Sensation and perception Flashcards
Perception
Process of selecting and interpretation of info from the environment
Top Down Processing
Using experiences and expectations to interpret the outside world
-seeing a chair for the 1st time vs seeing a chair and knowing its a chair (understanding what a chair is from experience)
Bottom Up Processing
Receiving info from our senses
-cow example
-trying to make sense of what they see if they have not seen it before
Absolute Thresholds
The point at which a stimulus can be detected 50 percent of the time
(knowing a stimulus occurred)
-when you first detect something like a sound
Difference Threshold
The Minimal change in stimulation that can be reliably detected 50 percent of the time
-Noticing a difference/change in a stimulus
-When you know a change in sound happened
-fan turned off and then you notice it
Weber’s law
The ability to tell the difference between 2 objects, must be of an constant percentage not a constant amount
-May be a 10 percent difference
-you can tell the difference between 5 and 10 pounds but not 105 and 110 pounds
Sensory Adaptation
When we are constantly exposed to the same stimulus that does not change, we become less aware of it because nerves fire less frequently
-if you get used to wearing a watch, you become less aware that you are wearing it
Sensory/SIgnal Detection Theory
Our expectations and experiences determine the sensitivity of when we perceive a stimulus
-When you are expecting a message, you are more likely to feel your phone buzzing bc you expect a message to come but if you did not expect a message, you might miss the buzz
Retina
contains sensory receptors that process visual information and sends it to the brain
Rods
Visual receptors cells located in the retina
-can only detect black and white
-respond to less light than cones do
Cones
Visual receptor cells located in the retina
-can detect sharp images and color
-need more light than rods
-many cones are clustered in the fovea at the center of the retina
Bipolar cells
Transmit signals from the photoreceptors to the ganglion cells
Ganglion cells
nerves that gather information and send their output to bipolar cells and into the brain through the optic nerve
Optic nerve
the nerve that carries neural impulses from the eye to the brain, creates a blindspot in our eye
Blindspot
Point where the optic nerve leaves the eye because there are no receptor cells located there
Feature Detectors
The ability to detect certain types of stimuli, like movements, shape, and angles, requires specialized cells in the brain called feature detectors. Without these, it would be difficult, if not impossible, to detect a round object, like a baseball, hurdling toward you at 90 miles per hour.
Parallel Processing
The brain processes hundred of buts of visual information a second, sorting out color, shapes, movements, brightness, combined with higher level connections like recognition, importances and uniqueness (all at the same time)
Dif wavelengths equal
different color
Amplitude/intensity
height
Amplitude determines..
brightness of color
What are the 3 types of cones
Red
Green
Blue
Additive color mixing
combinations of wavelengths by mixing lights
-addings lights together to get white
Subtractive color mixing
Mixing colors/paint to get black
Removing wavelengths by mixing paint
The Process of changing stimuli into neural impulses is known as….
Transduction
What allows you to see black and white?
Rods
What allows you to see color?
Cones
cones=color
Where does vision end up in the brain?
Association Areas
If Alice lives near a cattle plant, she probably doesn’t notice the neighborhood smell that visitors to her house complain about. What idea explains this phenomenon?
Sensory Adaptation
According to the opponent-process theory, ganglion cells that are stimulated by exposure to ________ light are inhibited by exposure to ________ light.
yellow; blue
In additive color mixing, the combination of red, green, and blue light creates
white
in subtractive color mixing, the combination of red, yellow, and blue paints creates ________.
black
Accommodation refers to the:
The process by which the lens changes its curvature
The negative afterimage created by looking at a white sheet of paper after staring at the green, black, and yellow flag occurs because
the ganglion cells excited by green, black and yellow are fatigued but the white light is sufficient to stimulate their opponent cells.
Put the visual transduction process in order
Retina
Ganglion cells
LGN of the thalamus
Primary visual cortex of the occipital lobe
Association Areas
The fovea is the:
the focus point of the eye, responsible for acuity.
The Helmholtz Trichromatic Theory explains vision at what level?
Cells in the Retina