PMC:2813722 / 1792-8407 JSONTXT

{"project":"MyTest","denotations":[{"id":"20161697-16371147-33634420","span":{"begin":561,"end":565},"obj":"16371147"},{"id":"20161697-18269510-33634421","span":{"begin":581,"end":585},"obj":"18269510"},{"id":"20161697-9681259-33634422","span":{"begin":979,"end":983},"obj":"9681259"},{"id":"20161697-9491811-33634423","span":{"begin":1296,"end":1300},"obj":"9491811"},{"id":"20161697-11431226-33634424","span":{"begin":1318,"end":1322},"obj":"11431226"},{"id":"20161697-8682515-33634425","span":{"begin":1398,"end":1402},"obj":"8682515"},{"id":"20161697-19927862-33634426","span":{"begin":1728,"end":1732},"obj":"19927862"},{"id":"20161697-14699419-33634427","span":{"begin":2434,"end":2438},"obj":"14699419"},{"id":"20161697-16192352-33634428","span":{"begin":2454,"end":2458},"obj":"16192352"},{"id":"20161697-12729494-33634429","span":{"begin":2716,"end":2720},"obj":"12729494"},{"id":"20161697-11804576-33634430","span":{"begin":2961,"end":2965},"obj":"11804576"},{"id":"20161697-12729494-33634432","span":{"begin":3310,"end":3314},"obj":"12729494"},{"id":"20161697-16310813-33634433","span":{"begin":3329,"end":3333},"obj":"16310813"},{"id":"20161697-18061633-33634434","span":{"begin":3348,"end":3352},"obj":"18061633"},{"id":"20161697-8507742-33634435","span":{"begin":3470,"end":3474},"obj":"8507742"},{"id":"20161697-10344188-33634436","span":{"begin":3496,"end":3500},"obj":"10344188"},{"id":"20161697-16513007-33634437","span":{"begin":3560,"end":3564},"obj":"16513007"},{"id":"20161697-12822595-33634438","span":{"begin":3634,"end":3639},"obj":"12822595"},{"id":"20161697-12729494-33634439","span":{"begin":3669,"end":3674},"obj":"12729494"},{"id":"20161697-12822595-33634440","span":{"begin":3889,"end":3893},"obj":"12822595"},{"id":"20161697-11738192-33634441","span":{"begin":3941,"end":3945},"obj":"11738192"},{"id":"20161697-16310813-33634442","span":{"begin":4021,"end":4025},"obj":"16310813"},{"id":"20161697-16310813-33634443","span":{"begin":4163,"end":4167},"obj":"16310813"},{"id":"20161697-16513007-33634444","span":{"begin":4207,"end":4211},"obj":"16513007"},{"id":"20161697-18606038-33634445","span":{"begin":4213,"end":4217},"obj":"18606038"},{"id":"20161697-11804576-33634446","span":{"begin":4329,"end":4333},"obj":"11804576"},{"id":"20161697-18061633-33634447","span":{"begin":4619,"end":4623},"obj":"18061633"},{"id":"20161697-17637487-33634448","span":{"begin":4655,"end":4659},"obj":"17637487"},{"id":"20161697-11738192-33634449","span":{"begin":4688,"end":4692},"obj":"11738192"},{"id":"20161697-12822595-33634450","span":{"begin":4784,"end":4788},"obj":"12822595"},{"id":"20161697-17381795-33634451","span":{"begin":5321,"end":5325},"obj":"17381795"},{"id":"20161697-16310813-33634452","span":{"begin":6006,"end":6010},"obj":"16310813"},{"id":"20161697-9735617-33634453","span":{"begin":6159,"end":6163},"obj":"9735617"},{"id":"20161697-11955467-33634454","span":{"begin":6165,"end":6169},"obj":"11955467"},{"id":"20161697-10924667-33634455","span":{"begin":6187,"end":6191},"obj":"10924667"},{"id":"20161697-15871602-33634456","span":{"begin":6208,"end":6212},"obj":"15871602"},{"id":"20161697-10924667-33634457","span":{"begin":6244,"end":6248},"obj":"10924667"}],"namespaces":[{"prefix":"_base","uri":"https://www.uniprot.org/uniprot/testbase"},{"prefix":"UniProtKB","uri":"https://www.uniprot.org/uniprot/"},{"prefix":"uniprot","uri":"https://www.uniprot.org/uniprotkb/"}],"text":"Introduction\nExecutive function (EF) – the conscious control of thought and action – develops markedly during the preschool years, in parallel with maturation of prefrontal cortex (see Zelazo et al., 2008 for review). Most research on EF in children has been conducted with Western samples, but an emerging corpus of cross-cultural comparisons suggests that Asian children may perform better than Western children on measures of EF despite comparable, or worse, performance on other measures of cognitive function, such as theory of mind (e.g., Sabbagh et al., 2006; Oh and Lewis, 2008).