Bio 5

Question 1

Which of the following best explains why rubbing your eyes in darkness can produce perceived flashes of light?

A. Mechanical pressure generates false action potentials in the optic nerve
B. Ganglion cells misinterpret tactile input from the fingers
C. Visual receptors respond to any form of excitation as visual information
D. The lens and cornea distort ambient darkness into illusory light

Answer 1

Answer: C
Explanation: The visual system interprets any excitation of the visual receptors as light. Rubbing your eyes mechanically stimulates these receptors, triggering the perception of light even in total darkness.

Question 2

Why is the retina organized so that messages travel from receptors to bipolar cells and then to ganglion cells instead of directly to the brain?

A. This layered structure maximizes the retina’s exposure to light
B. It allows processing and refinement of visual information before it leaves the eye
C. It ensures image orientation is corrected before reaching the brain
D. This organization evolved to make the optic nerve structurally stronger

Answer 2

Answer: B
Explanation: This arrangement allows intermediate cells (like amacrine cells) to process and refine visual signals before ganglion cells transmit them to the brain.

Question 3

Which principle explains why impulses from the auditory nerve are always interpreted as sound, regardless of the stimulation source?

A. The inverse projection principle
B. The encoding theory of perception
C. The law of specific nerve energies
D. Retinotopic mapping theory

Answer 3

Answer: C
Explanation: Johannes Müller’s law of specific nerve energies states that each sensory nerve produces a particular kind of sensation, no matter how it is stimulated.

Question 4

What is the brain’s response to the blind spot in the visual field?

A. The brain ignores it, resulting in frequent unnoticed gaps
B. The brain redirects neural signals from the adjacent retina
C. The brain fills in missing information based on surrounding visual input
D. The brain activates the optic chiasm to compensate for it

Answer 4

Answer: C
Explanation: The brain “fills in” the blind spot using surrounding visual patterns and information from the other eye, making the blind spot imperceptible in daily life

Question 5

Why is the inversion of the visual image on the retina not problematic for perception?

A. The retina inverts the image back before sending it to the brain
B. The brain stores images in pictorial format regardless of input
C. The brain codes visual information abstractly, not as spatial pictures
D. The eye compensates for the inversion through muscular coordination

Answer 5

Answer: C
Explanation: The brain encodes visual information in terms of neural activity patterns rather than spatially accurate images—similar to how a computer processes data without storing literal pictures.

Question 6

Why does the fovea provide the clearest and most detailed vision?

A. It contains both rods and cones in equal proportion
B. It is located near the optic nerve, which improves signal transmission
C. Each photoreceptor connects to a single bipolar and ganglion cell
D. It is surrounded by a high density of amacrine cells

Answer 6

Correct Answer: C
Explanation: The fovea provides acute vision because each cone connects to one bipolar cell and then to one ganglion cell, allowing for a high-resolution signal path to the brain.

Question 7

Why does the fovea provide the clearest and most detailed vision?

A. It contains both rods and cones in equal proportion
B. It is located near the optic nerve, which improves signal transmission
C. Each photoreceptor connects to a single bipolar and ganglion cell
D. It is surrounded by a high density of amacrine cells

Answer 7

Correct Answer: C
Explanation: The fovea provides acute vision because each cone connects to one bipolar cell and then to one ganglion cell, allowing for a high-resolution signal path to the brain.

Question 8

What is the main functional trade-off of the periphery of the retina compared to the fovea?

A. Better color discrimination but poorer depth perception
B. Higher sensitivity to dim light but lower detail resolution
C. Better detail resolution but only in black and white
D. Enhanced motion detection but decreased color accuracy

Answer 8

Correct Answer: B
Explanation: In the periphery, many receptors converge onto single ganglion cells, boosting sensitivity to dim light but sacrificing spatial detail.

Question 9

Which statement best explains why midget ganglion cells contribute disproportionately to visual input?

A. They transmit signals from multiple rods simultaneously
B. They are especially responsive to movement in the periphery
C. Each transmits signals from a single cone in the fovea
D. They receive input from both cones and rods across the retina

Answer 9

Correct Answer: C
Explanation: Midget ganglion cells, found in the fovea, each connect to a single cone, providing precise visual input—accounting for about 70% of input to the brain.

Question 10

How do hawks’ retinal adaptations reflect their ecological niche?

