Précis of How children learn the meanings of words

Normal children learn tens of thousands of words, and do so quickly and efficiently, often in highly impoverished environments. In How Children Learn the Meanings of Words, I argue that word learning is the product of certain cognitive and linguistic abilities that include the ability to acquire concepts, an appreciation of syntactic cues to meaning, and a rich understanding of the mental states of other people. These capacities are powerful, early emerging, and to some extent uniquely human, but they are not special to word learning. This proposal is an alternative to the view that word learning is the result of simple associative learning mechanisms, and it rejects as well the notion that children possess constraints, either innate or learned, that are specifically earmarked for word learning. This theory is extended to account for how children learn names for objects, substances, and abstract entities, pronouns and proper names, verbs, determiners, prepositions, and number words. Several related topics are also discussed, including na?ve essentialism, children's understanding of representational art, the nature of numerical and spatial reasoning, and the role of words in the shaping of mental life.     

Programmed to learn? The ontogeny of mirror neurons

Mirror neurons are increasingly recognized as a crucial substrate for many developmental processes, including imitation and social learning. Although there has been considerable progress in describing their function and localization in the primate and adult human brain, we still know little about their ontogeny. The idea that mirror neurons result from Hebbian learning while the child observes/hears his/her own actions has received remarkable empirical support in recent years. Here we add a new element to this proposal, by suggesting that the infant's perceptual‐motor system is optimized to provide the brain with the correct input for Hebbian learning, thus facilitating the association between the perception of actions and their corresponding motor programs. We review evidence that infants (1) have a marked visual preference for hands, (2) show cyclic movement patterns with a frequency that could be in the optimal range for enhanced Hebbian learning, and (3) show synchronized theta EEG (also known to favour synaptic Hebbian learning) in mirror cortical areas during self‐observation of grasping. These conditions, taken together, would allow mirror neurons for manual actions to develop quickly and reliably through experiential canalization. Our hypothesis provides a plausible pathway for the emergence of mirror neurons that integrates learning with genetic pre‐programming, suggesting new avenues for research on the link between synaptic processes and behaviour in ontogeny.     

Transfer of calibration in dynamic touch: what do perceivers learn when they learn about length of a wielded object?

Successfully performing everyday behaviours requires that perceptions and actions are properly calibrated to environmental properties. In three experiments, the authors tested whether calibration was specific to perception of a particular property of a wielded object from a particular grasp position on that object. The experiments investigate whether transfer of recalibration occurs across changes in grasp position (Experiment 1), object property (Experiment 2), and grasp position and object property (Experiment 3). The results suggest that a complete transfer of recalibration occurred in each case. Such results are consistent with recent research on dynamic touch and suggest that rather than recalibrating participants to one particular property of the wielded objects, feedback about a particular property served to recalibrate participants to the properties of the rod set as a whole.     

Does transfer of training help children learn juggling?

The effectiveness of four different learning sequences in teaching juggling to 5th grade students was investigated. Practice schedules using combinations of scarves, weighted scarves, beanbags, and balls allowed both identical task elements and learners' time-on-task to be varied during a 3-wk. practice period. The exclusive use of beanbags for practice, prior to testing with balls, resulted in significantly better juggling scores than did the other combinations. While transfer of training occurred for other groups, the amount of students' time-on-task during practice appeared to be a strong influence on final performance.     

Is the learn unit a fundamental measure of pedagogy?

We propose a measure of teaching, the learn unit, that explicitly describes the interaction between teachers and their students. The theoretical, educational research, and applied behavior analysis literatures all converge on the learn unit as a fundamental measure of teaching. The theoretical literature proposes the construct of the interlocking operant and embraces verbal behavior, social interaction, and translations of psychological constructs into complex theoretical respondent-operant interactions and behavior-behavior relations. Research findings in education and applied behavior analysis on engaged academic time, opportunity to respond, active student responding, teacher-student responding, student-teacher responding, tutor-tutee responding, tutee-tutor responding, and verbal episodes between individuals all support a measure of interlocking responses. More recently, research analyzing the components of both the students' and teachers' behavior suggests that the learn unit is the strongest predictor of effective teaching. Finally, we propose applications of the learn unit to other issues in pedagogy not yet researched and the relation of learn units to the verbal behavior of students.     

