PMC:2813722 / 28198-34719 JSONTXT

{"project":"MyTest","denotations":[{"id":"20161697-16371147-33634465","span":{"begin":172,"end":176},"obj":"16371147"},{"id":"20161697-18269510-33634466","span":{"begin":192,"end":196},"obj":"18269510"},{"id":"20161697-9681259-33634467","span":{"begin":307,"end":311},"obj":"9681259"},{"id":"20161697-10924667-33634468","span":{"begin":914,"end":918},"obj":"10924667"},{"id":"20161697-8507742-33634469","span":{"begin":1133,"end":1137},"obj":"8507742"},{"id":"20161697-10344188-33634470","span":{"begin":1159,"end":1163},"obj":"10344188"},{"id":"20161697-18061633-33634471","span":{"begin":1429,"end":1433},"obj":"18061633"},{"id":"20161697-15525290-33634472","span":{"begin":1459,"end":1463},"obj":"15525290"},{"id":"20161697-9753190-33634473","span":{"begin":2183,"end":2187},"obj":"9753190"},{"id":"20161697-10355680-33634474","span":{"begin":2189,"end":2193},"obj":"10355680"},{"id":"20161697-10393989-33634475","span":{"begin":2211,"end":2215},"obj":"10393989"},{"id":"20161697-12498755-33634476","span":{"begin":2217,"end":2221},"obj":"12498755"},{"id":"20161697-11738192-33634477","span":{"begin":2238,"end":2242},"obj":"11738192"},{"id":"20161697-11170305-33634478","span":{"begin":2258,"end":2262},"obj":"11170305"},{"id":"20161697-11804576-33634479","span":{"begin":2278,"end":2282},"obj":"11804576"},{"id":"20161697-14527595-33634480","span":{"begin":2298,"end":2302},"obj":"14527595"},{"id":"20161697-15050513-33634481","span":{"begin":2317,"end":2321},"obj":"15050513"},{"id":"20161697-17637487-33634482","span":{"begin":2344,"end":2348},"obj":"17637487"},{"id":"20161697-18061633-33634483","span":{"begin":2363,"end":2367},"obj":"18061633"},{"id":"20161697-19909763-33634484","span":{"begin":2384,"end":2388},"obj":"19909763"},{"id":"20161697-16039143-33634485","span":{"begin":2551,"end":2555},"obj":"16039143"},{"id":"20161697-1389117-33634486","span":{"begin":2739,"end":2743},"obj":"1389117"},{"id":"20161697-2708653-33634487","span":{"begin":2763,"end":2767},"obj":"2708653"},{"id":"20161697-9103728-33634488","span":{"begin":2793,"end":2797},"obj":"9103728"},{"id":"20161697-16310813-33634489","span":{"begin":3241,"end":3245},"obj":"16310813"},{"id":"20161697-16513007-33634490","span":{"begin":3261,"end":3265},"obj":"16513007"},{"id":"20161697-18606038-33634491","span":{"begin":3267,"end":3271},"obj":"18606038"},{"id":"20161697-12822595-33634492","span":{"begin":3449,"end":3453},"obj":"12822595"},{"id":"20161697-16371147-33634493","span":{"begin":4762,"end":4766},"obj":"16371147"},{"id":"20161697-11162267-33634494","span":{"begin":6029,"end":6033},"obj":"11162267"},{"id":"20161697-15577779-33634495","span":{"begin":6049,"end":6053},"obj":"15577779"}],"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":"Discussion\nRecent research suggests that Asian preschoolers may perform better than age-matched North American or British children on measures of EF (e.g., Sabbagh et al., 2006; Oh and Lewis, 2008), consistent with reported cultural differences in the emphasis placed on impulse control (e.g., Chen et al., 1998). This study provides a first look at whether the neural correlates of EF, measured in the context of a go/no-go task, differ systematically between European-Canadian and Chinese-Canadian 5-year-olds. Although no cultural group differences were observed in children's behavioral performance on the go/no-go task, substantial differences were revealed by ERP analyses, with Chinese-Canadian children showing larger N2 amplitudes than European-Canadian children. In studies comparing participants within a single age, N2 amplitude is often larger in groups performing better on EF (e.g., Pliszka et al., 2000), and in the current study, larger N2 amplitudes were associated with faster RTs (i.e., better performance).\nN2 amplitude is usually observed to be larger on successful no-go trials than on go trials (e.g., Eimer, 1993; Falkenstein et al., 1999). In the present study, N2 amplitudes were indeed larger on no-go trials than on go trials over the right frontal part of the scalp, a pattern of lateralization that has sometimes been observed in previous research with both children and adults (e.g., Todd et al., 2008; see also Lavric et al., 2004, who localized sources of N2 difference scores in right ventral and dorsolateral prefrontal cortex). In contrast, however, over the left frontal part of the scalp, N2 amplitudes were larger on go trials than on no-go trials. This asymmetrical pattern of scalp lateralization (to the right for no-go trials and to the left for go trials) was reflected in the results of the source analysis of