Sensory receptors convert physical energy, such as light or sound waves, into action potentials that the nervous system can use. What is this conversion called?
Transduction
✓
Perception
Accommodation
Adaptation
Correct Answer
Transduction
Transduction is the step in which a sensory receptor changes stimulus energy into neural impulses sent to the central nervous system. Perception is the later organization and interpretation of that information. Accommodation is the lens changing shape to focus at different distances. Adaptation is a reduced response to an unchanging stimulus.
Category: Sensation Basics
Question 2
In a hearing test, the volume of a tone is lowered until the listener detects it on only half of the trials. That intensity marks the listener's...
Difference threshold
Absolute threshold
✓
Signal-to-noise ratio
Adaptation level
Correct Answer
Absolute threshold
The absolute threshold is the minimum amount of stimulus energy a person detects 50 percent of the time. Difference threshold is the smallest detectable change between two stimuli, not detection of a stimulus at all. Signal-to-noise ratio compares a signal with background noise rather than defining a detection point. Adaptation level is not the term for the faintest detectable stimulus.
Category: Sensation Basics
Question 3
Weber's law states that the smallest change a person can detect in a stimulus is...
A fixed amount at every intensity
Equal to the absolute threshold
A constant fraction of the original stimulus
✓
Larger for dim stimuli than bright ones
Correct Answer
A constant fraction of the original stimulus
Ernst Weber proposed that the just noticeable difference is a constant proportion of the starting stimulus, so a stronger stimulus needs a larger change to be noticed. A fixed amount at every intensity is wrong because the detectable change grows with intensity. Equal to the absolute threshold confuses detecting a change with detecting a stimulus. Larger for dim stimuli than bright ones reverses the law, since bright stimuli need the larger change.
Category: Sensation Basics
Question 4
A new parent sleeps through traffic noise but wakes at the baby's faintest whimper. Which theory explains how a person picks out a meaningful stimulus from background noise, with motivation and expectation playing a role?
Opponent-process theory
Gate control theory
Place theory
Signal detection theory
✓
Correct Answer
Signal detection theory
Signal detection theory describes the ability to detect a stimulus against background noise and recognizes that motivation and expectations affect what gets detected. Opponent-process theory explains color vision. Gate control theory is an account of how pain signals are regulated in the spinal cord. Place theory explains how pitch is coded along the basilar membrane.
Category: Sensation Basics
Question 5
When you first walk into a friend's kitchen the smell of garlic is strong, but after 15 minutes you barely notice it, even though the odor is still present. This reduced response to a constant stimulus is called...
Sensory adaptation
✓
Inattentional blindness
Stimulus generalization
Top-down processing
Correct Answer
Sensory adaptation
Sensory adaptation is the decline in sensitivity to a stimulus that stays the same over time, which frees attention for changes in the environment. Inattentional blindness is failing to notice something because attention is directed elsewhere. Stimulus generalization is a conditioning term for responding to stimuli similar to a conditioned stimulus. Top-down processing is perception guided by knowledge and expectations.
Category: Sensation Basics
Question 6
In a well-known study, nearly half of the viewers who were counting basketball passes in a video failed to notice a person in a gorilla suit walking through the scene. This failure to see a plainly visible object while attention is focused elsewhere is called...
Sensory adaptation
Inattentional blindness
✓
Binocular rivalry
Perceptual constancy
Correct Answer
Inattentional blindness
Inattentional blindness is missing a fully visible stimulus because attention is engaged by something else, as Simons and Chabris showed with the gorilla video. Sensory adaptation is reduced sensitivity to an unchanging stimulus, not a lapse caused by attention. Binocular rivalry occurs when each eye sees a different image and perception alternates between them. Perceptual constancy is seeing objects as stable in size, shape or color despite changing sensory input.
Category: Attention and Processing
Question 7
A sudden crash of breaking glass grabs your attention in a restaurant even though you were focused on your conversation. Perception driven by the incoming stimulus itself, rather than by expectations, is called...
