General Cognitive Abilities and Psychosocial Development in Children and Adolescents Having a Co-Twin with Down Syndrome.

OBJECTIVE: To examine the general cognitive and psychosocial development in children and adolescents having a co-twin with Down syndrome. STUDY DESIGN: A case control study with an individually matched control group was conducted. Participants included families with twins discordant for Down syndrome as well as with typically developing twins. The group of unaffected co-twins aged 4-16 years was compared with a control group of typically developing twins in terms of general cognitive abilities, behavioral problems, and prosocial behavior. The age and sex and the sex composition of the twins were individually matched. The Sijnders-Oomen nonverbal intelligence test was applied to assess children's IQ, and parents completed the Strength and Difficulties Questionnaire. RESULTS: The unaffected co-twins did not differ from typically developing twins with respect to their IQ. Concerning the psychosocial development, significantly heightened values in unaffected co-twins twins were only obtained for the conduct problems scale (P = .01; r = 0.45), neither for the total difficulties score nor for the other behavioral problem scales significant differences were found. CONCLUSIONS: The general cognitive development of the unaffected co-twin of children with Down syndrome is not affected by the presence of their Down syndrome twin. Unaffected co-twins showed increased conduct problems, which is most pronounced in the younger children.

[The Effect of a Short-Term Mindfulness Program on Memory Performance in School-Aged Children]. / Die Wirkung achtsamkeitsbasierter Kurzzeitinterventionen auf das Kurz- und Langzeitgedächtnis im Grundschulalter.

The Effect of a Short-Term Mindfulness Program on Memory Performance in School-Aged Children A one-week mindfulness-based intervention designed to improve 8- to 10-year-old children's memory performance was investigated. Seventy-three children were quasi-randomly assigned either to one of two mindfulness-based intervention groups (breathing meditation or yoga), or to an active control group. The sessions were held on six consecutive days. Prior to intervention and after completing the intervention, children's short-term and long-term memory performance were assessed. In confirmation of prior studies, breathing meditation and yoga showed positive effects on memory performance when compared with the control group. Moreover, differences in the effectiveness of breathing meditation and yoga were found: While both interventions had comparable effects on long-term memory, only breathing meditation showed improvements in short-term memory performance. The present study provides valuable evidence on the effectiveness of meditation on cognitive functions in childhood and shows that school-aged children can already benefit from short-term meditation programs.

A model's natural group membership affects over-imitation in 6-year-olds.

The phenomenon of "over-imitation"-the copying of causally irrelevant actions-has influenced research of the past decade. Yet, the mechanisms underlying and factors affecting over-imitation are still under debate. This study aimed to contribute to this debate by investigating the role of the model's natural group membership in children's tendency to imitate irrelevant actions using a two-phase design. In Phase 1, 6-year-olds (N = 64) observed either an in-group model or an out-group model presenting a sequence of irrelevant actions, with only the last action bringing about the goal (target action) and retrieving a token. In Phase 2, the alternative model-the one that children had not seen in Phase 1-retrieved the token by performing the target action only. After the presentation in each phase, children were given the chance to retrieve the token themselves. Results indicated that children imitated the irrelevant actions to comparable levels from both models in Phase 1. In Phase 2, in contrast, over-imitation declined in children who observed the in-group model being successful with the target action only but not in children who observed the out-group model do so. Thus, children adapted their imitative behavior after observing the model of their own cultural group demonstrating a more efficient strategy. These findings speak for an integration of both social and instrumental accounts to explain the phenomenon of over-imitation.

Lifespan development of the bilateral deficit in a simple reaction time task.

Performing an action at a maximum speed or with a maximum strength simultaneously with two limbs leads to a lower performance than the sum of unimanual performances. This phenomenon is known as bilateral deficit. There is some evidence that the bilateral deficit changes over the lifespan, in a way that children and older adults show lower deficits than young adults. Inverse developmental changes of childrens' and older adults' brain structures connecting both hemispheres, i.e., the corpus callosum, might importantly contribute to this phenomenon. The seemingly similar developments have been observed with different experimental protocols in the different age groups, respectively. To test for similarities and differences in changes of the bilateral deficit at critical periods of the lifespan development of bimanual actions, children, young adults, and older adults performed a simple reaction time task uni- and bimanually. Reaction times and the resulting bilateral deficit, as well as reaction time variability were analyzed. As expected, reaction times were different for the young adults between the uni- and the bimanual task. Children and older adults performed both conditions with similar reaction times. However, a difference in the direction of the %bilateral deficit occurred between the two age groups. The findings demonstrated an absence of the bilateral deficit for children, but not for younger and older adults.

The Relationship between Emotion Comprehension and Internalizing and Externalizing Behavior in 7- to 10-Year-Old Children.

