Archives

  • 2018-07
  • 2018-10
  • 2018-11
  • 2019-04
  • 2019-05
  • 2019-06
  • 2019-07
  • 2019-08
  • 2019-09
  • 2019-10
  • 2019-11
  • 2019-12
  • 2020-01
  • 2020-02
  • 2020-03
  • 2020-04
  • 2020-05
  • 2020-06
  • 2020-07
  • 2020-08
  • 2020-09
  • 2020-10
  • 2020-11
  • 2020-12
  • 2021-01
  • 2021-02
  • 2021-03
  • 2021-04
  • 2021-05
  • 2021-06
  • 2021-07
  • 2021-08
  • 2021-09
  • 2021-10
  • 2021-11
  • 2021-12
  • 2022-01
  • 2022-02
  • 2022-03
  • 2022-04
  • 2022-05
  • 2022-06
  • 2022-07
  • 2022-08
  • 2022-09
  • 2022-10
  • 2022-11
  • 2022-12
  • 2023-01
  • 2023-02
  • 2023-03
  • 2023-04
  • 2023-05
  • 2023-06
  • 2023-07
  • 2023-08
  • 2023-09
  • 2023-10
  • 2023-11
  • 2023-12
  • 2024-01
  • 2024-02
  • 2024-03
  • 2024-04
  • 2024-05

    • In the present study no

    2018-11-13

    In the present study, no directional predictions were made regarding the association between 5-HTTLPR and selective attention, as the literature provides a basis for two very different predictions. On the one hand, across several studies, the short allele of 5-HTTLPR has been identified as a factor in vulnerability for unfavorable mental health outcomes, especially in the face of adversity (Caspi et al., 2010; Karg et al., 2011). While some reports contest the reliability of this link (Blakely and Veenstra-VanderWeele, 2011; Munafò et al., 2009; Risch et al., 2009), this finding is supported in a number of studies and meta-analyses (Conway et al., 2012; Jenness et al., 2011; Karg et al., 2011; Starr et al., 2014). As lower SES in childhood is commonly associated with adverse familial and environmental conditions (Baum et al., 1999; Evans, 2004), accordingly, it aminoguanidine is possible that short allele carriers from lower SES backgrounds show greater sensitivity to such environmental adversity, and thus show attenuated neural indices of selective attention. On the other hand, it has also been argued that the short allele marks hypervigilance, defined as greater sensitivity to environmental stimuli that are motivationally relevant (Dobson and Brent, 2013; Homberg and Lesch, 2011). This framework draws from several studies which reported superior performance in short allele carriers compared to long homozygotes in various areas of cognition such as decision making, executive function, and reversal learning (e.g., Borg et al., 2009; Jedema et al., 2010; Roiser et al., 2006). It is argued that such results stem from hyperreactivity of the corticolimbic structures, including PFC, in short allele carriers (Homberg and Lesch, 2011). As claimed by this framework, such hyperreactivity results in increased vigilance in short allele carriers, which in turn is advantageous for cognitive tasks, especially in the absence of stimuli that can evoke emotional responses. As our selective attention task does not include any emotional or social valence, this framework predicts short allele carriers to show increased vigilance to the attended channel and correspondingly enhanced neural responses in our sustained selective attention task. Since our study exclusively focused on a lower SES sample and used a task without emotional or social valence, both of these frameworks (i.e. vulnerability to adversity versus hypervigilance) appear plausible. Therefore, no directional predictions were specified. Importantly, any main effects of the 5-HTTLPR observed in the lower SES sample provide the groundwork for future research examining gene-by-environment or gene-by-intervention interactions and provide information on the contribution of the 5-HTTLPR to the development of neural systems for attention in young children from lower SES backgrounds.
    Method
    Results Exploratory data analyses were conducted for the ERP data, for all children together, as well as independently for each 5-HTTLPR genotype group (long-long, short-long, and short-short). No outliers (+/− 3 SD) were detected. All children with acceptable ERP data, based on the criteria described above, were included in the analyses. Table 1 displays the descriptive statistics by the 5-HTTLPR genotype groups for age, SES, number of correct answers children gave for the comprehension questions asked during the ERP task, and number of clean ERP trials used in the analyses. SES information was missing for 11 children (3 long-long, 8 short-long children). Table 2 presents the mean amplitudes of the ERPs of the selective attention effect for each of the three genotype groups, in each of the three electrode aggregates. Univariate ANOVAs were used to test whether age, SES, comprehension accuracy, or number of ERP trials varied as a function of 5-HTTLPR genotype. There were no main effects of 5-HTTLPR genotype on age, SES, comprehension accuracy, or number of ERP trials. The ANOVA statistics are reported in Table 3. Chi-square tests showed that there were also no significant differences in gender distribution between the 5-HTTLPR genotype groups, (2)=0.03, p=0.98. The parent reports of race/ethnicity were recoded as follows: white, not white, unknown/unreported, with subsequent chi-square tests revealing no significant differences in race/ethnicity between the 5-HTTLPR genotype groups, (4)=0.78, p=0.94. Similarly, when the children with unknown or unreported race/ethnicity information were excluded (n=26), there were no significant differences in the distributions between the genotype groups, (2)=0.12, p=0.94.