Ch. 5: Sensation and Perception (Questions)

The amplitude of a sound wave determines our perception of _(loudness/pitch).

loudness

The longer the sound waves are, the _(lower/higher) their frequency is and the _(higher/lower) their pitch.

lower; lower

Two examples of _ depth cues are interposition and linear perspective.

monocular

The brain's ability to process many aspects of an object or a problem simultaneously is called _ _.

parallel processing

Some night-loving animals, such as toads, mice, rats, and bats, have impressive night vision thanks to having many more _(rods/cones) than _(rods/cones) in their retinas. These creatures probably have very poor _(color/black-and-white) vision.

rods; cones; color

Using sound as your example, show how these concepts differ: absolute thresholds, subliminal stimulation, and difference thresholds.

Absolute threshold is the minimum stimulation needed to detect a particular sound (such as an approaching bike on the sidewalk behind us) 50 percent of the time. Subliminal stimulation happens when, without our awareness, our sensory system processes the sound of the approaching bike (when it is below our absolute threshold). A difference threshold is the minimum difference needed to distinguish between two sounds (such as between the familiar hum of a friend's bike and the unfamiliar sound of a different bike).

In the context of sensation and perception, what does it mean to say that "believing is seeing"?

Because of perceptual set, our experiences assumptions, and expectations shape our views of reality.

What do we mean when we say that, in perception, "the whole is greater than the sum of its parts"?

Gestalt psychologists used this saying to describe our perceptual tendency to organize clusters of sensations into meaningful forms or groups.

Does perceptual set involve bottom-up or top-down processing? Why?

It involves top-down processing, drawing on our experiences, assumptions, and expectations.

_ is your sense of body position and movement. Your _ _ specifically monitors your head's movement, with sensors in the inner ear.

Kinesthesia; vestibular sense

Where are kinesthetic sense and vestibular sense receptors located?

Kinesthetic sense receptors are located in our joints, tendons, and muscles. Vestibular sense receptors are located in our inner ear.

What is the rapid sequence of events that occurs when you see and recognize a friend?

Light waves reflect off the person and travel into your eye, where the receptor cells in your retina convert the light waves' energy into neural impulses sent to your brain. Your brain processes the different parts of this visual input - including color, depth, movement, and form - separately but simultaneously. It interprets this information based on previously stored information and your expectations into a conscious perception of your friend.

What is the rough distinction between sensation and perception?

Sensation is the bottom-up process by which the physical sensory system receives and represents stimuli. Perception is the top-down mental process of organizing and interpreting sensory input.

If an ESP event occurred under controlled conditions, what would be the next best step to confirm that ESP really exists?

The ESP event would need to be reproduced in other scientific studies.

What are two key theories of color vision? Do they contradict each other, or do they make sense together? Explain.

The Young-Helmholtz trichromatic theory shows that the retina contains color receptors for red, green, and blue. The opponent-process theory shows that we have opponent-process cells in the retina and thalamus for red-green, yellow-blue, and white-black. These theories make sense together. They outline the two stages of color vision: (1) The retina's receptors for red, green, and blue respond to different color stimuli. (2) The receptors' signals are then processed by the opponent-process cells on their way to the visual cortex in the brain.

What are the basic steps in transforming sound waves into perceived sound?

The outer ear collects sound waves, which are translated into mechanical waves by the middle ear and turned into fluid waves in the inner ear. The auditory nerve then translates the energy into electrical waves and sends them to the brain, which perceives and interprets the sound.

Why is it that after wearing shoes for a while, you cease to notice them (until questions like this draw your attention back to them)?

The shoes provide constant stimulation. Sensory adaptation allows us to focus on changing stimuli.

How do we normally perceive depth?

We are normally able to perceive depth thanks to (1) binocular cues (that are based on our retinal disparity), and (2) monocular cues (that include relative height, relative size, interposition, linear perspective, light and shadow, and relative motion).

We have specialized nerve receptors for detecting which five tastes? How did this ability aid our ancestors?

We have specialized receptors for detecting sweet, salty sour, bitter, and umami tastes. Being able to detect pleasurable tastes enabled our ancestor to seek out energy- and protein-rich foods. Detecting aversive tastes deterred them from eating toxic substances, increasing their chances of survival.

How does our system for sensing smell differ from our sensory systems for vision, touch, and taste?

We have two types of retinal receptors, four basic touch senses, and five taste sensations. But we have no basic smell receptors. Instead, different combinations of odor receptors send messages to the brain, enabling us to recognize some 10,000 different smells.

There are no receptor cells where the optic nerve leaves the eye. This creates a blind spot in your vision. To demonstrate, first close your left eye, look at the spot in Figure 5.13, and move your face away from the page to a distance at which one of the cars disappears. (Which one do you predict it will be?) Repeat with your right eye closed - and note that now the other car disappears. Can you explain why?

Your blind spot is on the nose side of each retina, which means that objects to your right may fall onto the right eye's blind spot. Objects on your left may fall on the left eye's blind spot. The blind spot does not normally impair your vision, because with but one eye open, your brain still fills in the blank spot.

What mental processes allow you to perceive a lemon as yellow?

