Prior knowledge: the effects of natural category size on memory for implicitly encoded concepts

Studying a familiar word activates its associates, and these associates affect the likelihood of recalling the studied word in a cued recall task. These experiments examined variables that normally affect memory for the studied word to determine if they have similar effects on memory for the word's associates. Memory for associates was tested by cued recall (Experiments 1-3) or by recognition (Experiments 4-5), with the number and strength of the associates varied in all experiments. In different experiments, test instructions (direct-indirect), distractor tasks, lag, and amount of practice were manipulated. Provided that subjects were not distracted prior to test, the probability of recalling associates of the studied word decreased with the number of associates activated and with their strength under all conditions. The strength of the associates but not their number affected recognition. In general, variables that affected recall and recognition of studied words had parallel effects on their associates.     

Generation and associative encoding in young and old adults: the effect of the strength of association between cues and targets on a cued recall task

The generation effect (i.e., better recall of the generated items than the read items) was investigated with a between-list design in young and elderly participants. The generation task difficulty was manipulated by varying the strength of association between cues and targets. Overall, strong associates were better recalled than weak associates. However, the results showed different generation effect patterns according to strength of association and age, with a greater generation effect for weak associates in younger adults only. These findings suggest that generating weak associates leads to more elaborated encoding, but that elderly adults cannot use this elaborated encoding as well as younger adults to recall the target words at test.     

Comparing word fragment completion and cued recall with letter cues

Cued recall with word stems as cues and fragment completion rely on different types of letter cues and also differ in the explicit-implicit nature of the retrieval orientation. Despite these differences, variables effective in one task may be effective in the other because both rely on letter cues. Two variables known to affect cued recall were manipulated: Lexical set size (number of words that fit the letter cue) and meaning set size (number of associates generated to the studied words). Across four experiments, subjects in each task were less likely to recover targets from larger lexical sets. However, meaning set size affected cued recall but not fragment completion. These results indicate that fragment completion and letter-cued recall are based on lexical search but that cued recall also involves a semantic search component. Furthermore, type of retrieval cue had a greater effect than type of retrieval orientation.     

Aging and Inhibition of Unconsciously Processed Information: No Apparent Deficit

Young and older adults were compared on a cued recall task designed to show effects of activation and inhibition of unconsciously processed information. The number of associates related to the target words by prior experience was varied, and the targets were studied either in the absence or the presence of meaningfully related context cues. The number of associates of the target had an effect on recall when context cues were absent during study, suggesting that the associates had been activated and encoded during study. In contrast, when context cues were present during study, no effect of the number of target associates was observed, suggesting that the associates had been inhibited during study. Comparable activation and inhibition effects were obtained for younger and older subjects. The results suggested little or no age-related deficit in inhibition when the to-be-inhibited information was unconsciously processed and not brought to conscious awareness.     

Lexical and semantic search in cued recall, fragment completion, perceptual identification, and recognition

Search processes in word-stem cued recall, fragment completion, perceptual identification, and recognition are contrasted. These retention tests involve letters as cues, but the lexical characteristics of these cues vary considerably. In word-stem cued recall, ending letters are presented as recall cues for studied targets (e.g., ONEY as a cue for HONEY). In fragment completion, the test cues consist of letters and spaces (e.g., HO__Y); in perceptual identification, they consist of letter features that survive the mask; and in recognition, they consist of all the letters of the studied word (e.g., HONEY). These differences in retention tests and lexical characteristics were evaluated by manipulating three variables with known effects in cued recall: (a) the presence of study context words emphasizing lexical information, (b) lexical set size corresponding to the number of words that fit the letter cue, and (c) meaning set size corresponding to the number of meaningful associates linked to the studied targets. The results indicated that (a) the presence of study contexts emphasizing lexical information reduced accuracy and response time equally in all tasks, (b) larger lexical set sizes reduced accuracy and response time in all tasks except recognition, and (c) larger meaning set size reduced accuracy in cued recall but not in the other tasks. Lexical search appears to be a significant component process in word-stem cued recall, fragment completion, and identification. Searching through meaning-related concepts encoded during study is a significant component process only in cued recall.     

Cue set size effects: Sampling activated associates or cross-target interference?

Previous findings indicate that test cues linked to more associates (more knowledge) produce lower levels of recall than cues with fewer associates. One hypothesis attributes this effect to cross-target interference arising during retrieval on the assumption that cues with more associates are more likely to be indirectly connected to studied words other than the target. Another attributes the effect to sampling associates of the cue on the assumption that the probability of sampling the target declines as more associates are activated. Findings from four experiments showed that recall varied with cue set size, and, more importantly, that cue set size affected recall independently of the interference produced by cross-target connections. These results were interpreted as supporting a model that attributes cue set size effects to sampling processes associated with the intersection of the test cue and its associates with the target and its associates.     

