Sensation And Perception Flashcards
Perception
Interpretation of raw sensory input.
Sensation
Detection and initial transformation of physical energy by sensory organs.
Transduction
Turning an outside signal into an action potential.
Adequate stimulus
The minimum amount of stimulation required to fire an action potential.
Law of Specific Energies
Other energy inputs can stimulate a sense. For instance putting pressure on your eyes can cause you to “see” lights.
Parts and functions of the eye
Cornea-covers an protects the eye
Iris-muscle that controls the size of the pupil
Lens-refracts light and focuses it on the back of the eye.
Retina-back of the eye which contains the photoreceptors.
Cones
Photoreceptors that process color.
Located in your fovea (where the center of attention of your vision is)
Respond best to bright light.
Have about 7million
Rods
Process gradations of light.
Found everywhere in your retina.
Work well in dim light an bright light.
You have about 120 million.
Optic disc
Where retinal (ganglion) cells exit the eye. Actually creates a blind spot that your brain fills in.
Bipolar Cells
Connect to the ganglion cells
Optic nerve
Bundle of nerves that go to the brain. The first synapse is in the thalamus. It then travels to the occipital lobe.
Ganglion
Leave the eye to go to the brain. First cell to fire an action potential.
Feature detectors
Nerves in the brain that respond only to very specific stimuli (ie lines and curves)
Trichromatic Theory
Based on the idea that there are three types of cones (one for each primary color light). Each type of cone has a different photochemical.
Each cone actually fires for all forms of light. Color is created by interpreting the firing rate of each color receptor.
Idea proposed by Young and Helmholtz because they realized they could create every color with only 3 specific colors. P
Trichromats
People with all three cones
