仙琴蛙颜色感知具有左脑优势

蛙类在暗视条件下能辨别不同颜色,但颜色感知时大脑神经活动的动态神经机制尚不清楚。本文通过分析峨眉仙琴蛙(Nidirana daunchina)在蓝、绿、黄三种颜色光刺激下脑电信号δ、θ、α、β4种节律的功率谱,研究脑电节律与颜色感知之间的关系,探索颜色感知的动态神经机制。首先采集不同颜色刺激下端脑、间脑和中脑的脑电信号,提取δ(0.5~5.5 Hz)、θ(5.5~8.5 Hz)、α(8.5~17 Hz)、β(17~45 Hz)四个节律,分析各节律的功率谱;使用三因素(颜色、脑区和性别)重复测量ANOVA和最小显著性差异法(LSD)进行统计分析。结果显示,对δ和θ节律,蓝光诱发的功率谱显著高于绿和黄颜色光;对θ、α、β三个节律,由颜色刺激引起的左间脑功率谱显著高于右间脑(P<0.05)。上述结果表明,蓝色光引发高觉醒水平,且颜色感知具有左脑优势。

Left-hemisphere Lateralization during Color Perception in the Emei Music Frog

Frogs can distinguish various colors even at the scotopic light level,however,the dynamic neural mechanism of cerebral neural activity in color perception is not yet clear.To explore this,electroencephalogram(EEG)was recorded when different colors(blue,green and yellow)were presented to the Emei Music Frog(Nidirana daunchina),and the power spectrum of each EEG rhythm for each color was calculated.Firstly,EEG signals of the telencephalon,diencephalon and mesencephalon were collected when the colors were presented.Then,four rhythms including delta(0.5-5.5 Hz),theta(5.5-8.5 Hz),alpha(8.5-17 Hz)and beta(17-45 Hz)were extracted.Finally,the power spectrum of each frequency rhythm was analyzed using Welch’s method with a Hamming window and 0.5 Hz resolution.The statistical analysis was conducted using the three-factor(color,brain region and gender)repeated measures of ANOVA and Least Significant Difference(LSD).Results showed that(1)for delta rhythm,the power spectra induced by blue,green and yellow were 9.952±0.421,9.930±0.370,9.460±0.393,respectively;while for theta rhythm,the power spectra induced by blue,green and yellow were 1.881±0.316,1.770±0.299,1.711±0.319,respectively(Fig.2);(2)the sequence of power spectra for delta or theta rhythm was blue>green>yellow(P<0.05,the difference between blue and green in delta,and that the difference between green and yellow in theta did not reach statistical significance,Fig.2 and Table 1);(3)the power spectra of theta,alpha and beta evoked in the left diencephalon were 1.945±0.341,3.020±0.280,-5.832±0.248,respectively and were significantly higher than those in the right counterpart respectively(P<0.05,Fig.2 and Table 1).In conclusion,these results show that blue color induces higher arousal level,and that color perception exhibits left-hemisphere lateralization.