Infant brain responses to felt and observed touch of hands and feet: an MEG study

There is growing interest concerning the ways in which the human body, both one's own and that of others, is represented in the developing human brain. In two experiments with 7‐month‐old infants, we employed advances in infant magnetoencephalography (MEG) brain imaging to address novel questions concerning body representations in early development. Experiment 1 evaluated the spatiotemporal organization of infants’ brain responses to being touched. A punctate touch to infants’ hands and feet produced significant activation in the hand and foot areas of contralateral primary somatosensory cortex as well as in other parietal and frontal areas. Experiment 2 explored infant brain responses to visually perceiving another person's hand or foot being touched. Results showed significant activation in early visual regions and also in regions thought to be involved in multisensory body and self–other processing. Furthermore, observed touch of the hand and foot activated the infant's own primary somatosensory cortex, although less consistently than felt touch. These findings shed light on aspects of early social cognition, including action imitation, which may build, at least in part, on infant neural representations that map equivalences between the bodies of self and other.     

Form and variability during sit-to-stand transitions: children versus adults

In performing the sit-to-stand transition, young children (6- to 7-year-olds) were expected to display a movement form similar to that of adults. However, movement consistency was predicted to be poorer in children than in adults because they lack refinement of motor control processes. Kinematic analysis of 10 repetitions of the sit-to-stand movement was carried out for 6 typically developing children and 6 adults. Supporting the authors' prediction of comparable form, no differences were evident between age groups for sequence of joint onsets, proportional duration of segmental motion, or in angle-angle plots of displacement at 2 segments. In contrast, within-participant variability was found to be higher for children: Coefficients of variation for most kinematic measures were twice those seen for adults. The authors interpret the children's lack of movement consistency as a reflection of inadequate stabilization of an internal model of intersegmental dynamics. Whereas adults have attained a skill level associated with refinement of that model, children have not. Children have an additional control problem because changes in body morphology throughout childhood require ongoing updating of the internal model that controls intrinsic dynamics.     

Elemental versus configurai models of categorization in children and adults

In experiment 1, 7-and 8-year-old children learned to classify six features, A–F, as belonging to one of two artificial categories, or to neither category. Feature A and the compound BC were designated as members of Category 1, the compounds DE and EF were members of category 2, while D alone and the compound AB, belonged to neither category. Following successful learning, the participants were asked to rate two groups of test features, ABC and DEF, as likely members of their respective categories. Participants' certainty ratings of the categorization of the compound DEF were greater than for the compound ABC. Experiment 2 replicated the results of experiment 1 with adult participants. These data are at odds with predictions from an elemental associative theory, that suggested by Rescorla and Wagner (1972), which assumes that category judgements are made on the basis of associations between individual features and a category.     

Elemental versus configurai models of categorization in children and adults

In experiment 1, 7-and 8-year-old children learned to classify six features, A–F, as belonging to one of two artificial categories, or to neither category. Feature A and the compound BC were designated as members of Category 1, the compounds DE and EF were members of category 2, while D alone and the compound AB, belonged to neither category. Following successful learning, the participants were asked to rate two groups of test features, ABC and DEF, as likely members of their respective categories. Participants' certainty ratings of the categorization of the compound DEF were greater than for the compound ABC. Experiment 2 replicated the results of experiment 1 with adult participants. These data are at odds with predictions from an elemental associative theory, that suggested by Rescorla and Wagner (1972), which assumes that category judgements are made on the basis of associations between individual features and a category.     

