The influence of linguistic labels on source‐monitoring decisions

Three studies explored the extent to which people use various object features, including linguistic label, shape, and category membership, to make decisions about the source of their memories. To isolate the influence of each feature, we used items that were related in the following four ways: as synonyms, as similar in shape and category membership, as homographs, or as unrelated. Participants read sentences and either saw or imagined a picture of the critical word's referent. Experiment 1 showed that participants committed more source errors for synonyms (e.g., rabbit and bunny) than for objects that were conceptually and perceptually similar (e.g., doughnut and bagel), which produced more errors than unrelated items. However, there was no effect of label, as people did not have more errors for homographs (e.g., baseball bat and flying bat) than unrelated items. In Experiment 2, presenting the critical word at study was not sufficient to lead people to use an item's label to make source decisions. However, Experiment 3 showed more source errors for homographs than unrelated pairs when semantic context was minimised at study, suggesting that people can use linguistic labels to make source decisions when other information is unavailable.     

Semantic priming of familiar songs

We explored the functional organization of semantic memory for music by comparing priming across familiar songs both within modalities (Experiment 1, tune to tune; Experiment 3, category label to lyrics) and across modalities (Experiment 2, category label to tune; Experiment 4, tune to lyrics). Participants judged whether or not the target tune or lyrics were real (akin to lexical decision tasks). We found significant priming, analogous to linguistic associative-priming effects, in reaction times for related primes as compared to unrelated primes, but primarily for within-modality comparisons. Reaction times to tunes (e.g., “Silent Night”) were faster following related tunes (“Deck the Hall”) than following unrelated tunes (“God Bless America”). However, a category label (e.g., Christmas) did not prime tunes from within that category. Lyrics were primed by a related category label, but not by a related tune. These results support the conceptual organization of music in semantic memory, but with potentially weaker associations across modalities.     

Natural categories: Well defined or fuzzy sets?

Thirty college students made category membership decisions for each of 540 candidate exemplar-category name pairs (e.g.,apple-fruit) in each of two separate sessions. For highly typical category members (e.g., chair for thefurniture category), and for items unrelated to a category (e.g.,cucumber-furniture), subjects agreed with each other and were consistent in their decisions. However, for intermediate-typicality items (e.g.,bookends-furniture), subjects disagreed with each other and were frequently inconsistent from one session to the next. These data suggest that natural categories are fuzzy sets, with no clear boundaries separating category members from nonmembers.     

Sentence context effects on lexically ambiguous words: Evidence for a postaccess inhibition process

Two experiments were conducted to investigate the process involved in selecting the contextually appropriate meaning of a homograph. Both experiments employed a grammaticality decision task. In Experiment 1, the primary (more frequent) and secondary (less frequent) meanings of homographs were used as the target items requiring a “yes” decision. The results indicated that the effect of relative frequency of these meanings of homographs was reduced when the target word was preceded either by a semantically congruous or anomalous sentence context relative to when it was preceded by the grammatical morpheme “the” or “to.” Experiment 2 indicated that “no” decisions were consistently slower for syntactically unambiguous, but semantically ambiguous words (e.g., ORGAN, FEET) than for syntactically and semantically unambiguous words (e.g., CENT, LEND), irrespective of the type of preceding context. The results, taken as a whole, are best interpreted within the postaccess inhibition model of sentence-context effects suggested by Forster (1981).     

False recognition across meaning,language, and stimulus format: Conceptual relatedness and the feeling of familiarity

Four experiments examined contributions of conceptual relatedness and feelings of familiarity to false recognition. Participants first studied lists of unrelated items (e.g., table, lock) followed by a recognition test with three types of items: (1) studied items (e.g., table), (2) semantically related lures (e.g., key), and (3) unrelated lures (e.g., cup). Participants falsely recognized more related than unrelated lures when the stimuli were words (Experiment 1A) and pictures (Experiment 1B), when the studied items and related lures differed in language (Experiment 2), and when they differed in perceptual format (Experiment 3). In Experiment 4, an attribution manipulation, designed to make feelings of familiarity nondiagnostic for memory judgments, eliminated the false-recognition effect obtained in Experiment 3. Overall, the study suggests that conceptual relatedness produces false recognition even in the absence of shared perceptual surface features between study and test items, and it does so by generating feelings of familiarity.     