Do consumers ever learn? Analysis of segment behavior in experimental markets

Economists argue that, despite cognitive limitations, economic agents arrive at optimal choice rules by learning. The assumption is that consumers, for example, are adaptively rational. Adaptive rationality raises a host of issues. We address three of these in the context of experimental markets: do consumers differ on the basis of learning; how do these differences, when aggregated, affect market efficiency; and how do consumers learn? Analysis of our experimental data reveals the following. First, multiple segments of consumers exist on the basis of learning. Second, the largest segment consists of subjects who do not learn despite timely feedback and motivation. Third, although some consumers do learn to make optimal choices, the effect of this segment on market efficiency is cancelled by an equal number of subjects who ‘learn' false relations. Finally, although subjects do not learn strict rationality even with experience, they are in the aggregate not so irrational as to allow highly suboptimal brands to survive. Further analysis of how consumers learn, specifically on the cues (signals) and the rules consumers employ in making choices over time leads to the following two conclusions. First, some signals make learning more easy than others: for example, providing market share information improves learning but not as much as providing quality information does. Second, people employ different rules depending upon the type of information they have. For example, consumers making decisions based only on price information are more likely to use a heuristic like ‘buy a medium‐priced product provided it has not failed in the past'. Consumers making decisions based on price and quality information may employ a heuristic such as ‘buy top quality products regardless of price'. We discuss the implications of these findings for theory and practice. Copyright © 2000 John Wiley & Sons, Ltd.     

The genesis of reading ability: What helps children learn letter-sound correspondences?

Knowledge of letter-sound correspondences underpins successful reading acquisition, and yet little is known about how young children acquire this knowledge and what prior information they bring to the learning process. In this study, we used an experimental training design to examine whether either prior letter awareness or prior phonemic awareness directly assists preliterate children in subsequently learning letter-sound correspondences. Here 76 preschoolers received 6 weeks of training in either letter awareness, phonemic awareness, or control tasks and then received a further 6 weeks of training in either letter-sound correspondences or control tasks. There was limited evidence that prior training in either phoneme or letter awareness directly assisted learning of letter-sound correspondences, although phonemically trained children appeared to show some advantage on recognition tasks. Overall, the data suggest that there is little value in training preschoolers in either letter forms or sounds in isolation in advance of providing instruction on the links between the two.     

Newborns learn to identify a face in eight/tenths of a second?

A number of recent studies have shown that newborns prefer to look at mother's face rather than at the face of a stranger. This preference can be seen as the result of familiarity with the mother's face, stemming from a greater number of encounters with mother's face. A schema theory can deal with this kind of recognition. Recent work with verbal stimuli has shown that newborns are sensitive to primacy and recency as well as simple familiarity. A pilot and one complete experiment were carried out to examine whether primacy and recency operated with faces as well. Results indicated that primacy, but not recency, was effective. The results show very rapid learning, learning that may outpace the capacity of any extant model of perceptual learning.     

What can we learn by looking for the first code of professional ethics?

The first code of professional ethics must: (1)be a code of ethics; (2) apply to members of a profession; (3) apply to allmembers of that profession; and (4) apply only to members of that profession. The value of these criteria depends on how we define “code”, “ethics”, and “profession”, terms the literature on professions has defined in many ways. This paper applies one set of definitions of “code”, “ethics”, and “profession” to a part of what we now know of the history of professions, there by illustrating how the choice of definition can alter substantially both our answer to the question of which came first and (more importantly) our understanding of professional codes (and the professions that adopt them). Because most who write on codes of professional ethics seem to take for granted that physicians produced the first professional code, whether the Hippocratic Oath, Percival’s Medical Ethics, the 1847 Code of Ethicsof the American Medical Association (AMA), or some other document, I focus my discussion on these codes. This revised version was published online in June 2006 with corrections to the Cover Date.     