Error-related electrocortical responses in 10-year-old children and young adults

Recent anatomical and electrophysiological evidence suggests that the anterior cingulate cortex (ACC) is relatively late to mature. This brain region appears to be critical for monitoring, evaluating, and adjusting ongoing behaviors. This monitoring elicits characteristic ERP components including the error-related negativity (ERN), error positivity (Pe) and correct-related negativity (CRN), with the ERN clearly relating to activation of the ACC; however, little attention has been paid to the examination of these ERP components in children. The present study examined developmental differences in the ERN, Pe, and CRN in normal 10-year-old children and young adults in a standard visual flanker task. We found that children had smaller ERNs than adults, with no between-group differences on the Pe, and some ambiguity concerning the CRN. Results provide electrophysiological support either for late maturation of the ACC or late involvement of the ACC in response monitoring. Results also suggest that there is some functional independence of response-monitoring ERP components. Error-related ERPs may be a useful tool in studying the development of this brain region and its role in behavior in normal and atypical development.     

When children are more logical than adults: experimental investigations of scalar implicature

A conversational implicature is an inference that consists of attributing to a speaker an implicit meaning that goes beyond the explicit linguistic meaning of an utterance. This paper experimentally investigates scalar implicature, a paradigmatic case of implicature in which a speaker's use of a term like Some indicates that the speaker had reasons not to use a more informative term from the same scale, e.g. All; thus, Some implicates Not all. Pragmatic theorists like Grice would predict that a pragmatic interpretation is determined only after its explicit, logical meaning is incorporated (e.g. where Some means at least one). The present work aims to developmentally examine this prediction by showing how younger, albeit competent, reasoners initially treat a relatively weak term logically before becoming aware of its pragmatic potential. Three experiments are presented. Experiment 1 presents a modal reasoning scenario offering an exhaustive set of conclusions; critical among these is participants' evaluation of a statement expressing Might be x when the context indicates that the stronger Must be x is true. The conversationally-infelicitous Might be x can be understood logically (e.g. as compatible with Must) or pragmatically (as exclusive to Must). Results from 5-, 7-, and 9-year-olds as well as adults revealed that (a) 7-year-olds are the youngest to demonstrate modal competence overall and that (b) 7- and 9-year-olds treat the infelicitous Might logically significantly more often than adults do. Experiment 2 showed how training with the modal task can suspend the implicatures for adults. Experiment 3 provides converging evidence of the developmental pragmatic effect with the French existential quantifier Certains (Some). While linguistically-sophisticated children (8- and 10-year-olds olds) typically treat Certains as compatible with Tous (All), adults are equivocal. These results, which are consistent with unanticipated findings in classic developmental papers, reveal a consistent ordering in which representations of weak scalar terms tend to be treated logically by young competent participants and more pragmatically by older ones. This work is also relevant to the treatment of scalar implicatures in the reasoning literature.     

The naturalistic fallacy: moral inferences drawn from research with children versus adults

The naturalistic fallacy occurs when a person reads a report of scientific research and concludes that the moral implication of the research was included in the article when, in fact, it was not. For example, the fallacy is committed when a study contains the conclusion that TV advertising increases preference for sugar-based foods, but the reader later believes that the study concluded that TV advertising should be controlled. Previous research indicates that the commission of the fallacy was strong when memory for social research was tested. The present study showed that the commission of the fallacy was stronger when the research which was read involved children as subjects compared to adult subjects. Increased empathy for the subjects of a research article strengthens commission of the fallacy.     

Kids observing other kids' hands: visuomotor priming in children

We investigated motor resonance in children using a priming paradigm. Participants were asked to judge the weight of an object shortly primed by a hand in an action-related posture (grasp) or a non action-related one (fist). The hand prime could belong to a child or to an adult. We found faster response times when the object was preceded by a grasp hand posture (motor resonance effect). More crucially, participants were faster when the prime was a child's hand, suggesting that it could belong to their body schema, particularly when the child's hand was followed by a light object (motor simulation effect). A control experiment helped us to clarify the role of the hand prime. To our knowledge this is the first behavioral evidence of motor simulation and motor resonance in children. Implications of the results for the development of the sense of body ownership and for conceptual development are discussed.     

