Conceptual combination: Conjunction and negation of natural concepts

The operation of negation on combinations of natural categories was examined in two experiments. In the first, category membership ratings of lists of items were obtained for pairs of concepts considered individually and in two logical combinations: conjunctions (e.g., “Tools which are also Weapons”) and negated conjunctions—forms of those conjunctions in which the modifier noun category was negated (“Tools which arenot Weapons”). For conjunctions, results supported earlier findings of overextension and the geometric averaging of constituent membership values (Hampton, 1988b). Previous findings of concept dominance and noncommutativity within conjunctions were also replicated, both for typicality ratings and for probability of class membership. For negated conjunctions, the pattern of dominance was similar but interacted with order within the conjunction. Negated conjunctions were also overextended. The second experiment explored how the attributes of negated conjunctions were derived from those of the two component concepts. Frequency of generation of attributes expressed positively (has wheels) or negatively (has no wheels) followed rated frequency in the negated category. The distinctiveness of an attribute to distinguish the complement from the head-noun class was associated with the generation of attributes, particularly when there was relatively high overlap between the two categories.     

Resolving conflicting social categories: the role of age-related executive ability

We investigated the effect of age-related decline in executive ability on the application of emergent features to incongruent social category conjunctions (e.g., male midwife). When forming an impression of an incongruent conjunction, older adults used more emergent attributes (attributes associated exclusively with the category conjunction and not the constituents), relative to younger adults. Moreover, this relationship was mediated by a reduction in inhibitory ability (measured using a Stroop task) and processing speed (measured using a Digit Symbol Substitution Test, DSST). These findings are consistent with the notion that executive ability is pivotal in understanding social functioning in older adults. We discuss the implications of these findings for the continuing development of models outlining the processes and stages involved in perceiving social category conjunctions.     

Combining Prototypes: A Selective Modification Model

We propose a model that accounts for how people construct prototypes for composite concepts out of prototypes for simple concepts. The first component of the model is a prototype representation for simple, noun concepts, such as fruit, which specifies: (1) the relevant attributes of the concepts, (2) the possible values of each attribute, (3) the salience of each value, and (4) the diagnosticity of each attribute. The second component of the model specifies procedures for modifying simple prototypes so that they represent new, composite concepts. The procedure for adjectival modification, as when red modifies fruit, consists of selecting the relevant attribute(s) in the noun concept (color), boosting the diagnosticity of that attribute, and increasing the salience of the value named by the adjective (red). The procedure for adverbial modification, as in very red fruit, consists of multiplication-by-o-scalar of the salience of the relevant value (red). The outcome of these procedures is a new prototype representation. The third component of the model is tversky's (1977) contrast rule for determining the similarity between a representation for a prototype and one for an instance. The model is shown to be consistent with previous findings about prototypes in general, as well as with specific findings about typicality judgments for adjective-noun conjunctions. Four new experiments provide further detailed support for the model.     

Attribute centrality and imaginative thought

Participants' representations of the concept human were examined to differentiate three types of associations between concepts and their component attributes: the capacity of concepts to cue attributes (attribute accessibility), the capacity of attributes to cue concepts (instance accessibility), and the extent to which attributes are thought of as central to concepts (attribute centrality). The findings provide information about the concept human itself and, more generally, about the functionally distinct roles those different attribute-concept associations play in guiding imaginative thought. College students listed attributes that differentiate humans from other animals, rated the centrality of those attributes, and listed animals that possess those attributes. Other students drew and described extraterrestrials that possessed some of the attributes that were found to vary across those listing and rating tasks. Rated centrality was the most important determinant of an attribute's impact on imaginative generation. When the imagined extraterrestrials were supposed to possess attributes that had been rated as central to humans (intelligence, emotional complexity, or opposable thumbs), participants projected more aspects of human form onto them than when the creatures were supposed to possess less central attributes or when attributes were unspecified.     

