Page 60 - The prevalence of the Val66Met polymorphism in musicians: Possible evidence for compensatory neuroplasticity from a pilot study

S. Si et al. NeuroImage 213 (2020) 116681
rs7122246(A), DRD2 rs6279(G) and COMT rs6269(G) might moderate creativity, using single genetic polymorphism and cumulative genetic
the relationship between father authoritativeness and flexibility; DRD2 score analyses. When polymorphisms were examined in isolation, there
rs7122246(A) and COMT rs5993883(G) might moderate the relationship were only two polymorphisms from COMT, rs5993882 and rs5993883,
between father permissiveness and flexibility; DRD2 rs7122246(A) and which were found to interact with mother authoritativeness to predict
COMT rs737865(C) might moderate the relationship between father creativity. Specifically, maternal authoritative parenting was only asso-
authoritarianism and flexibility. Therefore, those potential variants sus- ciated with creativity in individuals with rs5993883 GG and rs5993882
ceptible to the same parenting style for the same creativity dimension GG genotype. Since both rs5993882 and rs5993883 are in intron, the
were combined and then five genetic profiles- CGS (a-e) were developed. exact biochemical effects of them are largely not clear. A recent G E
Each of CGS (a-e) for individuals was computed by summing the number study found that, the second generation antipsychotic (SGA) treatment
of plasticity alleles (alleles indicated in parentheses above; 0, 1, or 2) for bipolar disorder was only associated with low verbal and cognitive
across the corresponding susceptibility variants. See Supplementary control in individuals with rs5993883 GG genotype (Flowers et al.,
Table 5 for the composition and distribution of CGS (a-e) . 2016). This probably implied that individuals with rs5993883 GG ge-
Regression analyses indicated there was a significant two-way inter- notype were more susceptible than others to environmental influence.
action between CGS a and mother authoritativeness for predicting origi- Hence, the effect of parenting style on creativity-related cognitive func-
nality (β ¼ 0.17, p ¼ 0.001). The interaction in isolation accounted for tion may be more prominent in those people who are more likely to be
2.7% of the variance in originality. Additionally, the interaction between affected. As for rs5993882, no study has been conducted to reveal its
CGS b and mother authoritativeness (β ¼ 0.19, p ¼ 0.000), CGS c and fa- change due to plasticity. Since rs5993882 also located in intron 1, it is
ther authoritativeness (β ¼ 0.15, p ¼ 0.001), CGS d and father permis- assumed to have similar influence to rs5993883 in the relationship be-
siveness (β ¼ 0.16, p ¼ 0.001), CGS e and father authoritarianism (β ¼ tween parenting style and creativity. Future studies focusing on these two
0.12, p ¼ 0.014) on flexibility were also significant, accounting for polymorphisms are warranted. Together, COMT variants may interact
3.6%、2.3%、2.5% and 1.3% of the variance in flexibility respectively. with parenting style to predict creativity.