When children succeed in changing their responses: Insights from three versions of a flexible categorization task

Cognitive flexibility is a hallmark of human cognition, but its development is still poorly understood. The present work examined the flexibility of categorization in preschool children. Thirty-three participants aged 3–4 years were divided into three groups, with each group receiving a different version of a flexible categorization task in which the targets belonged to two distinct categories. These versions manipulated the type of questions that were asked and the alternation of shape and color games. The children exhibited flexibility when the questions were specific (or asked about attributes). The results support the idea that instructions play a role in children’s performance in sorting tasks. Considering cognitive flexibility as an expression of the interaction between children’s knowledge and abilities on the one hand and the structure, specifics, or demands of the task on the other can help clarify what cognitive flexibility is and how it develops.     

Development of selective attention: perceptual load influences early versus late attentional selection in children and adults

The moderating effect of perceptual load on visual selective attention was examined in 2 studies. In Study 1, children and young adults searched displays of varying set size flanked by irrelevant distractors. Children's performance was as efficient as adults' under conditions of high but not low loads, suggesting that early selection engages rapidly maturing neural systems and late selection engages later-maturing systems. In Study 2, 4 age groups were tested, and place markers were set at empty locations to examine perceptual grouping effects. Study 1's pattem was replicated in all age groups, with onset of early selection occurring at lower loads for younger children. Overall, children initiated early selection at lower loads to compensate for immature anterior-system interference control processes.     

Item-cued directed forgetting of related words and pictures in children and adults: selective rehearsal versus cognitive inhibition

The main purpose of this study was to compare the relative importance of selective rehearsal and cognitive inhibition in accounting for developmental changes in the directed-forgetting paradigm developed by R. A. Bjork (1972). In two experiments, children in Grades 2 and 5 and college students were asked to remember some words or pictures and to forget others when items were categorically related. Their memory for both items and the associated remember or forget cues was then tested with recall and recognition. Fifth graders recognized more of the forget-cued words than college students did. The pattern of results suggested that age differences in rehearsal and source monitoring (i.e., remembering whether a word had been cued remember or forget) were better explanatory mechanisms for children's forgetting inefficiencies than retrieval inhibition was. The results are discussed in terms of a multiple process view of inhibition.     

False memories in children and adults: age,distinctiveness, and subjective experience

This study investigated developmental trends associated with the Deese/Roediger-McDermott false-memory effect, the role of distinctive information in false-memory formation, and participants' subjective experience of true and false memories. Children (5- and 7-year-olds) and adults studied lists of semantically associated words. Half of the participants studied words alone, and half studied words accompanied by pictures. There were significant age differences in recall (5-year-olds evinced more false memories than did adults) but not in recognition of critical lures. Distinctive information reduced false memory for all age groups. Younger children provided with distinctive information, and older children and adults regardless of whether they viewed distinctive information, expressed higher levels of confidence in true than in false memories. Source attributions did not significantly differ between true and false memories. Implications for theories of false memory and memory development are discussed.     

Development of and change in cognitive control: A comparison of children, young adults, and older adults

Cognitive control involves adjustments in behavior to conflicting information, develops throughout childhood, and declines in aging. Accordingly, developmental and age-related changes in cognitive control and response-conflict detection were assessed in a response-compatibility task. We recorded performance measures, pre-response time (pre-RT) activity and medial frontal negativity (MFN)—sequentially occurring, putative event-related potential (ERP) indexes, respectively, of cognitive control and response-conflict detection. When response conflict reached the highest levels by requiring incompatible responses on posterror trials, children and older adults showed the greatest performance decrements. ERPs indicated that young adults implemented control (pre-RT) and detected the increased conflict (MFN) only when that conflict was at the highest levels, whereas children and older adults did so at lower levels (e.g., posterror, compatible responses). Consequently, the developmental and age-related performance decrements observed here may be due to the undifferentiated and inefficient manner in which children and older adults recruited the processes associated with both cognitive control and response-conflict detection.     