A. Greater receptor density on the bottom half of the retina improves aerial vision
B. Two foveas per eye allow for near and far color vision simultaneously
C. Enhanced receptor density on the top retina supports downward focus for hunting
D. Predatory birds use the blind spot to track prey through motion compensation

Answer 10

Correct Answer: C
Explanation: Hawks have denser visual receptors on the top half of the retina to enhance downward vision—ideal for spotting prey from above

Question 11

Which of the following limits detail perception in the peripheral retina?

A. Lack of cones
B. Fewer bipolar cells
C. Absence of ganglion cells
D. Convergence of multiple receptors onto fewer ganglion cells

Answer 11

Correct Answer: D
Explanation: In the periphery, many photoreceptors converge onto fewer ganglion cells, making it difficult to localize stimuli precisely or see fine details.

Question 12

What visual limitation is demonstrated when you struggle to read a letter flanked by other letters in your peripheral vision?

A. Rod saturation
B. Lateral inhibition
C. Crowding effect
D. Visual neglect

Answer 12

Correct Answer: C
Explanation: The crowding effect refers to difficulty identifying an object in the periphery due to interference from nearby objects, limiting detail recognition.

Question 13

Why are rods ineffective for vision in daylight?

A. They are located only in the blind spot
B. Their photopigments regenerate too slowly
C. Bright light bleaches their photopigments
D. They are outnumbered by cones in the fovea

Answer 13

Correct Answer: C
Explanation: Bright light bleaches rods, rendering them temporarily nonfunctional, which is why they are not useful during the day.

Question 14

Despite being vastly outnumbered by rods, why do cones contribute more to the brain’s visual input?

A. Cones regenerate faster in low light
B. Each cone has a dedicated ganglion cell connection
C. Cones are more numerous in the retina
D. Rods do not transmit signals to the optic nerve

Answer 14

Correct Answer: B
Explanation: In the fovea, each cone connects individually to a ganglion cell, creating a high-resolution pathway and contributing ~90% of visual input.

Question 15

What explains the superior visual processing abilities in elite athletes?

A. Larger eyes and denser cones
B. Faster retinal regeneration
C. More axons in the optic nerve and a larger visual cortex
D. Reduced convergence in peripheral vision

Answer 15

Correct Answer: C
Explanation: Genetic differences allow some individuals to have more optic nerve axons and more neurons in the visual cortex, improving visual stimulus detection.

Question 16

What is the correct pathway for light-induced activation in photoreceptors?

A. All-trans-retinal → 11-cis-retinal → Second messengers
B. Opsins → 11-cis-retinal → Energy release
C. Light → 11-cis-retinal → All-trans-retinal → Second messengers
D. Opsins → All-trans-retinal → Direct neurotransmitter release

Answer 16

Correct Answer: C
Explanation: Light converts 11-cis-retinal to all-trans-retinal, which releases energy and activates second messengers in the photoreceptor cell.

Question 17

Which of the following best describes the distribution of rods and cones in the human retina?

A. Cones dominate in the periphery, rods in the fovea
B. Rods are only active in daylight, cones in the dark
C. Rods are concentrated in the periphery; cones are concentrated in the fovea
D. Rods and cones are evenly distributed throughout the retina

Answer 17

Correct Answer: C
Explanation: Rods are abundant in the periphery and help with low-light vision, while cones are centered in and near the fovea, crucial for color and detailed vision.

Question 18

Which of the following best explains why short-wavelength (blue) dots are harder to see from a distance than red or green ones?

A. Blue cones are not evenly distributed across the retina.
B. Short-wavelength cones are more numerous in the fovea.
C. Long- and medium-wavelength cones are more abundant than blue cones.
D. Blue light has less energy and thus stimulates the retina less effectively.

Answer 18

Correct Answer: C
Explanation: Long- and medium-wavelength cones (red and green) are far more numerous than short-wavelength (blue) cones, making it harder to resolve blue stimuli, especially small or distant ones.

Question 19

According to the trichromatic theory, what would happen if only the long-wavelength cones were active?

A. The person would perceive the color blue.
B. The person would perceive a desaturated yellow.
C. The person would perceive a shade of red.
D. The person would be unable to see color.

Answer 19

Correct Answer: C
Explanation: The trichromatic theory states that color perception is based on the relative activity of three types of cones. If only the long-wavelength cones are active, the brain interprets that as red.

Question 20

What key evidence originally led Helmholtz to conclude that three types of receptors are sufficient for color vision?