Learning to learn from video? 30-month-olds benefit from continued use of supportive scaffolding

Young children struggle to learn new words presented on video, but adult co-viewers can support them by providing scaffolds that explicitly connect the video and real world. In this study, we asked whether scaffolding facilitates children’s symbolic understanding of the video, such that they will subsequently transfer labels from video to real referents. Sixty-three 30-month-olds and 61 36-month-olds participated in a series of three word learning trials in one of three conditions. In the supportive condition, an in-person adult explicitly drew connections between each on-screen object and the corresponding real object in the room with the child. In the unsupportive condition, the in-person adult provided similar-length statements about the objects but did not draw connections between them. In the partial scaffold condition, the in-person adult provided the supportive scaffolds for the first two trials and the unsupportive version for the third trial. At 30 months, children selected the correct object on the third trial more often in the supportive than the unsupportive scaffold condition, and performance in the partial scaffold condition fell in between. At 36 months, performance on the third trial did not differ across conditions. The results showed that experiencing the scaffold twice was not enough to reliably support 30-month-olds in learning to think symbolically on the third trial; rather, they appeared to rely on the adult to connect the video image with its specific real-world referent. At 36 months, however, children did not rely on the adult scaffold to apply the video label to the real-world objects.     

What can we learn about immediate memory from the development of children's free recall?

We ask the question: Which aspects of immediate memory performance improve with age? In two studies, we reexamine the widely held view that primary memory capacity estimates derived from children's immediate free recall are age invariant. This was done by assessing children's immediate free-recall accuracy while also measuring the order in which they elected to recall items (Experiment 1) and by encouraging children to begin free recall with items from towards the end of the presented list (Experiment 2). Across samples aged between 5 and 8 years we replicated the previously reported age-related changes in free-recall serial position functions when aggregated across all trials of the standard task, including an absence of age differences in the recency portion of this curve. However, we also show that this does not reflect the fact that primary memory capacity is constant across age. Instead, when we incorporate order of report information, clear age differences are evident in the recall of list-final items that are output at the start of a participant's response. In addition, the total amount that individuals recalled varied little across different types of free-recall tasks. These findings have clear implications for the use of immediate free recall as a means of providing potential indices of primary memory capacity and in the study of the development of immediate memory.     

Can visual cognitive neuroscience learn anything from the philosophy of language? Ambiguity and the topology of neural network models of multistable perception

The Necker cube and the productive class of related stimuli involving multiple depth interpretations driven by corner-like line junctions are often taken to be ambiguous. This idea is normally taken to be as little in need of defense as the claim that the Necker cube gives rise to multiple distinct percepts. In the philosophy of language, it is taken to be a substantive question whether a stimulus that affords multiple interpretations is a case of ambiguity. If we take into account what have been identified as hallmark features of ambiguity and look at the empirical record, it appears that the Necker cube and related stimuli are not ambiguous. I argue that this raises problems for extant models of multistable perception in cognitive neuroscience insofar as they are purported to apply to these stimuli. Helpfully, similar considerations also yield reasons to suggest that the relevant models are well motivated for other instances of multistable perception. However, a different breed of model seems to be required for the Necker cube and related stimuli. I end with a sketch how one may go about designing such a model relying on oscillatory patters in neural firing. I suggest that distinctions normally confined to the philosophy of language are important for the study of perception, a perspective with a growing number of adherents.     

What do rats learn about the geometry of object arrays? Tests with exploratory behavior

Six experiments using habituation of exploratory behavior tested whether disoriented rats foraging in a large arena encode the shapes of arrays of objects. Rats did not respond to changes in position of a single object, but they responded to a change in object color and to a change in position of 1 object in a square array, as in previous research (e.g., C. Thinus-Blanc et al., 1987). Rats also responded to an expansion of a square array, suggesting that they encoded sets of interobject distances rather than overall shape. In Experiments 4-6, rats did not respond to changes in sense of a triangular array that maintained interobject distances and angles. Shapes of object arrays are encoded differently from shapes of enclosures.     

