Knowledge that Transforms

Two experiments utilized a think/no-think paradigm to examine whether cognitive control of memories differs depending on whether they contain information with negative or neutral emotional content. During a training phase, participants learned face-word pairs (Experiment 1) or face-picture pairs (Experiment 2). In a subsequent experimental phase, participants were shown faces and told to think of the items paired with some of the faces and to try not to think of the items paired with other faces. Finally, in a test phase, participants were again shown each face and asked to recall the item with which it had been paired previously. Results for both verbal (Experiment 1) and nonverbal (Experiment 2) items indicated that the facilitatory and inhibitory influences of cognitive control were larger for negative than neutral items.

Writing about emotional experiences is associated with a host of positive outcomes. This study extended the expressive-writing paradigm to the realm of romantic relationships to examine the social effects of writing. For 3 consecutive days, one person from each of 86 dating couples either wrote about his or her deepest thoughts and feelings about the relationship or wrote about his or her daily activities. In the days before and after writing, instant messages were collected from the couples. Participants who wrote about their relationship were significantly more likely to still be dating their romantic partners 3 months later. Linguistic analyses of the instant messages revealed that participants and their partners used significantly more positive and negative emotion words in the days following the expressive-writing manipulation if the participants had written about their relationship than if they had written about their daily activities. Increases in positive emotion words partially mediated the relation between expressive writing and relationship stability.

People represent many social categories, including gender categories, in essentialist terms: They see category members as sharing deep, nonobvious properties that make them the kinds of things they are. The present research explored the consequences of this mode of representation for social inferences. In two sets of studies, participants learned (a) that they were similar to a member of the other gender on a novel attribute, (b) that they were different from a member of the other gender on a novel attribute, or (c) just their own standing on a novel attribute. Results showed that participants made stronger inductive inferences about the attribute in question when they learned that it distinguished them from a member of the other gender than in the other conditions. We consider the implications of these results for the representation of social categories and for everyday social inference processes.

This report attempts to provide an evolutionary explanation for humans' motivation to strive for money in present-day societies. We propose that people's desire for money is a modern derivate of their desire for food. In three studies, we show the reciprocal association between the incentive value of food and of money. In Study 1, hungry participants were less likely than satiated participants to donate to charity. In Study 2, participants in a room with an olfactory food cue, known to increase the desire to eat, offered less money in a give-some game compared with participants in a room free of scent. In Study 3, participants' desire for money affected the amount of M&M's they ate in a subsequent taste test, but only among participants who were not restricting their food intake in order to manage their weight.

Performance finding a target improves when artificial cues direct covert attention to the target's probable location or locations, but how do predictive cues help observers search for objects in real scenes? Controlling for target detectability and retinal eccentricity, we recorded observers' first saccades during search for objects that appeared in expected and unexpected locations within real scenes. As has been found with synthetic images and cues, accuracy of first saccades was significantly higher when the target appeared at an expected location rather than an unexpected location. Observers' saccades with target-absent images make it possible to distinguish two mechanisms that might mediate this effect: limited attentional resources versus differential weighting of information (Bayesian priors). Endpoints of first saccades in target-absent images were significantly closer to the expected than the unexpected locations, a result consistent with the differential-weighting model and inconsistent with limited resources being the sole mechanism underlying the effect.

During navigation, humans combine visual information from their surroundings with body-based information from the translational and rotational components of their movement. Theories of navigation focus on the role of visual and rotational body-based information, even though experimental evidence shows they are not sufficient for complex spatial tasks. To investigate the contribution of all three sources of information, we asked participants to search a computer-generated virtual room for targets. Participants were provided with only visual information or with visual information supplemented with body-based information for all movement (walk group) or rotational movement (rotate group). The walk group performed the task with near-perfect efficiency, irrespective of whether a rich or impoverished visual scene was provided. The visual-only and rotate groups were significantly less efficient and frequently searched parts of the room at least twice. These results suggest that full physical movement plays a critical role in navigational search, but only moderate visual detail is required.

Children's questions may reveal a great deal about the characteristics of objects they consider to be conceptually important. Thirty-two preschool children were given opportunities to ask questions about unfamiliar artifacts and animals. The children asked ambiguous questions such as "What is it?" about artifacts and animals alike. However, they were more likely to ask about the functions of artifacts, but about category membership, food choices, and typical locations of animals. They never asked questions about either artifacts or animals that would be considered inappropriate by adults. The results indicate that children hold different expectations about the types of information important for categorizing living and artifact kinds. Young children conceive of artifacts in terms of functions, but conceive of animals in terms of biologically appropriate characteristics. Such results speak to debates about the role of function in children's biological reasoning and to accounts of children's artifact concepts.

Participants attempted to perform two tasks concurrently during simulated driving. In the choice task, they responded either manually or vocally to the number of times a visual or auditory stimulus occurred; in the braking task, they depressed a brake pedal in response to the lead car's brake lights. The time delay between the onset of the tasks' stimuli, or stimulus onset asynchrony (SOA), was varied. The tasks were differentially affected by the manipulations. Brake reaction times increased as SOA was reduced, showing the psychological refractory period effect, whereas the choice task showed large effects of the stimulus and response modalities but only a small effect of SOA. These results demonstrate that a well-practiced "simple" task such as vehicle braking is subject to dual-task slowing and extend the generality of the central-bottleneck model.

A system for nonverbally representing the approximate number of items in visual and auditory arrays has been documented in multiple species, including humans. Although many aspects of this approximate number system are well characterized, fundamental questions remain unanswered: how does attention select which items in a scene to enumerate, and how many enumerations can be computed simultaneously? Here we show that when presented an array containing different numbers of spatially overlapping dots of many colors, human adults can select and enumerate items on the basis of shared color and can enumerate approximately three color subsets from a single glance. This three-set limit converges with previously observed three-item limits of parallel attention and visual short-term memory. This suggests that participants can select a subset of items from a complex array as a single individual set, which then serves as the input to the approximate number system.

Although following another person's gaze is essential in fluent social interactions, the reflexive nature of this gaze-cuing effect means that gaze can be used to deceive. In a gaze-cuing procedure, participants were presented with several faces that looked to the left or right. Some faces always looked to the target (predictive-valid), some never looked to the target (predictive-invalid), and others looked toward and away from the target in equal proportions (nonpredictive). The standard gaze-cuing effects appeared to be unaffected by these contingencies. Nevertheless, participants tended to choose the predictive-valid faces as appearing more trustworthy than the predictive-invalid faces. This effect was negatively related to scores on a scale assessing autistic-like traits. Further, we present tentative evidence that the "deceptive" faces were encoded more strongly in memory than the "cooperative" faces. These data demonstrate the important interactions among attention, gaze perception, facial identity recognition, and personality judgments.