(see Table 4). However, the results of CGS analyses further indicated that these
interactions were moderated by DRD2 polymorphisms. Because it was
3.3. Sensitivity analyses found that CGS comprising of several potential susceptibility poly-
morphisms from DRD2 and COMT genes did indeed interact with
Sensitivity analyses were then performed to check whether the above parenting style to explain a significant amount of variance in the crea-
described significant CGS parenting style interactions conformed to tivity. For flexibility, we found four genetic profiles (CGS b-e ) that may
diathesis-stress model or differential susceptibility model. See Table 5 influence the relationship between parenting style and creativity. Spe-
and Fig. 3 for complete results. Take CGS a and mother authoritativeness cifically, the interaction of CGS e and authoritarian parenting style on
as an example, RoS on X and accompanying simple slopes tests revealed flexibility was significant. The negative effect of authoritarian parenting
significant effects of CGS a on originality at both high and low levels of style was only present in individuals with high CGS e , suggesting that
mother authoritativeness (within 2 SD). The RoS on Z test revealed individuals with high CGS e might be more susceptible to the adverse
significant effects of mother authoritativeness on originality for partici- environments, such as high father authoritarianism. This extends previ-
pants with high CGS a . Simple slopes of low CGS a and high CGS a differ ous findings by showing that the effect of father authoritarianism on
significantly from each other. Furthermore, the crossover point (origi- flexibility was moderated by both DRD2 and COMT. Besides, we for the
nality: -.37) was near 0 for mother authoritativeness which has been first time found the significant interaction of genetic profile (CGS b , CGS c ,
standardized, PoI (originality: 0.45) was near 0.50, and PA (originality: CGS d ) and positive parenting style (parental authoritativeness and father
0.64) was greater than 16% (Roisman et al., 2012). Nonlinear terms were permissiveness) on creativity. The post-hoc analyses further indicated
nonsignificant. Similar findings were found for CGS b , CGS c and CGS d on that the positive effects of mother authoritativeness, father authorita-
flexibility, although the G E pattern regarding CGS e did not conform to tiveness and permissiveness were respectively more prominent in in-
diathesis-stress model or differential susceptibility model (see Supple- dividuals with high CGS b , CGS c and CGS d , although there were statistical
mentary Table 6 and Fig. 1). Therefore, generally speaking, all these possibilities that mother authoritativeness negatively predicted flexi-
statistical indexes provided support for the hypothesis of differential bility for individuals with low CGS b and father authoritativeness nega-
susceptibility over diathesis-stress. tively predicted flexibility for individuals with low CGS c . These probably
highlight flexibility will be affected by both negative and positive envi-
4. Discussion ronments. And the effect of environment on flexibility may be deter-
mined by several genetic profiles derived from COMT (frontal) and DRD2
The current study examined the interactive effects of variants in (striatal). Because the striatum and prefrontal cortex are strongly inter-
DRD2 and COMT genes and parenting styles (mother/father authorita- connected and conditioned by the neurotransmitter dopamine (Alex-
tiveness, authoritarianism, permissiveness) on individual differences in ander et al., 1986), CGS may influence flexibility—a key cognitive

Table 5
Regression estimates, regions of significance (RoS), and proportion of interaction index (PoI) for statistically significant (p<.05) CGS parenting styles interactions.
2
RoS of X Simple slopes at 2 RoS of Z Simple slopes for two PoI PA X or ZX 2 Crossover
SD X groups of Z
Lower bound Higher bound 2 SD þ2 SD Lower bound Higher bound 1 SD þ1 SD
CGS a MA 1.18 .17 -.27** .40*** 1.32 .10 -.10 .24*** .45 .64 ns -.37
CGS b MA -.96 .17 -.31** .43*** -.77 .33 -.15* .22** .43 .62 ns -.31
CGS c FA -.85 .42 -.33** .38** 1.06 .27 -.13y .22** .36 .55 ns -.14
CGS d FP 1.20 .16 -.27** .39*** 1.35 .08 -.10 .24*** .45 .65 ns -.37
Note. RoS, regions of significance; PoI, the proportion of interaction; PA, the proportion affected; MA, mother authoritativeness; FA, father authoritativeness; FP, father
permissiveness; X, parenting style; Z, cumulative genetic score (CGS); RoS on X indicates that outside of noted bounds there is a significant effect of CGS on creativity;
simple slopes of the effect of CGS on creativity at 2 SD of X are also presented. RoS on Z indicates that outside of noted bounds there is a significant effect of X on
2
2
2
2
creativity; simple slopes of the effect of X on creativity for two groups of CGS (low and high CGS) are also presented; X or ZX represents whether X or ZX , or the set of
2
2
both nonlinear terms together was statistically significant in the equation Y ¼ b 0 þb 1 X þ b 2 Z þ b 3 XZ þ b 4 X þb 5 ZX ; ns, Not significant; Crossover denotes the value of X
(parenting style, standardized to M ¼ 0, SD ¼ 1) at which the regression lines intersected.
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