Perception
- set of processes by which we recognize, organize, and make sense of the sensations we receive
from environmental stimuli
- sometimes, we cannot perceive what does exist and at other times, we perceive things that does
not exist
Perceptual illusions
- suggests that what we sense (in our sensory organs) is not necessarily what we perceive (in our
minds)
- our minds must be taking available sensory information and manipulating that information to
create mental representations of objects, properties and spatial relationships of our environments
- the way we represent objects will depend on our viewpoint in perceiving the objects
From sensation to perception
1. Visions begins when light passes through the protective covering of the eye
o Cornea – a clear dome that protects the eye
o Pupil – opening in the center of the iris
2. Light passes through the crystalline lens (transparent membrane behind the iris which
makes us view objects both close and at a distance) and vitreous humor (gel-like
substance that comprise majority of they eye; provides support for the eye)
How does our visual system work?
o Refraction – change in the direction and speed of the light entering the eye
o Refracted light focuses on the retina (a network of neuron extending over most of the back
/ posterior surface of the interior of the eye
o The retina is where electromagnetic light energy is transduced – converted into neural
electrochemical impulses
Layers of neural tissue of retina
1. Layer of ganglion cells
- closest to the front, outward-facing surface of the eye whose axons constitute the optic
nerve
2. Interneuron cells, amacrine cells, and horizontal cells
- make single lateral connections among adjacent areas of the retina in the middle-layer
cells
o Bipolar cells – dual connections forward and outward to the ganglion cells and
backward and inward to the third layer of retinal cells
3. Photoreceptors
- transduce light energy into electrochemical energy transmitted by neurons to the brain
- enables the eye to detect visual stimulation
- farthest from the light source
- light must pass through the other two layers first
- set of processes by which we recognize, organize, and make sense of the sensations we receive
from environmental stimuli
- sometimes, we cannot perceive what does exist and at other times, we perceive things that does
not exist
Perceptual illusions
- suggests that what we sense (in our sensory organs) is not necessarily what we perceive (in our
minds)
- our minds must be taking available sensory information and manipulating that information to
create mental representations of objects, properties and spatial relationships of our environments
- the way we represent objects will depend on our viewpoint in perceiving the objects
From sensation to perception
1. Visions begins when light passes through the protective covering of the eye
o Cornea – a clear dome that protects the eye
o Pupil – opening in the center of the iris
2. Light passes through the crystalline lens (transparent membrane behind the iris which
makes us view objects both close and at a distance) and vitreous humor (gel-like
substance that comprise majority of they eye; provides support for the eye)
How does our visual system work?
o Refraction – change in the direction and speed of the light entering the eye
o Refracted light focuses on the retina (a network of neuron extending over most of the back
/ posterior surface of the interior of the eye
o The retina is where electromagnetic light energy is transduced – converted into neural
electrochemical impulses
Layers of neural tissue of retina
1. Layer of ganglion cells
- closest to the front, outward-facing surface of the eye whose axons constitute the optic
nerve
2. Interneuron cells, amacrine cells, and horizontal cells
- make single lateral connections among adjacent areas of the retina in the middle-layer
cells
o Bipolar cells – dual connections forward and outward to the ganglion cells and
backward and inward to the third layer of retinal cells
3. Photoreceptors
- transduce light energy into electrochemical energy transmitted by neurons to the brain
- enables the eye to detect visual stimulation
- farthest from the light source
- light must pass through the other two layers first
