How activation, entanglement, and searching a semantic network contribute to event memory.

Free-association norms indicate that words are organized into semantic/associative neighborhoods within a larger network of words and links that bind the net together. We present evidence indicating that memory for a recent word event can depend on implicitly and simultaneously activating related words in its neighborhood. Processing a word during encoding primes its network representation as a function of the density of the links in its neighborhood. Such priming increases recall and recognition and can have long-lasting effects when the word is processed in working memory. Evidence for this phenomenon is reviewed in extralist-cuing, primed free-association, intralist-cuing, and single-item recognition tasks. The findings also show that when a related word is presented in order to cue the recall of a studied word, the cue activates the target in an array of related words that distract and reduce the probability of the target's selection. The activation of the semantic network produces priming benefits during encoding, and search costs during retrieval. In extralist cuing, recall is a negative function of cue-to-distractor strength, and a positive function of neighborhood density, cue-to-target strength, and target-to-cue strength. We show how these four measures derived from the network can be combined and used to predict memory performance. These measures play different roles in different tasks, indicating that the contribution of the semantic network varies with the context provided by the task. Finally, we evaluate spreading-activation and quantum-like entanglement explanations for the priming effects produced by neighborhood density.

A case of infraorbital lichen sclerosus.

We present a 57-year-old man with erosive lichen sclerosus isolated to the infraorbital area.

What is preexisting strength? Predicting free association probabilities, similarity ratings, and cued recall probabilities.

Measuring lexical knowledge poses a challenge to the study of the influence of preexisting knowledge on the retrieval of new memories. Many tasks focus on word pairs, but words are embedded in associative networks, so how should preexisting pair strength be measured? It has been measured by free association, similarity ratings, and co-occurrence statistics. Researchers interpret free association response probabilities as unbiased estimates of forward cue-to-target strength. In Study 1, analyses of large free association and extralist cued recall databases indicate that this interpretation is incorrect. Competitor and backward strengths bias free association probabilities, and as with other recall tasks, preexisting strength is described by a ratio rule. In Study 2, associative similarity ratings are predicted by forward and backward, but not by competitor, strength. Preexisting strength is not a unitary construct, because its measurement varies with method. Furthermore, free association probabilities predict extralist cued recall better than do ratings and co-occurrence statistics. The measure that most closely matches the criterion task may provide the best estimate of the identity of preexisting strength.

Spreading activation or spooky action at a distance?

How do preexisting connections among a word's associates facilitate its cued recall and recognition? A spreading-activation model assumes activation spreads to, among, and from a studied word's associates, and that its return is what strengthens its representation. An activation-at-a-distance model assumes strengthening is produced by the synchronous activation of the word's associates. The spread model predicts that connections among the studied word's associates will have a greater effect on memory when more of its associates return activation. The distance model predicts that total connections are important, not their direction. The results of cued recall experiments supported the distance model in showing that that connections among the associates facilitated recall regardless of the number of returning connections.

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.

Implicitly activated memories are associated to general context cues.

Words having more densely entangled associative structures are more likely to be recalled in the presence of related extralist cues. A context-modified PIER2 model predicts that the implicit activation of such structures during study connects them to the context of the learning episode. In two experiments, we evaluated this assumption by varying the associative density of the study words and the accessibility of context information. In Experiment 1, we varied context accessibility by manipulating context awareness and by delaying testing and filling the delay with different types of interfering tasks. In Experiment 2, we varied accessibility by manipulating test delay and type of interference in a factorial design. The effects of associative density were reduced by using implicit testing that never refers to context, by performing interpolated interference tasks, and finally, by extending the length of the delay. Information that is implicitly activated during an episodic experience is associated to the context of that experience.

How implicitly activated and explicitly acquired knowledge contribute to the effectiveness of retrieval cues.

The extralist cued recall task simulates everyday reminding because a memory is encoded on the fly and retrieved later by an unexpected cue. Target words are studied individually, and recall is cued by associatively related words having preexisting forward links to them. In Experiments 1 and 2, forward cue-to-target and backward target-to-cue strengths were varied over an extended range in order to determine how these two sources of strength are related and which source has a greater effect. Forward and backward strengths had additive effects on recall, with forward strength having a consistently larger effect. The PIER2 model accurately predicted these findings, but a plausible generation-recognition version of the model, called PIER.GR, could not. In Experiment 3, forward and backward strengths, level of processing, and study time were varied in order to determine how preexisting lexical knowledge is related to knowledge acquired during the study episode. The main finding indicates that preexisting knowledge and episodic knowledge have additive effects on extralist cued recall. PIER2 can explain these findings because it assumes that these sources of strength contribute independently to recall, whereas the eSAM model cannot explain the findings because it assumes that the sources of strength are multiplicatively related.

How does delayed testing reduce effects of implicit memory: context infusion or cuing with context?

