Perceptual and Clinical Neuroscience Group and Monash Alfred Psychiatry Research Centre, School of Psychology & Psychiatry, Monash University, Melbourne, Victoria 3145, Australia.
Proc Natl Acad Sci U S A. 2010 Feb 9;107(6):2664-8. doi: 10.1073/pnas.0912149107. Epub 2010 Jan 21.
Binocular rivalry occurs when conflicting images are presented in corresponding locations of the two eyes. Perception alternates between the images at a rate that is relatively stable within individuals but that varies widely between individuals. The determinants of this variation are unknown. In addition, slow binocular rivalry has been demonstrated in bipolar disorder, a psychiatric condition with high heritability. The present study therefore examined whether there is a genetic contribution to individual variation in binocular rivalry rate. We employed the twin method and studied both monozygotic (MZ) twins (n = 128 pairs) who are genetically identical, and dizygotic (DZ) twins (n = 220 pairs) who share roughly half their genes. MZ and DZ twin correlations for binocular rivalry rate were 0.51 and 0.19, respectively. The best-fitting genetic model showed 52% of the variance in binocular rivalry rate was accounted for by additive genetic factors. In contrast, nonshared environmental influences accounted for 18% of the variance, with the remainder attributed to measurement error. This study therefore demonstrates a substantial genetic contribution to individual variation in binocular rivalry rate. The results support the vigorous pursuit of genetic and molecular studies of binocular rivalry and further characterization of slow binocular rivalry as an endophenotype for bipolar disorder.
当冲突的图像呈现在双眼的相应位置时，就会发生双眼竞争。感知在图像之间交替的速度在个体内部相对稳定，但在个体之间差异很大。这种变化的决定因素尚不清楚。此外，在具有高遗传性的精神疾病双相情感障碍中已经证明了缓慢的双眼竞争。因此，本研究探讨了个体双眼竞争率的个体差异是否存在遗传贡献。我们采用了双胞胎方法，研究了遗传完全相同的同卵双胞胎（n = 128 对）和遗传相似度约为一半的异卵双胞胎（n = 220 对）。双眼竞争率的 MZ 和 DZ 双胞胎相关性分别为 0.51 和 0.19。最佳拟合的遗传模型表明，双眼竞争率的 52%差异由加性遗传因素解释。相比之下，非共享环境影响占方差的 18%，其余归因于测量误差。因此，本研究证明了个体双眼竞争率的个体差异存在很大的遗传贡献。研究结果支持对双眼竞争的遗传和分子研究的大力开展，并进一步将缓慢的双眼竞争作为双相情感障碍的内表型进行表征。
