Rhesus monkeys use geometric and nongeometric information during a reorientation task

Rhesus monkeys (Macaca mulata) were subjected to a place finding task in a rectangular room perfectly homogeneous and without distinctive featural information. Results of Experiment 1 show that monkeys rely on the large-scale geometry of the room to retrieve a food reward. Experiments 2 and 3 indicate that subjects use also nongeometric information (colored wall) to reorient. Data of Experiments 4 and 5 suggest that monkeys do not use small angular cues but that they are sensitive to the size of the cues (Experiments 6, 7, and 8). Our findings strengthen the idea that a mechanism based on the geometry of the environment is at work in several mammalian species. In addition, the present data offer new perspectives on spatial cognition in animals that are phylogenetically close to humans. Specifically, the joint use of both geometric and landmark-based cues by rhesus monkeys tends to demonstrate that spatial processing became more flexible with evolution.     

Developmental change in young children's use of haptic information in a visual task: the role of hand movements

Preschoolers who explore objects haptically often fail to recognize those objects in subsequent visual tests. This suggests that children may represent qualitatively different information in vision and haptics and/or that children’s haptic perception may be poor. In this study, 72 children (2½-5 years of age) and 20 adults explored unfamiliar objects either haptically or visually and then chose a visual match from among three test objects, each matching the exemplar on one perceptual dimension. All age groups chose shape-based matches after visual exploration. Both 5-year-olds and adults also chose shape-based matches after haptic exploration, but younger children did not match consistently in this condition. Certain hand movements performed by children during haptic exploration reliably predicted shape-based matches but occurred at very low frequencies. Thus, younger children’s difficulties with haptic-to-visual information transfer appeared to stem from their failure to use their hands to obtain reliable haptic information about objects.     

Understanding inference as a source of knowledge: children's ability to evaluate the certainty of deduction, perception, and guessing

Three experiments investigated children's understanding of inference as a source of knowledge. Children observed a puppet make a statement about the color of one of two hidden toys after the puppet (a) looked directly at the toy (looking), (b) looked at the other toy (inference), or (c) looked at neither toy (guessing). Most 4-, 5-, and 6-year-olds did not rate the puppet as being more certain of the toy's color after the puppet looked directly at it or inferred its color than they did after the puppet guessed its color. Most 8 and 9-year-olds distinguished inference and looking from guessing. The tendency to explain the puppet's knowledge by referring to inference increased with age. Children who referred to inference in their explanations were more likely to judge deductive inference as more certain than guessing.     

Young children's knowledge of their memory span: effects of task and experience

This study investigated the hypothesis that young children have knowledge about their memory that they may be unable to articulate, but are able to reflect on and use in problem-solving. Forty-eight kindergarteners made one of two types of judgments about their memory span for words. Half of the children made prospective verbal predictions about the number of words they thought they could recall from a list of 10. The other half made concurrent, nonverbal predictions by listening to words on a tape and manually stopping the tape when they heard as many words as they thought they could recall. Children's actual recall for words was then assessed. All children participated in multiple trials to assess the effect of task experience on their predictions. Analyses revealed that predictions made in the concurrent task were significantly more accurate than those made in the prospective task. All children lowered their predictions across trials, although only in the concurrent task were children's final-trial predictions not significantly greater than their actual recall. No meaningful effects or interactions were associated with actual recall scores. These results revealed that young children manifested greater memory knowledge when this knowledge was assessed through their concurrent problem-solving behavior rather than through their prospective verbal predictions.     

Strategies in the information search process: interaction among task structure, knowledge, and source

The authors explored the information search strategies of 145 individuals in the predecisional stage. Decision-making participants selected pieces of information from a list including relevant and irrelevant data. The authors investigated the influence of the individual's knowledge and information source. In Experiment 1, the authors experimentally manipulated the information source reliability. The results revealed that participants tended to use a sequential strategy when the authors presented information as supplied by a reliable source. In Experiment 2, the authors analyzed the interaction between information source and the individuals' knowledge. When participants believed the source to be reliable, even knowledgeable participants adopted a strategy as sequential as that chosen by naive individuals. In Experiment 3, a mediational model corroborated the hypothesis that the search strategy affects the final judgment. The results were consistent with the constructivist framework, which emphasizes the role of individual, task, and context in the decision-making process.     

