Sensation and Perception Flashcards
This section comprises 5-7% of the Psychology GRE subject test. When finished with this deck, you should have a better understanding of the following: Signal Detection, Attention, Perceptual Organization, Vision, Audition, Gustation, Olfaction, Somatosenses, Vestibular and Kinesthetic Senses.
What is the difference between sensation and perception?
Sensation is what happens when our sensory modalities (vision, hearing, taste, etc.) are activated.
Perception is how we understand these senses.
What are the three stages of sensation?
- reception
- transduction
- transmission through neural pathways to the brain
Stimuli from the outside world are converted into neural impulses to be processed by our brains through what process?
transduction
What two processes stop you from feeling your shirt press against the hairs on your arms all day?
- sensory adaptation: when the hairs on our arms are constantly being pressed, we simply stop responding to the feeling of pressure
- sensory habituation: the pressure on our hairs stops being novel, so there is no reason for us to continue paying attention to it
If you are zoning out in class and your teacher suddenly uses a swear word, you will snap back to attention. What is the phenomenon called that is responsible for this?
The cocktail party phenomenon/effect involuntarily focuses our attention on something salient, like hearing our name in a roomful of people, or hearing a teacher curse.
What are the “energy senses” and why are they called that?
- vision
- audition (hearing)
- touch
These senses convert stimuli into energy, like light, sound waves, and pressure.
What are the “chemical senses” and why are they called that?
- taste (gustation)
- smell (olfaction)
These senses take stimuli and convert them into chemical signals to be processed.
What is a human’s dominant sense?
vision
What are the factors in seeing a bright light or a blue sky versus a black jacket?
Light intensity will affect how bright an object appears, and color or hue is affected by the light wavelength in the visual color spectrum an object reflects. Objects that appear black actually absorb all colors, while objects that are white reflect all light wavelengths. The blue sky absorbs all colors but blue, which it reflects.
Describe the part of the eye:
cornea
The cornea is the protective covering of the eye, where light first enters and is focused.
Describe the part of the eye:
pupil
The black part in the middle of the eye, the pupil acts like the shutter of a camera, and is controlled by the iris.
Describe the part of the eye:
iris
The iris is the colored disc surrounding the pupil that changes its dilation, allowing more or less light in.
Describe the part of the eye:
lens
The lens focuses light entering through the pupil (called accomodation), then flips and inverts the image and projects it onto the retina.
Describe the part of the eye:
retina
The upside-down and inverted image is projected onto the retina, where neurons are activated to interpret the image via transduction. The retina has several layers of cells involved in transduction.
What are the parts of the retina?
- rods and cones
- fovea
- ganglion cells
- blind spot
When the sun sets and everything in the dark around you looks bluish, are your rods or your cones activated?
Rods are activated. Rods react to light, rather than color, with the exception of blue, which explains why we can only see shades of blue in the dark. Cones are activated by other colors.
Describe the part of the eye:
fovea
The fovea is an indentation in the retina. It is the eye’s fixation point, or the part of the eye used when attending to detail.
Why do we have a “blind spot”?
The area where the optic nerve leaves the retina has no photoreceptors (rods or cones).
The optic nerve is comprised of axons from what?
ganglion cells
What is the lateral geniculate nucleus (LGN)?
It is the visual part of the thalamus that receives information from the optic nerve.
Information from the left side of the retinas go to the left side of the brain, and information from the right side of the retinas go to the right side of the brain. Where does the information get routed to each side?
optic chiasm
Since the optic chiasm, where this information intersects, is shaped like an X, an easy way to remember this is to remember that “chi” is the letter X in Greek.
After visual impulses are processed in the thalamus, where do they end up?
Vision is ultimately processed by the occipital lobe.
There are five feature detectors in vision, labeled V1 through V5. Who won the Nobel Prize for their discovery?
David Hubel and Torsten Wiesel
In the context of vision, what does each of the five feature detectors do?
- V1. mental image formation and imagination
- V2. illusory contours
- V3. location
- V4. color analysis and pattern recognition
- V5. motion and direction
What is the trichromatic theory?
It is the theory that the cones in our retinas perceive blue, green, and red, and are activated in combination to create a perception of all the colors in the visual spectrum.
When you look at the sun for a while and then look away, why is there a dark spot in your vision for a period of time?
This is called an afterimage.
Afterimages of red are green, and afterimages of blue are yellow and vice-versa. The opponent-process theory states that when you look at something of one color, you inhibit its color pair, which you see when you look away.
Why would the opponent-process theory help explain color blindness?
The opponent process theory hypothesizes that the retina has its sensory receptors arranged in color pairs, and if a person is missing a specific pair, he will be unable to perceive either of those colors.
What characteristics of a sound wave determine what we actually hear?
The amplitude of a soundwave determines the loudness of a sound (decibels).
The frequency of a soundwave determines the pitch of a sound (hertz).
Describe the part of the ear:
pinna
The pinna is the flap of skin outside the ear that helps capture and focus sound.
Describe the part of the ear:
eardrum
The eardrum or tympanic membrane concentrates sound energy, vibrating when sound from the ear canal hits it.
Describe the part of the ear:
ossicles
Ossicles are three tiny bones in the middle ear that connect the eardrum to the oval window.
- hammer (malleus)
- anvil (incus)
- stirrup (stapes)
Describe the part of the ear:
oval window
The oval window compresses the fluid in the cochlea and connects the middle ear to the inner ear.
Describe the part of the ear:
cochlea
The fluid-filled cochlea is small and coiled, like a snail’s shell, and converts vibrational activity into neural energy.
Describe the part of the ear:
organ of Corti
The organ of Corti is the part within the cochlea that actually converts soundwaves into neural energy. The hair cells attached to the basilar membrane on the cochlea move in response to compression of fluid, which causes transduction in the organ of Corti, sending neural information to the brain.
What is place theory?
Place theory believes that pitch processing is activated spatially on receptors in the cochlea, the same way that a piano’s notes are arranged spatially. A higher pitch would move a hair cell on a certain part of the cochlea that a lower pitch would not.
What is frequency theory?
Frequency theory (or volley theory) says that we hear different pitches because of the frequency at which the hair cells in the cochlea fire.
When you go to a loud concert and stand by the speakers, what kind of deafness are you causing for yourself?
nerve deafness
Loud noises damage the hair cells on the cochlea, preventing them from firing for any sounds at all, so no neural impulses reach the brain.
What kind of deafness is caused when one of the mechanisms used to move sound from the outer ear to the cochlea is damaged?
conduction deafness
What sensory modality responds to pressure or temperature?
touch
If you stub your toe, then fall down and break your wrist, which one will you feel more, and what theory predicts this?
You will feel your broken wrist more than your stubbed toe, which is predicted by gate-control theory.
This theory hypothesizes that pain messages are prioritized and the high-priority messages will be delivered first, while the low-priority messages will be shut out, like a swinging gate.
Pain killers also help close the gate, as will natural endorphins in the brain.
What are papillae?
Papillae are the bumps on your tongue that hold taste buds.
What are the five different tastes we perceive?
- salty
- sweet
- bitter
- sour
- umami (savory or meaty tastes)
What is another word for “taste”?
gustation
What makes smell different from the other senses? Why do certain smells trigger memories?
It is not processed through the thalamus. Instead, the nerves of the olfactory bulb connect with the amygdala and hippocampus, which are attached to memory and emotional response.