Blindsight Flashcards
Flashcard 1
Q: What is blindsight?
A: A phenomenon seen in cortical blindness, where individuals can perform visual tasks without conscious awareness.
Flashcard 2
Q: What causes blindsight?
A: Damage to the visual cortex (striate cortex or V1) in one hemisphere of the brain.
Flashcard 3
Q: What is the result of damage to the visual cortex in blindsight?
A: Blindness for the opposite visual field, a condition called hemianopia.
Flashcard 4
Q: Can people with blindsight perceive visual stimuli consciously?
A: No, they cannot consciously see visual stimuli but can still respond to them unconsciously.
Flashcard 5
Q: Which animals and humans show blindsight?
A: Some animals and humans with cortical blindness due to visual cortex damage.
Flashcard 6
Q: How do individuals with blindsight perform visual tasks without awareness?
A: They rely on non-conscious neural pathways to process visual information.
Flashcard 1
Q: Who is patient TN?
A: Patient TN is a man who became blind due to strokes that damaged his visual cortex in both hemispheres.
Flashcard 2
Q: What does patient TN report about his vision?
A: He reports being completely “blind” and unable to see consciously.
Flashcard 3
Q: How does patient TN demonstrate blindsight?
A: Despite being blind, TN can detect objects in his environment without being aware of them, such as navigating a maze.
Flashcard 4
Q: What does this phenomenon in patient TN demonstrate?
A: It illustrates that even with blindness, individuals can process visual information unconsciously, showing signs of blindsight.
Flashcard 1
Q: What did David Ferrier (1875) conclude about the localization of vision?
A: Ferrier concluded that the angular gyrus in the parietal lobe was the seat of vision, based on animal lesion studies.
Flashcard 2
Q: What mistake did David Ferrier make in his research on vision?
A: Ferrier wrongly attributed vision to the angular gyrus (parietal lobe) rather than the occipital lobe.
Flashcard 3
Q: Who corrected Ferrier’s conclusion about vision localization?
A: Hermann Munk (1878; 81) demonstrated that vision is actually localized in the occipital lobe.
Flashcard 4
Q: How did Hermann Munk show that vision is localized in the occipital lobe?
A: Munk conducted experiments on dogs and monkeys, showing that damage to the occipital lobe impairs vision.
Flashcard 5
Q: What did Munk discover about the visual pathways?
A: Munk found that each eye is connected to both hemispheres of the brain.
Flashcard 6
Q: What was William James’ (1890) statement about the occipital lobes?
A: William James stated that the occipital lobes are indispensable for vision and that damage to them causes blindness.
Flashcard 7
Q: What happens when both occipital lobes are damaged?
A: Damage to both occipital lobes results in total blindness, both sensory and psychic.
Flashcard 8
Q: How do individuals with damage to the occipital cortex report their vision?
A: They report not seeing anything at all, as the occipital cortex is essential for visual perception.
Flashcard 1
Q: What is the Primary Visual Cortex (V1) also known as?
A: The Primary Visual Cortex is also known as the Striate Cortex.
Flashcard 2
Q: Where is the Primary Visual Cortex (V1) located?
A: The Primary Visual Cortex is located in the occipital lobe of the brain
Flashcard 3
Q: What is the function of the Primary Visual Cortex (V1)?
A: V1 is the first cortical area that processes visual input from the retina, handling basic visual features like light, contrast, and color.
Flashcard 1
Q: How does Prof. Nicholas Humphrey describe blindsight?
A: Prof. Humphrey describes blindsight as “unconscious vision.”
Flashcard 2
Q: How did Weiskrantz (1990) define blindsight?
A: Weiskrantz defined blindsight as “visual discrimination in the absence of acknowledged awareness.”
Flashcard 3
Q: What does blindsight involve?
A: Blindsight involves responding to visual stimuli without being consciously aware of them.
Flashcard 4
Q: What kind of tasks can individuals with blindsight perform?
A: Individuals with blindsight can perform tasks like detecting objects or navigating without conscious visual perception.
Flashcard 1
Q: Who popularized the term “blindsight”?
A: The term “blindsight” was popularized by Larry Weiskrantz.
Flashcard 2
Q: What does “blindsight” refer to?
A: Blindsight refers to behavioral findings where individuals can respond to visual stimuli without being consciously aware of them.
Flashcard 3
Q: What is “hindsight” in the context of blindsight?
A: Hindsight refers to the role of the hindbrain and subcortical visual pathways in vision, suggesting these pathways contribute to blindsight.
Flashcard 4
Q: What is the evolutionary significance of the hindbrain?
A: The hindbrain is the oldest part of the brain in evolutionary terms and plays a role in blindsight.
Flashcard 5
Q: How many nerve fibers are involved in the main visual pathway from the eye to the visual cortex?
A: The main visual pathway involves about one million nerve fibers, or 90% of the total.