\nCorrelations with culture are always difficult to interpret because of the numerous, often unmeasured, differences between groups, but the finding that Asian children sometimes display better EF than age-matched Western children is consistent with reports that Chinese parents expect their children to master impulse control at a relatively young age (e.g., Ho, 1994; Wu, 1996; Chen et al., 1998), and that impulse control in daycare settings is more highly valued in China than it is in North America (Tobin et al., 1989). It is also consistent with the finding that the 7-repeat allele of the dopamine D4 receptor gene (DRD4), which has been linked to behavior problems involving EF (e.g., Swanson et al., 1998; Faraone et al., 2001), is extremely rare in individuals from East and South Asia (Chang et al., 1996).\nThe observation that children from different cultures may show differences in EF abilities raises the question of whether children's brain function varies in systematic ways across cultures, and if so, to what extent. There is currently considerable interest in the specific neural correlates of EF (e.g., Bunge and Crone, 2009), but as with behavioral research on this topic, nearly all of this work has been conducted with Western samples, and indeed, to date, there have been no published cross-cultural comparisons of these neural correlates. It seems plausible, however, that genetic and/or environmental influences associated with culture may be reflected not only in children's behavior, but also in their neural function. Recent research on neural plasticity, for example, supports the suggestion that neural development is experience dependent (e.g., Neville, 1993; Huttenlocher, 2002), and indeed, interventions designed to promote EF have been found to produce changes in neural function related to EF (Olesen et al., 2004; Rueda et al., 2005).\nOne task that has been used to examine the neural correlates of EF in young children is the go/no-go task, in which children must respond on the majority of trials (go stimuli) but inhibit responding on certain trials (no-go stimuli) (e.g., Davis et al., 2003). Event-related fMRI research comparing adults and school-age children on go/no-go-type tasks indicates that several regions of prefrontal cortex, including ventrolateral prefrontal cortex and anterior cingulate cortex (e.g., Bunge et al., 2002; Durston et al., 2002a,b), play an important role in successful performance on this task. Electroencephalographic (EEG) recordings during performance on the task yield a well-studied ERP component, the N2, which in children is usually observed at medial-frontal sites between 250 and 500 ms following stimulus presentation (e.g., Davis et al., 2003; Lamm et al., 2006; Todd et al., 2008). N2 amplitude has been found to be larger on successful no-go trials than on go trials in both adults (e.g., Eimer, 1993; Falkenstein et al., 1999) and children (e.g., Johnstone et al., 2005; Lewis et al., 2006) although this is not always the case (e.g., see Nieuwenhuis et al., 2003 for adults, and Davis et al., 2003 for children). Consistent with fMRI results, source analyses of the N2 in adults have identified cortical generators in both dorsomedial prefrontal cortex (e.g., dorsal anterior cingulate cortex Nieuwenhuis et al., 2003) and ventral prefrontal cortex (Bokura et al., 2001), and similar results have been obtained with children (e.g., Lamm et al., 2006). In children, the location and activation strength of these sources appears to be related to individual differences in EF (Lamm et al., 2006) and emotion regulation (Lewis et al., 2006, 2008).\nAn important consideration in neurocognitive research with children is hemispheric laterality. Bunge et al. (2002) found that interference suppression was related to prefrontal activation in the opposite hemisphere in adults as in 8- to 12-year-old children. Moreover, ERP studies of the N2 component on No-go trials have revealed a right-lateralized topography in both young children (Todd et al., 2008; see also Perez-Edgar and Fox, 2007) and adults (Bokura et al., 2001), although this pattern has not usually been reported in adults (e.g., Nieuwenhuis et al., 2003).