Interitem Associations Research Articles

Novel popout without novelty.

Localization of a novel word in an array with several familiar words is typically enhanced relative to localization in an all-novel array (between-array novel popout) and sometimes enhanced relative to familiar words in one-novel arrays (within-array novel popout). Christie and Klein (1996) have questioned the reality of the latter effect, suggesting that it may be an artifact of guessing bias. The present Experiment 1 replicated within-array novel popout with the novel word probed at chance (i.e., on only one quarter of trials). Experiments 2 and 3 demonstrated a similar popout effect for a categorically unrelated word among three categorically related words, despite superior performance on all-related arrays relative to all-unrelated arrays. Repetition of constant sets of words within the experimental context is therefore unnecessary for a popout effect, contrary to assertions by Johnston and Hawley (1994). Interitem associations appear to be sufficient to produce a popout effect; as such, "novel popout" appears to be a misnomer for a phenomenon that does not depend on novelty.

ERPs to encoding and recognition in two different inter-item association tasks.

EVENT-RELATED potentials were obtained during study and recognition of word pairs in an incidental learning paradigm. Word pairs were studied either by performing a semantic judgment separately for each word (non-associative encoding) or by creating a semantic association between the two words (associative encoding). Only word pairs encoded associatively elicited a reliable dm-effect with a right frontal maximum. Recognition of previously studied word pairs revealed two topographically and temporally distinct old/new effects: an earlier parietal effect which was only reliable for associatively encoded items and a right frontal effect which was of equal magnitude for word pairs from both encoding tasks. The findings suggest that ERP effects of distinct memory processes are differentially influenced by the encoding instructions.

Human hippocampus establishes associations in memory.

Studies of amnesia have demonstrated that the hippocampus is necessary for long-term memory, but its precise role in memory is unknown. We designed a positron emission tomography experiment with tailored encoding and retrieval tasks that permitted the isolation of different mnemonic functions theorized to be mediated by the hippocampus. These functions included encoding single items, establishing interitem associations, novelty detection, and retrieving recently formed associations. Of these, we found hippocampal and parahippocampal activation only during associative learning. Our results indicate that the hippocampal formation may be particularly involved in the establishment of associations among components of an episode in memory.

The Context of Memory Retrieval

Subjects read short paragraphs of text and then received an item recognition test. Target words were primed by words from the same sentence, by words from different sentences, or by words that had not appeared in the texts (“foil” primes). Recognition priming occurred but there was no evidence of foil-prime inhibition. These results are difficult to explain in theories of memory in which associative priming is attributed to the presence of primes in retrieval cues, but are consistent with theories in which items and interitem associations are mentally represented independently, and with spreading-activation theories. This conclusion was supported by quantitative tests of the models ACT*, SAM, and TODAM. These models were fit to the present recognition results and to data obtained from other experiments using the lexical decision task. Collectively, the results suggest that memory retrieval may be guided by an object's associations with context but not by context itself.

Direction of report in spatial and verbal serial short-term memory.

Four experiments examined the role played by item and order information in determining the effects of order of report of a sequence from short-term memory. Experiments in which list items were re-presented prior to recall so that only their order had to be reported showed no differences in performance between the forward and backward direction of report. This result was found with lists of auditory-verbal, visual-verbal, and spatial stimuli. When the list items were not re-presented, so that recall of both items and order was required, recall in the backward direction of report was significantly worse than in the forward direction of report, both in spatial and verbal tasks. The results point to the symmetry of inter-item associations, though only equivocally so, but they suggest strongly that the processes of spatial and verbal serial recall share many functional characteristics.

Effect of spaced repetitions on amnesia patients' recall and recognition performance.

This study examined the effects of repetition and spacing of repetitions on amnesia patients' recognition and recall of a list of words. Like controls, amnesia patients recognized items better when repetitions were spaced compared with when they were massed. This finding was attributed to the additional rehearsal that distributed presentations typically encourage. Amnesia patients also showed normal spacing effects in a recall task, suggesting that they were able to benefit from the variable encoding that spaced repetitions allow to establish additional retrieval cues. However, even though instructions to encode repeated items in a variable manner enhanced massed presentations to the point where spacing no longer produced an advantage for the normal controls, it did not have a similar effect for the amnesia patients. This led to the conclusion that amnesia patients cannot take advantage of strategically provided opportunities to enhance their variable encoding of interitem associations. Instead, it is suggested that the automatic activation of different aspects of items and interitem associations is responsible for the spacing effect in their recall.

