Question 1

What is the optic chiasm

Accepted Answer

The optic chiasm is the point where the optic nerves from each eye cross over one another before continuing on to the occipital lobe of the brain, which is responsible for processing visual information.

Question 2

What is most likely to occur when light hits the centre of a receptive field but does not hit the centre-surround

Accepted Answer

When light hits the center of a receptive field, the associated visual cell will be stimulated and fire an action potential regardless of whether or not the light hits the surrounding area. This is due to the fact that the center of the receptive field is the primary area of sensitivity for the visual cell.

Question 3

Where does the ventral stream project to after leaving the primary visual cortex

Accepted Answer

The ventral stream, also known as the "what" pathway, projects to the temporal lobes after leaving the primary visual cortex. This pathway processes visual information about object recognition and identification.

Question 4

While finger painting,Imran mixed yellow paint and blue paint and ended up with green.Which mixing method did Imran use

Accepted Answer

Subtractive color mixing occurs when mixing pigments, such as paints, where mixing yellow and blue yields green. This process subtractively filters light reflected from the mixture.

Question 5

Deanne can see and recognize objects,but she seems to be unable to reach out and grasp them appropriately.She often knocks over cups and drops pencils because she doesn't orient her hand to grip them.If this problem is related to brain damage to the perceptual system,which area is most likely to be damaged

Accepted Answer

The dorsal stream is responsible for processing the visual information necessary for the guidance of movements or actions in response to visual stimuli. Damage to this area can result in difficulties in reaching and grasping objects (known as optic ataxia). The ventral stream is responsible for object recognition, so damage to this area would lead to difficulties in recognizing objects. The primary visual cortex is responsible for initial visual processing, so damage to this area would lead to visual deficits rather than difficulties in reaching and grasping objects. The superior colliculus is involved in the control of rapid eye movement and in orienting the head and eyes towards sensory events, but it is not directly involved in the control of reaching and grasping movements.

Question 6

Charley has visual agnosia and is unable to recognize common,everyday objects.Damage to which component of the visual system does this condition most likely result from

Accepted Answer

Visual agnosia, the inability to recognize common objects, is associated with damage to the ventral stream of the visual system. This pathway is responsible for processing and interpreting visual information related to object recognition and perception. Damage to other parts of the visual system, such as the feature detectors, superior colliculus or lateral geniculate nucleus, may impact other aspects of visual processing, but not necessarily object recognition.

Question 7

Which technique would allow you to maximize visual acuity at night

Accepted Answer

Looking slightly above or below the object you wish to see is a technique that maximizes visual acuity at night by utilizing the peripheral areas of the retina, which are more sensitive to low light levels than the central part of the retina used for direct vision.

Question 8

In which lobe would you find that brain damage leads to visual agnosia

Accepted Answer

The answer of In which lobe would you find that...

Question 9

What does the receptive field of a visual cell refer to

Accepted Answer

The receptive field of a visual cell refers to the specific area of the retina (i.e. the area of rods and cones) that causes the cell to fire, in response to light stimulation.

Question 10

What is stimulated when light hits the centre-surround of a receptive field

Accepted Answer

The centre-surround of a receptive field is a region of the retina that is divided into two parts: the centre and the surround. The centre is the part of the receptive field that is stimulated by light, while the surround is the part of the receptive field that is not stimulated by light. When light hits the centre of the receptive field, it stimulates the excitatory synapse to the visual cell. This causes the visual cell to fire an action potential, which is then transmitted to the optic nerve.

Question 11

After visual input has been processed in the primary visual cortex,signals are processed further along a number of pathways.Where is information about object recognition processed

Accepted Answer

Information about object recognition is processed in the temporal lobes, specifically in an area called the inferotemporal cortex.

Question 12

Through which brain area do visual signals travel just before reaching primary visual cortex

Accepted Answer

Visual signals are relayed from the eyes to the thalamus before reaching the primary visual cortex. The thalamus acts as a relay station for sensory information, including visual signals.

Question 13

You see a delicious-looking doughnut sitting on the counter in front of you,and you guide your hand toward the doughnut and pop it into your mouth.What do we call the second visual process for guiding your hand

Accepted Answer

The second visual process that guides your hand towards the doughnut is known as "vision for action". This process involves the use of visual information to guide movements and actions. It relies on the dorsal visual pathway, which is responsible for processing visual information related to object location and movement. The other options, such as "Hubel vision", "conscious vision", and "subcortical vision", do not accurately describe this specific visual process.

Question 14

In which lobe would you find the primary visual cortex

Accepted Answer

The primary visual cortex is located in the occipital lobe, which is responsible for receiving and processing visual information. The frontal lobe is involved in higher-order thinking and decision-making, the temporal lobe is associated with hearing and language processing, and the parietal lobe is responsible for processing sensory information such as touch and spatial awareness.

Question 15

What would you be unable to recognize if you had a condition known as agnosia

Accepted Answer

The answer of What would you be unable to recognize...

Question 16

After visual input has been processed in the primary visual cortex,signals are processed further along a number of pathways.Which type of visual information would be processed in the temporal lobe,along the ventral stream

Accepted Answer

The temporal lobe, along the ventral stream, is responsible for processing "what" the stimulus is based on its form and color. This is also known as the "what pathway" and is responsible for object recognition and identification.

Question 17

Which activity would be difficult for you to do if you sustained damage to your dorsal stream

Accepted Answer

The dorsal stream is responsible for spatial perception and coordination of visual information for movement. Picking up a cup requires visual guidance and coordination of movements, which would be difficult with damage to the dorsal stream. The other options relate more to the ventral stream, which is responsible for object recognition and visual memory.

Question 18

Which cells in the visual cortex respond selectively to specific details of complex stimuli

Accepted Answer

Feature detectors are cells in the visual cortex that respond selectively to specific details of complex stimuli, such as lines, edges, angles, and colors. They are specialized neurons that play a crucial role in object recognition and visual perception. Ventral cells are also involved in object recognition but are located in the ventral stream of the visual cortex. Centre-surround detectors are cells that respond to contrast differences in the visual field, while ganglion cells are located in the retina and are responsible for sending visual information to the brain.

Question 19

In the case study of "DF," a woman experienced brain damage as a result of carbon-monoxide poisoning and she lost the ability to recognize the forms of objects.What type of deficit did "DF" have

Accepted Answer

"DF" had agnosia, which is the inability to recognize objects or people despite having intact sensory functions such as vision, hearing, and touch. In this case, her brain damage resulted in the loss of her ability to recognize the forms of objects. The other options (amnesia, failure of vision for action, dorsal stream damage) refer to different types of deficits that were not present in this case study.

Question 20

What is most likely to occur when light hits the centre-surround of a receptive field but does not hit the centre

Accepted Answer

The centre-surround receptive field has two parts - the centre and the surround. When light hits the centre, the associated visual cell will fire, but when light hits the surround, the cell will be inhibited. Therefore, if light hits the centre-surround but not the centre, the associated visual cell will be inhibited.

Quiz 4: A: Sensation and Perception