\nIn the present study, we used high-density (128-channel) EEG to compare the neural correlates of EF in young European-Canadian and Chinese-Canadian children as they performed a go/no-go task. We examined 5-year-old children because Western children at this age typically display considerable advances in EF and related skills (Zelazo et al., 2008 for review), and because the acquisition of these skills at this age appears to be critical for the transition to school, where demands on EF may be increased (e.g., Blair and Razza, 2007). We focused on the N2 waveform and its estimated underlying sources, and expected to find evidence of cultural differences in neurocognitive function. As children from a Chinese background have been found to perform better on measures of EF than North American children, and may be more conscientious, we expected to find larger N2 (i.e., more negative) amplitudes for the Chinese-Canadian children than the same-age European-Canadian children. Although studies with school-age children generally report that N2 amplitude decreases with age across the school-age years and into adolescence, and that these decreases co-occur with continued improvements in EF (e.g., Lamm et al., 2006), our prediction is based on studies showing larger N2 amplitudes to be associated with better EF within a single age group (e.g., Overtoom et al., 1998, 2002; Pliszka et al., 2000; Liotti et al., 2005). For example, Pliszka et al. (2000) found larger N2 amplitudes for controls, as compared to children with ADHD, over right inferior frontal cortex on a go/no-go-type task. In addition, in light of evidence for the recruitment of right prefrontal cortex on the go/no-go task and other EF tasks, we expected to find a right-lateralized N2 on no-go trials, as well as right-lateralized source activation."}

{"project":"2_test","denotations":[{"id":"20161697-16371147-33634420","span":{"begin":561,"end":565},"obj":"16371147"},{"id":"20161697-18269510-33634421","span":{"begin":581,"end":585},"obj":"18269510"},{"id":"20161697-9681259-33634422","span":{"begin":979,"end":983},"obj":"9681259"},{"id":"20161697-9491811-33634423","span":{"begin":1296,"end":1300},"obj":"9491811"},{"id":"20161697-11431226-33634424","span":{"begin":1318,"end":1322},"obj":"11431226"},{"id":"20161697-8682515-33634425","span":{"begin":1398,"end":1402},"obj":"8682515"},{"id":"20161697-19927862-33634426","span":{"begin":1728,"end":1732},"obj":"19927862"},{"id":"20161697-14699419-33634427","span":{"begin":2434,"end":2438},"obj":"14699419"},{"id":"20161697-16192352-33634428","span":{"begin":2454,"end":2458},"obj":"16192352"},{"id":"20161697-12729494-33634429","span":{"begin":2716,"end":2720},"obj":"12729494"},{"id":"20161697-11804576-33634430","span":{"begin":2961,"end":2965},"obj":"11804576"},{"id":"20161697-12729494-33634432","span":{"begin":3310,"end":3314},"obj":"12729494"},{"id":"20161697-16310813-33634433","span":{"begin":3329,"end":3333},"obj":"16310813"},{"id":"20161697-18061633-33634434","span":{"begin":3348,"end":3352},"obj":"18061633"},{"id":"20161697-8507742-33634435","span":{"begin":3470,"end":3474},"obj":"8507742"},{"id":"20161697-10344188-33634436","span":{"begin":3496,"end":3500},"obj":"10344188"},{"id":"20161697-16513007-33634437","span":{"begin":3560,"end":3564},"obj":"16513007"},{"id":"20161697-12822595-33634438","span":{"begin":3634,"end":3638},"obj":"12822595"},{"id":"20161697-12729494-33634439","span":{"begin":3669,"end":3673},"obj":"12729494"},{"id":"20161697-12822595-33634440","span":{"begin":3889,"end":3893},"obj":"12822595"},{"id":"20161697-11738192-33634441","span":{"begin":3941,"end":3945},"obj":"11738192"},{"id":"20161697-16310813-33634442","span":