Sensation and perception

• Sensation: sensation is the process of our sensory organs receiving information from the environment and then sending it to the brain
• processes of sensation: Reception, transduction, and transmission
• Process of reception:

  -Light enters the eye through the cornea

  -it passes through the pupil

  -the lens then focuses the light on the retina

  -the retina contains photoreceptors which are light sensitive cells called cones and rods
• Process of transduction:

  -transduction is the electromagnetic energy that we know as light energy, is converted by the cones and rods into electromagnetical nerve impulses

  -this allows visual information to travel along the fibers of the optic nerve to the brain
• process of transmission:

  -the next task is for the rods and cones to send the nerve impulses along the optic nerve to the primary visual cortex, at the very back of the brain where specialised receptor cells respond as the process of visual perception continues
• Processes of perception: Selection, organisation, and interpretation.
• selection:

  -millions of stimuli enter the eye and its impossible to process them all at once, so we are very selective about what we give attention to.

  -at this stage of the process, the image is broken up by specialised cells called feature detectors (cells in the optic nerve and primary visual cortex that individually respond to lines of a certain length, angle or direction, to break up an image for visual perception.)
• Organisation:

  -our visual cortex in the brain recognises information so that we can make sense of it, we do this by following the visual perception principles;

  -perceptual consistencies

  -gestalt principles

  -depth cues

  -once the image is assembled using the principles, it travels along two pathways simultaneously: to the temporal lobe to identify the object, and to the paretial lobe to judge where the object is in space.
• Interpretation:

  -this is the process where the visual stimulus is given meaning

  -the temporal loves identify the stimulus by comparing incoming information with information already stored in memory

  -past experiences, motives, values and contect help us to understand what we are looking at by contributing to our perceptual set.
• cones and rods: are photoreceptors that are responsible for detecting visual stimuli
• the rods: 125000000 in each eye, photoreceptors that are particularly sensitive to black and white, we typically use these at night
• the cones: 6500000 in each eye, are involved in providing clear colour vision, and rely on bright light to function
• what happens when rocky sees cam?

  his cones and rods go swoon swoon