Through experience , I noticed that sounds , videos , pictures , ... have psychological effects on the human . For example , we smile sometimes when we hear some sounds , but we feel sadness when we hear some others .

So I'm wondering why ? , and how is that happening

 

I'm eagerly waiting for some opinions .

 

Thanks in advance

Humans have been programmed by their evolutionary past to respond to sensory information both automatically and to learned responses to sensory information. This also includes all the other senses, not just vision and audition, and this evolutionary programming presumably allowed our species to survive. Information processed by sensory brain areas is passed off to multiple other brain systems and if the pattern matches an automatic or learned trigger it causes a response to occur. Your question is a bit vague, and so is this answer, however, much of the high level neural processing beyond sensory (and motor) areas is poorly understood.

 

One interesting recent illustrative finding involves the study of mice that don't have an amygdala (a brain area), bilaterally, that don't show fear behaviors. The researchers found a woman with a rare genetic disease, Urbach-Wiethe disease, in which both the right and left amygdalas are destroyed in middle age. This person was not afraid of anything, not a very dangerous situation that happened to her, not scary movies or animals (she completely lost her earlier fear of snakes and spiders), and not having to talk in front of an audience. In light of previous research, this finding is not a very big surprise. Knowing this bit of information makes it easier to understand how some sensory information (e.g. a large approaching spider) is processed into knowledge of what it is, and then assigned as fearful by the amygdala. SM