A. People could match any color using a combination of three primary pigments.
B. Some individuals see ultraviolet light.
C. All cones have overlapping wavelength sensitivity.
D. The retina contains only three layers of photoreceptors.

Answer 20

Correct Answer: A
Explanation: Helmholtz observed that people could match any visible color by mixing just three specific wavelengths of light, suggesting the existence of three types of cones.

Question 21

The phenomenon in which staring at a red object leads to seeing green on a white surface is best explained by:

A. Trichromatic theory
B. Cortical adaptation theory
C. Opponent-process theory
D. Saturation inversion theory

Answer 21

Correct Answer: C
Explanation: The opponent-process theory accounts for afterimages. Prolonged exposure to red fatigues the red-green mechanism, leading to a perception of green in the absence of stimulation.

Question 22

If a bipolar cell is excited by short-wavelength cones and inhibited by long- and medium-wavelength cones, what color would likely decrease its activity the most?

A. Red
B. Blue
C. Green
D. Yellow

Answer 22

Correct Answer: D
Explanation: Yellow light strongly activates medium- and long-wavelength cones and minimally activates short-wavelength cones, leading to strong inhibition of that bipolar cell.

Question 23

Why is the response of a single cone considered ambiguous?

A. Cones cannot detect intensity variations.
B. A single cone type responds identically to all wavelengths.
C. Its response could be due to various combinations of wavelength and intensity.
D. Each cone only responds to a single, narrow wavelength.

Answer 23

Correct Answer: C
Explanation: The output of a single cone doesn’t unambiguously indicate the wavelength of light—it could reflect high-intensity short wavelength or low-intensity long wavelength. The brain resolves this by comparing responses across cone types.

Question 24

Which phenomenon best motivated the development of the Retinex theory over previous theories of color vision?

A. The discovery of colorblindness in individuals with normal visual acuity
B. The perception of motion in peripheral vision
C. The ability to recognize object colors under different lighting conditions
D. The finding that cones respond to overlapping wavelengths of light

Answer 24

Correct Answer: C
Explanation: Retinex theory was developed to explain color constancy—the brain’s ability to perceive consistent colors despite changes in lighting, which earlier theories couldn’t fully explain.

Question 25

What is the core mechanism behind the Retinex theory of color and brightness perception? A. Lateral inhibition between ganglion cells B. Cortical comparison across multiple retinal inputs C. Exclusive reliance on individual cone responses D. Photopigment adaptation in the fovea

Answer 25

Correct Answer: B Explanation: Retinex theory proposes that the cortex compares information from different areas of the retina to determine both brightness and color—a key distinction from purely retinal theories.

Question 26

. In which situation does Retinex theory best explain a visual phenomenon that trichromatic and opponent-process theories cannot? A. Perceiving the exact hue of a laser beam in darkness B. Seeing an afterimage after looking at a strong color C. Identifying the true color of an object under tinted lighting D. Suffering from red-green color deficiency

Answer 26

Correct Answer: C Explanation: Retinex theory explains color constancy, like still seeing a banana as yellow under green lighting—something earlier theories cannot explain adequately.

Question 27

Which statement provides the strongest evidence against the idea that color is purely a property of light itself? A. Certain animals can see in the ultraviolet range B. Identical wavelengths can appear as different colors depending on context C. Blue cones are less sensitive in low-light conditions D. Cones respond faster in bright light

Answer 27

Correct Answer: B Explanation: The same wavelength can be perceived as different colors depending on surrounding light and context, supporting the idea that color is a product of brain processing, not just light.

Question 28

A person with red-green color deficiency has which of the following most likely occurring in their retina? A. A total absence of blue-sensitive cones B. Only one type of rod photopigment C. Identical photopigments in medium- and long-wavelength cones D. Damage to retinal ganglion cells responsible for color transmission

Answer 28

Correct Answer: C Explanation: Red-green deficiency typically involves abnormal similarity or identity in the photopigments of medium- and long-wavelength cones, reducing the ability to distinguish red from green.

Question 29

What does the success of gene therapy in red-green color-deficient monkeys suggest about the human brain's potential for color vision? A. Adult brains cannot adapt to new visual inputs B. The retina, not the brain, limits color perception C. Cortical plasticity may allow full color perception if cone diversity is restored D. Only early-life exposure determines color processing ability

Answer 29

Correct Answer: C Explanation: The monkeys’ ability to learn to discriminate colors after gaining a third cone type suggests the brain can adapt to new retinal inputs, implying cortical plasticity.

