AP Psych Unit 4- Sensation and Perception

What does the field of psychophysics research?

Psychophysics researches the physical energy we can detect and its effects on our psychological experiences.

Discuss the findings and implications of two of the studies on the relationship between attention and accidents.

- Truckers were tracked for 18 months with cameras in the cabs of their trucks recording their texting while driving behavior. They were 23 times more likely to have a collision while texting. The United States banned truckers and bus drivers from texting while driving. -The implications of all of these studies is that attention cannot be successfully diverted or separated between tasks—if we are driving, our attention needs to be on driving in order to avoid accidents.

bipolar cells

activate ganglion cells

What are the three steps basic to our sensory systems?

1. Receiving sensory information. 2. Transforming that stimulation into neural impulses. 3. Delivering the neural information to our brain.

If Jenny were lifting 20 pounds and added 2 pounds to her load, she would notice that it was heavier. According to Weber's law, how much weight would Jenny have to add to 40 pounds of weight to notice the same difference?

20/2 = 40/4. Jenny would have to add 4 pounds

How do context effects relate to top-down processing

A brain can work backward in time to allow a later stimulus to determine how we perceive an earlier one

What is a difference threshold and why is it important to humans?

A difference threshold is the point at which you can tell a stimulus has increased or decreased. This is important because we need to detect small differences.

How large is the portion of light visible to humans related to the spectrum of electromagnetic energy?

A relatively small portion of the electromagnetic spectrum is actually visible to humans. The wavelengths from about 400 to 700 nanometers make up what we call the visible spectrum.

Define and give a real-life example of bottom-up processing.

Bottom-up processing is analysis that begins with the sensory receptors and works up to the brain's integration of sensory information.

How does vision in the fovea relate to placement and quantity of rods and cones? How might the experience of nocturnal animals be different from humans with regard to their visual system's physiology?

Cones are concentrated near the center of the retina and objects that fall on that portion of the retina are seen more clearly. Rods, which line the perimeter in greater numbers aid in peripheral vision. Nocturnal animals have a greater number of rods and are better suited to seeing with minimal light stimulus.

What are the two physical characteristics of light and how do they determine our awareness of hue and intensity?

Frequency or wavelength determines hue (or color). Amplitude or wave height determines intensity (or brightness)

Why can't a classmate who wears a lot of cologne notice that they are doing so?

He won't notice how much cologne he is wearing because of sensory adaptation—the more we are around a stimulus, the less aware we become of it because our nerve cells fire less frequently

How do our expectations, emotions, and motivations influence our perceptions?

Hearing sad rather than happy music can predispose people to perceive a sad meaning in spoken homophonic words—for example, mourning rather than morning, die rather than dye.

. change blindness:

Humans fail to notice changes in our environment.

inattentional blindness:

Humans tend to focus on some part of our environment so much that other stimuli are not seen.

How do the processes of sensation and perception work together when we process from the bottom-up? How about top-down?

If we see something unfamiliar, we process from the bottom up by taking in specific details of lines, angles, colors, and so on and then perceptual processes help us to understand, categorize, and make schemas for what we are sensing. From the top down, we use preexisting knowledge or expectations to guide our perception and send our senses looking for stimuli that support those expectations.

How does the cocktail party effect function as an example of selective attention?

It is the ability to focus on only one voice among many—one stimulus among many stimuli.

. How does the unit opening story of Heather Sellers explain why we study sensation and perception in psychology?

It shows that there is a difference between how we physically see the world and how we cognitively perceive it in our minds. It also shows the impact of sensation and perception on behavior and mental processes. Because Heather cannot recognize faces, she has adapted behaviors, such as smiling to others as she passes them, to avoid making people upset

Cite research from the text that explains the scientific opinion regarding the existence of ESP.

Most research psychologists and scientists are skeptical that paranormal phenomena exist. For example, in 2010, when a mine collapsed trapping 33 miners, the Chilean government reportedly consulted 4 psychics who told them all the miners were dead—of course, 69 days later, all 33 were rescued.

Other than stimulus strength, what additional factor determines whether we will detect a sound, sight, taste, touch or smell stimulus? What is meant by that? Give an example.

Our psychological state—our experience, expectations, motivation, and alertness—also determines whether we will detect a stimulus. A tired mom would hear a faint cry from a baby but not a louder, unimportant sound.

How does sensory adaptation explain why television programming has the power to grab our attention?

Our sense receptors become less active when we are exposed to a constant stimulus. Television programming exposes our eyes and ears to ever-changing stimuli and thus keeps our attention. Quick editing of the image, fluctuations in the volume of commercials or scenes in the show, all keep our receptors firing.

How does priming work? Give an example from your own life of a time you have primed someone else or been primed yourself to perceive stimuli in your environment.

Priming is the activation of often unconscious associations that predisposes people's perception, memories, or response.

Describe the relationship between sensation and perception that underlies a belief in ESP

Perception can occur without sensation.

How does perceptual set relate to top-down processing

Perceptual set is a a set of mental tendencies and assumptions that greatly affects (top-down) what we perceive.

What is the difference between sensation and perception?

Sensation is the gathering of sensory information through our various sense receptors, while perception is the making sense of it.

Define and give an example from the text of sensory adaptation. Give an example from your own life of sensory adaptation.

Sensory adaptation is diminished sensitivity as a consequence of constant stimulation. An example from the text is to move your watch up your wrist by an inch—you will only feel it for a few moments.

What determines if a signal is subliminal?

Subliminal means you cannot detect the signal 50 percent of the time.

Why does human vision have a blind spot?

The "blind spot" is a section of the retina that does not contain receptor cells (rods and cones) because that is where the optic nerve exits the back of the eye.

What do signal detection theorists try to understand about human sensation? Be sure to elaborate your answer.

They seek to understand why people respond differently to the same stimuli and why the same person's reactions vary as circumstances vary.

What does Weber's law tell us about human perception?

To be perceived as different, two stimuli must differ by a constant minimum percentage (rather than a constant amount).

Define and give a real-life example of top-down processing.

Top-down processing is guided by higher-level mental processes, as when we construct perceptions drawing on our experience and expectations.

Define transduction.

Transduction is conversion of one form of energy into another. In sensation, the transforming of stimulus energies, such as sights, sounds, and smells, into neural impulses our brains can interpret.

How does the cartoon of the motorcycle officer on page 164 explain perceptual set?

We expect to see a radar gun when a police officer is pulled over like this, so we act accordingly.

choice blindness:

We frequently fail to notice when we are presented with something different than what we actually want—we think we have made a choice and will defend that choice, but it may not be any different than the other item we were choosing from.

How does selective attention work?

Your awareness focuses on a specific stimulus and disregards the stimuli around it

iris

a ring of muscle tissue that controls the size of the pupil opening

Many people today claim to be "multitaskers," capable of processing multiple tasks at one time. Use your knowledge of this section on attention to respond to that claim.

attention cannot truly and fully be split between separate tasks.

lens

changes shape to help focus images on the retina

retina

light-sensitive inner surface of the eye, containing the rods and cones that begin the processing of visual information

cornea

protects the eye and bends light to provide focus

rods

retinal receptors that detect black, white, and gray; necessary for peripheral and twilight vision

cones

retinal receptors that function in well-lit conditions. Detect fine detail and give rise to color sensations.

pupil

the center of the eye through which light enters

fovea

the central focal point in the retina, around which the eye's cones cluster

optic nerve

the nerve that carries neural impulses from the eye to the brain

blind spot

the point at which the optic nerve leaves the eye, creating a "blind spot" because no receptor nerves are located there

ganglion cells

the strands that form the optic nerve