sensation adn perception Flashcards
Sensation
detect physical energy from the environment and encode it as neutral signals
Perception
is the process of selecting, organizing and interpreting our sensations
Bottom-up processing
analysis that begins with the sense receptors and works up to the brain’s integration of sensory info
Top-down processing
Information processing guided by higher level mental processes
Absolute threshold
the minimum stimulation needed to detect a particular stimulus 50% of the time
Just noticeable difference
minimum difference a person can detect between any two stimuli 50% of the time
Weber’s law
two stimuli must differ by a constant proportion to be perceived as different
Signal Detection theory
focuses on decision making about stimuli under conditions of uncertainty
Attention
is the process of focusing awareness on a narrowed aspect of the environment
Selective attention
focusing on a specific aspect of experience while ignoring others
Cocktail party effect
the ability to concentrate on one voice in a noisy place
Shiftable attention
the ability to have your attention shift from one sensory perception to another
Inattentional blindness
refers to the failure to detect unexpected events when our attention is engaged by a task
Emotion-induced blindness
when we encountered an emotionally charged stimulus, we often fail to recognize a stimulus that is presented immediately after it.
Perceptual set
predisposition or readiness to perceive something in a particular way
Sensory adaptation
a change in the responsiveness of the sensory system based on the average level of surrounding stimulation
Cornea
clear membrane just in front of the eye
Lens
a transparent and flexible disk-shaped structure filled with gelatin material
Rods
are receptors in the retina that are sensitive to light
Cones
are receptors that we use for color perception
Fovea
a tiny area in the center of the retina at which vision is best
Visual processing in the brain
Neural impulses in the retina are sent to the brain
Optic nerve carries information about light toward brain
Optic chiasm
the division of optic nerve fibers in the brain dividing information between the left and right occipital lobe
Optic nerve
carries visual information to the brain (occipital lobe) for further processing
Afterimages
sensations that remain after stimulus is removed
hue
ganglion cells
saturation
richness of a visual stimuli
brightness
Blind spot
place where optic nerve leaves the retina
dicromata
Trichromatic theory
Afterimages- sensations that remain after stimulus is removed
Green -> red
Yellow -> blue
Opponent-process theory
the sensory receptors come in pairs
If one sensor is stimulated the pair is inhibited from firing
So stare at red, get tired, look at white the opponent part fires and you see green
color blindness
due to the lack of a particular chemical in the eye