Question 30

Why might some women have more nuanced color perception than men? A. They have more cones in general B. They often carry genes for colorblindness C. They may have two genetically distinct long-wavelength cones D. Their cones regenerate photopigments faster

Answer 30

Correct Answer: C Explanation: Due to X-linked genetic variation, some women inherit two slightly different versions of long-wavelength receptors, enhancing their ability to distinguish subtle color differences.

Question 31

In the mammalian visual system, which of the following cell types sends inhibitory signals directly onto bipolar cells? A) Rods and cones B) Ganglion cells C) Horizontal cells D) Amacrine cells

Answer 31

Answer: C) Horizontal cells Explanation: Horizontal cells receive input from rods and cones and provide inhibitory feedback to bipolar cells, helping create lateral inhibition and sharpen contrast.

Question 32

When the optic nerves reach the optic chiasm in humans, what happens to the information from the nasal half of each retina? A) It remains on the same side (ipsilateral). B) It crosses to the contralateral hemisphere. C) It is discarded before reaching the brain. D) It bypasses the thalamus and goes directly to the cortex.

Answer 32

Answer: B) It crosses to the contralateral hemisphere. Explanation: In humans, fibers from the nasal half of each retina cross over to the opposite side of the brain at the optic chiasm, ensuring that each hemisphere processes the visual field from the opposite side

Question 33

Which structure receives the majority of the optic nerve axons and acts as a key relay station to the visual cortex? A) Superior colliculus B) Hypothalamus C) Lateral geniculate nucleus D) Temporal cortex

Answer 33

Answer: C) Lateral geniculate nucleus Explanation: Most ganglion cell axons terminate at the lateral geniculate nucleus (LGN) in the thalamus, which then sends visual information to the visual cortex.

Question 34

In lateral inhibition within the retina, stimulation of a photoreceptor leads to: A) Excitation of surrounding bipolar cells. B) Inhibition of surrounding bipolar cells via horizontal cells. C) Direct inhibition of surrounding ganglion cells. D) Inhibition of the originating photoreceptor itself.

Answer 34

Answer: B) Inhibition of surrounding bipolar cells via horizontal cells. Explanation: The activated photoreceptor excites horizontal cells, which then inhibit neighboring bipolar cells, creating enhanced edge contrast.

Question 35

What is the direct effect of light striking rods and cones? A) It causes them to increase their spontaneous firing rate. B) It increases their excitatory output to bipolar cells. C) It decreases their inhibitory output, resulting in excitation of bipolar cells. D) It directly depolarizes ganglion cells.

Answer 35

Answer: C) It decreases their inhibitory output, resulting in excitation of bipolar cells. Explanation: Light reduces the normal spontaneous inhibitory output of rods and cones; this decrease in inhibition leads to net excitation of bipolar cells.

Question 36

In the cookie analogy for lateral inhibition, which position would experience the greatest loss relative to their starting number of cookies? A) Someone in the center of the group receiving extra cookies. B) Someone at the edge of the group receiving cookies. C) Someone just outside the group receiving cookies. D) Someone far away from the cookie distribution area.

Answer 36

Answer: C) Someone just outside the group receiving cookies. Explanation: These individuals receive no cookies but lose one to their neighbor, similar to how cells adjacent to a lighted area are inhibited without direct stimulation.

Question 37

What is the primary purpose of lateral inhibition in the retina? A) To prevent overstimulation of bipolar cells. B) To create a uniform response across the retina. C) To sharpen the perception of edges and contrasts. D) To decrease the overall energy consumption of retinal cells.

Answer 37

Answer: C) To sharpen the perception of edges and contrasts. Explanation: Lateral inhibition enhances contrast at edges, making borders in the visual field more distinct and easier to detect.

Question 38

Which feature of horizontal cells makes them particularly suited for spreading inhibition locally within the retina? A) They have long axons that transmit impulses far distances. B) They fire rapid action potentials. C) They have no axons and spread signals through graded potentials. D) They connect only to ganglion cells, not bipolar cells.

Answer 38

Answer: C) They have no axons and spread signals through graded potentials. Explanation: Horizontal cells transmit signals by graded depolarization (not action potentials), which decay with distance, providing localized inhibition.