Associative retrieval processes in free recall.

I present a new method for analyzing associative processes in free recall. While previous research has emphasized the prominence of semantic organization, the present method illustrates the importance of association by contiguity. This is done by examining conditional response probabilities in the output sequence. For a given item recalled, I examine the probability and latency that it follows an item from a nearby or distant input position. These conditional probabilities and latencies, plotted as a function of the lag between studied items, reveal several regularities about output order in free recall. First, subjects tend to recall items more often and more rapidly from adjacent input positions than from remote input positions. Second, subjects are about twice as likely to recall adjacent pairs in the forward than in the backward direction and are significantly faster in doing so. These effects are observed at all positions in the output sequence. The asymmetry effect is theoretically significant because, in cued recall, nearly symmetric retrieval is found at all serial positions (Kahana, 1995; Murdock, 1962). An attempt is made to fit the search of associative memory model (Raaijmakers & Shiffrin, 1980, 1981) with and without symmetric interitem associations to these data. Other models of free recall are also discussed.

Investigations of the Testing Effect

This paper focuses on methodological problems arising in the study of the testing effect. These problems arise because processes that are correlated with, but logically independent of, the process of testing often differ across the study and test conditions. Carrier and Pashler (1992) recently reviewed these problems and proposed a paired-associate procedure for alleviating them. In this procedure, robust testing effects occurred, suggesting that the processes underlying testing may differ from those in a standard study condition. One potential problem with Carrier and Pashler's procedure is that opportunities to restudy previously tested items may be contributing to the testing effect. We use a modified Brown-Peterson paradigm (Peterson & Peterson, 1959) to provide converging evidence for Carrier and Pashler's (1992) conclusions. The results of Experiment 1 demonstrate testing effects even when there are no opportunities to restudy previously tested items. Experiment 2 examines whether, as suggested by Carrier and Pashler (1992), stronger interitem associations might be producing the testing effect arising from an intervening free recall test. The results demonstrate that testing effects occur even when single item lists are used, ruling out the view that testing effects are due solely to stronger interitem associations.

Using a computer model to explore impairments of acquisition processes following ingestion of diazepam

Hypotheses about the information processes impaired in diazepam-induced amnesia were tested by fitting the output from a computer simulation of list learning to observed serial position curves and to overt rehearsal protocols. Twenty-four subjects received an average weight-relative dosage of 0.18 mg/kg oral diazepam; 24 subjects received placebo. Immediate free recall of 16-word lists was examined at 2- and 8-s presentation times. Subjects receiving diazepam recalled significantly fewer words than placebo subjects (diazepam = 6.77 +/- 2.39 words; placebo = 9.29 +/- 1.42 words); their memory impairment was greater at the 8-s than 2-s presentation time. Tests of nonlinear regression models based on computer simulations of list learning performance were consistent with the hypothesis that diazepam reduces rehearsal capacity and disrupts the formation or utilization of contextual and inter-item associations. Among these causes of diazepam-induced amnesia, the disruption of contextual associations appears most important. The results further suggest that quantitative modeling of memory data may complement traditional methods of inferring relationships between brain processes and cognitive dysfunction in amnesic states.

A Test for Order Relevance in a Three-Element Serial Learning Task

Rats were trained in a straight runway on a simple three-element series of differing reward quantities. The first trial of the series ended with a two-pellet reward, and the second and third trials ended with a 12-pellet reward and a nonreward, respectively (2-12-0). All animals developed accurate anticipation of the terminal nonreward in the 2-12-0 series before it was rearranged for two test days during which the elements appeared in the order 12-2-0. The rats' anticipation of the terminal nonreward did not transfer to the reordered series, a result taken to mean that anticipation had been based upon interitem associations among memorial representations of the differing reward quantities. A second transfer test to 0-0-0, given after anticipation was reestablished to the 2-12-0 series, gave evidence that the ordinal position of the series elements was also a source of anticipation; the animals continued to run relatively slowly on the third trial in extinction. In neither transfer test was there evidence that the rats employed the strategy of enumerating rewarded trials, because counting is an order-irrelevant process.

