in a social context are discussed.     

Memory for modality: Evidence for an automatic process

Three experiments were conducted to explore the “automatic” encoding of information about presentation modality and the use of such information during word retrieval. Children (Grades 2, 3, and 6) and adults (college students) were asked to attend to a mixed-modality (auditory and visual) list of nouns, then to recall the target words, and finally to identify the presentation modality of each word on a recognition list. Instructions (incidental vs. intentional), list length, and list organization (unrelated words vs. words from taxonomic categories) were varied across the experiments. Although these manipulations affected the recall of target words, they did not change the amount of modality information retained, which was clearly above chance in all three experiments. As predicted by the Hasher and Zacks (1979) model for automatic processing, there were no developmental changes on memory for modality, instructions to remember modality information had no effect on modality identification, and a tradeoff between word recall and modality identification rarely occurred.     

Word frequency effects in associative and item recognition

The word frequency effect (WFE) has been taken as evidence that recall and recognition are in some way fundamentally different. Consequently, most models assume that recall and recognition operate via very different retrieval mechanisms. Experiment 1 showed that the WFE reverses for associative recognition, which requires discrimination between intact test pairs and recombinations of study list words from different study pairs. Experiment 2, in which word triples were used, revealed an interaction between word frequency and test type: for item recognition, performance was better for low-frequency words; however, for associative recognition and free recall, performance was better for high-frequency words. In Experiment 3, item recognition was tested: although overall performance was better for low-frequency words, the recognition advantage for items in intact pairs was larger for high-frequency words, suggesting two components in recognition memory. These results imply common mechanisms in recall and recognition. Theoretical implications are discussed within the framework of the SAM model.     

The fSAM model of false recall

The authors report a new theory of false memory building upon existing associative memory models and implemented in fSAM, the first fully specified quantitative model of false recall. Participants frequently intrude unstudied critical words while recalling lists comprising their strongest semantic associates but infrequently produce other extralist and prior-list intrusions. The authors developed the theory by simulating recall of such lists, using factorial combinations of semantic mechanisms operating at encoding, retrieval, or both stages. During encoding, unstudied words' associations to list context were strengthened in proportion to their strength of semantic association either to each studied word or to all co-rehearsed words. During retrieval, words received preference in proportion to their strength of semantic association to the most recently recalled single word or multiple words. The authors simulated all intrusion types and veridical recall for lists varying in semantic association strength among studied and critical words from the same and different lists. Multiplicative semantic encoding and retrieval mechanisms performed well in combination. Using such combined mechanisms, the authors also simulated several core findings from the Deese-Roediger-McDermott paradigm literature, including developmental patterns, specific list effects, association strength effects, and true-false correlations. These results challenge existing false-memory theories.     

The effects of individual differences in test anxiety and type of orienting task on levels of organization in free recall

In Experiment 1, high and low test-anxious subjects recalled a list composed of words that could be organized either by taxonomic categories or first letters. High-anxiety subjects showed less recall and conceptual clustering. There was no anxiety difference in alphabetic clustering, but low-anxiety subjects used alphabetic clusters to bridge transitions between conceptual categories more often than did high-anxiety subjects. An initial orienting task which required semantic processing reduced the recall deficit for high-anxiety subjects but not the clustering deficit. Low-anxiety subjects seemed minimally affected by a nonsemantic-orienting task. Experiment 2 used a list that could be organized by associates or rhymes. High-anxiety subjects recalled less and exhibited less clustering of both types. The nonsemantic-orienting task depressed performance for both anxiety levels, though the effect was somewhat greater for high-anxiety subjects. Overall, these results provide little evidence to support the hypothesis that high-anxiety subjects process differently only for semantic content, but methodological limitations preclude unequivocally rejecting that view.     

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.     

Dissociative effects of true and false recall as a function of different encoding strategies

Goodwin, Meissner, and Ericsson (2001) proposed a path model in which elaborative encoding predicted the likelihood of verbalisation of critical, nonpresented words at encoding, which in turn predicted the likelihood of false recall. The present study tested this model of false recall experimentally with a manipulation of encoding strategy and the implementation of the process-tracing technique of protocol analysis. Findings indicated that elaborative encoding led to more verbalisations of critical items during encoding than rote rehearsal of list items, but false recall rates were reduced under elaboration conditions (Experiment 2). Interestingly, false recall was more likely to occur when items were verbalised during encoding than not verbalised (Experiment 1), and participants tended to reinstate their encoding strategies during recall, particularly after elaborative encoding (Experiment 1). Theoretical implications for the interplay of encoding and retrieval processes of false recall are discussed.     

