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1.
Developmental studies have demonstrated that cognitive processes such as attention, suppression of interference and memory develop throughout childhood and adolescence. However, little is currently known about the development of top-down control mechanisms and their influence on cognitive performance. In the present study, we used functional magnetic resonance imaging to investigate modulation of activity in the ventral visual cortex in healthy 7–11-year-old children and young adults. The participants performed tasks that required attention to either face (Fs task) or scene (Sf task) images while trying to ignore distracting scene or face images, respectively. A face-selective area in the fusiform gyrus (fusiform face area, FFA) and an area responding preferentially to scene images in the parahippocampal gyrus (parahippocampal place area, PPA) were defined using functional localizers. Children responded slower and less accurately in the tasks than adults. In children, the right FFA was less selective to face images and regulation of activity between the Fs and Sf tasks was weaker compared to adults. In the PPA, selectivity to scenes and regulation of activity, there according to the task demands were comparable between children and adults. During the tasks, children activated prefrontal cortical areas including the middle (MFG) and superior (SFG) frontal gyrus more than adults. Functional connectivity between the right FFA and left MFG was stronger in adults than children in the Fs task. Children, on the other hand, had stronger functional connectivity than adults in the Sf task between the right FFA and right PPA and between right MFG and medial SFG. There were no group differences in the functional connectivity between the PPA and the prefrontal cortex (PFC). Together the results suggest that, in 7–11-year-old children, the FFA is still immature, whereas the selectivity to scenes and regulation of activity in the PPA is comparable to adults. The results also indicated functional immaturity of the PFC in children compared to adults and weaker connectivity between the PFC and the rFFA, explaining the weaker regulation of activity in the rFFA between the Fs and Sf tasks.  相似文献   

2.
Inhibitory control has been suggested as a key predictive measure of problem-solving skills in human and nonhuman animals. However, there has yet to be a direct comparison of the inhibitory skills of the nonhuman apes and their development in human children. We compared the inhibitory skills of all great ape species, including 3–5-year-old children in a detour-reaching task, which required subjects to avoid reaching directly for food and instead use an indirect reaching method to successfully obtain the food. We tested 22 chimpanzees, 18 bonobos, 18 orangutans, 6 gorillas and 42 children. Our sample included chimpanzees, bonobos and orangutans housed in zoos (N = 27) and others housed in sanctuaries in their native habitats (N = 37). Overall, orangutans were the most skilful apes, including human children. As expected older children outperformed younger children. Sanctuary chimpanzees and bonobos outperformed their zoo counterparts whereas there was no difference between the two orangutan samples. Most zoo chimpanzees and bonobos failed to solve the original task, but improved their performance with additional training, although the training method determined to a considerable extent the level of success that the apes achieved in a transfer phase. In general, the performance of the older children was far from perfect and comparable to some of the nonhuman apes tested.  相似文献   

3.
Gender differences regarding aggressive behaviour were investigated in 167 school children, 11 to 12 years of age, through peer-rating techniques supported by self-ratings and interviews. The social structure of the peer groups also was studied. The principal finding was that girls made greater use of indirect means of aggression, whereas the boys tended to employ direct means. Gender differences in verbal aggression were less pronounced. The social structure of peer groups was found to be tighter among girls, making it easier for them to exploit relationships and harm their victims by indirect manipulative aggression. Because indirect aggression has rarely been satisfactorily studied with tests of aggression, this finding may help to explain 1) the generally lower correlation found between peer-rated and self-rated aggression in girls than among boys (indirect means not being so readily recognized by the subject as a kind of aggression) and 2) the low stability of aggressiveness in girls often found in developmental studies.  相似文献   

4.
Samples of spontaneous speech of 110 nursery school children, aged 2 yr, 1 mo to 6 yr, were written down. Two of the children were regarded as stutterers by the parents and the nursery school personnel. Instances of word and phrase repetitions and word fragmentations were marked. Fragmentation of a word before the whole word is pronounced was used as criterion of stuttering. The nonstutterers had an average frequency of word repetitions of 6.3%, while word fragmentations were virtually nonoccurrent. The frequency of word repetitions decreased with increasing age. Relating word repetitions to grammatical complexity of speech, it was found that the decrease was particularly large at a certain point of the grammatical development. The two stutterers had, in addition to normal frequencies of word repetitions, marked occurences of word fragmentations (2.8 and 4.1%).  相似文献   