the N2 in the current study, which suggested that a cortical generator in left VLPFC may contribute more to go N2s whereas a cortical generator in right VLPFC may contribute more to no-go N2s. Together, these findings are in line with a large body of research on EF tasks that show a lateralized pattern (e.g., Konishi et al., 1998, 1999; Garavan et al., 1999, 2002; Bokura et al., 2001; Menon et al., 2001; Bunge et al., 2002; Rubia et al., 2003; Aron et al., 2004; Perez-Edgar and Fox, 2007; Todd et al., 2008; Madsen et al., 2009) as well as with research revealing other lateralized ERP components implicated in emotion regulation (e.g., the late positive potential, LPP; Cunningham et al., 2005), and research on EEG alpha power asymmetry, indicating a greater role for left PFC in approach behavior and a greater role for right PFC in withdrawal or inhibition (e.g., Davidson, 1992; Davidson and Fox, 1989; Harmon-Jones and Allen, 1997). At least in young children in the context of this task, therefore, the amplitude of the N2 may provide an index not only of the inhibitory aspects of EF (over right PFC) but also of effective goal-directed approach behavior (over left PFC).\nIn general, the prefrontal sources modeled in the present study fit well with previous research on the regions implicated in the go/no-go task with children (e.g., Durston et al., 2002b; Lamm et al., 2006; Lewis et al., 2006, 2008). In addition, the regions modeled in the VMPFC and DMPFC are roughly consistent with studies modeling sources of the N2 that are centrally localized (e.g., Nieuwenhuis et al., 2003), although it should be noted that these studies used different approaches to source modeling than the present study and modeled the N2 difference between no-go and go trials (i.e., the N2 effect).\nThe asymmetric pattern of lateralization to emerge in this study was more pronounced for Chinese-Canadian children than it was for European-Canadian children. It was not simply that Chinese-Canadian children showed more activation overall than European-Canadian children; rather, they showed a more differentiated pattern, congruent with the different task demands inherent in the go/no-go task: Chinese-Canadian children showed larger N2 amplitudes than European-Canadian children on the right side of the scalp on no-go trials, as well as on the left side of the scalp on go trials. In addition, left-minus-right difference scores, which were positive for no-go trials and negative for go trials for all children, were larger in absolute magnitude for the Chinese-Canadian children. Further work is needed to examine the origin and implications of this group difference in lateralization.\nThe lack of behavioral differences between the cultural groups in this study differs from previous findings that Chinese children outperformed North American children on behavioral measures of EF (e.g., Sabbagh et al., 2006), although this earlier research focused on younger children and did not examine go/no-go performance. In addition, the Chinese-Canadians in the current study grew up in Canada, whereas previous research has examined Asian children living in Asia. In any case, it would appear that at least in some situations, EEG can provide a measure of cultural differences in neurocognitive function that is more sensitive than behavioral data alone.\nFurther work remains to be done to clarify the nature of the group differences in neurocognitive function observed in the current study. Neurocognitive abilities are undoubtedly influenced by both genes and environment, and both types of influence are likely to vary across cultures. For example, cultural differences in the importance that parents place on impulse control could affect children's motivation to succeed on a task like the go/no-go task, resulting in greater PFC activation. Neither number of languages spoken in the home nor parent-reported individualism–collectivism accounted for the observed differences, but there are several possible factors that may contribute to them, including genetic differences related to EF and possible group differences in skull density, thickness, and shape (Zilles et al., 2001; Knott et al., 2004), as well as any number of other unmeasured variables. Regardless of the origin of the observed group differences, however, the findings underscore the fact that the neural correlates of EF may vary across samples of healthy participants, even in children. One simply cannot assume that neural function is the same in all samples of healthy children – cultural background, and whatever may be correlated with cultural background, needs to be taken into consideration."}