Grapheme–color synesthesia can enhance immediate memory without disrupting the encoding of relational cues

Previous evidence has suggested that grapheme–color synesthesia can enhance memory for words, but little is known about how these photisms cue retrieval. Often, the encoding of specific features of individual words can disrupt the encoding of ordered relations between words, resulting in an overall decrease in recall accuracy. Here we show that the photisms arising from grapheme–color synesthesia do not function like these item-specific cues. The influences of high and low word frequency on the encoding of ordered relations and the accuracy of immediate free recall were compared across a group of 10 synesthetes and 48 nonsynesthetes. The main findings of Experiment 1 showed that the experience of synesthesia had no adverse effect on the encoding of ordered relations (as measured by input–output correspondence); furthermore, it enhanced recall accuracy in a strictly additive fashion across the two word frequency conditions. Experiment 2 corroborated these findings by showing that the synesthetes only outperformed the nonsynesthetes when the materials involved words and letters, not when they involved digits and spatial locations. Altogether, the present findings suggest that synesthesia can boost immediate memory performance without disrupting the encoding of ordered relations.     

Executive processing in free recall of categorized lists

The present study examines the cognitive processes that operate in free recall of categorized lists by manipulating semantic structure of the lists and using a dual task methodology to restrict the processes that make demands on limited-capacity resources, the central executive resources. Relying on the assumption that, in free recall of categorized lists, the search for category names is a strategic controlled process that demands executive resources, lists with different numbers of categories ranging from 2 to 6 were employed. The results showed an effect of a secondary task on retrieval in the 4- and the 6-category list conditions, but not in the 2-category list condition. In contrast to retrieval, the secondary task interference at encoding produced an effect on recall of all three types of lists. An interesting finding was that an effect on clustering was found only when interference was present at encoding, not when it was at retrieval. This finding was in line with the suggestion (Troyer, Moscovitch, Winocur, Alexander, & Stuss, 1998) that switching (shifting between different category items) rather than clustering is related to executive functioning, and suggested that clustering may be a measure of two different types of processing: (1) executive processing at encoding and (2) automatic processing at retrieval. In addition, a different pattern of results was obtained when low frequency category words were used, indicating that the frequency of category words is an important determinant in free recall of categorized lists. Overall, the present results support the two-process account of retrieval of category words (Rosen & Engle, 1997) and the view that there are fundamental differences between encoding and retrieval processes (Naveh-Benjamin, Craik, Guez, & Dori, 1998; Naveh-Benjamin & Guez, 2000).     

Retrieval dynamics in recognition and list discrimination: Further evidence of separate processes of familiarity and recall

Two experiments tested the hypothesis that the time course of retrieval from memory is different for familiarity and recall. The response-signal method was used to compare memory retrieval dynamics in yes-no recognition memory, as a measure of familiarity, with those of list discrimination, as a measure of contextual recall. Responses were always made with regard to membership in two previous study lists. In Experiment 1 an exclusion task requiring positive responses to words from one list and negative responses to new words and words from the nontarget list was used. In Experiment 2, recognition and list discrimination were separate tasks. Retrieval curves from both experiments were consistent, showing that the minimal retrieval time for recognition was about 100 msec faster than that for list discrimination. Repetition affected asymptotic performance but had no reliable effects on retrieval dynamics in either the recognition or the list-discrimination task.     

Retrieval strategies in recall of natural categories and categorized lists

Experiments 1 and 2 examined the effect of retrieval strategies on 3 or 12 min of recall from a natural category. Experiment 3 examined the effect of strategy on 6 min of recall from a subset of a category presented as a list. In Experiments 1 and 2, a large recall deficit was produced by retrieval strategies involving recall in alphabetic order and by size of the words' referents, relative to free recall. In Experiment 3, four strategies, alphabetic, size, serial order, and free recall, gave similar levels of recall after 6 min, though the growth rate of the cumulative output functions differed among the strategies. An extension of the search of associative memory (SAM) model of Raaijmakers and Shiffrin was developed to explain these results; the new model postulates attention sharing among probe cues and the use of idiosyncratic strategies for free recall from natural categories.