Your brain constructs this perception of color in two stages. In the first stage, the lemon reflects light energy into your eyes, where it is transformed into neural messages. Three sets of cones, each sensitive to a different light frequency (red, blue, and green) process color. In this case, the light energy stimulates both red-sensitive and green-sensitive cones. In the second stage, opponent-process cells sensitive to paired opposites of color (red/green, yellow/blue, and black/white) evaluate the incoming neural messages as they pass through your optic nerve to the thalamus and visual cortex. When the yellow-sensitive opponent-process cells are stimulated, you identify the lemon as yellow.

Why do you feel a little dizzy immediately after a rollercoaster ride?

Your vestibular sense regulates balance and body positioning through kinesthetic receptors triggered by fluid in your inner ear. Wobbly legs and a spinning world are signs that these receptors are still responding to the ride's turbulence. As your vestibular sense adjusts to solid ground, your balance will be restored.

The amplitude of a sound wave determines our perception of loudness. The amplitude of a light wave determines our perception of a. brightness. b. color. c. meaning. d. distance.

a. brightness.

Our perceptual set influences what we perceive. This mental tendency reflects our a. experiences, assumptions, and expectations. b. perceptual adaptation. c. priming ability. d. difference thresholds.

a. experiences, assumptions, and expectations.

In listening to a concert, you attend to the solo instrument and perceive the orchestra as a accompaniment. This illustrates the organizing principle of a. figure-ground. b. shape constancy. c. grouping. d. depth perception.

a. figure-ground.

Of the four skin senses that make up our sense of touch, only _ has its own identifiable receptor cells. a. pressure b. warmth c. cold d. pain

a. pressure

Weber's law states that for a difference to be perceived, two stimuli must differ by a. a fixed or constant energy amount. b. a constant minimum percentage. c. a constantly changing amount. d. more than 7%.

b. a constant minimum percentage.

Sensation is to _ as perception is to _. a. absolute threshold; difference threshold b. bottom-up processing; top-down processing c. interpretation; detection d. grouping; priming

b. bottom-up processing; top-down processing

The visual cliff experiments suggest that a. infants have not yet developed depth perception. b. crawling human infants and very young animals perceive depth. c. we have no way of knowing whether infants can perceive depth. d. unlike other species, humans are able to perceive depth in infancy.

b. crawling human infants and very young animals perceive depth.

Perceiving a tomato as consistently red, despite lighting shifts, is an example of a. shape constancy. b. perceptual constancy. c. a binocular cue. d. continuity.

b. perceptual constancy.

After surgery to restore vision, patients who had been blind from birth had difficulty a. recognizing objects by touch. b. recognizing objects by sight. c. distinguishing figure from ground. d. distinguishing between bright and dim light.

b. recognizing objects by sight.

Which of the following options has NOT been proven to reduce pain? a. Distraction b. Hypnosis c. Phantom limb sensations d. Endorphins

c. Phantom limb sensations

Cones are the eye's receptor cells that are especially sensitive to _ light and are responsible for our _ vision. a. bright; black-and-white b. dim; color c. bright; color d. dim; black-and-white

c. bright; color

Depth perception underlies our ability to a. group similar items in a gestalt. b. perceive objects as having a constant shape or form. c. judge distances. d. fill in the gaps in a figure.

c. judge distances

The blind spot in your retina is located where a. there are rods but no cones. b. there are cones but no rods. c. the optic nerve leaves the eye. d. the bipolar cells meet the ganglion cells.

c. the optic nerve leaves the eye.

The snail-shaped tube in the inner ear, where sound waves are converted into neural activity, is called the _.

cochlea

Which of the following ESP events is supported by solid, replicable scientific evidence? a. Telepathy b. Clairvoyance c. Precognition d. None of these answers

d. None of these answers

Subliminal stimuli are a. too weak to be processed by the brain in any way. b. consciously perceived more than 50% of the time. c. always strong enough to affect our behavior. d. below our absolute threshold for conscious awareness.

d. below our absolute threshold for conscious awareness.

Our tendencies to fill in the gaps and to perceive a pattern as continuous are two different examples of the organizing principle called a. interposition. b. depth perception. c. shape constancy. d. grouping.

d. grouping.

Sensory adaptation helps us focus on a. visual stimuli. b. auditory stimuli. c. constant features of the environment. d. important changes in the environment.

d. important changes in the environment.

A food's aroma can greatly enhance its taste. This is an example of a. sensory adaptation. b. chemical sensation. c. kinesthesia. d. sensory interaction.

d. sensory interaction.

Two theories together account for color vision.The Young-Helmholtz trichromatic (three-color) theory shows that the eye contains _, and the opponent-process theory accounts for the nervous system's having _. a. opposing retinal processes; three pairs of color receptors b. opponent-process cells; three types of color receptors c. three pairs of color receptors; opposing retinal processes d. three types of color receptors; opponent-process cells

d. three types of color receptors; opponent-process cells

The cells in the visual cortex that respond to certain lines, edges, and angles are called _ _.

feature detectors

In terms of perception, a band's lead singer would be considered _(figure/ground), and the other musicians would be considered _(figure/ground).

figure; ground

Another term for difference threshold is the _ _ _.

just noticeable difference

The process by which we organize and interpret sensory information is called _.

perception

In experiments, people have worn glasses that turned their visual fields upside down. After a period of adjustment, they learned to function quite well. This ability is called _ _.

perceptual adaptation

Cats are able to open their _ much wider than we can, which allows more light into their eyes so they can see better at night.

pupils

The characteristic of light that determines the color we experience, such as blue or green, is _.

wavelength