{"begin":4021,"end":4025},"obj":"16310813"},{"id":"20161697-16310813-33634443","span":{"begin":4163,"end":4167},"obj":"16310813"},{"id":"20161697-16513007-33634444","span":{"begin":4207,"end":4211},"obj":"16513007"},{"id":"20161697-18606038-33634445","span":{"begin":4213,"end":4217},"obj":"18606038"},{"id":"20161697-11804576-33634446","span":{"begin":4329,"end":4333},"obj":"11804576"},{"id":"20161697-18061633-33634447","span":{"begin":4619,"end":4623},"obj":"18061633"},{"id":"20161697-17637487-33634448","span":{"begin":4655,"end":4659},"obj":"17637487"},{"id":"20161697-11738192-33634449","span":{"begin":4688,"end":4692},"obj":"11738192"},{"id":"20161697-12822595-33634450","span":{"begin":4784,"end":4788},"obj":"12822595"},{"id":"20161697-17381795-33634451","span":{"begin":5321,"end":5325},"obj":"17381795"},{"id":"20161697-16310813-33634452","span":{"begin":6006,"end":6010},"obj":"16310813"},{"id":"20161697-9735617-33634453","span":{"begin":6159,"end":6163},"obj":"9735617"},{"id":"20161697-11955467-33634454","span":{"begin":6165,"end":6169},"obj":"11955467"},{"id":"20161697-10924667-33634455","span":{"begin":6187,"end":6191},"obj":"10924667"},{"id":"20161697-15871602-33634456","span":{"begin":6208,"end":6212},"obj":"15871602"},{"id":"20161697-10924667-33634457","span":{"begin":6244,"end":6248},"obj":"10924667"}],"text":"Introduction\nExecutive function (EF) – the conscious control of thought and action – develops markedly during the preschool years, in parallel with maturation of prefrontal cortex (see Zelazo et al., 2008 for review). Most research on EF in children has been conducted with Western samples, but an emerging corpus of cross-cultural comparisons suggests that Asian children may perform better than Western children on measures of EF despite comparable, or worse, performance on other measures of cognitive function, such as theory of mind (e.g., Sabbagh et al., 2006; Oh and Lewis, 2008).\nCorrelations with culture are always difficult to interpret because of the numerous, often unmeasured, differences between groups, but the finding that Asian children sometimes display better EF than age-matched Western children is consistent with reports that Chinese parents expect their children to master impulse control at a relatively young age (e.g., Ho, 1994; Wu, 1996; Chen et al., 1998), and that impulse control in daycare settings is more highly valued in China than it is in North America (Tobin et al., 1989). It is also consistent with the finding that the 7-repeat allele of the dopamine D4 receptor gene (DRD4), which has been linked to behavior problems involving EF (e.g., Swanson et al., 1998; Faraone et al., 2001), is extremely rare in individuals from East and South Asia (Chang et al., 1996).\nThe observation that children from different cultures may show differences in EF abilities raises the question of whether children's brain function varies in systematic ways across cultures, and if so, to what extent. There is currently considerable interest in the specific neural correlates of EF (e.g., Bunge and Crone, 2009), but as with behavioral research on this topic, nearly all of this work has been conducted with Western samples, and indeed, to date, there have been no published cross-cultural comparisons of these neural correlates. It seems plausible, however, that genetic and/or environmental influences associated with culture may be reflected not only in children's behavior, but also in their neural function. Recent research on neural plasticity, for example, supports the suggestion that neural development is experience dependent (e.g., Neville, 1993; Huttenlocher, 2002), and indeed, interventions designed to promote EF have been found to produce changes in neural function related to EF (Olesen et al., 2004; Rueda et al., 2005).