Question 39

When several photoreceptors (6–10) are excited simultaneously, which bipolar cells respond the most strongly? A) Those in the center of the excited region. B) Those at the edges of the excited region. C) Those outside the excited region. D) Those far away from the excited region.

Answer 39

Answer: B) Those at the edges of the excited region. Explanation: Bipolar cells at the edges (like cells 6 and 10) are less inhibited from neighboring sides compared to those in the center, leading to stronger responses.

Question 40

In systems like olfaction, touch, and hearing, lateral inhibition is used to: A) Sharpen spatial and temporal contrast of stimuli. B) Eliminate all weak stimuli. C) Slow down sensory processing to avoid overload. D) Increase the size of receptive fields.

Answer 40

Answer: A) Sharpen spatial and temporal contrast of stimuli. Explanation: Lateral inhibition across senses helps highlight important information (like edges, specific smells, or speech) while reducing background noise.

Question 41

Which statement best describes the receptive field of a ganglion cell compared to a photoreceptor? A) It is smaller because it receives input from only one rod or cone. B) It is larger because it integrates inputs from multiple bipolar cells. C) It is the same size, maintaining consistent sensitivity throughout. D) It only responds to color information from cones.

Answer 41

Answer: B Explanation: Ganglion cells receive input from multiple bipolar cells, which themselves integrate signals from multiple rods or cones, leading to a larger receptive field.

Question 42

Damage to the primary visual cortex (V1) most likely results in: A) Loss of peripheral vision but enhanced central vision. B) Inability to detect motion but preservation of color vision. C) Conscious blindness, but possible unconscious responses to visual stimuli (blindsight). D) Total inability to receive any visual input from the retina.

Answer 42

Answer: C Explanation: Damage to V1 leads to conscious blindness but blindsight, where individuals can respond to stimuli without conscious awareness.

Question 43

Which type of ganglion cell would most likely detect fine visual details and color differences? A) Magnocellular B) Koniocellular C) Parvocellular D) Photocellular

Answer 43

Answer: C Explanation: Parvocellular neurons, found near the fovea, have small receptive fields and specialize in detecting fine detail and color.

Question 44

Blindsight phenomena can best be explained by: A) Regeneration of the damaged photoreceptors in the retina. B) Intact alternate pathways from the thalamus to other brain areas like the temporal cortex. C) Activation of the magnocellular pathways in the occipital lobe. D) Hyperactivity of the damaged area V1.

Answer 44

Answer: B Explanation: Alternate visual pathways (especially thalamus to temporal cortex) allow unconscious visual processing even when V1 is damaged.

Question 45

Continuous flash suppression demonstrates that: A) The retina must be constantly moving to perceive stable images. B) Conscious visual perception can be suppressed while unconscious detection persists. C) Only magnocellular ganglion cells are active during unconscious perception. D) Damage to the lateral geniculate nucleus leads to blindness.

Answer 45

Answer: B Explanation: Under continuous flash suppression, people unconsciously detect the stimulus (e.g., faces, tools) despite reporting no conscious awareness.

Question 46

Which property best distinguishes magnocellular from parvocellular neurons? A) Magnocellular neurons have smaller cell bodies and receptive fields. B) Magnocellular neurons are specialized for color discrimination. C) Magnocellular neurons respond strongly to movement and broad patterns. D) Magnocellular neurons are found only in the fovea.

Answer 46

Answer: C Explanation: Magnocellular neurons, with large receptive fields, are specialized for detecting movement and overall patterns, not color or fine detail.

Question 47

When recording from a neuron, if shining light on a specific spot inhibits its activity, that spot belongs to: A) The excitatory center. B) The inhibitory surround. C) The foveal cluster. D) The primary optic nerve field.

Answer 47

Answer: B Explanation: If light inhibits a neuron's firing, that spot is part of its inhibitory surround in the receptive field.

Question 48

What discovery led Hubel and Wiesel to realize how cells in the occipital cortex respond to visual stimuli? A) Cells responded strongly to dots of light projected on a screen B) Cells responded when they moved a slide into place, detecting an edge C) Cells were unresponsive to any type of light stimulus D) Cells responded only to flashing lights

Answer 48

Answer: B) Cells responded when they moved a slide into place, detecting an edge Explanation: Hubel and Wiesel discovered that cortical cells responded strongly when a light edge, not a dot, was moved across the retina, leading to their identification of edge-detecting receptive fields.

