Perception Test prep

Question 1

What is the central question in the philosophy of perception?

Answer 1

What are the objects of perception? What do we directly perceive?

Question 2

What phenomena motivate the problem of perception?

Answer 2

Perceptual illusions and hallucinations.

Question 3

How does the problem of perception challenge our ordinary understanding?

Answer 3

It suggests that perception may not be direct awareness of the external world.

Question 4

What is the main argument that generates the problem of perception?

Answer 4

The argument from illusion.

Question 5

What is the base case of the argument from illusion?

Answer 5

In an illusion, we seem to perceive something that isn’t there, like a bent pencil.

Question 6

What does the argument from illusion conclude about the objects of perception?

Answer 6

That we always perceive sense-data, not external objects.

Question 7

What is naive realism?

Answer 7

The view that we directly perceive mind-independent objects and their qualities.

Question 8

How does naive realism respond to the argument from illusion?

Answer 8

By rejecting the argument’s inferences; illusions are cases of seeing how things look under certain conditions.

Question 9

What is indirect realism?

Answer 9

The view that we perceive mind-dependent sense-data, and infer the existence of external objects.

Question 10

What skeptical consequence does indirect realism lead to?

Answer 10

A “veil of perception” between the mind and the external world.

Question 11

What is disjunctivism?

Answer 11

A form of naive realism that holds veridical and non-veridical perceptions differ in nature.

Question 12

How does disjunctivism respond to the argument from illusion?

Answer 12

By rejecting that there must be a common element between veridical and non-veridical cases.

Question 13

What is phenomenalism?

Answer 13

The view that statements about the external world are just statements about actual or possible sense experiences.

Question 14

How does phenomenalism relate to idealism?

Answer 14

It leads to a form of idealism, the view that reality is fundamentally mental.

Question 15

What is intentionalism/representationalism?

Answer 15

The view that perceptual states are representations of the world with “intentional content”.

Question 16

How does intentionalism/representationalism explain perceptual error?

Answer 16

In non-veridical cases, perceptual states misrepresent the world.

Question 17

What is the “Phenomenal Principle” and how is it challenged?

Answer 17

The inference from “X appears Y” to “There is something that is Y”. Critics argue this inference is fallacious.

Question 18

What are the two forms of intentionalism/representationalism?

Answer 18

One accepts qualia (qualia theory), the other eliminates them (eliminativism).

Question 19

What is the relationship between sense-data and qualia?

Answer 19

Qualia are often considered the qualitative properties of sense-data.

Question 20

What is the “veil of perception”?

Answer 20

A metaphor for the skeptical idea that perception doesn’t directly access the external world, but only mental representations.

Question 21

What are the three worlds in perception, and how are they connected?

Answer 21

Physical world (stimuli), neural world (brain activity), and psychological world (subjective experience) are connected through perception but are distinct.

Question 22

What is transduction in perception?

Answer 22

Sensory receptors transduce physical stimuli into neural impulses in the brain.

Question 23

How does the jelly bean experiment demonstrate the connection between the three worlds?

Answer 23

Physical stimuli (taste, smell) are transduced into neural impulses, which the brain combines to create the subjective experience of flavour.

Question 24

What does the falling tree question reveal about perception?

Answer 24

It highlights the difference between physical air vibrations and the psychological experience of sound, which only exists when the brain interprets neural impulses.

Question 25

How does the electromagnetic spectrum relate to colour perception?

Answer 25

The spectrum is continuous, but the brain interprets specific wavelength ranges as distinct colours, showing colour is a subjective psychological experience.

Question 26

How do variations in colour vision demonstrate the relationship between sensory systems and perception?

Answer 26

Differences in colour receptors lead to variations in colour perception, showing sensory systems directly influence subjective perceptual experience.

Question 27

What is an Umwelt, and how does it relate to the subjectivity of sensory experience?

Answer 27

An Umwelt is an organism’s unique perceptual world, determined by its specific sensory systems, emphasizing the diversity of subjective experiences.