Top-down processing
Perceptual hypothesis
Bottom-up processing
✓
Perceptual set
Correct Answer
Bottom-up processing
Bottom-up processing builds perception from the sensory input arriving from the environment, so a loud, unexpected sound captures attention on its own. Top-down processing is the opposite, with knowledge and expectations guiding perception. Perceptual hypothesis refers to an educated guess about what a stimulus is, which is a top-down influence. Perceptual set is a readiness to perceive things a certain way based on expectations, also a top-down influence.
Category: Attention and Processing
Question 8
Differences in the wavelength of visible light are perceived as differences in...
Brightness
Intensity
Saturation
Hue
✓
Correct Answer
Hue
Hue, or color, is determined by wavelength, with red at the long end of the visible spectrum and blue and violet at the short end. Brightness depends on the amplitude of the light wave, not its wavelength. Intensity is another way of describing amplitude. Saturation refers to how pure or vivid a color is, not which color it is.
Category: Light and Sound Waves
Question 9
What is the approximate range of sound frequencies that a typical young human can hear?
20 to 20,000 Hz
✓
200 to 2,000 Hz
2 to 200 Hz
2,000 to 200,000 Hz
Correct Answer
20 to 20,000 Hz
Human hearing spans roughly 20 to 20,000 hertz, with the greatest sensitivity in the middle of that range. The range 200 to 2,000 Hz is far too narrow and leaves out much of speech and music. The range 2 to 200 Hz is mostly below what humans can hear. The range 2,000 to 200,000 Hz extends far into ultrasound, which some animals such as bats can hear but humans cannot.
Category: Light and Sound Waves
Question 10
Light is normally focused on a small pit in the center of the retina that is densely packed with cones and provides the sharpest vision. What is this region called?
Blind spot
Fovea
✓
Optic chiasm
Iris
Correct Answer
Fovea
The fovea is the small indentation in the retina where images are normally focused, and its dense cones give the highest visual acuity. Blind spot is the place where the optic nerve leaves the eye and there are no photoreceptors. Optic chiasm is where the optic nerves meet below the front of the brain, outside the eye. Iris is the colored muscle that controls the size of the pupil.
Category: Vision
Question 11
Which retinal cells serve as the photoreceptors for vision in dim light and for detecting movement at the edges of the visual field?
Cones
Bipolar cells
Rods
✓
Ganglion cells
Correct Answer
Rods
Rods work well in low light and respond to motion in peripheral vision, though they provide little detail and no color. Cones are the photoreceptors for bright light, fine detail and color. Bipolar cells relay signals from photoreceptors but do not detect light themselves. Ganglion cells receive signals from the inner retina and send their axons out as the optic nerve.
Category: Vision
Question 12
Each eye has a blind spot in its field of view. What causes it?
The cornea is thickest at that point
Only rods are found in that area
The lens cannot focus light there
The optic nerve leaves the eye there
✓
Correct Answer
The optic nerve leaves the eye there
Where the optic nerve exits the back of the eye there are no photoreceptors, so light falling on that spot is not detected. The cornea is thickest at that point is wrong because the cornea is at the front of the eye and does not create the gap. Only rods are found in that area is wrong because rods would still detect light. The lens cannot focus light there is wrong because the problem is missing receptors, not focus.
Category: Vision
Question 13
Which theory of color vision holds that colors are coded in pairs, such as red-green and yellow-blue, so that a cell excited by one color of a pair is inhibited by the other?
Opponent-process theory
✓
Trichromatic theory
Place theory
Temporal theory
Correct Answer
Opponent-process theory
Opponent-process theory proposes paired color channels in which one member of a pair inhibits the other, which explains negative afterimages and why no color looks reddish-green. Trichromatic theory explains color through three types of cones and applies at the level of the retina. Place theory and temporal theory are theories of how pitch is coded in hearing.
Category: Vision
Question 14
Looking down a straight railroad track, the parallel rails seem to come together in the distance. This monocular depth cue is called...