Question 49

What is the shape of the receptive field in simple cells of the visual cortex? A) Circular B) Spiral C) Bar-shaped or edge-shaped D) Triangular

Answer 49

Answer: C) Bar-shaped or edge-shaped Explanation: Simple cells in the visual cortex have receptive fields that are bar-shaped or edge-shaped, which are sensitive to specific orientations of light.

Question 50

What happens if the orientation of a bar of light is tilted slightly when stimulating a simple cell? A) The cell's response increases B) The cell's response decreases C) The cell's response stays the same D) The cell becomes unresponsive permanently

Answer 50

Answer: B) The cell's response decreases Explanation: Simple cells have fixed excitatory and inhibitory zones, so when the orientation of the bar changes, it can reduce the cell's response as inhibitory zones are activated.

Question 51

Compared to diagonal orientations, simple cells are more responsive to which orientations? A) Curved lines B) Circular patterns C) Horizontal and vertical lines D) Random movement

Answer 51

Answer: C) Horizontal and vertical lines Explanation: Simple cells are more responsive to horizontal and vertical lines because these orientations are more common in the environment, making them more relevant for vision.

Question 52

Which of the following best describes the response of a complex cell? A) It only responds to a stimulus at an exact location B) It responds to a specific pattern of light in any location within a large receptive field C) It only responds to stationary objects D) It ignores all vertical patterns

Answer 52

Answer: B) It responds to a specific pattern of light in any location within a large receptive field Explanation: Complex cells are different from simple cells because they respond to patterns of light, such as a bar, anywhere within their receptive field, regardless of exact location.

Question 53

What characteristic helps differentiate a complex cell from a simple cell? A) Its preference for darker stimuli B) Its response to the stimulus across a broad receptive field rather than one fixed location C) Its preference for circular receptive fields D) Its inability to detect movement

Answer 53

Answer: B) Its response to the stimulus across a broad receptive field rather than one fixed location Explanation: Unlike simple cells, complex cells respond to stimuli anywhere within their large receptive field, making them less location-specific.

Question 54

End-stopped (hypercomplex) cells differ from complex cells by having: A) No excitatory zones B) A strong inhibitory area at one end of their receptive field C) A preference for horizontal lines only D) A response only to flashing lights

Answer 54

Answer: B) A strong inhibitory area at one end of their receptive field Explanation: End-stopped cells have an inhibitory zone at one end of their receptive field, making them respond to bars of light within a specific range but not beyond a certain point.

Question 55

In the visual cortex, cells with similar properties are grouped into: A) Hemispheres B) Lobes C) Columns D) Layers

Answer 55

Answer: C) Columns Explanation: Cells with similar orientation preferences or responses are organized into columns perpendicular to the cortical surface in the visual cortex.

Question 56

The columnar organization of the visual cortex suggests that: A) Layers of the cortex are independent of each other B) Layers of the cortex communicate richly with one another C) Each layer processes completely unrelated information D) Only one layer is involved in vision

Answer 56

Answer: B) Layers of the cortex communicate richly with one another Explanation: The columnar organization indicates that different layers of the cortex work together and communicate, processing similar types of information rather than working in isolation.

Question 57

What key evidence supports the idea that some visual cortex neurons act as feature detectors? A) Neurons respond more strongly to random noise than to specific patterns. B) Prolonged exposure to a visual feature decreases sensitivity to that feature. C) Cells in V1 respond exclusively to color, not shape. D) Visual cortex responses remain unchanged regardless of experience.

Answer 57

Answer: B Explanation: Fatiguing of specific detectors (e.g., motion aftereffects like the waterfall illusion) supports the idea that neurons specialize in detecting certain features.

Question 58

What phenomenon challenges the idea that simple feature detection alone explains vision? A) Feature fatigue after exposure B) Waterfall illusion C) Mooney face recognition D) Sine wave gratings

Answer 58

Answer: C Explanation: Mooney faces show that interpretation and top-down processing are needed beyond just raw feature detection.

Question 59

According to research, neurons in the primary visual cortex (V1) are most responsive to which type of stimulus? A) Single bars and edges only B) Spatial frequencies like sine wave gratings C) Complete, recognizable objects D) Random noise patterns

Answer 59

Answer: B Explanation: V1 neurons respond strongly to specific spatial frequencies, suggesting they detect features we don't consciously perceive as sine waves.