Question 28

How do echolocation and magnetoreception illustrate the relationship between sensory systems and perception?

Answer 28

These sensory modalities, which some animals possess but humans lack, demonstrate that sensory systems shape perceptual experience and interactions with the world.

Question 29

Why is it important to understand that sensory experience is subjective?

Answer 29

It helps recognize that perception is shaped by unique sensory systems and neural processing, promoting empathy and appreciation for diverse perceptual experiences.

Question 30

What is perception?

Answer 30

Perception is the use of sensory stimulation to produce subjective experience and an interpretation of the environment, in the service of adaptive behaviour.

Question 31

How many basic tastes are there?

Answer 31

There are only five basic tastes: sweet, salty, sour, bitter, and umami.

Question 32

What is flavour?

Answer 32

Flavour is a combination of taste and smell, resulting from the integration of information from the gustatory and olfactory systems in the brain.

Question 33

What is the stimulus for vision?

Answer 33

The stimulus for vision is light, which is a form of electromagnetic energy.

Question 34

What is the visible spectrum for humans?

Answer 34

The visible spectrum for humans ranges from approximately 400 to 700 nanometres.

Question 35

What are the three types of cones in the human retina?

Answer 35

The three types of cones in the human retina are S cones (short-wave), M cones (medium-wave), and L cones (long-wave).

Question 36

What is trichromatic vision?

Answer 36

Trichromatic vision is the ability to perceive colours based on the relative activity of three types of cones in the retina.

Question 37

What is monochromacy?

Answer 37

Monochromacy, also known as colour blindness, is a condition in which an individual has no functioning cones or only one cone type, resulting in the inability to distinguish colours.

Question 38

What is dichromacy?

Answer 38

Dichromacy, also known as colour deficiency, is a condition in which an individual has two functioning cone types, resulting in a reduced ability to distinguish colours.

Question 39

What are Ishihara plates?

Answer 39

Ishihara plates are a type of colour vision test that uses patterns of coloured dots to identify colour vision deficiencies.

Question 40

What is tetrachromatic vision?

Answer 40

Tetrachromatic vision is the ability to perceive colours based on the relative activity of four types of cones in the retina, resulting in the perception of a greater range of colours and more subtle colour distinctions.

Question 41

What is a sensory/perceptual modality?

Answer 41

sensory/perceptual modality is the type of perceived experience that is evoked by a certain category of physical stimulation.

Question 42

What is psychophysics?

Answer 42

Psychophysics is the study of the relationship between physical sensation and the perception it evokes.

Question 43

What is the concept of Umwelt?

Answer 43

Umwelt is a concept proposed by Jakob von Uexküll, referring to the unique sensory bubble or perceptual world that each animal experiences based on its sensory capabilities.

Question 44

What is echolocation?

Answer 44

Echolocation is a sensory modality used by some animals, such as dolphins and bats, in which they emit sound waves and perceive their environment based on the reflections of those sound waves.

Question 45

What are the three main objectives of the “Stimulus to Percept” lectures?

Answer 45

The three main objectives are to understand how the physical, neural, and psychological worlds are connected but different; to appreciate how the nature of our sensory systems determines the nature of our perceptual experience; and to explain why sensory experience is subjective.

Question 46

What are the main components of the visual signal’s journey from the eye to the brain?

Answer 46

Optic nerve, optic chiasm, optic tract, lateral geniculate nucleus (LGN) of the thalamus, optic radiations, primary visual cortex (V1).

Question 47

How many rods and cones are in the human retina, and how do they differ in distribution?

Answer 47

There are approximately 120 million rods and 6 million cones. The fovea contains only cones, while the periphery has both rods and cones, with a higher proportion of rods.

Question 48

What is the principle of convergence in retinal processing?

Answer 48

Convergence involves the compression of information from multiple photoreceptors onto a single ganglion cell, allowing for detection of dim light and efficient transmission of visual information.

Question 49

How do rods and cones differ in terms of spatial resolution and response thresholds?

Answer 49

Cones have better spatial resolution than rods but require higher light intensity to generate a response in ganglion cells for the same illuminated area.