Dual semantic encoding of homographs and homophones embedded in context

Dual encoding of homographs and homophones was inferred from the intrusion of their alternative meanings across trials in two experiments using a modified Brown-Peterson paradigm. In Experiment 1 subjects heard a word triad and then engaged in a 10.5-sec distractor task. Written recall was then demanded. On context trials a homophone with alternative meanings belonging to two distinct categories was embedded in a triad biasing one meaning, e.g., helpless,/wik/, fragile. On the next trial, words from the category of the other meaning were presented, e.g., year, month, decade. A significant number of intrusions of the alternative coding of the homophone, e.g., WEEK, across the category boundary were observed. Experiment 2 employed visual presentation of embedded homographs, e.g., plunged, jumped, DOVE, and oral recall but was logically similar to Experiment 1. Intrusions of the alternative codings of homographs across category boundaries, e.g., pigeon, sparrow,/d Λ v/, were again noted.     

Speeded induction under uncertainty: The influence of multiple categories and feature conjunctions

When people are uncertain about the category membership of an item (e.g., Is it a dog or a dingo?), research shows that they tend to rely only on the dominant or most likely category when making inductions (e.g., How likely is it to befriend me?). An exception has been reported using speeded induction judgments where participants appeared to use information from multiple categories to make inductions (Verde, Murphy, &; Ross, 2005). In two speeded induction studies, we found that participants tended to rely on the frequency with which features co-occurred when making feature predictions, independently of category membership. This pattern held whether categories were considered implicitly (Experiment 1) or explicitly (Experiment 2) prior to feature induction. The results converge with other recent work suggesting that people often rely on feature conjunction information, rather than category boundaries, when making inductions under uncertainty.     

The spontaneous use of a group typology as an organizing principle in memory

Five studies investigated the spontaneous use of group typology in encoding information about various social groups. Participants saw faces or behaviors along with a label indicating the group membership of the face or the behavior. Labels corresponded to 2 groups each of 3 group types (i.e., 2 intimacy groups, 2 task-oriented groups, and 2 social categories). Recognition results showed more within-group-type errors than between-group-types errors. A free-recall task replicated these results, as the sequence of remembering items showed that memory organization reflected the group typology. A final study investigated the effects of group typology on the speed and accuracy of category membership verification. Results demonstrate the spontaneous use of an implicit group typology and its influence on the cognitive organization of information about groups.     

Noncategorical approaches to feature prediction with uncertain categories

In four experiments, we investigated how people make feature predictions about objects whose category membership is uncertain. Artificial visual categories were presented and remained in view while a novel instance with a known feature, but uncertain category membership was presented. All four experiments showed that feature predictions about the test instance were most often based on feature correlations (referred to as feature conjunction reasoning). Experiment 1 showed that feature conjunction reasoning was generally preferred to category-based induction in a feature prediction task. Experiment 2 showed that people used all available exemplars to make feature conjunction predictions. Experiments 3 and 4 showed that the preference for predictions based on feature conjunction persisted even when category-level information was made more salient and inferences involving a larger number of categories were required. Little evidence of reasoning based on the consideration of multiple categories (e.g., Anderson, (Psychological Review, 98:409–429, 1991)) or the single, most probable category (e.g., Murphy & Ross, (Cognitive Psychology, 27:148–193, 1994)) was found.     

A rule-based categorization deficit in Alzheimer's disease?

