Knowledge that Transforms

Four experiments that show an early ability to encode and retain information about extent are presented. We found that infants discriminate between the heights of dowels in a habituation task. We also found that toddlers discriminate between heights on a choice task in which a target dowel is presented and removed and they then choose between the target and a foil. Until 4 years of age, however, discrimination occurs only in the presence of a perceptually salient standard. Adults do not require a perceptually present standard; they can assess extent across temporal or spatial gaps by imposing a standard (measure). The present findings indicate that infants and toddlers do not possess an adult ability to establish extent, but that they do possess a skill that provides a start point for this important intellectual achievement.

Considerable evidence indicates that people overattribute causality to a given stimulus when it is salient or the focus of their attention--the so-called illusory-causation phenomenon. Although illusory causation has proved to be quite robust and generalizable, a compelling explanation for it has not been empirically documented. Four social-attribution studies were conducted to test the hypothesis that illusory causation occurs because salient information is initially registered, or perceptually organized, differently than nonsalient information. The results provide considerable support for the notion that people's literal point of view affects how they initially perceive, or extract, information from an observed interaction, which in turn affects their judgments regarding the causal influence exerted by each interactant.

In mirror reflections, visual stimuli in near peripersonal space (e.g., an object in the hand) can project the retinal image of far, extrapersonal stimuli "beyond" the mirror. We studied the interaction of such visual reflections with tactile stimuli in a cross-modal congruency task. We found that visual distractors produce stronger interference on tactile judgments when placed close to the stimulated hand, but observed indirectly as distant mirror reflections, than when directly observed in equivalently distant far space, even when in contact with a dummy hand or someone else's hand in the far location. The stronger visual-tactile interference for the mirror condition implies that near stimuli seen as distant reflections in a mirror view of one's own hands can activate neural networks coding peripersonal space, because these visual stimuli are coded as having a true source near to the body.

Anecdotal evidence from players and coaches indicates that cognitive processing (e.g., expectations about the upcoming pitch) plays an important role in successful baseball batting, yet this aspect of hitting has not been investigated in detail. The present study provides experimental evidence that prior expectations significantly influence the timing of a baseball swing. A two-state Markov model was used to predict the effects of pitch sequence and pitch count on batting performance. The model is a hitting strategy of switching between expectancy states using a simple set of transition rules. In a simulated batting experiment, the model provided a good fit to the hitting performance of 6 experienced college baseball players, and the estimated model parameters were highly correlated with playing level.

We used a visual evoked-potential measure to study the development of two components of pattern vision, vernier acuity and grating acuity, in humans from early infancy through adolescence. These two visual functions develop at similar rates and have nearly the same absolute values between 1 month and 6 years of age. After age 6, grating acuity is constant at the adult level, but vernier acuity continues to improve, becoming a hyperacuity. Vernier acuity reaches asymptotic levels around age 14 years. These results suggest that adultlike vernier hyperacuity is not limited by spatial resolution or sensitivity of small receptive fields, but rather that the limitation is imposed by higher-level processing. Sensitivity, connections in visual cortical areas, or both therefore retain plasticity throughout childhood and into adolescence.

Drawing on the hot-cool systems analysis of self-regulation, we examined whether attentionalfocus mediates the negativity of cognitive-affective reactions to interpersonal rejection. The hypothesis was that whereas a hot, arousing focus to representing rejection experiences should increase anger-hostility, accessing the cool system through distraction and distancing should attenuate such responses. Participants imagined an autobiographical rejection experience, focusing either on their physiological and emotional reactions (hot focus) or on the physical setting of the experience (cool focus). Participants in a third condition received no specific attentional instructions. Both implicit and explicit measures showed that hostile thoughts and feelings were attenuated in the cool-focus compared with the hot-focus condition. The findings support the adaptive value of activating a cooling strategy under hot, arousing conditions that otherwise elicit automatic, hot-system responses.

People hardly ever realize that their belief in their high rate of success in detecting family resemblances is affected by their knowledge of the actual genetic link between individuals. In the three studies reported here, 100 men and 100 women were requested to estimate the facial resemblance of photographically portrayed child-adult pairs, while being given either truthful or deceitful information, or no information, about their relatedness. Believing that the members of a pair were parent and offspring was the main predictor of the perceived similarity between them. Men and women agreed in judging children as more similar to female than to male adults, except when the pair members were believed to be related; in this case, men judged the child as resembling the alleged parents equally. Common remarks on family resemblance thus appear to ensue less from a conscious desire to please or reassure the parents than from general hypothesis-testing biases in human reasoning, made perhaps more specific in men by a concern with the problem of uncertain paternity.

Three experiments were conducted to investigate whether surprising color singletons capture attention. Participants performed a visual search task in which a target letter had to be detected among distractor letters. Experiments 1 and 2 assessed accuracy as the dependent variable. In Experiment 1, the unannounced presentation of a color singleton 500 ms prior to the letters (and in the same position as the target letter) resulted in better performance than in the preceding conjunction search segment, in which no singleton was presented, and performance was as good in this surprise-singleton trial as in the following feature search segment, in which the singleton always coincided with the target. In contrast, no improvement was observed when the color singleton was presented simultaneously with the letters in Experiment 2, indicating that attentional capture occurred later in the surprise trial than in the feature search segment. In Experiment 3, set size was varied, and reaction time was the dependent variable. Reaction time depended on set size in the conjunction search segment, but not in the surprise trial nor in the feature search segment. The results of the three experiments support the view that surprising color singletons capture attention independently of a corresponding attentional set.

Women's reactions to men shift during the menstrual cycle. For example, during the phase of high conception risk, women prefer men with masculinized facial features. A favored explanation for this effect is that women display an enhanced sensitivity to stimuli that have significant reproductive relevance during the phase of the menstrual cycle in which conception risk is high. Consistent with this viewpoint, the present research demonstrated that women's cycle-dependent attentiveness to "maleness" also extends to basic aspects of the person-perception process. Specifically, during the phase of high conception risk, women displayed an enhanced ability both to categorize men and to access associated category-related (i.e., stereotypic) material from semantic memory. The implications of these findings for contemporary treatments of person perception are considered.

In addition to perceiving the colors, shapes, and motions of objects, observers can perceive higher-level properties of visual events. One such property is causation, as when an observer sees one object cause another object to move by colliding with it. We report a striking new type of contextual effect on the perception of such collision events. Consider an object (A) that moves toward a stationary object (B) until they are adjacent, at which point A stops and B starts moving along the same path. Such "launches" are perceived in terms beyond these kinematics: As noted in Michotte's classic studies, observers perceive A as being the cause of B's motion. When A and B fully overlap before B's motion, however observers often see this test event as a completely noncausal "pass": One object remains stationary while another passes over it. When a distinct launch event occurs nearby, however, the test event is "captured": It too is now irresistibly seen as causal. For this causal capture to occur, the context event need be present for only 50 ms surrounding the "impact," but capture is destroyed by only 200 ms of temporal asynchrony between the two events. We report a study of such cases, and others, that help define the rules that the visual system uses to construct percepts of seemingly high-level properties like causation.