Question 50

What is lateral inhibition, and how does it affect visual perception?

Answer 50

Lateral inhibition is a process where neurons inhibit the activity of neighbouring neurons, enhancing the perception of edges and boundaries between surfaces with different brightness levels.

Question 51

What is a receptive field in the context of visual processing?

Answer 51

A receptive field is a region of the visual field in which stimulation changes a neuron’s response.

Question 52

Describe the centre-surround organization of retinal ganglion cells’ receptive fields.

Answer 52

Retinal ganglion cells have circular receptive fields with an excitatory centre and an inhibitory surround (on-centre) or an inhibitory centre and an excitatory surround (off-centre).

Question 53

What is the main function of centre-surround receptive fields in the retina?

Answer 53

Centre-surround receptive fields maximize the detection of changes in the visual field over space and time.

Question 54

How is the lateral geniculate nucleus (LGN) organized?

Answer 54

The LGN has 6 layers, with layers 2, 3, and 5 receiving input from the ipsilateral eye and layers 1, 4, and 6 receiving input from the contralateral eye. Each layer is organized retinotopically.

Question 55

What is retinotopy, and how is it observed in the LGN?

Answer 55

Retinotopy is the organization in which neighbouring cells have neighbouring receptive fields, responding to inputs from adjacent points in the retina and visual field. Each layer of the LGN contains a retinotopic map of a visual hemifield.

Question 56

What is the role of the LGN in visual processing beyond relaying information from the retina?

Answer 56

The LGN receives over 90% of its input from other brain regions, allowing for top-down regulation, filtering, and enhancement of visual information before it is passed on to the cortex.

Question 57

What is opponent processing, and how does it relate to colour perception in the LGN?

Answer 57

Opponent processing is a mechanism in the LGN that contributes to colour perception by comparing the responses of different types of cones.

Question 58

What is neural adaptation, and why is it an important operating principle in perception?

Answer 58

Neural adaptation is a gradual decrease in the responsiveness of the sensory system to a constant stimulus over time. It is important for maintaining sensitivity to changes in the environment and can lead to aftereffects that provide insights into perceptual processes.

Question 59

What are the primary visual cortex’s alternative names?

Answer 59

V1, striate cortex, and Area 17.

Question 60

How are simple cells in the primary visual cortex characterized?

Answer 60

Simple cells in V1 are orientation-selective, responding to lines in particular orientations. They have ON and OFF regions and can be monocular or binocular.

Question 61

What is a neural tuning curve?

Answer 61

A neural tuning curve represents a neuron’s response as a function of a stimulus parameter, such as orientation, demonstrating the neuron’s selectivity for that parameter.

Question 62

What is the role of the optic nerve in the visual system?

Answer 62

The optic nerve carries visual information from the retina to the brain, forming from the bundled axons of retinal ganglion cells.

Question 63

What happens at the optic chiasm?

Answer 63

At the optic chiasm, information from the nasal retina of each eye crosses over to the opposite side of the brain, while information from the temporal retina remains on the same side.

Question 64

How does the optic tract differ from the optic nerve?

Answer 64

The optic tract contains information from both eyes but only from one half of the visual field (left or right), whereas the optic nerve contains information from one eye only.

Question 65

What is the lateral geniculate nucleus (LGN), and where is it located?

Answer 65

The LGN is a structure in the thalamus that receives input from the optic tract and relays visual information to the primary visual cortex.

Question 66

What are the optic radiations?

Answer 66

The optic radiations are the axons of LGN neurons that carry visual information to the primary visual cortex in the occipital lobe.

Question 67

What are the main layers of the retina, and what is their order from the back to the front of the eye?

Answer 67

The main layers of the retina from back to front are: pigment epithelium, photoreceptors (rods and cones), bipolar cells, amacrine cells, and ganglion cells.

Question 68

What types of photoreceptors are found in the human retina, and what are their functions?