What do children learn about biology from factual information? A comparison of interventions to improve understanding of contagious illnesses

Background . Children have been shown to hold misconceptions about illness, and previous work has indicated that their knowledge can be improved through the use of interventions. Aims . This study aims to evaluate interventions based on the provision of factual information for improving understanding of contagious illness. Sample . The participants were 96 children from two age groups: 7 and 11 years. Methods . During the pre‐test, the children were asked about three contagious illnesses and one novel illness. There were three intervention conditions, differing in the level of factual information provided: explanations provided, no explanations provided and scientific factual style. The interventions were focused on contagious illnesses (cold, chickenpox). A post‐test was conducted 6 weeks later. Results . Results from the pre‐test show that the older children have more sophisticated understanding of illness than the younger children. Mean pre‐ to post‐test change was calculated and analyses revealed that there is greater pre‐ to post‐test change in the explanation and scientific fact conditions when compared with that in the no‐explanation condition. The improvements in knowledge generalized to other contagious illnesses, and the older children showed more improvements than the younger children. Conclusions . These findings add to the literature on children's understanding of contagious illnesses and contribute towards discussions on the best approach to health education.     

Can cuttlefish learn by observing others?

Observational learning is the ability to learn through observing others’ behavior. The benefit of observational learning is apparent in that individuals can save time and energy without trial-and-error, thus enhance the chance of survival and reproduction. Cephalopods (octopus, squid, and cuttlefish) have the most sophisticated central nervous system among invertebrates, and it is conceivable that cephalopods can develop some forms of cognition. Although it has been suggested that octopuses have the capacity of observational learning, a previous study indicates that cuttlefish do not improve their predation tactics by observing conspecifics. Given that the danger avoidance is important for animals’ survival, we sought to reevaluate whether cuttlefish show some form of observational learning or observational conditioning under threatening conditions. Cuttlefish (Sepia pharaonis) were divided into three groups: the Experiencer group, the Observer group, and the Control group. In the training phase, a toy submarine was remotely controlled to expel the cuttlefish from its initially preferred place to establish the threat-place association in the Experiencer group. In the Observer group, the threat-place association was established by expelling a conspecific demonstrator at the observer’s initially preferred place while the observer watched the whole process from behind a transparent divider. In the Control group, the observer watched a conspecific and a static toy submarine without actual threat. In the testing phase, the choice of safe place in the absence of threat was used to probe the learning/conditioning of cuttlefish. In the Experiencer group, we found that animals chose the safe place more often than their initially preferred place after training, an indication of the association learning/conditioning. However, in the Observer group, only a subset of animals showed this threat-place association by observation, while the place preference was unchanged in the Control group. These results indicate that most cuttlefish did not learn by observing others, but individual differences exist, and some cuttlefish may have the potential of observational learning/conditioning within their cognitive capacities.     

Can chimpanzees learn a phonemic language?

Two groups of investigators have recently reported some success in teaching language to chimpanzees. This finding has been generally attributed to the choice of a favorable communication modality. However, the fact that the languages employed were not phonemic also seems critical. It is doubtful whether chimpanzees could learn a phonemic language.This research was supported in part by PHS Grants No. GM01789 and GM16735 to The Rockefeller University.     

What did Popper learn from Lakatos?

The canonical version of the history of twentieth century philosophy of science tells us that Lakatos was Popper’s disciple, but it is rarely mentioned that Popper would have learned anything from Lakatos. The aim of this paper is to examine Lakatos’ influence on Popper’s philosophical system and to argue that Lakatos did have an important, yet somewhat unexpected, impact on Popper’s thinking: he influenced Popper’s evolutionary model for ‘progress’ in science. And Lakatos’ influence sheds new light on why and how Popper continually revised one of the central claims of his philosophy of science: the evolutionary account of scientific theory change.