This study examined the categorization processes that Alzheimer's disease (AD) patients use during assessments of semantic memory. Rule-based categorization involves the careful, analytic processing of strict criteria to determine category membership, particularly for items from graded categories with ambiguous category membership; similarity-based categorization requires an overall comparison of a test stimulus with a prototype or remembered exemplar of the category and is relatively effective for the rapid categorization of items with unambiguous category membership. To assess these processes in AD, patients were asked to decide the category membership of test stimuli for categories with poorly defined or fuzzy boundaries (e.g., VEGETABLE) and for categories with well-defined boundaries (e.g., FEMALE) and then to judge the representativeness of the test stimulus for its chosen category. A subgroup of AD patients demonstrated a typical pattern of impaired semantic memory compared to healthy control subjects; that is, difficulty deciding the category membership of test items from fuzzy categories. Among these patients, we found no deficit in category membership decisions about items taken from well-defined categories. We also found that AD patients and healthy controls do not differ in their representativeness judgments of items within a correctly judged category. These findings are most consistent with the hypothesis that rule-based categorization difficulty limits semantic memory in AD.     

The inaction effect in the psychology of regret

Previous research showed that decisions to act (i.e., actions) produce more regret than decisions not to act (i.e., inactions). This previous research focused on decisions made in isolation and ignored that decisions are often made in response to earlier outcomes. The authors show in 4 experiments that these prior outcomes may promote action and hence make inaction more abnormal. They manipulated information about a prior outcome. As hypothesized, when prior outcomes were positive or absent, people attributed more regret to action than to inaction. However, as predicted and counter to previous research, following negative prior outcomes, more regret was attributed to inaction, a finding that the authors label the inaction effect. Experiment 4, showing differential effects for regret and disappointment, demonstrates the need for emotion-specific predictions.     

Induction with uncertain categories: When do people consider the category alternatives?

These three experiments examined how people make property inferences about exemplars whose category membership is uncertain. Participants were shown two categories and a novel exemplar with a feature that indicated that the exemplar was more likely to belong to one category (target) than to the other (nontarget). Participants then made categorization decisions and property inferences about the novel exemplar. In some conditions, property inferences could be made only by considering both target and nontarget categories. In other conditions, predictions could be based on both categories or on the target category alone. Consistent with previous studies (e.g., Murphy & Ross, 1994, 2005), we found that many people made predictions based only on consideration of the target category. However, the prevalence of such single-category reasoning was greatly reduced by highlighting the costs of neglecting nontarget alternatives and by asking for inferences before categorization decisions. The results suggest that previous work may have exaggerated the prevalence of single-category reasoning and that people may be more flexible in their use of multiple categories in property inference than has been previously recognized.     

Monitoring memory errors: the influence of the veracity of retrieved information on the accuracy of judgements of learning

The current study examined the degree to which predictions of memory performance made immediately or at a delay are sensitive to confidently held memory illusions. Participants studied unrelated pairs of words and made judgements of learning (JOLs) for each item, either immediately or after a delay. Half of the unrelated pairs (deceptive items; e.g., nurse-dollar) had a semantically related competitor (e.g., doctor) that was easily accessible when given a test cue (e.g., nurse-do_ _ _r) and half had no semantically related competitor (control items; e.g., subject-dollar). Following the study phase, participants were administered a cued recall test. Results from Experiment 1 showed that memory performance was less accurate for deceptive compared with control items. In addition, delaying judgement improved the relative accuracy of JOLs for control items but not for deceptive items. Subsequent experiments explored the degree to which the relative accuracy of delayed JOLs for deceptive items improved as a result of a warning to ensure that retrieved memories were accurate (Experiment 2) and corrective feedback regarding the veracity of information retrieved prior to making a JOL (Experiment 3). In all, these data suggest that delayed JOLs may be largely insensitive to memory errors unless participants are provided with feedback regarding memory accuracy.     

Learning and retention through predictive inference and classification

Work in category learning addresses how humans acquire knowledge and, thus, should inform classroom practices. In two experiments, we apply and evaluate intuitions garnered from laboratory-based research in category learning to learning tasks situated in an educational context. In Experiment 1, learning through predictive inference and classification were compared for fifth-grade students using class-related materials. Making inferences about properties of category members and receiving feedback led to the acquisition of both queried (i.e., tested) properties and nonqueried properties that were correlated with a queried property (e.g., even if not queried, students learned about a species' habitat because it correlated with a queried property, like the species' size). In contrast, classifying items according to their species and receiving feedback led to knowledge of only the property most diagnostic of category membership. After multiple-day delay, the fifth-graders who learned through inference selectively retained information about the queried properties, and the fifth-graders who learned through classification retained information about the diagnostic property, indicating a role for explicit evaluation in establishing memories. Overall, inference learning resulted in fewer errors, better retention, and more liking of the categories than did classification learning. Experiment 2 revealed that querying a property only a few times was enough to manifest the full benefits of inference learning in undergraduate students. These results suggest that classroom teaching should emphasize reasoning from the category to multiple properties rather than from a set of properties to the category.     