The influence of internalizing and externalizing problems on children's understanding of others' emotions has mainly been investigated on basic levels of emotion comprehension. So far, studies assessing more sophisticated levels of emotion comprehension reported deficits in the ability to understand others' emotions in children with severe internalizing or externalizing symptoms. The aim of this study was to investigate the relation between emotion comprehension and interindividual differences, with a focus on internalizing and externalizing behavior in children aged 7-10 years from the general population. A sample of 135 children was tested for emotion understanding using the Test of Emotion Comprehension. Information on internalizing and externalizing behavior was assessed with the Child Behavior Checklist 4/18. Age, bilingual upbringing, and amount of paternal working hours were significant control variables for emotion comprehension. In contrast to prior research, overall level of emotion understanding was not related to externalizing symptoms and correlated positively with elevated levels of somatic complaints and anxious/depressed symptoms. In addition, and in line with previous work, higher levels of social withdrawal were associated with worse performance in understanding emotions elicited by reminders. The present results implicate not only an altered understanding of emotions among more specific internalizing symptoms, but also that these alterations occur already on a low symptom level in a community based sample.

Tom Is Not More Likely to Imitate Lisa Than Ying: The Influence of a Model's Race Indicated by Physical Appearance on Children's Imitation.

Recent research has shown that infants and young children up to the age of 5 years are more likely to imitate in-group members than out-group members. Cues like gender, race, age, and language are robust indicators for social categories and, thus, for group membership. Concerning imitation, research mainly focuses on language and accent, whereas race indicated by physical appearance is rarely investigated. Research has shown that the aforementioned factors served as indicators of group membership and influenced children's imitative behavior in such ways that the in-group member was more likely to be imitated. Nevertheless, the question arises how physical appearance of a person itself influences the imitative behavior. In this study, we investigated the effect of group membership (in-group vs. out-group) in 4-year-old children (N = 48) on children's imitative behavior. Children observed either an in-group or an out-group model (German vs. Chinese), defined by physical appearance only, which presented novel manual actions in four different tasks. After each presentation, children got the opportunity to imitate the target actions. Furthermore, children were either assigned to a live or a video condition to control for the influence of the presentation mode. Results indicated that 4-year-old children did not imitate the in-group model more often than the out-group model. Furthermore, there was no difference between the two presentation modes. Results were discussed on the basis of research on the in-group-out-group effect. We suggested that a pure difference in the model's physical appearance might not be sufficient to elicit an in-group-out-group effect.

No Interrelation of Motor Planning and Executive Functions across Young Ages.

The present study examined the developmental trajectories of motor planning and executive functioning in children. To this end, we tested 217 participants with three motor tasks, measuring anticipatory planning abilities (i.e., the bar-transport-task, the sword-rotation-task and the grasp-height-task), and three cognitive tasks, measuring executive functions (i.e., the Tower-of-Hanoi-task, the Mosaic-task, and the D2-attention-endurance-task). Children were aged between 3 and 10 years and were separated into age groups by 1-year bins, resulting in a total of eight groups of children and an additional group of adults. Results suggested (1) a positive developmental trajectory for each of the sub-tests, with better task performance as children get older; (2) that the performance in the separate tasks was not correlated across participants in the different age groups; and (3) that there was no relationship between performance in the motor tasks and in the cognitive tasks used in the present study when controlling for age. These results suggest that both, motor planning and executive functions are rather heterogeneous domains of cognitive functioning with fewer interdependencies than often suggested.

Life span changes: Performing a continuous 1:2 bimanual coordination task.

The experiment was conducted to determine the influence of mirror movements in bimanual coordination during life span. Children, young adults, and older adults were instructed to perform a continuous 1:2 bimanual coordination task by performing flexion-extension wrist movements over 30s where symmetrical and non-symmetrical coordination patterns alternate throughout the trial. The vision of the wrists was covered and Lissajous-feedback was provided online. All age groups had to perform 10 trials under three different load conditions (0kg, .5kg, 1.0kg: order counterbalanced). Load was manipulated to determine if increased load increases the likelihood of mirror movements. The data indicated that the performance of the young adults was superior compared to the children and older adults. Children and older adults showed a stronger tendency to develop mirror movements and had particular difficulty in performing the non-symmetrical mode. This type of influence may be attributed to neural crosstalk.

Effects of short-term experience on anticipatory eye movements during action observation.

Recent studies have shown that anticipatory eye movements occur during both action observation and action execution. These findings strongly support the direct matching hypothesis, which states that in observing others' actions, people take advantage of the same action knowledge that enables them to perform the same actions. Furthermore, a connection between action experience and the ability to anticipate action goals has been proposed. Concerning the role of experience, most studies concentrated on motor experts such as athletes and musicians, whereas only few studies investigated whether motor programs can be activated by short-term experience. Applying a pre-post design, we examined whether short-term experience affects anticipatory eye movements during observation. Participants (N = 150 university students) observed scenes showing an actor performing a block stacking task. Subsequently, participants performed either a block stacking task, puzzles, or a pursuit rotor task. Afterward, participants were again provided with the aforementioned block stacking task scenes. Results revealed that the block stacking task group directed their gaze significantly earlier toward the action goals of the block stacking task during posttest trials, compared with Puzzle and pursuit rotor task groups, which did not differ from each other. In accordance with the direct matching hypothesis, our study provides evidence that short-term experience with the block stacking task activates task-specific action knowledge.