Question 61

What mathematical concept helps explain how spatial frequencies combine to form complex visual patterns? A) Quantum analysis B) Fourier analysis C) Bayesian inference D) Gestalt summation

Answer 61

Answer: B Explanation: Fourier analysis shows how multiple sine waves combine to create any complex visual pattern.

Question 62

If both eyes are deprived of visual experience early in life, what initially happens to cortical responsiveness? A) Cortex becomes completely inactive. B) Cortex remains responsive but lacks binocular connections. C) Cortex develops stronger auditory responses immediately. D) Cortex preferentially strengthens one eye’s input.

Answer 62

Answer: B Explanation: With both eyes deprived, the cortex stays somewhat responsive, but cells mostly favor input from only one eye, losing normal binocular integration.

Question 63

How can a "new" sensitive period be experimentally induced in older animals? A) Closing one eye for an extended time B) Transplanting inhibitory neurons from young animals C) Repeated exposure to bright lights D) Complete sensory deprivation

Answer 63

Answer: B Explanation: Transplanting inhibitory neurons from infants into adults can reopen a sensitive period, increasing cortical plasticity

Question 64

After a sensitive period ends, how does the visual cortex behave when one eye is deprived of input for a week? A) No changes occur. B) Large-scale reorganization happens instantly. C) Small but measurable plastic changes still occur. D) The visual cortex permanently loses its ability to respond.

Answer 64

Answer: C Explanation: Although plasticity is greatest early, even adults show small changes after prolonged deprivation.

Question 65

What is necessary for stereoscopic depth perception? A) Eye muscle strength B) Detection of retinal disparity C) Equal brightness in both eyes D) Color matching between the two eyes

Answer 65

Answer: B) Detection of retinal disparity Explanation: Stereoscopic depth perception relies on detecting small differences (disparities) between the images seen by each eye.

Question 66

In infants, astigmatism affects vision by: A) Causing sensitivity to all lines equally B) Blurring lines in a specific direction C) Blocking all light from reaching the eye D) Enhancing color perception

Answer 66

Answer: B) Blurring lines in a specific direction Explanation: Astigmatism results from uneven eye curvature, blurring vision for certain orientations (e.g., vertical, horizontal).

Question 67

In adults who regain vision after decades of blindness, which ability remains especially impaired? A) Color detection B) Shape recognition C) Face recognition D) Light sensitivity

Answer 67

Answer: C) Face recognition Explanation: Even after years of regained vision, recognizing faces (e.g., gender or emotion) remained very difficult.

Question 68

What is the primary function of the ventral stream of visual processing? A) Controlling eye movements B) Guiding hand and body movements C) Recognizing and identifying objects D) Detecting motion and depth

Answer 68

Answer: C) Recognizing and identifying objects Explanation: The ventral stream, running through the temporal cortex, is known as the "what" pathway because it is critical for identifying and recognizing objects.

Question 69

Which type of impairment would most likely result from damage to the dorsal stream? A) Difficulty recognizing familiar faces B) Inability to accurately reach and grasp objects C) Complete loss of vision D) Hallucinations of objects

Answer 69

Answer: B) Inability to accurately reach and grasp objects Explanation: Damage to the dorsal stream (parietal cortex) disrupts the ability to integrate vision with movements, causing trouble with reaching, grasping, and navigating around objects.

Question 70

Patient DF, who had damage to her ventral stream, showed what key deficit? A) Complete blindness B) Difficulty recognizing objects but preserved ability to act upon them C) Inability to move her arms and legs D) Loss of memory

Answer 70

Answer: B) Difficulty recognizing objects but preserved ability to act upon them Explanation: Patient DF could not recognize or describe objects but could still accurately interact with them, demonstrating preserved action pathways despite impaired perception.

Question 71

In which part of the brain do cells learn to recognize meaningful objects, regardless of viewpoint? A) Primary visual cortex (V1) B) Inferior temporal cortex C) Parietal cortex D) Prefrontal cortex

Answer 71

Answer: B) Inferior temporal cortex Explanation: The inferior temporal cortex specializes in recognizing objects, even when they appear from different angles or in different lighting.

Question 72

What condition results from damage to the ventral pathway, leading to difficulty recognizing objects despite normal vision? A) Hemianopia B) Visual agnosia C) Prosopagnosia D) Neglect syndrome

Answer 72

Answer: B) Visual agnosia Explanation: Visual agnosia is the inability to recognize objects despite otherwise normal vision, typically caused by damage to the temporal cortex (ventral stream).