Part-list cuing and the dynamics of false recall

False recall of an unpresented critical word after studying its semantic associates can be reduced substantially if the strongest and earliest-studied associates are presented as part-list cues during testing (Kimball & Bjork, 2002). To disentangle episodic and semantic contributions to this decline in false recall, we factorially manipulated the cues’ serial position and their strength of association to the critical word. Presenting cues comprising words that had been studied early in a list produced a greater reduction in false recall than did presenting words studied late in the list, independent of the cues’ associative strength, but only when recall of the cues themselves was prohibited. When recall of the cues was permitted, neither early-studied nor late-studied cues decreased false recall reliably, relative to uncued lists. The findings suggest that critical words and early-studied words share a similar fate during recall, owing to selective episodic strengthening of their associations during study.     

Implicit processing in the cued recall of young and old adults.

Two cued recall experiments were reported in which younger and older subjects studied target words varying in number of preexperimental associates. In Experiment 1, targets were studied in either the absence or presence of meaning-related context cues, with recall always prompted by the cues. In the absence of context, words with smaller sets of associates were easier to recall than those with larger sets, but this effect was reduced for older subjects. The presence of a study context cue facilitated recall and eliminated the effect of associative set size for both ages. In Experiment 2, targets were studied and tested in the presence of unrelated words. In this situation, words with smaller sets of associates were less likely to be recalled than words with larger sets; again the effect was reduced for older subjects. The results are interpreted as an age decrement in processing implicitly activated information.     

Selective access in cued recall: The roles of retrieval cues and domains of encoding

The purpose of these experiments was to determine whether retrieval access in cued recall can be selectively restricted to a single domain of encoding when information has been encoded within two domains as different as word sound and word meaning. In Experiment 1, the subjects studied pairs of rhyming words differing in rhyme set size under verbal-repetition or interactive-imagery instructions. Recall was cued with study-context rhymes, with extralist rhymes, or with extralist associates. The results indicated that rhyme set size and instructional effects were found no matter how recall was cued, indicating that both domains of encoding were always accessed. In Experiment 2, potential effects of study time and overt naming of the test cues were explored. These results indicated that both domains of encoding were accessed, except when long study times were available and subjects did not have to name the rhyme test cues. Rhyme set-size effects were eliminated under these conditions, suggesting that selective access to encoded meaning is possible in cued recall. Retrieval access in this task appears to be more controlled by domains of encoding than by information directly available in the cue, and access to encoded information can be restricted to a single domain.     

Tests of the generality of the principle of encoding specificity

Two empirical tests of the principle of encoding specificity are reported. In Experiment I, the normative strength of the cues presented on the input and on the recall trial was varied factorially. To lessen the emphasis on strictly associative learning, only half the items were cued in each phase of the study-recall cycle. Recall was higher when the cues remained the same than when they changed. However, regardless of the condition of input cuing, strong output cues were substantially more effective than weak ones. In Experiment II, the to-be-remembered words were shown in the presence of weak cues on the input trial. Recognition in the context of strong extralist cues was compared with recall to the original input cues. On the test of cued recognition, the target words were either generated by the subjects as free associates or presented to them as items on a test constructed by the experimenter. Contrary to previous findings, recall was not found to be superior to recognition. The phenomena of cue-dependent forgetting that have been interpreted as evidence for the principle of encoding specificity appear to have limited generality.     

Encoding context and retrieval conditions as determinants of the effects of natural category size

Studying a familiar word activates its associates in long-term memory. In the present experiments we manipulated the number of associates activated by words studied in the presence of unrelated context words, meaningfully related context words, or in the absence of modifying context words. Memory was tested by either cued or free recall. The results showed that the number of directly activated associates can facilitate, have no effect, or disrupt recall for studied words. The direction and magnitude of the effects of number of activated associates is shown to be determined by the encoding/retrieval context. Implications for the distinction between episodic and semantic memory are discussed.     

Remembering remembering

We developed a laboratory analogue of the "forgot-it-all-along" effect that J. W. Schooler, M. Bendiksen, and Z. Ambadar (1997) proposed for cases of "recovered memories" in which individuals had forgotten episodes of talking about the abuse when they were supposedly amnestic for it. In Experiment 1, participants studied homographs with disambiguating context words; in Test 1 they received studied- or other-context words as cues; and in Test 2 they received studied-context cues and judged whether they had recalled each item during Test 1. In Experiment 2, retrieval cues were manipulated on both tests. In Experiment 3, both the studied- and other-context cues corresponded to the same meaning of each homograph. In Experiment 4, Test 1 was free recall, and studied- versus other-context cues were presented in Test 2. Participants more often forgot that they had previously recalled an item if they were cued to think of it differently on the two tests.     

What is this thing called frequency?

When researchers are interested in the influence of long-term knowledge on performance, printed word frequency is typically the variable of choice. Despite this preference, we know little about what frequency norms measure. They ostensibly index how often and how recently words are experienced, but words appear in context, so frequency potentially reflects an influence of connections with other words. This paper presents the results of a large free association study as well as the results of experiments designed to evaluate the hypothesis that common words have stronger connections to other words. The norms indicate that common words tend to be more concrete but they do not appear to have more associates, stronger associates, or more connections among their associates. Two extralist cued recall experiments showed that, with other attributes being equal, high- and low-frequency words were equally effective as test cues. These results suggest that frequency does not achieve its effects because of stronger or greater numbers of connections to other words, as implied in SAM. Other results indicated that common words have more connections from other words, including their associates, and that free association provides a valid index of associative strength.     