Studying a word implicitly activates related associates that affect its recall in the extralist cuing task. Recall is more likely when one of these associates becomes the test cue and when other associates of the studied word activate this associate. Context disruptions occurring between study and test reduce these effects, suggesting that implicitly activated memories are linked to context. The context infusion hypothesis assumes that context information spreads throughout a word's associative network during study, decreasing with distance from the studied word. Interactive cuing assumes that context is linked only to the studied word and that recall is based on retrieving information from the test cue and the context. The infusion hypothesis predicts that effects of disruptions will depend on link distance whereas interactive cuing predicts that distance will have no effect. The experiments evaluate these explanations by manipulating target-to-cue strength, associate-to-cue strength, and context disruption. Experiment 1 varies disruption by testing under the same or different conditions (room, modality, experimenter). Experiment 2 tests recall immediately or after 5 m, 10 m, or 20 m of multiplication. The results are inconsistent with context infusion and support the interactive cuing explanation.

The English Lexicon Project.

The English Lexicon Project is a multiuniversity effort to provide a standardized behavioral and descriptive data set for 40,481 words and 40,481 nonwords. It is available via the Internet at elexicon.wustl.edu. Data from 816 participants across six universities were collected in a lexical decision task (approximately 3400 responses per participant), and data from 444 participants were collected in a speeded naming task (approximately 2500 responses per participant). The present paper describes the motivation for this project, the methods used to collect the data, and the search engine that affords access to the behavioral measures and descriptive lexical statistics for these stimuli.

Recursive reminding: effects of repetition, printed frequency, connectivity, and set size on recognition and judgments of frequency.

In the present experiments, predictions of common path and recursive-reminding models of recognition (RG) and judgments of frequency (JOFs) were contrasted. The results indicated that each task is affected by study frequency, printed frequency, and associative connectivity. However, effect size analyses indicated that study frequency and item attributes show a double dissociation over tasks. Study frequency has a greater effect on JOFs than on RG, whereas printed frequency and associative connectivity have greater effects on RG than on JOFs. The recursive-reminding model predicts differential effects of study frequency, because it assumes that although both tasks are influenced by familiarity, JOF is more likely to be affected by recollective reminding as a procedure for encoding event frequency. Associative set size effects were absent in each task, suggesting that competitors play no role in either task.

Experiencing a word can prime its accessibility and its associative connections to related words.

This paper reports the results of manipulations of word features for the magnitude of priming effects. In Experiment 1, the printed frequency of the target words and the number of connections among their associates were varied, and during testing participants were given cues and asked to produce the first word to come to mind as rapidly as possible in implicit free association. Priming effects were greater for low-frequency words and for those with many connections among their associates. In Experiments 2 and 3, target words were presented under incidental or intentional learning conditions during study, and the presence of direct preexisting connections from target to cue and from cue to target was varied. Priming effects were greater when either connection was present, with each connection having additive effects. In Experiments 4 and 5, priming effects for indirect links (shared associates and mediators) were examined. The results of these experiments indicate that priming in free association depends on both the general accessibility of the target as a response and the strengthening of direct target-to-cue connections. These findings raise problems for theories that attribute priming only to target accessibility or only to target-to-cue association.

Disrupting attention: the need for retrieval cues in working memory theories.

Sometimes in conversation, something is said that causes us to want to comment, but before our impending but implicit thoughts can be expressed, the conversation is disrupted. Later, we cannot recall what we wanted to say, but still later, we can. We used the extralist cuing task to model this phenomenon, and across experiments we varied the strength, direction, and directness of the relationship between the retrieval cues and the targeted information. Disruption was varied by switching attention to a different task before testing and by changing the testing context. Such disruptions reduced recall for the target and its implicitly activated memories. Following a disruption, stronger cues that were related to the target or to both the target and its implicit memories were more effective than those that were related to implicit memories. The findings were consistent with a model of long-term working memory that attributes forgetting to a loss of access to what has been activated, which loss is relative to the strength of the retrieval cue. Decay alone does not explain the results, indicating that many models of working memory need to be revised to take the nature of retrieval cues into account.

Strengthening the activation of unconsciously activated memories.

Reading a word activates a set of associated words-for example, reading CAB activates car, driver, and other associates. This research was conducted to determine whether the unconscious activation of these associates adds activation to other associates in the same set. Words were studied, and recall was tested with cues comprised of associates directly activated by the target. On the basis of preexisting links, the associates serving as test cues also received strong (e.g., car) or weak (e.g., driver) additional inputs from other associates in the set. Cues receiving stronger inputs from other associates were more effective, indicating that unconsciously activated associates strengthen one another. This effect declined when conditions disrupted the retrieval of context features linked to the episode. Attending to another task during or after study or receiving implicit test instructions decreased the effects of input from other associates. Importantly, disruptions affected input from other associates more than direct input from the target, suggesting that the influence of context wanes as the links in the network become more distant.

The University of South Florida free association, rhyme, and word fragment norms.