The attribute priming effect in patients with Alzheimer's disease

Experiments with semantic priming (SP) paradigms have documented early hypopriming in patients with AD when concepts are used as primes and attribute concept features as targets, suggesting that concept attributes are vulnerable to damage very early in the disease course. The aims of this study were to confirm early priming reduction in the attribute condition in patients with AD and to determine which of several semantic indexes (such as the level of distinctiveness, correlation or feature dominance of concept features) best predicts the priming effect size in AD. We administered an SP attribute condition paradigm to 20 mildly demented patients with AD and to 10 NCs. We used concept–attribute pairs for which normative data of semantic indexes relative to both concept primes (i.e., number, type, mean level of dominance, distinctiveness and correlation of features constituting the concepts) and target features (i.e., level of feature dominance, correlation and distinctiveness) were available. Results showed that compared to NCs, the AD group obtained very reduced priming facilitation. Furthermore, the item regression analyses showed that the priming decrement in the AD group was predicted by the feature dominance of the target in the related pairs; that is, the lower the target feature dominance, the lower the priming effect elicited. These results confirmed hypopriming in the attribute condition from the very early phase of AD and support the view that attributes which are more salient for the identification of a given concept are also those most resistant to semantic memory degradation in AD pathology.     

The Importance of Being Emergent: A Theoretical Exploration of Impression Formation in Novel Social Category Conjunctions

Social category conjunction is a form of multiple categorization involving the combination of two simultaneously salient constituent categories to form a complex category (e.g., female soldier). Research has reliably demonstrated that perceivers often apply emergent traits when forming impressions of novel incongruent social category conjunctions, that is, traits not associated with the simple constituent categories (e.g., Kunda, Miller, & Claire, 1990 ). However, the theoretical literature modeling the mechanisms underlying impression formation in novel social category conjunctions is less well established and inconsistent. In this article, we critically evaluate the current state of empirical research and theory on novel social category conjunction, with particular reference to emergent traits, aiming to provide a more coherent framework for future research and theory. In addition, we seek to emphasize the wider importance of emergent traits, by drawing out links between research and theory on social category conjunctions with broader perspectives of impression formation.     

Preserved organization of semantic attributes in Alzheimer's disease

This study investigated whether Alzheimer's disease (AD) disrupts the basic organization of the semantic attributes of concepts. Young and normal older subjects and AD patients were presented with a target concept followed by a stimulus word and were to decide whether the stimulus was related to the target. On those trials where it was, the stimulus was either a high-, medium-, or low-dominance attribute of the target. The higher the normative dominance, the more important the attribute to concept meaning. In all 3 subject groups, decision time varied as a function of dominance. The higher the dominance, the faster the decision. Attribute dominance affected the performance of AD patients more than that of normal subjects. These results suggest that AD patients retain their knowledge of the relative importance that the different attributes of a concept have for concept meaning.     

Visual feature integration and focused attention: Response competition from multiple distractor features

Predictions from Treisman’s feature integration theory of attention were tested in a variant of the response-competition paradigm. Subjects made choice responses to particular color-shape conjunctions (e.g., a purple cross vs. a green circle) while withholding their responses to the opposite conjunctions (i.e., a purple circle vs. a green cross). The results showed that compatibility effects were based on both distractor color and shape. For unattended distractors in preknown irrelevant positions, compatibility effects were equivalent for conjunctive distractors (e.g., a purple cross and a blue triangle) and for disjunctive distractors (e.g., a purple triangle and a blue cross). Manipulation of attention to the distractor positions resulted in larger compatibility effects from conjoined features. These results accord with Treisman’s claim that correct conjunction information is unavailable under conditions of inattention, and they provide new information on response-competition effects from multiple features.     

Verifying visual properties in sentence verification facilitates picture recognition memory

According to the perceptual symbols theory (Barsalou, 1999), sensorimotor simulations underlie the representation of concepts. We investigated whether recognition memory for pictures of concepts was facilitated by earlier representation of visual properties of those concepts. During study, concept names (e.g., apple) were presented in a property verification task with a visual property (e.g., shiny) or with a nonvisual property (e.g., tart). Delayed picture recognition memory was better if the concept name had been presented with a visual property than if it had been presented with a nonvisual property. These results indicate that modality-specific simulations are used for concept representation.     

