Question

How do sensation and perception interact?Describe at least three major structures or areas of the brain that are involved With sensation and perception.If one of these areas of the brain stopped functioning or did not function properly,how would this change your daily quality of life and functioning?

Answer 1

Sensation is the process or medium through which external stimuli is detected with the help of our senses in form of touch, vision, smell and sound.Perception is the knowledge based interpretation of these sensations .The neural impulses from sensory organs send information to the brain in raw form, it is then decoded for meaning by sensory cortices which is when perception takes place.Both processes work hand in hand to let us have meaningful experiences.

The brain structures involved in sensation and perception are

1.Primary Visual Cortex located in the occipital lobe , it contains neurons that process selective visual stimuli based on spatial orientation. It has a striped appearence due axons called as the line of Gennari present along the edges.

2. Primary Auditory Cortex located in temporal lobe in Broadmann area 41. It processes sound stimulus for pitch, volume and the location of source of sound.The neurons in the primary auditory cortex are organized tonotopically, cells at one end perceive lower frequencies and those at other end higher frequencies.

3.Primary somatosensory cortex is situated in the postcentral gyrus in the parietal lobe. It is responsible for perception of tactile information.Neurons are arranged somatotopically , so that sensations from various contralateral parts of the body have a precise decoding or representation point with toes at the top and mouth at the bottom.

If any of these areas suffered from a lesion their functioning will be impaired.

For example the primary visual cortex is not functioning , then it can result in chronic blindness.If only this area is effected people exhibit blindsight which is the ability to respond to the edges and motion of visual stimuli. We will lose our ability to experience the world with its rich colours, and detect visual cues like facial expressions hampering the quality of life that we live now.