\nOne task that has been used to examine the neural correlates of EF in young children is the go/no-go task, in which children must respond on the majority of trials (go stimuli) but inhibit responding on certain trials (no-go stimuli) (e.g., Davis et al., 2003). Event-related fMRI research comparing adults and school-age children on go/no-go-type tasks indicates that several regions of prefrontal cortex, including ventrolateral prefrontal cortex and anterior cingulate cortex (e.g., Bunge et al., 2002; Durston et al., 2002a,b), play an important role in successful performance on this task. Electroencephalographic (EEG) recordings during performance on the task yield a well-studied ERP component, the N2, which in children is usually observed at medial-frontal sites between 250 and 500 ms following stimulus presentation (e.g., Davis et al., 2003; Lamm et al., 2006; Todd et al., 2008). N2 amplitude has been found to be larger on successful no-go trials than on go trials in both adults (e.g., Eimer, 1993; Falkenstein et al., 1999) and children (e.g., Johnstone et al., 2005; Lewis et al., 2006) although this is not always the case (e.g., see Nieuwenhuis et al., 2003 for adults, and Davis et al., 2003 for children). Consistent with fMRI results, source analyses of the N2 in adults have identified cortical generators in both dorsomedial prefrontal cortex (e.g., dorsal anterior cingulate cortex Nieuwenhuis et al., 2003) and ventral prefrontal cortex (Bokura et al., 2001), and similar results have been obtained with children (e.g., Lamm et al., 2006). In children, the location and activation strength of these sources appears to be related to individual differences in EF (Lamm et al., 2006) and emotion regulation (Lewis et al., 2006, 2008).\nAn important consideration in neurocognitive research with children is hemispheric laterality. Bunge et al. (2002) found that interference suppression was related to prefrontal activation in the opposite hemisphere in adults as in 8- to 12-year-old children. Moreover, ERP studies of the N2 component on No-go trials have revealed a right-lateralized topography in both young children (Todd et al., 2008; see also Perez-Edgar and Fox, 2007) and adults (Bokura et al., 2001), although this pattern has not usually been reported in adults (e.g., Nieuwenhuis et al., 2003).\nIn the present study, we used high-density (128-channel) EEG to compare the neural correlates of EF in young European-Canadian and Chinese-Canadian children as they performed a go/no-go task. We examined 5-year-old children because Western children at this age typically display considerable advances in EF and related skills (Zelazo et al., 2008 for review), and because the acquisition of these skills at this age appears to be critical for the transition to school, where demands on EF may be increased (e.g., Blair and Razza, 2007). We focused on the N2 waveform and its estimated underlying sources, and expected to find evidence of cultural differences in neurocognitive function. As children from a Chinese background have been found to perform better on measures of EF than North American children, and may be more conscientious, we expected to find larger N2 (i.e., more negative) amplitudes for the Chinese-Canadian children than the same-age European-Canadian children. Although studies with school-age children generally report that N2 amplitude decreases with age across the school-age years and into adolescence, and that these decreases co-occur with continued improvements in EF (e.g., Lamm et al., 2006), our prediction is based on studies showing larger N2 amplitudes to be associated with better EF within a single age group (e.g., Overtoom et al., 1998, 2002; Pliszka et al., 2000; Liotti et al., 2005). For example, Pliszka et al. (2000) found larger N2 amplitudes for controls, as compared to children with ADHD, over right inferior frontal cortex on a go/no-go-type task. In addition, in light of evidence for the recruitment of right prefrontal cortex on the go/no-go task and other EF tasks, we expected to find a right-lateralized N2 on no-go trials, as well as right-lateralized source activation."}