Visually directed pointing as a function of target distance,direction, and available cues

In pointing at visual targets without sight of the hand, large errors occur. There is a tendency to overreach targets, and this tendency is much greater (about 25 em) when convergence is the only cue to distance than when there are many cues (2–11 cm). Angular errors of up to 10 deg also occur. These tend to be to the side opposite the sighting eye, when the favored hand is used. The variance of the pointing response with convergence alone is reduced by approximately half with the introduction of several spatial cues. These results are interpreted as indicating that, for a target within the reach of the arm and with convergence alone as a cue, the depth signal produced by the visual system corresponds to a greater distance than that produced when many cues are available. The results are also consistent with the hypothesis that perceived direction tends to approximate direction from the sighting eye.     

The role of testimony in young children's solution of a gravity-driven invisible displacement task

Previous research has shown that young children make a perseverative, gravity-oriented, error when asked to predict the final location of a ball dropped down an S-shaped opaque tube (Hood, 1995). We asked if providing children with verbal information concerning the role that the tubes play, in determining the ball's trajectory would improve their performance. Experiment 1 showed that performance of 3.5-year-olds improved after hearing testimony about the movement of the ball. Experiment 2 showed that the specific content of the testimony – rather than any accompanying non-verbal cues – helped children improve. These findings suggest that other people's testimony can be a valuable source of information when young children learn about the physical world. Indeed, under some circumstances children seem to benefit more from verbal than visual information. An educational implication is that it may sometimes be ineffective to focus on the impact of first-hand experience while marginalizing the role of verbal information.     

The inadvertent use of prior knowledge in a generative cognitive task

In four experiments with 332 participants, participants were asked to generate novel nonwords for English categories. When participants were shown examples embedded with regular orthographic structures, participants’ nonwords tended to conform orthographically to the examples, despite instructions to avoid using features of the examples. The effect was found with immediate testing (Experiment 1) and delayed testing (Experiment 2). The effect was also found with arbitrary features (Experiments 1–4), as well as with naturally occurring orthographic regularities (Experiment 4). Participants had difficulty avoiding the use of this prior knowledge, despite being able to list the features they were asked to avoid (Experiment 3). The results are discussed in terms of the inadvertent use of prior knowledge in generative cognitive tasks.     

Number words in young children's conceptual and procedural knowledge of addition, subtraction and inversion

Three studies addressed children's arithmetic. First, 50 3- to 5-year-olds judged physical demonstrations of addition, subtraction and inversion, with and without number words. Second, 20 3- to 4-year-olds made equivalence judgments of additions and subtractions. Third, 60 4- to 6-year-olds solved addition, subtraction and inversion problems that varied according to the inclusion of concrete referents and number words. The results indicate that number words play a different role in conceptual and procedural development. Children have strong addition and subtraction concepts before they can translate the physical effects of these operations into number words. However, using number words does not detract from their calculation procedures. Moreover, consistent with iterative relations between conceptual and procedural development, the results suggest that inversion acquisition depends on children's calculation procedures and that inversion understanding influences these procedures.     

Schematic knowledge changes what judgments of learning predict in a source memory task

Source monitoring can be influenced by information that is external to the study context, such as beliefs and general knowledge (Johnson, Hashtroudi, & Lindsay, 1993). We investigated the extent to which metamnemonic judgments predict memory for items and sources when schematic information about the sources is or is not provided at encoding. Participants made judgments of learning (JOLs) to statements presented by two speakers and were informed of the occupation of each speaker either before or after the encoding session. Replicating earlier work, prior knowledge decreased participants’ tendency to erroneously attribute statements to schematically consistent but episodically incorrect speakers. The origin of this effect can be understood by examining the relationship between JOLs and performance: JOLs were equally predictive of item and source memory in the absence of prior knowledge, but were exclusively predictive of source memory when participants knew of the relationship between speakers and statements during study. Background knowledge determines the information that people solicit in service of metamnemonic judgments, suggesting that these judgments reflect control processes during encoding that reduce schematic errors.     