5.
Motor unit (MU) firing rates of the vastus lateralis in children and adults were examined. Seven healthy adult males (mean ± SD, age = 21 ± 2.6 yrs) and six healthy male children (mean ± SD age = 8.8 ± 1.7) volunteered. Surface electromyography (EMG) signals were recorded from 20% and 60% maximal voluntary contractions (MVC). Surface EMG signals were decomposed into firing events of individual MUs and slopes and y-intercepts were calculated for the mean firing rate (MFR, pps) at steady torque vs. recruitment thresholds (RT) relationships for each subject. Muscle cross-sectional area (mCSA) was measured, via ultrasonography, with specific torque calculated (MVC/mCSA). Adults possessed greater mCSA (p = .002; children = 11.5 ± 2.1 cm2; adults = 31.80 ± 12.15 cm2) and greater specific torque (p = .018; children = 4.63 ± 1.4 Nm/cm2; adults = 7.1 ± 1.8 Nm/cm2) compared to children. The y-intercepts were significantly (p < .001) greater during the 60% (28.91 ± 4.56 pps) than the 20% MVC (23.5 ± 4.9 pps) collapsed across groups while the children had significantly (p = .036) lower y-intercepts (23.9 ± 5.4 pps) than the adults (28.2 ± 4.8 pps) when collapsed across intensities. Slopes of the MFR vs RT relationships were greater for the 60% (−0.342 ± 0.127 pps/%MVC) contraction than the 20% (−0.50 ± 0.159 pps/%MVC) MVC when collapsed across groups. Adults had greater firing rates regardless of recruitment threshold than children. This may be due to lower recruitment potential and overall excitation to the motoneuron pool of children as indicated with differences in specific torque and/or differences in antagonist co-activation.  相似文献   

6.
Individual studies have shown that visuomotor coordination and aspects of binocular vision, such as stereoacuity and dynamic vergence control, continue to improve in normally developing children between birth and early teenage years. However, no study has systematically addressed the relationship between the development of binocular vision and fine manipulation skills. Thus, the aim of this cross-sectional study was to characterize performance of complex manipulation tasks during binocular and monocular viewing. Fifty-two children, between 5 and 13 years old, performed 2 manipulation tasks: peg-board and bead-threading under randomized viewing conditions. Results showed that binocular viewing was associated with a significantly greater improvement in performance on the bead-threading task in comparison to the peg-board task and the youngest children showed the greatest decrement in task performance under the monocular viewing condition when performing the bead-threading task. Thus, the role of binocular vision in performance of fine manipulation skills is both task- and age-dependent. These findings have implications for assessment of visuomotor skills in children with abnormal binocular vision, which occurs in 2–3% of otherwise typically developing children.  相似文献   

7.
We studied children’s inductive inferences within the domain of food categories. There has so far been little research on inductive reasoning about food among children, despite the theoretical and practical importance of knowing what knowledge children bring to the table and how they use it. We tested the hypotheses that children’s food category-based induction performances and their food rejection are negatively correlated, and that these performances are influenced by the colour typicality of the food items. We recruited 126 children aged 2–6 years, and administered a category-based induction task. Participants were successively shown 8 sets of three pictures containing one target picture (a vegetable) and two test pictures (a vegetable dissimilar in colour to the target picture and a fruit similar in colour to the target picture). For each set, participants were told a novel property about the target picture and asked to generalise this property to one of the two test pictures. Additionally, the parents of each child filled out a questionnaire about his or her food rejection tendencies. Results on accuracy (i.e. if participants generalised the properties according to category membership, not perceptual similarity) provided the first empirical evidence in favour of a negative relationship between children’s food rejection and food category-based induction.  相似文献   

8.
In two experiments, we explored whether 2.5-year-olds can use delayed video information to locate objects placed somewhere covertly after first being given pre-test video experience. Our findings revealed that children had little difficulty passing a surprise-object task, that is, a teddy bear hidden in a box that was placed behind the child and hence only visible in the delayed video. In contrast, the children did not pass the surprise-mark task or delayed self-recognition (DSR) task, even with pre-test video training. Similarly, delayed self-image experience and pre-test video training did not facilitate DSR performance in 2.5-year-olds. Children were also just as likely to fail a live video self-recognition task, suggesting that object-retrieval tasks pertaining to self using video information are difficult for children at this age. The findings are discussed in light of possible changes in representational capabilities; the implications for the development of a temporally extended self are also noted.  相似文献   