The role of conceptual knowledge and metamemory in the development of organizational processes in memory

The present study investigated the relationship between developmental shifts in the organization of materials and developmental changes in deliberate strategy use. Second and fourth grade children were presented with clusterable sort/recall lists representing the factorial combinations of high and low interitem association, and high and low category relatedness. Strategy use in the task was rated by the experimenter and also assessed via self reports. General and task-related strategy knowledge (metamemory) was also examined. Second graders displayed more category clustering during recall for highly associated items than for weakly associated items, whereas older children's recall organization (but not recall) was unaffected by this organizational dimension. Correlations among measures of metamemory and organizational behavior indicated that second graders in general were unaware of the importance of categorization strategies for facilitation of recall. On the other hand, sorting during study and task-related metamemory were the most important predictors of fourth graders' recall performance, thus indicating that most fourth graders used categorization strategies deliberately.

Active and Passive Processing during Primary Rehearsal

Two incidental learning experiments examined the formation of interitem associations under task demands that encouraged different types of rehearsal in short-term memory. Subjects were assumed to engage in primary rehearsal when the task required them merely to keep information available in memory until the appearance of a decision word. Active primary rehearsal, on the other hand, required interactive processing of the stored material continuously throughout the rehearsal interval. The main question of interest asked whether active as opposed to passive rehearsal would typically lead to continued growth in interitem associative learning, even though no final memory test was anticipated. The results suggested that associative learning will not continue to develop as a simple by-product of attention, or temporal contiguity; rather, rehearsal will promote the formation of associations only while the subject continues to look for relations among co-rehearsed items. These data are discussed in terms of the distinction

Associative and categorical hypotheses of organization in the free recall of adults and children

Associative and categorical explanations for the organization children and adults display in free recall were tested. It was expected that young children would show output clustering as a function of associations between individual items within categories rather than relationship to the taxonomy itself. Kindergarten, fourth-grade, and tenth-grade subjects were presented with pictures representing the four factorial combinations of high and low interitem association and high and low category relatedness. Each set of pictures could be divided into four taxonomic categories of six items each. Kindergarteners displayed greater category clustering of highly associated items than weak associates. Older subjects showed sensitivity to both organizational dimensions. These data support a hypothesis that young children cluster in recall as a function of associations while older individuals show organizational flexibility which serves to facilitate greater recall.

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.

Serial learning, interitem associations, phrasing cues, interference, overshadowing, chunking, memory, and extinction

Two experiments indicated that two approaches to serial learning are too extreme—the classical view that it consists only of interitem associations and various recent views that it involves no interitem associations. The novel assumption introduced here was that phrasing cues, normally conceptualized as merely segregating long series into smaller units or chunks, may also enter into associations with items, thereby reducing interitem interference and facilitating serial learning. It was found that one item could become a signal for another item, an interitem association, or be overshadowed by a phrasing cue, such as a brightness and temporal cue, also signaling that item. The items were .045-g pellets. Rats traversed a runway for items arranged in ordered series, 14-7-3-1-0 pellets (Experiment 1) or 10-2-0-10 (Experiment 2). Complete tracking of, for example, the 10-2-0-10 series would consist of fastest running to 10 pellets and slowest running to 0 pellets. In both investigations, the interitem association overshadowed was that between 0 pellets and the subsequent rewarded item, 0 → 14 (Experiment 1) or 0 → 10 (Experiment 2). Either repetitions of the 14-7-3-1-0 subpattern (Experiment 1) or merely the terminal 10-pellet item (Experiment 2) were phrased, both methods producing identical results. Overshadowing the 0-pellet item produced superior serial learning, more rapid extinction, and, in Experiment 1, considerable elevation of responding when the brightness phrasing cue was introduced in extinction, an effect said to be conceptually identical to spontaneous recovery and one demonstrating directly that phrasing cues are in reality overshadowing cues. It was suggested that many effects attributed to forgetting may be due to unrecognized overshadowing of memory cues by phrasing cues, giving rise to exaggerated estimates of forgetting.