The effects of word length and phonemic similarity in young children's short-term memory

Two experiments tested the hypothesis that word length and phonemic similarity effects in young children's recall with auditory presentation result from verbal output, and not: (1) rehearsal in the case of word length effects; (2) confusion at input in the case of phonemic similarity effects. In an auditorily presented probed recall task, where there were no full verbal output requirements, children aged five years did not show either effect. Children aged seven years showed both word length and phonemic similarity effects. It was concluded that, in children of age five, word length effects can not necessarily be taken as evidence for rehearsal, nor can the phonemic similarity effect be assumed to result from confusion at input. It is suggested that the process of saying a list verbally may cause both of these effects, and that care must be taken to distinguish input and output processes in the development of children's short-term memory.     

Modularity as a fish (Xenotoca eiseni) views it: conjoining geometric and nongeometric information for spatial reorientation

When disoriented in a closed rectangular tank, fish (Xenotoca eiseni) reoriented in accord with the large-scale shape of the environment, but they were also able to conjoin geometric information with nongeometric properties such as the color of a wall or the features provided by panels located at the corners of the tank. Fish encoded geometric information even when featural information sufficed to solve the spatial task. When tested after transformations that altered the original arrangement of the panels, fish were more affected by those transformations that modified the geometric relationship between the target and the shape of the environment. Finally, fish appeared unable to use nongeometric information provided by distant panels. These findings show that a reorientation mechanism based on geometry is widespread among vertebrates, though the joint use of geometric and nongeometric cues by fish suggest that the degree of information encapsulation of the mechanism varies considerably between species.     

Personal epistemology and theory of mind: deciphering young children's beliefs about knowledge and knowing

The beliefs that individuals hold about knowledge and knowing have been the focus of a growing body of work on “personal epistemology.” There has been general agreement among researchers about a developmental trajectory of epistemological understanding that takes place in adolescence and adulthood. Rarely has this research included children, however, and we know little about the origins of epistemological awareness or its early development. A separate group of researchers have investigated children's “theory of mind,” or the ability to understand others’ beliefs, actions, and desires, with primary attention to the onset of this cognitive achievement between the ages of 3 and 5. This article reviews the theoretical foundation for a proposed relation between these constructs, and reports on an exploratory investigation with 3–5 year olds, in which epistemological level was significantly related to theory of mind ability. Results are discussed in relation to a general timeline depicting the development of children's beliefs about knowledge and knowing, a process that involves an ongoing tension between objective and subjective perspectives. We propose that the trajectory of epistemological development be expanded to include an initial period of egocentric subjectivity that characterizes epistemological thinking prior to the achievement of theory of mind.     

Dynamic testing with tangible electronics: Measuring children's change in strategy use with a series completion task

Aims. This study sought to explore the use of a novel approach that incorporates dynamic testing and tangible electronics in the assessment of children's learning potential and strategy use. Sample. A total of 77 children with a mean age 8.9 years participated in the study; half of them were dynamically tested using graduate prompt techniques; the others served as a control group. Method. Children in the experimental group received a series of inputs consisting of a pre‐test, two training sessions, and a post‐test all involving a number of series completion tasks; the controls received only pre‐ and post‐tests. All test sessions were undertaken individually using a specially designed programme incorporating an electronic console and tangible materials equipped internally with sensors. Results. As a consequence of training, children significantly outperformed controls on a number of series completion tasks. Significant individual differences were noted in terms of the children's response to assistance. The study's hypothesis that dynamic testing would increase analytical, and reduce trial‐and‐error, behaviour was supported. While a significant proportion of the children employed strategies that had earlier been identified as optimal, a sizeable minority demonstrated rather more idiosyncratic approaches. Conclusions. Findings from the study demonstrate the potential value of electronic dynamic testing using graduated prompts. However, a number of further refinements to improve the procedure are suggested.     