Words created by children versus aphasic adults: an analysis of their form and communicative effectiveness

The creation of words through the novel combination of English morphemes (e.g., "map ball" to refer to a globe) was studied in 40 preschool children, 40 grade school children, and 40 adults. These lexical innovations were collected while subjects named pictured objects, and were evaluated in terms of incidence, communicative effectiveness, novelty, semantic accuracy, and certain linguistic characteristics. Preschool children's innovations were as communicatively effective as those of grade school children and adults and contained the highest proportion of innovations with redundant elements. Grade school children produced the highest proportion with semantic inaccuracies. This suggests that preschoolers invent words from a limited set of highly familiar terms, whereas grade schoolers rely more on partially known terms. In addition, the children's innovations differed significantly from those previously collected from aphasic adults. This demonstrates that aphasia does not cause a regression to an early level of linguistic sophistication.     

Detecting lies in young children,adolescents and adults

The ability of teachers, social workers, police officers and laypersons (undergraduate and postgraduate students) to detect truths and lies told by 5–6 year‐olds, adolescents and adults was tested in the present experiment. Lie detectors judged the veracity of statements from 18 liars and 18 truth tellers belonging to these three age groups. Accuracy scores were around 60% for each of these three age groups, both for detecting truths and for detecting lies. No occupational differences emerged. Moreover, judgements made by teachers, social workers and police officers showed an overlap, suggesting that an erroneous decision made by a member of one group may not easily be detected by a member of the other groups. The lie detectors were inclined to judge cues of nervousness, cognitive demand and attempted behavioural control as cues to deceit, even when truth tellers were displaying these cues. Copyright © 2006 John Wiley & Sons, Ltd.     

Moral virtue and practical wisdom: theme comprehension in children, youth, and adults

The authors tested 3 hypotheses about the relation of moral comprehension to prudential comprehension by contrasting comprehension of themes in moral stories with comprehension of themes in prudential stories among third-grade, fifth-grade, and college students (n = 168) in Study 1, and among college students, young and middle-aged adults, and older adults (n = 96) in Study 2. In both studies, all groups were statistically significantly better at moral theme comprehension than prudential theme comprehension, suggesting that moral comprehension may develop prior to prudential comprehension. In Study 2, all groups performed equally on moral theme generation whereas both adult groups were significantly better than college students on prudential theme generation. Overall, the findings of these studies provide modest evidence that moral and prudential comprehension each develop separately, and that the latter may develop more slowly.     

Rorschach responses in healthy, community dwelling older adults

Five predicted relationships between age and intellectual level and 16 Rorschach variables were examined through a cross-sectional analysis of 47 healthy, community-dwelling elderly men and women. Subjects were compared by age and intellectual level using gender, level of medication, and scores on the Geriatric Depression Scale (GDS) and the Geriatric Social Readjustment Questionnaire (GSRQ) as covariates. Screening tests for psychiatric and physical illness, recent life events, and hearing and vision loss were administered. In contrast to prior research suggesting changes in Rorschach scores with differences in age and intellectual level, only one significant difference was found for these variables. The data suggest that age and intellectual level may contribute less to Rorschach responses than was previously thought.     

Lexical configuration and lexical engagement: When adults learn new words

People know thousands of words in their native language, and each of these words must be learned at some time in the person’s lifetime. A large number of these words will be learned when the person is an adult, reflecting the fact that the mental lexicon is continuously changing. We explore how new words get added to the mental lexicon, and provide empirical support for a theoretical distinction between what we call lexical configuration and lexical engagement. Lexical configuration is the set of factual knowledge associated with a word (e.g., the word’s sound, spelling, meaning, or syntactic role). Almost all previous research on word learning has focused on this aspect. However, it is also critical to understand the process by which a word becomes capable of lexical engagement—the ways in which a lexical entry dynamically interacts with other lexical entries, and with sublexical representations. For example, lexical entries compete with each other during word recognition (inhibition within the lexical level), and they also support the activation of their constituents (top-down lexical-phonemic facilitation, and lexically-based perceptual learning). We systematically vary the learning conditions for new words, and use separate measures of lexical configuration and engagement. Several surprising dissociations in behavior demonstrate the importance of the theoretical distinction between configuration and engagement.