Essential and Perceptual Attributes of Words in Reflective and On-line Processing

Access to essential and perceptual attributes of word meanings was investigated in a series of tasks. First, perceptual attributes of a number of natural kind concepts were determined by asking participants to generate the most salient features of those concepts; they were asked to assess the importance of both those features and features that fit criteria for essential attributes. Attributes fitting the criteria for essential attributes were found to be judged more important than perceptual attributes in identifying an object and to have more connections to other attributes of the concept. Semantic priming for both types of features was then investigated. Prime-target pairs consisting of the natural kind concept term and the perceptual or essential attribute were presented for lexical decision (Experiments 1a and 1b) or naming (Experiments 2a and 2b). Interstimulus intervals were either 0 or 200 ms. Both types of features were primed at a 200 ms interstimulus interval but only in the lexical decision task.     

The moderating role of attribute accessibility in conditioning multiple specific attributes

Attribute conditioning (AC) refers to people's changed assessment of stimuli's (conditioned stimuli, CSs) attributes due to pairings with stimuli possessing these attributes (unconditioned stimuli, USs). Up to now, research only showed conditioning of only one attribute within a conditioning session (e.g., athleticism) and measured assessment changes in only this single attribute. The current study shows attribute‐specific AC effects in multi‐attribute environments and shows that attribute accessibility determines which of a US's multiple attributes are conditioned. Experiment 1 shows AC effects for artificial logos with attributes varying across USs (e.g., athletic, intelligent, or funny). Experiment 2 shows that these AC effects persist over time. Experiment 3 directly manipulated accessibility for attributes varying between and within USs (e.g., a US being sexy and familial) with a priming procedure. Priming‐specific attributes prior to conditioning determined which attribute of a US was conditioned to paired CSs. We discuss theoretical implications for AC, as well as practical implications for brand image formation and advertising. Copyright © 2013 John Wiley & Sons, Ltd.     

More than meets the eye: the role of language in binding and maintaining feature conjunctions

We investigated the effects of language on vision by focusing on a well-known problem: the binding and maintenance of color-location conjunctions. Four-year-olds performed a task in which they saw a target (e.g., a split square, red on the left and green on the right) followed by a brief delay and then were asked to find the target in an array including the target, its reflection (e.g., red on the right and green on the left), and a square with a different geometric split. Errors were overwhelmingly reflections. This finding shows that the children failed to maintain color-location conjunctions. Performance improved when targets were accompanied by sentences specifying color and direction (e.g., "the red is on the left"), but not when the conjunction was highlighted using a nonlinguistic cue (e.g., flashing, pointing, changes in size), nor when sentences specified a nondirectional relationship (e.g., "the red is touching the green"). The relation between children's matching performance and their long-term knowledge of directional terms suggests two distinct mechanisms by which language can temporarily bridge delays, providing more stable representations.     

Learning efficient visual search for stimuli containing diagnostic spatial configurations and color-shape conjunctions

Visual search is often slow and difficult for complex stimuli such as feature conjunctions. Search efficiency, however, can improve with training. Search for stimuli that can be identified by the spatial configuration of two elements (e.g., the relative position of two colored shapes) improves dramatically within a few hundred trials of practice. Several recent imaging studies have identified neural correlates of this learning, but it remains unclear what stimulus properties participants learn to use to search efficiently. Influential models, such as reverse hierarchy theory, propose two major possibilities: learning to use information contained in low-level image statistics (e.g., single features at particular retinotopic locations) or in high-level characteristics (e.g., feature conjunctions) of the task-relevant stimuli. In a series of experiments, we tested these two hypotheses, which make different predictions about the effect of various stimulus manipulations after training. We find relatively small effects of manipulating low-level properties of the stimuli (e.g., changing their retinotopic location) and some conjunctive properties (e.g., color-position), whereas the effects of manipulating other conjunctive properties (e.g., color-shape) are larger. Overall, the findings suggest conjunction learning involving such stimuli might be an emergent phenomenon that reflects multiple different learning processes, each of which capitalizes on different types of information contained in the stimuli. We also show that both targets and distractors are learned, and that reversing learned target and distractor identities impairs performance. This suggests that participants do not merely learn to discriminate target and distractor stimuli, they also learn stimulus identity mappings that contribute to performance improvements.     