The relationship of adolescent mothers' expectations,knowledge, and beliefs to their young children's coping behavior

Developmental researchers have begun to explore parental cognitions in an effort to better understand adolescent parenthood. However, most research on adolescent mothers has failed to relate cognitions of the mother to the child's functioning. To extend the research on adolescent-parent families, we examined the association between adolescent mothers' knowledge of child development, parental expectations, and child-rearing beliefs to their infants' or toddlers' coping behavior. Trained observers rated children on the three subscales of the Early Coping Inventory–Sensorimotor, Reactive Behavior, and Self-Initiated Behavior. The findings indicated that the adolescent mothers' self-reports of their expectations for their own and their children's behaviors and emotions accounted for a significant proportion of the variance in objective ratings of the children's coping behavior in the sensorimotor and reactive behavior domains. Adolescent mothers who reported more positive, more realistic, and more mature expectations about parenting, children, and the parent-child relationship had children who were rated to display more adaptive and effective sensorimotor and reactive behavior coping capacities. An interaction between the adolescent mothers' knowledge and beliefs significantly predicted self-initiated child behaviors. Implications of the findings include the importance of exploring a “good match” in adolescent mother-child relationships.     

The development of landmark and beacon use in young children: evidence from a touchscreen search task

Children ages 2, 3 and 4 years participated in a novel hide-and-seek search task presented on a touchscreen monitor. On beacon trials, the target hiding place could be located using a beacon cue, but on landmark trials, searching required the use of a nearby landmark cue. In Experiment 1, 2-year-olds performed less accurately than older children on landmark trials but performed equivalently on beacon trials. In Experiment 2, the number of items on the screen was reduced and 2-year-olds' performance improved. Use of the landmark transformation technique in Experiment 3 revealed that older children formed a more precise landmark-target spatial relationship than 2-year-olds. Experiment 4 showed that the transformation itself was not responsible for the youngest participants' decreased accuracy in Experiment 3. Overall, beacons were utilized effectively by all participants, but the use of landmark cues is refined between the ages of 2 and 4.     

Navigation in the Morris swim task as a baseline for drug discrimination: a demonstration with morphine

A morphine versus saline discrimination was demonstrated using the Morris swim task as the behavioral baseline. The apparatus was a large circular pool filled with water made opaque by floating polypropylene pellets. Rats were placed in the tank in randomly selected locations (12 trials per session) and could escape by swimming to a platform submerged 2 cm below the surface. Morphine (5.6 mg/kg) or saline was injected prior to training sessions. The position of the platform in a given session depended on the drug condition, thus forming the basis for discriminative responding. Three of the 4 rats acquired the discrimination, as evidenced by direct swims to the condition-appropriate platform. Generalization probe sessions were conducted following acquisition. Probe sessions were preceded by injections of morphine (0, 1.0, 3.0, 5.6, or 10.0 mg/kg) and involved placing the rat in the pool for 1 min without a platform. Swim patterns revealed a gradient, with probe swimming more concentrated in the area of the morphine platform position after higher morphine doses. In addition, dose-dependent increases in the likelihood of swimming first to the morphine-associated platform location were obtained. These results illustrate the generality of drug discrimination across different behavioral procedures, and of particular interest with respect to spatial learning, demonstrate interoceptive stimulus control of navigation.     

Family as a salient source of meaning in young adulthood

Five studies demonstrated the role of family relationships as an important source of perceived meaning in life. In Study 1 (n?=?50), 68% participants reported that their families were the single most significant contributor to personal meaning. Study 2 (n?=?231) participants ranked family above 12 likely sources of meaning. Studies 3 (n?=?87) and 4 (n?=?130) demonstrated that participants’ reports of their closeness to family (Study 3) and support from family (Study 4) predicted perceived meaning in life, even when controlling for several competing variables. Study 5 (n?=?261) ruled out social desirability as an alternative explanation to the proposed relationship between family and meaning. We conclude that for young adults, family relationships are a primary source of meaning in life and they contribute to their sense of meaning.