Interposition
Linear perspective
✓
Binocular disparity
Relative size
Correct Answer
Linear perspective
Linear perspective is the cue in which parallel lines appear to converge as they recede, signaling greater distance. Interposition is the cue in which one object partly blocks another and so appears closer. Binocular disparity requires both eyes, so it is not a monocular cue. Relative size is the cue in which a smaller image of a familiar object suggests it is farther away.
Category: Vision
Question 15
Which structure transmits vibrations directly to the oval window of the cochlea?
Malleus
Incus
Stapes
✓
Tympanic membrane
Correct Answer
Stapes
The stapes, or stirrup, is the last of the three middle ear bones and presses into the oval window, passing vibrations into the fluid of the cochlea. Malleus is the hammer, which picks up vibrations from the eardrum. Incus is the anvil, which links the malleus to the stapes. Tympanic membrane is the eardrum, which vibrates first and passes motion to the malleus.
Category: Hearing
Question 16
High-frequency sounds most strongly vibrate the base of the basilar membrane, while low-frequency sounds vibrate its tip. Which theory of pitch perception is built on this pattern?
Temporal theory
Trichromatic theory
Opponent-process theory
Place theory
✓
Correct Answer
Place theory
Place theory holds that pitch is coded by the location along the basilar membrane that responds most to a sound. Temporal theory codes frequency by the firing rate of auditory neurons instead, which cannot cover very high frequencies. Trichromatic theory and opponent-process theory are explanations of color vision.
Category: Hearing
Question 17
After an ear infection, fluid trapped behind a child's eardrum keeps sound vibrations from being carried efficiently to the inner ear. This is an example of...
Conductive hearing loss
✓
Sensorineural hearing loss
Congenital deafness
Auditory nerve damage
Correct Answer
Conductive hearing loss
Conductive hearing loss occurs when sound energy is not delivered to the cochlea, from causes such as fluid behind the eardrum, a hole in the eardrum or problems with the ossicles. Sensorineural hearing loss is a failure of neural signals to travel from the cochlea to the brain. Congenital deafness means being born without hearing. Auditory nerve damage is a neural problem, not a blockage of sound transmission.
Category: Hearing
Question 18
A sound coming from your left reaches your left ear a split second before it reaches your right ear. Which binaural cue does this describe?
Interaural level difference
Interaural timing difference
✓
Monaural cue
Place code
Correct Answer
Interaural timing difference
Interaural timing difference is the small delay between a sound's arrival at the near ear and the far ear, which helps locate sounds along the horizontal plane. Interaural level difference is the difference in loudness at the two ears because the head blocks some sound. Monaural cue uses information from one ear, not a comparison of two. Place code refers to coding pitch by location on the basilar membrane.
Category: Hearing
Question 19
A figure skater keeps her balance through a fast spin. Which sense, served by the fluid-filled semicircular canals of the inner ear, makes this possible?
Kinesthesia
Proprioception
Vestibular sense
✓
Auditory sense
Correct Answer
Vestibular sense
The vestibular sense supports balance and posture through the semicircular canals, utricle and saccule, which contain fluid and hair cells next to the cochlea. Kinesthesia is the perception of the body's movement, based on receptors in muscles, joints and tendons. Proprioception is the perception of body position from those same receptors. Auditory sense is hearing, which depends on the cochlea rather than the semicircular canals.
Category: Other Senses
Question 20
Six identical dots are printed in a row, with small gaps inside each pair and larger gaps between pairs. Viewers see three pairs rather than six separate dots. Which Gestalt principle explains this grouping?
Similarity
Closure
Continuity
Proximity
✓
Correct Answer
Proximity
Proximity is the tendency to group elements that are near one another, the same principle that lets spaces separate words when reading. Similarity groups elements that look alike, but these dots are identical. Closure fills in gaps to see a complete figure. Continuity favors smooth, unbroken lines over jagged ones.
Category: Gestalt Principles