{"project":"2_test","denotations":[{"id":"20161697-16371147-33634465","span":{"begin":172,"end":176},"obj":"16371147"},{"id":"20161697-18269510-33634466","span":{"begin":192,"end":196},"obj":"18269510"},{"id":"20161697-9681259-33634467","span":{"begin":307,"end":311},"obj":"9681259"},{"id":"20161697-10924667-33634468","span":{"begin":914,"end":918},"obj":"10924667"},{"id":"20161697-8507742-33634469","span":{"begin":1133,"end":1137},"obj":"8507742"},{"id":"20161697-10344188-33634470","span":{"begin":1159,"end":1163},"obj":"10344188"},{"id":"20161697-18061633-33634471","span":{"begin":1429,"end":1433},"obj":"18061633"},{"id":"20161697-15525290-33634472","span":{"begin":1459,"end":1463},"obj":"15525290"},{"id":"20161697-9753190-33634473","span":{"begin":2183,"end":2187},"obj":"9753190"},{"id":"20161697-10355680-33634474","span":{"begin":2189,"end":2193},"obj":"10355680"},{"id":"20161697-10393989-33634475","span":{"begin":2211,"end":2215},"obj":"10393989"},{"id":"20161697-12498755-33634476","span":{"begin":2217,"end":2221},"obj":"12498755"},{"id":"20161697-11738192-33634477","span":{"begin":2238,"end":2242},"obj":"11738192"},{"id":"20161697-11170305-33634478","span":{"begin":2258,"end":2262},"obj":"11170305"},{"id":"20161697-11804576-33634479","span":{"begin":2278,"end":2282},"obj":"11804576"},{"id":"20161697-14527595-33634480","span":{"begin":2298,"end":2302},"obj":"14527595"},{"id":"20161697-15050513-33634481","span":{"begin":2317,"end":2321},"obj":"15050513"},{"id":"20161697-17637487-33634482","span":{"begin":2344,"end":2348},"obj":"17637487"},{"id":"20161697-18061633-33634483","span":{"begin":2363,"end":2367},"obj":"18061633"},{"id":"20161697-19909763-33634484","span":{"begin":2384,"end":2388},"obj":"19909763"},{"id":"20161697-16039143-33634485","span":{"begin":2551,"end":2555},"obj":"16039143"},{"id":"20161697-1389117-33634486","span":{"begin":2739,"end":2743},"obj":"1389117"},{"id":"20161697-2708653-33634487","span":{"begin":2763,"end":2767},"obj":"2708653"},{"id":"20161697-9103728-33634488","span":{"begin":2793,"end":2797},"obj":"9103728"},{"id":"20161697-16310813-33634489","span":{"begin":3241,"end":3245},"obj":"16310813"},{"id":"20161697-16513007-33634490","span":{"begin":3261,"end":3265},"obj":"16513007"},{"id":"20161697-18606038-33634491","span":{"begin":3267,"end":3271},"obj":"18606038"},{"id":"20161697-12822595-33634492","span":{"begin":3449,"end":3453},"obj":"12822595"},{"id":"20161697-16371147-33634493","span":{"begin":4762,"end":4766},"obj":"16371147"},{"id":"20161697-11162267-33634494","span":{"begin":6029,"end":6033},"obj":"11162267"},{"id":"20161697-15577779-33634495","span":{"begin":6049,"end":6053},"obj":"15577779"}],"text":"Discussion\nRecent research suggests that Asian preschoolers may perform better than age-matched North American or British children on measures of EF (e.g., Sabbagh et al., 2006; Oh and Lewis, 2008), consistent with reported cultural differences in the emphasis placed on impulse control (e.g., Chen et al., 1998). This study provides a first look at whether the neural correlates of EF, measured in the context of a go/no-go task, differ systematically between European-Canadian and Chinese-Canadian 5-year-olds. Although no cultural group differences were observed in children's behavioral performance on the go/no-go task, substantial differences were revealed by ERP analyses, with Chinese-Canadian children showing larger N2 amplitudes than European-Canadian children. In studies comparing participants within a single age, N2 amplitude is often larger in groups performing better on EF (e.g., Pliszka et al., 2000), and in the current study, larger N2 amplitudes were associated with faster RTs (i.e., better performance).\nN2 amplitude is usually observed to be larger on successful no-go trials than on go trials (e.g., Eimer, 1993; Falkenstein et al., 1999). In the present study, N2 amplitudes were indeed larger on no-go trials than on go trials over the right frontal part of the scalp, a pattern of lateralization that has sometimes been observed in previous research with both children and adults (e.g., Todd et al., 2008; see also Lavric et al., 2004, who localized sources of N2 difference scores in right ventral and dorsolateral prefrontal cortex). In contrast, however, over the left frontal part of the scalp, N2 amplitudes were larger on go trials than on no-go trials. This asymmetrical pattern of scalp lateralization (to the right for no-go trials and to the left for go trials) was reflected in the results of the source analysis of the N2 in the current study, which