Test-expectancy and semantic-organization effects in recall and recognition

Two experiments examined whether people expecting recall are, compared with people expecting recognition, more likely to form associations between semantically related words in a list of to-be-remembered words. People were induced to expect either a recall or a recognition test on a critical list that included three conditions of semantic organization. Words in the unrelated (U) condition were semantically unrelated to all other words on the list, whereas words in the two related conditions were semantically related to one other list word. In the related-spaced (R-S) condition, the two related words appeared in input positions separated by 5-11 other items, whereas in the related-massed (R-M) condition, they appeared in adjacent input positions. Different groups received either an expected or unexpected recall (Experiment 1) or recognition (Experiment 2) test on the critical list. In both recall and recognition, (l) people expecting recall did better than those expecting recognition, (2) memory was worst for U words, next best for R-S words, and best for R-M words, and (3) the test-expectancy and semantic-organization effects were additive. A standardizedz-score measure of category dependency in memory indicated that (1) people expecting recall were not more likely than those expecting recognition to form interitem associations between the related words and (2) recognition was category dependent, but less so than recall. Within the framework of Anderson and Bower’s (1972, 1974) theory, these data indicate that, compared with people expecting recognition, those expecting recall are not more likely to form interitem associations by tagging more pathways connecting semantically related nodes but, rather, are more likely to tag the nodes themselves. The implications that semantic-organization effects in recognition have for the Anderson-Bower theory were also discussed.

Cued recall for four-word categories presented in separate pairs

Theoretical arguments and empirical evidence are presented that support the view that interitem associations develop among items of the same category during learning of categorized lists. The theoretical arguments question the interpretation of certain cued recall studies that failed to find effects of cues beyond aiding retrieval of the category itself. The empirical evidence is an experiment that shows that cues are more effective at aiding the retrieval of category mates presented adjacent to the cue than of those presented in more remote positions. There was also evidence of within-category subclusters induced by clustering in the presentation order.

The Effects of Item Contiguity and Probing on Measures of Anomia

Data from a 1971 Detroit Area Study survey are applied to investigate whether agreeing response bias is greater (1) when four anomia items are grouped as a series (rather than when they are presented separately), and (2) when uncertain respondents are probed for opinions (rather than not probed). The results of a split-ballot experiment show that for respondents at all educational levels, item contiguity had a negligible effect upon univariate response distributions and associations among items. Probing uncertain respondents significantly altered response distribution and interitem associations in several cases, but the effects were slight and were not due to agreeing response bias. Thefindings suggest that variations in the placement of anomia items, and in the extent to which uncertain respondents are probed, are not likely to influence survey results.

Consensus, constraint, and political polarization in recent presidential elections

By reexamining the structure of political attitudes among Americans in the period 1956–72, using both the items and coding scheme as given inThe Changing American Voter (1976) by Nie and his associates and using only domestic attitude items, but including all available responses, we have found that the major type of change between the 1950s and the 1970s is not an increase in internal constraint (ideological thinking of any sort) but an increase in political attitude polarization. Further, this analysis indicates that when interitem associations are used to measure constraints present in the entire population, a major source of political attitude constraint is ignored—the constraints present within the social, political and demographic groupings within the society. The major types of attitude constraints in our society are likely to be external to the attitudes themselves. Understanding electoral outcomes will necessitate understanding the nature of electoral coalitions formed across social and political groupings.

Presentation Rate Effects in Transfer from Serial to Paired-Associate Learning

Summary The effect of presentation rate, 1 or 3 seconds per item, upon the formation of interitem associations in serial learning was investigated by examining transfer from serial to paired-associate (PA) learning. The influence of PA presentation rate, 2:2, 2:6, 6:2, or 6:6, was also assessed. With total time held constant, serial learning proceeded more rapidly at the 3-second rate, thus providing a violation in total time invariance. Furthermore, transfer in terms of performance differences between experimental pairs, formed from adjacent items in the serial list, and control pairs, composed of new items, was significantly greater following serial learning at the 3-second rate. These results were viewed as suggesting that usual organizational strategies are disrupted at the fast presentation rate. With respect to PA variables, it was observed that maximal transfer was obtained at a 6:2 rate.