Answer 68

The human retina contains two types of photoreceptors: rods, which are sensitive to low light levels and are important for peripheral and night vision, and cones, which are responsible for colour vision and high-acuity central vision.

Question 69

What is the fovea, and how does it differ from the peripheral retina?

Answer 69

The fovea is a small, central region of the retina that contains a high density of cones and no rods, providing high visual acuity. The peripheral retina has a lower density of cones and a higher density of rods.

Question 70

What is the primary visual cortex, and where is it located?

Answer 70

The primary visual cortex, also known as V1, striate cortex, or Area 17, is the first cortical area to process visual information. It is located in the occipital lobe at the back of the brain.

Question 71

What are the main types of cells found in the primary visual cortex?

Answer 71

The primary visual cortex contains two main types of cells: simple cells, which are orientation-selective and have ON and OFF regions, and complex cells, which respond to specific orientations and directions of motion but have larger receptive fields than simple cells.

Question 72

What is the inverse problem of perception?

Answer 72

The inverse problem refers to the fact that many different external stimuli can lead to the same sensations, creating ambiguity about the true causes of our perceptual experience.

Question 73

According to Helmholtz, how does the perceptual system solve the inverse problem?

Answer 73

Helmholtz proposed that perception is a process of unconscious inference, where we infer the most likely causes of our sensations based on the available sensory evidence and prior knowledge.

Question 74

What are the two main types of processes that contribute to perceptual inference?

Answer 74

Bottom-up processes, which involve organizing and interpreting sensory features, and top-down processes, which involve applying prior knowledge, concepts, and context to the sensory data.

Question 75

What are some examples of Gestalt principles of perceptual organization?

Answer 75

Proximity, similarity, continuity, closure, common fate, and figure-ground organization.

Question 76

What is the central idea behind Selfridge’s Pandemonium model?

Answer 76

The Pandemonium model proposes that perception is based on feature detection, with different “demons” responding selectively to specific features and activating letter and word representations.

Question 77

What are some strengths and weaknesses of the Pandemonium model?

Answer 77

Strengths include neural plausibility, emergence of intelligent behavior from simple units, and parallel processing. Weaknesses include limited scalability, flexibility, and lack of top-down influences.

Question 78

What is reification in perception?

Answer 78

Reification refers to the perceptual process of creating “real” percepts out of incomplete or ambiguous sensory information, such as illusory contours or subjective shapes.

Question 79

What is the perception-action cycle?

Answer 79

The perception-action cycle refers to the continuous interplay between perceiving the world, forming intentions and plans, and acting on the environment, with each process informing and guiding the others.

Question 80

What are the two main visual processing pathways in the brain, and what are their functions?

Answer 80

The ventral “what” pathway is involved in object recognition and perception, while the dorsal “where/how” pathway is involved in spatial processing and vision for action.

Question 81

What is the double dissociation between temporal and parietal lobe lesions in monkeys, and what does it suggest?

Answer 81

Temporal lesions impair object discrimination but not landmark discrimination, while parietal lesions show the opposite pattern, suggesting a dissociation between the two visual streams.

Question 82

What deficits did patient DF exhibit, and what do they reveal about the two visual streams?

Answer 82

DF had impaired perceptual matching (ventral stream) but intact grasping (dorsal stream), providing evidence for the dissociation between vision for perception and vision for action.

Question 83

What is Balint’s syndrome, and what deficits does it involve?

Answer 83

Balint’s syndrome, caused by bilateral parietal damage, involves optic ataxia (impaired reaching), simultanagnosia (inability to perceive multiple objects), and optic apraxia (impaired eye movements).

Question 84

What is prosopagnosia, and what causes it?

Answer 84

Prosopagnosia is a deficit in face recognition, often caused by damage to the fusiform face area in the ventral stream

Question 85

What is the difference between physical sensation and psychological perception?

Answer 85

Physical sensation refers to the detection of external stimuli by sensory receptors, while psychological perception is the subjective interpretation and experience of those sensations in the brain

Question 86

What are the main structures of the human eye?