Development of spatial preferences for counting and picture naming.

The direction of object enumeration reflects children's enculturation but previous work on the development of such spatial preferences has been inconsistent. Therefore, we documented directional preferences in finger counting, object counting, and picture naming for children (4 groups from 3 to 6 years, N = 104) and adults (N = 56). We found a right-side preference for finger counting in 3- to 6-year-olds and a left-side preference for counting objects and naming pictures by 6 years of age. Children were consistent in their special preferences when comparing object counting and picture naming, but not in other task pairings. Finally, spatial preferences were not related to cardinality comprehension. These results, together with other recent work, suggest a gradual development of spatial-numerical associations from early non-directional mappings into culturally constrained directional mappings.

Infant shy temperament predicts preschoolers Theory of Mind.

The aim of this longitudinal study was to investigate the relation between infant temperament at 18 months and early Theory of Mind (ToM) abilities at 3 years of age. Temperament was assessed with the Early Childhood Behavior Questionnaire (ECBQ) and ToM by assessing children's understanding of divergent desires and beliefs, and of knowledge access. Our results are in line with a social-emotional reactivity perspective postulating more sophisticated ToM abilities for children with less reactive more observant temperament. Children with shy temperament at 18 months and at 3 years were better in reasoning about others' mental states at age 3. Language, siblings and parental education had no effect on ToM. Findings indicate that temperament is related to ToM earlier in development than previously found, and that this relation is thus not unique to false-belief understanding.

Visual habituation tasks: the role of infant temperament.

This longitudinal study investigated the relation between infant temperament and dropout rate in two visual habituation tasks when infants (N=80) were 6 and 12 months of age. At both age points, infant temperament was assessed with the Infant Behavior Questionnaire Revised (IBQ-R) and infants were presented with the same two habituation tasks that were similar in set-up and procedure but different in content. Consistent with previous German work, a two-factor solution was found at each age point indicating Surgency/Extraversion and Negative Affectivity as underlying temperament dimensions. Dropout rates in the habituation tasks ranged from 21% to 68%. Overall, only few IBQ-R subscales, especially Duration of Orienting, had an impact on dropout rate. This suggests that the relatively high dropout rates reported in infant looking time studies are not systematically related to infant temperament. However, findings also suggest that temperament might have an impact on the likelihood of dropout when a habituation task is conducted at the end of a longer test session.

Narrowing perceptual sensitivity to the native language in infancy: exogenous influences on developmental timing.

The infancy literature situates the perceptual narrowing of speech sounds at around 10 months of age, but little is known about the mechanisms that influence individual differences in this developmental milestone. We hypothesized that such differences might in part be explained by characteristics of mother-child interaction. Infant sensitivity to syllables from their native tongue was compared longitudinally to sensitivity to non-native phonemes, at 6 months and again at 10 months. We replicated previous findings that at the group level, both 6- and 10- month-olds were able to discriminate contrasts in their native language, but only 6-month-olds succeeded in discriminating contrasts in the non-native language. However, when discrimination was assessed for separate groups on the basis of mother-child interaction-a 'high contingency group' and a 'moderate contingency' group-the vast majority of infants in both groups showed the expected developmental pattern by 10 months, but only infants in the 'high contingency' group showed early specialization for their native phonemes by failing to discriminate non-native contrasts at 6-months. The findings suggest that the quality of mother-child interaction is one of the exogenous factors influencing the timing of infant specialization for speech processing.

The end-state comfort effect in 3- to 8-year-old children in two object manipulation tasks.

The aim of the study was to compare 3- to 8-year-old children's propensity to anticipate a comfortable hand posture at the end of a grasping movement (end-state comfort effect) between two different object manipulation tasks, the bar-transport task, and the overturned-glass task. In the bar-transport task, participants were asked to insert a vertically positioned bar into a small opening of a box. In the overturned-glass task, participants were asked to put an overturned-glass right-side-up on a coaster. Half of the participants experienced action effects (lights) as a consequence of their movements (AE groups), while the other half of the participants did not (No-AE groups). While there was no difference between the AE and No-AE groups, end-state comfort performance differed across age as well as between tasks. Results revealed a significant increase in end-state comfort performance in the bar-transport task from 13% in the 3-year-olds to 94% in the 8-year-olds. Interestingly, the number of children grasping the bar according to end-state comfort doubled from 3 to 4 years and from 4 to 5 years of age. In the overturned-glass task an increase in end-state comfort performance from already 63% in the 3-year-olds to 100% in the 8-year-olds was significant as well. When comparing end-state comfort performance across tasks, results showed that 3- and 4-year-old children were better at manipulating the glass as compared to manipulating the bar, most probably, because children are more familiar with manipulating glasses. Together, these results suggest that preschool years are an important period for the development of motor planning in which the familiarity with the object involved in the task plays a significant role in children's ability to plan their movements according to end-state comfort.

