Attentional bias is the interaction that occurs between emotion and attention. Monoamine oxidase and dopamine β-hydroxylase are involved in the balances of neurotransmitters in the cortex. Much evidence has shown that those enzymes play important roles in human emotion and attention. To investigate the potential influences of some functional polymorphisms in DBH, MAOA, and MAOB on attentional bias, we performed a population-based study in a young Chinese Han group. The results indicated that -1021C/T in DBH was associated with index effect of the neutral facial expressions in spatial cueing task (F = 4.940, P = 0.007), and there was a positive correlation between the dosage of C allele and the index effect (r = 0.068, P = 0.040). Furthermore, we found significant interactions between 19-bp Ins/Del in DBH and VNTR of MAOA on attentional biases for negative expressions in spatial cueing task (F = 3.397, P = 0.009) and dot-probe task (F = 2.827, P = 0.024). The present study suggests that DBH and MAOA can influence human attentional biases, and there is a gene-gene interaction between the DBH and MAOA on attentional bias for negative expressions.

No abstract

No abstract

Studies have revealed that catechol-O-methyltransferase (COMT) and dopaminegic receptor2 (DRD2) modulate human attention bias for palatable food or tobacco. However, the existing evidence about the modulations of COMT and DRD2 on attentional bias for facial expressions was still limited. In the study, 650 college students were genotyped with regard to COMT Val158Met and DRD2 TaqI A polymorphisms, and the attentional bias for facial expressions was assessed using the spatial cueing task. The results indicated that COMT Val158Met underpinned the individual difference in attentional bias for negative emotional expressions (P = 0.03) and the Met carriers showed more engagement bias for negative expressions than the Val/Val homozygote. On the contrary, DRD2 TaqIA underpinned the individual difference in attentional bias for positive expressions (P = 0.003) and individuals with TT genotype showed much more engagement bias for positive expressions than the individuals with CC genotype. Moreover, the two genes exerted significant interactions on the engagements for negative and positive expressions (P = 0.046, P = 0.005). These findings suggest that the individual differences in the attentional bias for emotional expressions are partially underpinned by the genetic polymorphisms in COMT and DRD2.

No abstract