Preexisting word knowledge is accessed in many cognitive tasks, and this article offers a means for indexing this knowledge so that it can be manipulated or controlled. We offer free association data for 72,000 word pairs, along with over a million entries of related data, such as forward and backward strength, number of competing associates, and printed frequency. A separate file contains the 5,019 normed words, their statistics, and thousands of independently normed rhyme, stem, and fragment cues. Other files provide n x n associative networks for more than 4,000 words and a list of idiosyncratic responses for each normed word. The database will be useful for investigators interested in cuing, priming, recognition, network theory, linguistics, and implicit testing applications. They also will be useful for evaluating the predictive value of free association probabilities as compared with other measures, such as similarity ratings and co-occurrence norms. Of several procedures for measuring preexisting strength between two words, the best remains to be determined. The norms may be downloaded from www.psychonomic.org/archive/.

A hipótese da acessibilidade conceitual para a tipicidade e a produção lingüística / The hypothesis of conceptual accessibility for typicality and linguistic production

Este artigo estende a hipótese da acessibilidade conceitual proposta por Janczura e Nelson (1999) para a tarefa de produção lingüística e propõe um procedimento alternativo para avaliar a participação dos atributos dos conceitos em julgamentos de tipicidade. Os resultados evidenciaram que diferentes graus de tipicidade não estão relacionados à probabilidade de um atributo ser considerado como presente em um membro de uma categoria, mas podem ser previstos pela força associativa do membro em relação à categoria que pertence. Demonstrou-se, também, que a produção lingüística pode ser determinada em termos da acessibilidade dos membros de categorias na memória e que este resultado é paralelo à tarefa de julgamentos de tipicidade. Ou seja, membros de categorias mais acessíveis na memória são considerados como melhor representantes do que menos acessíveis. Sugere-se que julgamentos de tipicidade são apoiados na memória para a informação categórica. Quanto maior for o acesso ao conhecimento que o indivíduo tiver sobre o membro ou suas características, maior será a percepção de sua representatividade. Propõe-se que, para categorias conhecidas, a tipicidade deveria ser reinterpretada como uma medida de acessibilidade ao invés de representatividade conceitual.

This paper extends the accessibility hypotheses proposed by Janczura and Nelson (1999) to linguistic production and presents a procedure for evaluating the participation of attributes in typicality judgments. The results show that different degrees of typicality are not related to the probability of an attribute being considered a part of an exemplar but can be predicted by the strength of association between an instance and its category. It also demonstrates that accuracy in a linguistic production task can be explained in terms of the accessibility of category members in memory. These results parallel typicality judgments. That is, more accessible members in memory are considered better category exemplars. It suggests that memory for category information may underlie typicality judgments. The more a subject knows a category exemplar or its features, the better it is perceived as representing the category. This paper proposes that, for known categories, typicality should be re-interpreted as a measure of category accessibility rather than category representativeness.

A hipótese da acessibilidade conceitual para a tipicidade e a produção lingüística / The hypothesis of conceptual accessibility for typicality and linguistic production

Este artigo estende a hipótese da acessibilidade conceitual proposta por Janczura e Nelson (1999) para a tarefa de produção lingüística e propõe um procedimento alternativo para avaliar a participação dos atributos dos conceitos em julgamentos de tipicidade. Os resultados evidenciaram que diferentes graus de tipicidade não estão relacionados à probabilidade de um atributo ser considerado como presente em um membro de uma categoria, mas podem ser previstos pela força associativa do membro em relação à categoria que pertence. Demonstrou-se, também, que a produção lingüística pode ser determinada em termos da acessibilidade dos membros de categorias na memória e que este resultado é paralelo à tarefa de julgamentos de tipicidade. Ou seja, membros de categorias mais acessíveis na memória são considerados como melhor representantes do que menos acessíveis. Sugere-se que julgamentos de tipicidade são apoiados na memória para a informação categórica. Quanto maior for o acesso ao conhecimento que o indivíduo tiver sobre o membro ou suas características, maior será a percepção de sua representatividade. Propõe-se que, para categorias conhecidas, a tipicidade deveria ser reinterpretada como uma medida de acessibilidade ao invés de representatividade conceitual.(AU)

This paper extends the accessibility hypotheses proposed by Janczura and Nelson (1999) to linguistic production and presents a procedure for evaluating the participation of attributes in typicality judgments. The results show that different degrees of typicality are not related to the probability of an attribute being considered a part of an exemplar but can be predicted by the strength of association between an instance and its category. It also demonstrates that accuracy in a linguistic production task can be explained in terms of the accessibility of category members in memory. These results parallel typicality judgments. That is, more accessible members in memory are considered better category exemplars. It suggests that memory for category information may underlie typicality judgments. The more a subject knows a category exemplar or its features, the better it is perceived as representing the category. This paper proposes that, for known categories, typicality should be re-interpreted as a measure of category accessibility rather than category representativeness.(AU)