Significance of understanding human nervous system for psychology

Overall, the understanding of human nervous system helps us relate it with behavioural manifestations, thus enriching our knowledge about human behaviour. It is not possible to de-link human behaviour from physiological control and regulatory mechanisms. Let us take two most commonly talked about topics in psychology— colour naming and Müller-Lyer illusion. We all know that there are cultural differences in naming certain colours. Some languages spoken in cultures near to the equator fail naming colours at the blue end of the spectrum such that green and blue, blue and black, or green, blue and black are not given different names. Interestingly, if you look at it from bio-behavioural perspective, this difference is based on physiological difference in colour vision. Physiologically, the people living near to the equator have increased interocular yellow pigmentation and this leads to decreased sensitivity for the blue end of the spectrum.

Let us look at the Müller-Lyer illusion wherein the length of feather-headed line is overestimated as compared to the length of arrow-headed line. An explanation for such illusion is interocular pigmentation. It has been observed that the increase in interocular pigmentation leads to decreased image contrast on the retina. This generates more veridical perception of the figure eliciting illusion. Similarly there are many more examples endorsing the importance of understanding human behaviour from a bio-behavioural perspective.