suggested that a cortical generator in left VLPFC may contribute more to go N2s whereas a cortical generator in right VLPFC may contribute more to no-go N2s. Together, these findings are in line with a large body of research on EF tasks that show a lateralized pattern (e.g., Konishi et al., 1998, 1999; Garavan et al., 1999, 2002; Bokura et al., 2001; Menon et al., 2001; Bunge et al., 2002; Rubia et al., 2003; Aron et al., 2004; Perez-Edgar and Fox, 2007; Todd et al., 2008; Madsen et al., 2009) as well as with research revealing other lateralized ERP components implicated in emotion regulation (e.g., the late positive potential, LPP; Cunningham et al., 2005), and research on EEG alpha power asymmetry, indicating a greater role for left PFC in approach behavior and a greater role for right PFC in withdrawal or inhibition (e.g., Davidson, 1992; Davidson and Fox, 1989; Harmon-Jones and Allen, 1997). At least in young children in the context of this task, therefore, the amplitude of the N2 may provide an index not only of the inhibitory aspects of EF (over right PFC) but also of effective goal-directed approach behavior (over left PFC).\nIn general, the prefrontal sources modeled in the present study fit well with previous research on the regions implicated in the go/no-go task with children (e.g., Durston et al., 2002b; Lamm et al., 2006; Lewis et al., 2006, 2008). In addition, the regions modeled in the VMPFC and DMPFC are roughly consistent with studies modeling sources of the N2 that are centrally localized (e.g., Nieuwenhuis et al., 2003), although it should be noted that these studies used different approaches to source modeling than the present study and modeled the N2 difference between no-go and go trials (i.e., the N2 effect).\nThe asymmetric pattern of lateralization to emerge in this study was more pronounced for Chinese-Canadian children than it was for European-Canadian children. It was not simply that Chinese-Canadian children showed more activation overall than European-Canadian children; rather, they showed a more differentiated pattern, congruent with the different task demands inherent in the go/no-go task: Chinese-Canadian children showed larger N2 amplitudes than European-Canadian children on the right side of the scalp on no-go trials, as well as on the left side of the scalp on go trials. In addition, left-minus-right difference scores, which were positive for no-go trials and negative for go trials for all children, were larger in absolute magnitude for the Chinese-Canadian children. Further work is needed to examine the origin and implications of this group difference in lateralization.\nThe lack of behavioral differences between the cultural groups in this study differs from previous findings that Chinese children outperformed North American children on behavioral measures of EF (e.g., Sabbagh et al., 2006), although this earlier research focused on younger children and did not examine go/no-go performance. In addition, the Chinese-Canadians in the current study grew up in Canada, whereas previous research has examined Asian children living in Asia. In any case, it would appear that at least in some situations, EEG can provide a measure of cultural differences in neurocognitive function that is more sensitive than behavioral data alone.\nFurther work remains to be done to clarify the nature of the group differences in neurocognitive function observed in the current study. Neurocognitive abilities are undoubtedly influenced by both genes and environment, and both types of influence are likely to vary across cultures. For example, cultural differences in the importance that parents place on impulse control could affect children's motivation to succeed on a task like the go/no-go task, resulting in greater PFC activation. Neither number of languages spoken in the home nor parent-reported individualism–collectivism accounted for the observed differences, but there are several possible factors that may contribute to them, including genetic differences related to EF and possible group differences in skull density, thickness, and shape (Zilles et al., 2001; Knott et al., 2004), as well as any number of other unmeasured variables. Regardless of the origin of the observed group differences, however, the findings underscore the fact that the neural correlates of EF may vary across samples of healthy participants, even in children. One simply cannot assume that neural function is the same in all samples of healthy children – cultural background, and whatever may be correlated with cultural background, needs to be taken into consideration."}