Sensory responses - Essay Example

06. Feb 2008 Sensory responses of a human Every human in this world gathers information primarily through his sensory organs andits responses. These include the sense to visualize things, the sense of speech, sense of hearing things and of course, the sense to think. Speaking of which, the visual and auditory senses act as the main source of gathering environmental information. In order to understand them completely, their background information and mechanism should be thoroughly investigated.

A minute difference, objects thrown at a flash, a slight change in the flow of a music composition etc. can be easily recognized by the human brain. It is capable of detecting even the smallest visual and auditory changes. Seeing and hearing are senses which does not require physical contact, but tells us about distant objects with help of electromagnetic waves present in air. . If the sense of touch is considered, the brain could detect within no time, which part of the body was touched. Such is the response and reflex actions.

The brain in turn, is composed of two hemispheres and shares the information sensed by the organs equally among the two parts For the complete sensation in visual and hearing, both halves are equally important. The visual and aural senses strongly depend upon the differences between its neighboring senses. Visual perception consists of perceiving the image of outside objects and then, processing them into an interpretation that can be understood by the brain. The human eye does this mechanism of converting light into electrical energy.

Here, the sense of hearing is done by an excellent auditory system which perceives the sound produced rather than the source that produces it. The sound is received by the ear through the vibrations in air and transmits them to the brain. Just imagine a ball being thrown on a wall coming back to u again. That's what happens in our sensory system. An impulse stimulates a receptor, carried by an afferent pathway reaches some centre in brain and the brain through its memory data commands the body to respond to the impulse through its afferent limb.

That's how we react to different intensity of stimulus. When we see a bright light the rods and cones in our retina of eye perceives them and through the optic nerve it reaches the opposite side of brain. This takes less than a fraction of a second. Same happens in the brain when we hear a melodious sound but it takes different pathway. With the receptors in the scala vestibule and scala media, the sound impulses travel through the vestibulocochlear nerve, reaches the brain and brain commands the body to react to it by sending impulses through various motor and cranial nerves.

For about 120 years, the accepted figures for mean simple reaction times for college-age individuals have been about 190 ms (0.19 sec) for light stimuli and about 160 ms for sound stimuli (Welford, 1980).The sensory responses are mainly controlled by the brain whereas the reflex actions of human organs are controlled by the spinal chord. This is why most of the reflexes take place so quickly. Some of the reflexes are automatically done, which we can never take control of it. Some are the blinking of eye when seeing a bright light, digestion etc.

All these activities of the brain are done unconsciously and very rapidly. In moments of anxiety and pressure, we make up things from incomplete data , hear things which we don't hear in a normal state. The joy of seeing, smelling, hearing the whole world can be attributed to the sensory responses of human beings. Works CitedSeeing, Hearing and Smelling the world. (1997). Howard Hughes Medical Institute. 06 Feb. 2008 Senses. (1997). Gatech. 06 Feb. 2008. The human brain: Detective of auditory and visual change.

18 January, 2008. 06 Feb. 2008 Welford, A. T. 1980. Choice reaction time: Basic concepts. In A. T. Welford (Ed.), Reaction Times. Academic Press, New York, pp. 73-128.