Question 73

Which brain region responds most strongly to faces? A) Parahippocampal cortex B) Fusiform gyrus C) Occipital pole D) Prefrontal cortex

Answer 73

Answer: B) Fusiform gyrus Explanation: The fusiform gyrus, especially in the right hemisphere, is highly specialized for face recognition.

Question 74

Damage to which stream would cause a person to bump into furniture while being able to describe it? A) Ventral stream B) Dorsal stream C) Inferior temporal cortex D) Primary motor cortex

Answer 74

Answer: B) Dorsal stream Explanation: Damage to the dorsal stream causes difficulty in using vision to guide movement, leading to bumping into objects despite recognizing them visually.

Question 75

People with prosopagnosia have difficulty with: A) Remembering people's names B) Recognizing faces C) Understanding speech D) Identifying colors

Answer 75

Answer: B) Recognizing faces Explanation: Prosopagnosia specifically impairs face recognition, not general memory, vision, or speech.

Question 76

Electrical stimulation of the fusiform gyrus can cause: A) Enhanced memory recall B) Temporary prosopagnosia or face distortions C) Hearing voices D) Paralysis of the face muscles

Answer 76

Answer: B) Temporary prosopagnosia or face distortions Explanation: Stimulating the fusiform gyrus can lead to difficulty perceiving faces or cause vivid face distortions.

Question 77

Which of the following statements is TRUE about people with prosopagnosia? A) They usually have vision problems affecting reading. B) They can describe individual facial features but fail to recognize the whole face. C) They cannot recognize voices. D) They are unable to recognize non-human objects like chairs and tables.

Answer 77

Answer: B) They can describe individual facial features but fail to recognize the whole face. Explanation: People with prosopagnosia can see and describe parts of a face but struggle to integrate them into a recognizable whole.

Question 78

Which brain area is primarily responsible for detecting motion at a particular speed and direction? a) V1 b) MT (V5) c) LGN d) MST

Answer 78

Answer: b) MT (V5) Explanation: MT (also called V5) responds selectively to motion, including speed and direction.

Question 79

What kind of visual input do areas MT and MST mainly receive? a) Parvocellular input (color and fine detail) b) Magnocellular input (motion and large patterns) c) Koniocellular input (blue-yellow color contrast) d) Auditory input

Answer 79

Answer: b) Magnocellular input (motion and large patterns) Explanation: MT and MST receive information from the magnocellular pathway, which specializes in motion and broad visual patterns, not color.

Question 80

Answer: b) Magnocellular input (motion and large patterns) Explanation: MT and MST receive information from the magnocellular pathway, which specializes in motion and broad visual patterns, not color.

Answer 80

What visual experience is most impaired if area MT is damaged? a) Color vision b) Depth perception c) Motion perception d) Shape recognition

Question 81

What symptom did the famous motion blindness patient “LM” report? a) Seeing flashing colors constantly b) People appearing suddenly without apparent movement c) Hearing hallucinated sounds d) Loss of vision entirely

Answer 81

Answer: b) People appearing suddenly without apparent movement Explanation: LM described people as “suddenly here or there” because she could not see their movement.

Question 82

During voluntary eye movements (saccades), why don't we see our eyes moving in the mirror? a) Eye movements are too fast to detect b) MT activity is suppressed during saccades c) Our brain ignores mirror images d) Eye muscles temporarily paralyze the visual cortex

Answer 82

Answer: b) MT activity is suppressed during saccades Explanation: To prevent confusion, MT and parietal areas reduce activity just before and during eye movements.

Question 83

Which area responds best to complex patterns like expansion, contraction, or rotation? a) Area MT b) Area MST (dorsal part) c) Primary visual cortex (V1) d) Parietal lobe

Answer 83

Answer: b) Area MST (dorsal part) Explanation: Dorsal MST is specialized for interpreting more complex, large-scale motion patterns like optic flow during head movements.

Question 84

How is it possible for someone blind from V1 damage to still detect motion? a) Retina directly processes motion b) MT gets input directly from the LGN c) MST compensates fully for V1 d) Visual cortex regenerates spontaneously

Answer 84

Answer: b) MT gets input directly from the LGN Explanation: MT receives some direct input from the lateral geniculate nucleus (LGN), allowing basic motion detection even when V1 is damaged.