Understanding goal-directed human actions and physical causality: the role of mother-infant interaction.

This study addresses the relation between early cognitive development and mother-infant interaction. Infants at the age of 6 and 10 months recruited from labs in three European countries--Germany, Great Britain, and France--were tested on two cognitive tasks: understanding of goal-directed human action and physical causality. Mother-infant interaction was assessed with the CARE-Index. In the goal-directed action task, the overall sample of the 6-month olds did not yet reliably discriminate between an object-change and a path-change trial while a subsample of infants of modestly controlling mothers did. All infants at 10 months of age showed discrimination. In the physical causality task, the overall sample of the 6-month olds did not yet reliably discriminate between an expected and an unexpected launching event. At 10 months of age, the overall sample showed discrimination, due to the major subsample of infants of highly sensitive mothers. Our findings support the view that exogenous factors influence cognitive development within a particular time window, in highly specific ways, depending on the age of the subjects, the cognitive domain, and the quality of mother-infant interaction.

The peer model advantage in infants' imitation of familiar gestures performed by differently aged models.

Infants' imitation of differently aged models has been predominately investigated with object-related actions and so far has lead to mixed evidence. Whereas some studies reported an increased likelihood of imitating peer models in contrast to adult models, other studies reported the opposite pattern of results. In the present study, 14-month-old infants were presented with four familiar gestures (e.g., clapping) that were demonstrated by differently aged televised models (peer, older child, adult). Results revealed that infants were more likely to imitate the peer model than the older child or the adult. This result is discussed with respect to a social function of imitation and the mechanism of imitating familiar behavior.

Infants' attentional preference for object-related actions of older children compared to object-related actions of peers and adults.

Previous research reports mixed results concerning infants' differential interest for a specific age group. Most of these findings are based on studies using static photographs and drawings as stimuli. Moreover, only behavioral data were used to investigate infants' attentional preferences. In the present study, we showed video sequences of differently aged models (peers, 3.5-year-olds, and adults) manipulating an object, and measured heart rate as an objective psychophysiological measurement of infants' attention, in addition to looking time and banging rate. The results showed that 12-month-olds preferred watching older children's object-related actions compared to those of peers and adults, but 6- and 9-month-olds did not. In subsequent control experiments, alternative explanations that this preference relied merely on the visual appearance or a higher activity level of older children were excluded. We explain this observed developmental shift by the increasing importance of social learning and object use at this age. Thus, 12-month-olds prefer watching more knowledgeable individuals who provide an action repertoire that infants of this age are about to develop.

Perception and production of object-related grasping in 6-month-olds.

In this study, 6-month-olds' perception of an object-related human grasping action was compared with their level of grasping performance using a within-participants design. In the action perception task, infants were presented with the video of an actor's grasping movement toward an occluded target object. Subsequently, an expected and an unexpected final state of this grasping movement were presented simultaneously, and infants' looking times were measured. In the action production task, infants were presented with three graspable objects. Infants' grasping behavior was coded to be either palmar or thumb-opposite grasping. Results indicate that infants who were already able to perform a thumb-opposite grasp differentiated between the two final states in the action perception task by looking longer toward the unexpected final state. In contrast, infants who showed only palmar grasps looked equally long toward both final states. This finding supports the assumption that action perception and action control are already closely related in infants as young as 6 months.

The link between preschoolers' executive function and theory of mind and the role of epistemic states.

The aim of this study was to assess the specific relation between 3- to 6-year-olds' performance on a task measuring executive function (EF), the Dimensional Change Card Sort task (DCCS), and different developmental attainments in their theory of mind (ToM) by employing a battery of scaled ToM tasks that were comparable in task format and task demands. In addition, individual differences on the temperamental dimensions emotionality, activity, sociability, and shyness were assessed by parental rating. The main findings show that children's (N=195) performance on the DCCS related to their overall performance on the ToM scale but that this relation was specific to those ToM tasks that tap children's understanding of epistemic states such as knowledge access, diverse beliefs, and false beliefs regarding content and location. The relation between children's EF and overall ToM performance remained significant after controlling for age, sentence comprehension, child temperament, and parental education. Individual differences in child activity showed consistent negative relation to EF and ToM abilities. The findings point to a differential involvement of the various EF components in reasoning about different mental concepts.