Searching for two things at once: Evidence of exclusivity in semantic and autobiographical memory retrieval

We examined whether retrieval from semantic memory (Experiment 1) and autobiographical memory (Experiment 2) is exclusive, or whether people can search for two things at once. In Experiment 1, participants retrieved items as quickly as possible over 4 ruin from single categories (e.g., foods, countries) and from disjunctive categories (e.g., foods or countries). In Experiment 2, participants retrieved autobiographical episodes associated with single cue words (e.g., flower, ticket) or with disjunctive cue words (e.g., flower or ticket). In both experiments, retrieval of items from the disjunctive category did not exceed predictions based on optimal sequencing of retrieval from the corresponding two single categories. That is, exclusivity was observed to occur in retrieval from among multiple nonoverlapping categories in both semantic and autobiographical memory.     

Domain differences in the structure of artifactual and natural categories

In three experiments, different methodologies, measures, and items were employed to address the question of whether, and to what extent, membership in a semantic category is all or none (i.e., absolute) or a matter of degree (i.e., graded). Resemblance theory claims that categorization is based on similarity, and because similarity is graded, category membership may also be graded. Psychological essentialism asserts that categorization is based on the presumption of the category essence. Because artifactual (e.g., FURNITURE) and natural (e.g., FRUIT) categories have different sorts of essences, artifacts and natural kinds may be categorized in qualitatively different manners. The results converged onthe finding of a robust domain difference in category structure: Artifactual categories were more graded than natural categories. Furthermore, typicality reliably predicted absolute category membership, but failed to predict graded category membership. These results suggest that resemblance theory and psychological essentialism may provide a concerted account of representation and categorization across domains.     

Domain differences in absolute judgments of category membership: evidence for an essentialist account of categorization

There has been some debate about the correspondence between typicality gradients and category membership. The present study investigates the relationship between these two measures in the domains of animals and artifacts. Forty-two adults judged the degree of typicality or category membership of 293 animals and artifacts. The subjects’ tendency for animals, but not for artifacts, was to make more absolute ratings on category membership (i.e., judging exemplars as definitely members or definitely not members of their respective category) than on typicality. More importantly, at almost every level of typicality, subjects were more likely to make absolute judgments of category membership for animals than for artifacts. These results indicate that people treat category membership of animals as relatively absolute (which best fits an essentialist model of categorization) and treat category membership of artifacts as relatively graded (which best fits a prototype model of categorization). These domain differences add crucial supporting evidence for claims about the domain-specificity of essentialism.     

Am I blue? Depressed mood and the consequences of self-focus for the interpretation and recall of ambiguous words

In two experiments, dysphoric and nondysphoric students first concentrated on either self-focused or other-focused phrases and then performed an ostensibly unrelated task involving the interpretation of homographs with both personal and impersonal meanings. In Experiment 1, they constructed sentences for the homographs; dysphoric students' sentences were more emotionally negative (although not more personal) in the self-focused condition than in the other-focused condition. In Experiment 2, they freely associated to the homographs, and the percentage of personal meanings reflected by the associations revealed an effect of self versus other focus that depended on mood group. Following free associations, they attempted to recall the homographs. Dysphoric students (but not nondysphoric students) recalled a greater percentage of personally interpreted homographs if they had focused on self than if they had focused on other matters. In general, these results suggest that ruminative or self-focused thinking by people in depressed moods transfers to novel ambiguous situations, encouraging more negative interpretations and better recall of personal interpretations.