9.
The current investigation tested the efficacy of the Extended Class Exchange Program (ECEP) in reducing prejudicial attitudes. Three hundred and twenty-two 3rd and 4th grade students from both Israeli–Jewish and Israeli–Palestinian schools in the ethnically mixed city of Jaffa were randomly assigned to either intervention or control classes. Members of the intervention classes engaged in ECEP's activities, whereas members of the control classes engaged in a social–emotional learning program. The program's outcomes were measured a week before, immediately after, and 15 months following termination. Results showed that the ECEP decreased stereotyping and discriminatory tendencies toward the other group and increased positive feelings and readiness for social contact with the other group upon program termination. Additionally, the effects of the ECEP were generalized to an ethnic group (i.e., Ethiopians) with whom the ECEP's participants did not have any contact. Finally, the ECEP retained its significant effect 15 months after the program's termination, despite the serious clashes between Israel and the Palestinians that occurred during that time. This empirical support for the ECEP'S utility in reducing prejudice makes it potentially applicable to other areas in the world, especially those that are characterized by ethnic tension and violent conflicts.  相似文献   

10.
It has been suggested that children with dyslexia have difficulties in visual–phonological working memory (WM) binding, supporting the hypothesis that this ability is crucial in the formation of associations between written forms and phonological codes required by reading. However, research on this topic is currently scarce and has not clarified to what extent binding may be supported by spatial and temporal information. The present study examined visual–phonological WM binding performance in a group of children with dyslexia compared to a control group of typically developing children matched for age, gender, and grade. Children had to memorize ephemeral associations between meaningless shapes and nonwords, with stimuli presented in either fixed or variable spatial locations, and in either fixed or variable temporal order across trials; performance was assessed using a recognition task. Results showed that children with dyslexia have a deficit in visual–phonological WM binding in every presentation condition and that, unlike control children, they are not able to use fixed spatial locations as an aid to bind information. Crucially, however, children with dyslexia still benefit from the presentation of stimuli in a fixed temporal order. These findings support the hypothesis that a WM binding deficit is crucial in children with dyslexia, and have potential implications for treatment strategies.  相似文献   

11.
The aim of the present investigation was to study the visual communication between humans and dogs in relatively complex situations. In the present research, we have modelled more lifelike situations in contrast to previous studies which often relied on using only two potential hiding locations and direct association between the communicative signal and the signalled object. In Study 1, we have provided the dogs with four potential hiding locations, two on each side of the experimenter to see whether dogs are able to choose the correct location based on the pointing gesture. In Study 2, dogs had to rely on a sequence of pointing gestures displayed by two different experimenters. We have investigated whether dogs are able to recognise an ‘indirect signal’, that is, a pointing toward a pointer. In Study 3, we have examined whether dogs can understand indirect information about a hidden object and direct the owner to the particular location. Study 1 has revealed that dogs are unlikely to rely on extrapolating precise linear vectors along the pointing arm when relying on human pointing gestures. Instead, they rely on a simple rule of following the side of the human gesturing. If there were more targets on the same side of the human, they showed a preference for the targets closer to the human. Study 2 has shown that dogs are able to rely on indirect pointing gestures but the individual performances suggest that this skill may be restricted to a certain level of complexity. In Study 3, we have found that dogs are able to localise the hidden object by utilising indirect human signals, and they are able to convey this information to their owner.  相似文献   

12.
13.
Counting is often considered to be the coordination of two actions: saying the number-words and pointing to each object. We report three experiments to test the hypothesis that this coordination requires the use of the central executive (A. D. Baddeley, 1990), and that the cost of coordination decreases with age. Participants were 5- and 9-year-old children and adults. At all ages tested, the manipulation of the difficulty of each component affected counting performance but did not make coordination more difficult. These results suggest that, at least from the age 5, counting is a procedure in which the control of coordination is not attention demanding.  相似文献   

14.
Performances on the Five-Point Test of 161 Italian children aged 6 to 11 years were investigated, along with phonemic fluency, visual-motor integration, visual perception, motor coordination, visuospatial memory, and fluid intelligence. Five-Point Test accuracy was significantly related to phonemic fluency and visual-motor integration, while phonemic fluency was linked to motor coordination. The two fluency measures increased linearly with age, but the developmental progression of Five-Point Test accuracy was less influenced by age. Different age effects were also found on the relationship between fluid intelligence and the two fluency measures. The inspection of qualitative aspects of Five-Point Test performance (errors and strategies) suggested that strategy usage enhanced both productivity and accuracy in children; age-related changes were observed in the relationship between the number of errors and the total number of designs produced.  相似文献   