Impaired ranking of semantic attributes in dementia

The present work explored the loss of semantic attributes that is said to occur in dementia. In the first two experiments, subjects had to select attributes that went with concepts like airplane and church. The finding that demented subjects maintained high levels of accuracy when selecting attributes suggested that the semantic content of their concepts was relatively well preserved. The organization of the content was explored in a third experiment by having subjects order attributes according to their relative importance in defining concepts. While demented subjects performed better than chance, they did not rank attributes as well as healthy aged subjects, suggesting a disruption in organization whereby the importance of central attributes is reduced. The hypothesized disruption in organization is viewed in relation to the learning and memory deficit that is the hallmark of the dementias.     

When choices give in to temptations: Explaining the disagreement among importance measures

Respondents’ overt statements of relative importance rarely correspond to weights derived from a regression analysis of their decisions. This paper conjectures that differential effects of high-level goals on importance beliefs and choices can explain these discrepancies. It is argued that the goal to justify decisions influences importance beliefs more than choices whereas the goal to assess preferences accurately affects choices more than importance beliefs. It is also argued that differential effects of high-level goals on importance statements and choices vary as a function of whether decision-maker controls the information flow and the extent of prior knowledge and experiences with choice options. These predictions were tested within the context of a contraceptive decision-making task. Choices among contraceptives made the justification goal salient to subjects by requiring tradeoffs between attributes that are either considered rational or tempting in making such decisions (e.g., health risks vs. pleasure/convenience). As predicted, subjects assigned larger importance weights to rational attributes in their subjective evaluations than in their choices whereas the impact of tempting attributes was stronger for choices than for subjective importance evaluations. Moreover, these observed discrepancies between importance measures were reduced in favor of rational attributes when subjects controlled the information flow and could not access their prior experiences. Overall, the results suggest that, although tempting attributes affect choices, decision makers appear to be unwilling to acknowledge the impact of tempting attributes on their decisions in judging attribute importance.     

Parallel coding of conjunctions in visual search

Two experiments investigated whether the conjunctive nature of nontarget items influenced search for a conjunction target. Each experiment consisted of two conditions. In both conditions, the target item was a red bar tilted to the right, among white tilted bars and vertical red bars. As well as color and orientation, display items also differed in terms of size. Size was irrelevant to search in that the size of the target varied randomly from trial to trial. In one condition, the size of items correlated with the other attributes of display items (e.g., all red items were big and all white items were small). In the other condition, the size of items varied randomly (i.e., some red items were small and some were big, and some white items were big and some were small). Search was more efficient in the size-correlated condition, consistent with the parallel coding of conjunctions in visual search     

What counts as a decision? Predictors of perceived decision making

We examined lay perceptions of what counts as a decision. Eighty-six subjects read 10 scenarios that described clear decisions (e.g., choosing a graduate school), clear “nondecisions” (e.g., an accidental wrong turn), or ambiguous actions (e.g., eating a donut when on a diet or allowing someone else to make the decision). The subjects rated each scenario as to whether the actor had made a decision and also rated six other attributes. The scenarios were rated as clearly illustrating a decision if the actor engaged in a lot of thought and did not act reflexively. Consideration of consequences and having alternatives were moderately related to decision ratings, whereas having self-control problems and the influence of physiological drives showed little relationship with decision ratings. Thus, lay concepts of decision making differ from decision theory in that thoughtful, intentional behavior is more important in defining a decision than are decision theoretic components, such as alternatives and consequences.     

Six of One, Half Dozen of the Other: Expanding and Contracting Numerical Dimensions Produces Preference Reversals

ABSTRACT— The scales used to describe the attributes of different choice options are usually open to alternative expressions, such as inches versus feet or minutes versus hours. More generally, a ratio scale can be multiplied by an arbitrary factor (e.g., 12) while preserving all of the information it conveys about different choice alternatives. We propose that expanded scales (e.g., price per year) lead decision makers to discriminate between choice options more than do contracted scales (e.g., price per month) because they exaggerate the difference between options on the expanded attribute. Two studies show that simply increasing the size of an attribute's scale systematically changes its weight in both multiattribute preferences and willingness to pay: Expanding scales for one attribute shifts preferences to alternatives favored on that attribute.