Biopsychology Essay Essays - Nervous System, Perception,

Biopsychology Essay Juliet M. Kyeva University of Roehampton Introduction The human senses are continuously receiving information that needs to be attended to, processed and then perceived. Through attention and perception, we can make sense of the world around us. Each person has their capacity for attention and level of perception depending on their physiological makeup . The human visual system is an integral part of the central nervous system. The visual system enables us to process visual sensory receptors (stimuli) and to form a representation (visual perception) of the stimulus needed for decision making. Without visual perception, a person is said to be blind. Visual System Anatomy The Anatomy The eye is physically made up of the cornea, the lens , the pupil, the iris and the retina working together as a team for the proper functioning of the eye. The cornea is the protective outer layer of the eye which allows light to pass through. The lens' function is to focus light to the back of the retina. For the purpose of focusing, the lens chang es its shape producing clear images of what the eye sees. The retina is that part of the eye that is sensitive to light. It lines the back of the eye and posses se s photoreceptor cells to detect color and light. The retina receives the light signals from the lens and then projects images from the light signals through the optic nerve. The lens of eye lies between the pupil and the iris. In the unfortunate case of the retina detaching itself from where it lies, this could potentially lead to blindness . The eye's retina senses visual information . The retina has two primary visual receptor cells. The first receptor cell is the codes (for color vision and sharpness of vision) situated in the center of the retina. The second receptor cell is the rods (specialized for vision in dim light and movement detection) loc ated in the outer parts of the retina. Light signals pass through the cornea to the iris. The Iris has the pupil which regulates the amount of light passing through the eye. A lens focuses this light to the back of the eye. (Eysenck Keane 2010 pg 36 ). Physiology T he retina's c ells are sensitive to light. These cells trigger nerve signals impulses which then travel along the optic nerve through ganglion cells' axons to signal the brain. Visual stimuli use two different paths. Light received through the right hemifield is directed to the left retina sending signals to the left lateral geniculate nucleus (LGN) while light received through the left hemifield is directed to the right retina sending message s to the right lateral geniculate nucleus (LGN) . Each eye has an optic nerve, so both nerves meet at the optic chiasma. From here, the signals continue traveling along the right and left optical tracts inside the brain to the lateral geniculate nucleus (LGN). The final destination for these signals is the primary and secondary visual cortex where further visual processing takes place. The visual cortex occupies about twenty percent of the entire cortex. (Eysenck Keane 2010 pg 37). Different parts of the brain process different visual stimuli, for example, color, movement, facial recognition, depth, object recognition , etc. Brain damage affecting a particular region can cause visual disorders. For example, a patient diagnosed with prosopagnosia loses the ability to recognize faces , but they will still be able to identify objects. (Rensink, R.A. 2013) Function of vision Neurological studies and research have helped us to see how the eye is a vital physiological component in Information process. The retina and the prima ry visual cortex act as filters, choosing the most relevant stimuli that will be attended to, processed and later perceived. Output data passes through the retina to the next higher levels of Information processing of more complex stimuli such as human faces. ( Rensink, R.A. 2013) The nervous system and how it relates to B iopsychology Biopsychology is a branch of psychology where that studies the nervous system (the brain and neurotransmitters) as pertains to the mind and thoughts, feelings behavior. The nervous system coordinates out actions and transmits