Answer 86

The main structures of the human eye include the cornea, pupil, iris, lens, retina (containing rods and cones), optic nerve, and sclera.

Question 87

How do dogs’ visual capabilities differ from humans’?

Answer 87

Dogs are dichromats, having only two types of cone cells in their retinas. They primarily see colours in the blue and yellow range, while humans are trichromats and can see a broader spectrum of colours.

Question 88

What unique visual capability do bees possess?

Answer 88

Bees have trichromatic vision that extends into the ultraviolet range, allowing them to perceive UV patterns on flowers that are invisible to humans.

Question 89

How does the visual system of birds differ from that of humans?

Answer 89

Most birds are tetrachromats, having four types of cone cells in their retinas. This allows them to see a broader range of colours compared to humans, including ultraviolet light.

Question 90

What is computer vision (CV)?

Answer 90

Computer vision is a subfield of machine learning that trains models to interpret and make decisions based on visual data, aiming to mimic or surpass human vision capabilities at scale and without fatigue.

Question 91

How does the image capture process differ between human and computer vision?

Answer 91

In human vision, eyes capture images, while in computer vision, cameras or sensors capture digital images in various formats like RGB or infrared.

Question 92

How does image processing differ between human and computer vision?

Answer 92

In human vision, images are processed in the retina and visual cortex. In computer vision, images undergo pre-processing, feature extraction, and high-level processing via algorithms.

Question 93

How does decision-making differ between human and computer vision?

Answer 93

Human decision-making is based on past experiences, context, and instincts. Computer vision decision-making relies on algorithms, pattern matching, and trained models.

Question 94

What are the speed and accuracy differences between human and computer vision?

Answer 94

Computer vision can process data quickly and excels at repetitive tasks, while human vision is limited by biological neural processing speed. Humans are accurate for everyday tasks but can be deceived, while computer vision is highly accurate in trained tasks but can be misled by poor training data.

Question 95

What is a pixel in a digital image?

Answer 95

A pixel is the smallest unit of information in a digital image, representing a single point of color.

Question 96

How are images represented in computer vision?

Answer 96

Images are represented as matrices (2D grids) of pixel values, with rows (height) and columns (width). The total number of pixels is called the resolution.

Question 97

What is the difference between grayscale and color images?

Answer 97

Grayscale images have pixel values ranging from 0 (black) to 255 (white), while color images have three channels (RGB) representing red, green, and blue values for each pixel.

Question 98

What is the purpose of feature extraction in computer vision?

Answer 98

Feature extraction techniques create high-level features from raw pixels, providing more informative representations of the image content for algorithms to process.

Question 99

What was a key development in modern computer vision in the 2010s?

Answer 99

The rise of deep learning with convolutional neural networks (CNNs), which can automatically learn and extract features from images, revolutionized computer vision in the 2010s.

Question 100

What are some applications of computer vision in healthcare?

Answer 100

Computer vision is used in healthcare for tasks such as tumor detection, X-ray analysis, and personalized treatment planning.

Question 101

How is computer vision used in autonomous vehicles?

Answer 101

Autonomous vehicles rely on computer vision for object detection and route mapping to navigate safely.

Question 102

What are some concerns regarding the use of computer vision in retail?

Answer 102

The use of facial recognition technology for shoplifter detection in retail stores, such as Countdown supermarkets in New Zealand, raises concerns about biased predictions and privacy issues.

Question 103

How can biased datasets impact computer vision systems?

Answer 103

Biased datasets can lead to biased predictions in computer vision systems, disproportionately affecting certain demographics and perpetuating societal biases.

Question 104

What are some potential misuses of computer vision technology?

Answer 104

Computer vision technology can be misused for creating deepfakes and spreading misinformation, fabricating evidence in legal settings, and committing financial fraud or cyberbullying.

Question 105

What is SoRA, and how does it demonstrate the potential impact of computer vision on industries?

Answer 105

SoRA is OpenAI’s text-to-video model that generates realistic videos based on text prompts. Its ability to create content raises concerns about the impact on the animation and film industry, as it could replace human-created content.