Are implicitly activated associates selectively activated?

What constitutes a word’s associative past? Words differ in how many associates they activate in memory and, following a brief encounter, those with fewer associates are more likely to be recalled in the presence of related cues. The issue addressed in the present article is whether associative set size effects are produced through the selective activation of strong associates or through the activation of both strong and weak associates. The set size of the strongest associates was varied factorially with the set size of the associates of these associates. We assume that associate set size indexes a word’s weaker associates. Experiments 1 and 2 showed that recall varied inversely with both target and associate set sizes. Such results held over variations in study time and participant age. Experiment 3 showed that weak associates of the target had a greater effect on recall when there were more connections among the strongest associates in the set. The findings suggest that activation is not strength selective but includes both weak and strong associates.     

Retrieval processes in perceptual recognition and cued recall: The influence of category size

The purpose of these experiments was to determine whether nonsemantic category size and other variables would influence perceptual recognition as they influence cued recall. Procedures developed by Jacoby and his associates were replicated with words belonging to either small or large nonsemantic categories and with recognition tested under bright-target/patterned-mask conditions. The results indicated that words belonging to larger nonsemantic sets were more difficult to identify. This finding and the results of other manipulations are discussed in relation to the interactive activation model and to the proposal that perceptual recognition performance is dependent on a retrieval process similar to that involved in recall prompted by nonsemantic cues.     

Episodic remembering in young adults, 73-year-olds, and 82-year-olds

Younger adults (mean age = 20.6), 73-year-olds, and 82-year-olds were examined in free and cued recall of words preceded by standard instructions or organizational instructions. The younger adults outperformed the elderly groups in free and cued recall preceded by standard instructions. When organizational instructions were provided, recall differences between the younger adults and the 73-year-olds were eliminated, while both these groups outperformed the 82-year-olds. Within-group comparisons showed that the younger group was relatively independent of contextual support at encoding (organizational instructions) and retrieval (cues) respectively. Furthermore, the group of 73-year-olds was able to utilize support at both stages of remembering, whereas the group of 82-year-olds utilized contextual support only at retrieval. The results were compared with research on memory development in childhood through the application of Ribot's law.     

The information that amnesic patients do not forget

The performance of three kinds of amnesic patients and control subjects was assessed using four methods for testing memory: free recall, recognition, cued recall, and word completion. Whereas amnesic patients were impaired on free recall, recognition, and cued recall, they were normal on word completion. Moreover, performance on the word-completion test declined at a normal rate reaching chance after about 120 min. The word-completion test resembled the cued-recall test in that the initial letters of previously presented words were given as cues. It differed from cued recall only in the instructions, which directed subjects away from the memory aspects of the test and asked them to complete each three-letter cue with the first word that came to mind. The present results offer an explanation of conflicting findings that have been obtained with amnesic patients on tests of the cued-recall type. The results are considered in terms of a process (activation or procedural learning), which is spared in amnesia and not dependent on the integrity of the damaged brain regions.     

Sentence encoding and implicitly activated memories

Some words have fewer direct associates than others, and, when words varying in set size are studied in a list-learning task, those with smaller sets are more likely to be recalled. This set-size effect is found in cued recall when the words are studied in the absence of related words, but not when studied in the presence of related words. Related words provide context and theoretically inhibit irrelevant associates. The present research determined that set-size effects are found when words are encoded in sentence contexts. In contrast to list-learning experiments, the results of three experiments found such effects even when lexically related words were present in the sentences. Other findings indicated that target-set-size effects were determined by the proximity of related words in the sentence and the nature of the test cue. The results are discussed in relation to a model for explaining set-size effects and to selective findings from the sentence-comprehension literature.     

Item-specific and relational encoding effects in children's recall and recognition memory for words

This study tests the hypothesis that children's deficiency in encoding itemspecific and relational information in episodic events contributes to age differences in recall and recognition. In two experiments, grade school children and college adults were presented with word triplets varying in categorical relatedness. The processing of the item-specific and relational information in the triplets was independently manipulated. Experiment 1 assessed cued recall, and Experiment 2 assessed recognition of both the central target and incidental contextual members of each triplet. The results showed that the processing manipulations had independent and different effects on recall and recognition, on memory for the members of the different kinds of triplets, on the use of the retrieval cues, and on memory for target and incidental words. Developmental differences were found in both recall and recognition, and of both target and incidental words, that varied with triplet type and the processing manipulations and that were attributable to differences in the encoding of item-specific and relational information in the triplets. The discussion contrasts alternative accounts of children's encoding deficiency, and suggests that the distinction between automatic, age-invariant, and strategic age-sensitive encoding processes needs to be redrawn.