15.
A significant clinical feature of disorders of antisocial behaviour involves difficulties in social functioning. It has been suggested that deficits in “theory of mind” (ToM) reasoning—the ability to decode others’ emotions and thoughts—may underlie social difficulties in these populations. Success in demonstrating ToM impairment associated with antisocial behaviour and psychopathy in adults and children have been limited. In the current study, parent-reported conduct problems were concurrently measured with performance on an advanced test of ToM developed for children, the Child Eyes Test (Journal of Developmental and Learning Disorders, 5, 47–78). Preadolescent and young adolescent children (n=79) drawn from a community sample were required to identify emotions from photographic stimuli depicting the eye region of the face only. Findings suggested a generalised impairment in ToM in children with conduct problems, as indicated by a significant relationship between poor Eyes Test performance and conduct problems, even when IQ, sex and age were controlled for. The findings are discussed in the context of the amygdala theory of psychopathy, and the neural systems suggested to mediate performance on the Eyes Test.  相似文献   

16.
The day–night task is a widely used measurement of interference control in young children between ages 3 and 7. This integrative review examines the development of interference control by describing day–night task performance. We outline essential task demands and task variants, describe theoretical explanations of performance, highlight key methodological concerns relevant to future research, and speculate upon the neural events that likely correspond to distinct components of task performance. The review concludes with suggestions for future investigation.  相似文献   

17.
The present study investigated the role of the causal status of features and feature type in biological categorizations by young children. Study 1 showed that 5-year-olds are more strongly influenced by causal features than effect features; 4-year-olds exhibit no such tendency. There therefore appears to be a conceptual change between the ages of 4 and 5 in the evaluation of the causal relations between features that characterize biological categories. The aim of Study 2 was to identify the nature of the abstract beliefs that underlie children's categorial choices. Results show that 5-year-olds base category choices on causal features only when the status of the cause is associated with an internal feature and not if the feature is merely a surface feature. Children thus use biological knowledge to perform the task.  相似文献   

18.
The use of parenting measures that are developed for use with Western families without testing their validity among families from non-Western cultural backgrounds may not be appropriate. Similar parenting behaviors may affect child outcomes in different ways across different cultures. This study examined the cross-cultural validity of an observational Maternal Responsiveness coding system and of self-reports of lax/inconsistent parenting in Euro–Canadian (n = 23) and East Asian immigrant mothers (n = 23) of 4- to 7-year-old sons. In Euro–Canadian mothers, observed parenting responsiveness was associated with less lax/inconsistent parenting and fewer child behavior problems. In East Asian immigrant mothers, however, observations of greater responsiveness were not related to reports of lax/inconsistent parenting, and were associated with greater child behavior problems. Implications for the use of these parenting measures across culture groups are discussed.  相似文献   

19.
When reading narratives, adults monitor shifts in time, space, characters, goals, and causation. Shifts in any of these dimensions affect both moment-by-moment reading and memory organization. The extant developmental literature suggests that middle school children have relatively sophisticated understandings of each of these dimensions but does not indicate whether they spontaneously monitor these dimensions during reading experiences. In four experiments, we examined the processing of event shifts by adults and children, using both an explicit verb-clustering task and a reading time task. The results indicate that middle school children’s and adults’ post-reading memory is organized using these dimensions but that children do not monitor dimensions during moment-by-moment reading in the same manner as adults. These differences were not a function of differentially difficult texts for children and adults, or between-group differences. The findings have implications for models of adult and child text processing and for understanding children’s developing narrative comprehension.  相似文献   

20.
Theoretical advances in the study of the development of aggressive behaviors indicate that parenting behaviors and child aggression mutually influence one another. This study contributes to the body of empirical research in this area by examining the development of child aggression, maternal responsiveness, and maternal harsh discipline, using 5-year longitudinal data from a nationally representative sample of Turkish children (n = 1009; 469 girls and 582 boys). Results indicated that: (i) maternal responsiveness and harsh discipline at age 3 were associated with the subsequent linear trajectory of aggression; (ii) reciprocally, aggressive behaviors at age 3 were associated with the subsequent linear trajectories of these two types of parenting behaviors; (iii) deviations from the linear trajectories of the child and mother behaviors tended to be short lived; and, (iv) the deviations of child behaviors from the linear trajectories were associated with the subsequent changes in mother behaviors after age 5. These findings are discussed in the cultural context of this study.  相似文献   

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