Sensation and Perception

Question 1

Sensation

Answer 1

The process by which our sensory organs receive stimulus energies from the environment and transduce them into the electrical energy of the nervous system. Stimulation of sensory organs (what our senses do).

Question 2

Transduction

Answer 2

The transformation of sensory stimulus energy from the environment into neural impulses. Translation of physical energy from the environment to neural signals.

Question 3

Perception

Answer 3

The neural processing of electrical signals to form an internal mental representation inside your brain of what’s on the outside. Processing, organization, and interpretation of sensory input (what our brains do (internal representation of the world. Experiences can play a role)). May not be what is actually happening or real.

Question 4

Psychophysics

Answer 4

The study of the relationship between the physical characteristics of environmental stimuli and our mental experience of them (what can we detect? How intense does it have to be? How sensitive are we?).

Question 5

Absolute Threshold

Answer 5

The minimum amount of stimulation necessary for someone to detect a stimulus half of the time. It isn’t stable (can differ between people or overtime).

Question 6

Conservative Response Bias

Answer 6

Not giving a response unless you are a hundred percent sure.

Question 7

Liberal Response Bias

Answer 7

Giving a response even if you are not sure about it in order to do “well”.

Question 8

Signal Detection Theory

Answer 8

An approach to measuring thresholds that takes into account both the intensity of the stimulus and psychological biases for a more accurate assessment.

Question 9

Hits

Answer 9

Seeing the stimulus.

Question 10

Misses

Answer 10

Not seeing the stimulus.

Question 11

False Alarms

Answer 11

Seeing the stimulus when there is none.

Question 12

Correct Rejections

Answer 12

Not seeing the stimulus when there is none.

Question 13

Difference Threshold/Just-Noticeable Difference (JND)

Answer 13

The minimum difference required between two stimuli for an observer to detect a difference half the time (just noticeable difference). Depends on the intensity of the original stimulus.

Question 14

Weber’s Law

Answer 14

The observation that the likelihood of perceiving a stimulus change is proportional to the magnitude of the stimuli. It’s not about the absolute amount of stimulus that is added/taken away, it’s about the proportion. In order to notice a difference, the two stimuli must differ by a constant proportion (lighting is 8%, object weight is 2%, and sound is 0.3%).

Question 15

Plasticity of Perceptual Systems

Answer 15

When neurons change their sensitivity and selectivity with experience. Ex. if you got a bee sting when you were young, you may have increased sensitivity for detecting bees buzzing around you.

Question 16

Adaptation

Answer 16

A phenomenon whereby an individual stops noticing a stimulus that remains constant over time, resulting in enhanced detection of stimulus changes.

Question 17

Sensory Adaptation

Answer 17

Occurs at the level of sensory receptors.

Question 18

Perceptual Adaptation

Answer 18

Occurs higher up in the brain.

Question 19

Aftereffects

Answer 19

Opposing distortions that occur after adaptation (you perceive the opposite of what your senses and brain have adapted to).

Question 20

Wavelength

Answer 20

The distance between any two consecutive crests or troughs of a wave.

Question 21

Frequency

Answer 21

The number of cycles per second of a wave.

Question 22

Amplitude

Answer 22

The height of the crests of a wave.

Question 23

Pupil

Answer 23

A hole in the iris where light enters the eye. Controls the amount of light that goes in. The black portion of the eye.

Question 24

Iris

Answer 24

The coloured muscle circling the pupil (aka the eye colour).

Question 25

Lens

Answer 25

A membrane at the front of the eye that focuses the incoming light on the retina. More focus based on distance (second step of focusing).

Question 26

Accommodation

Answer 26

Adjustment of the lens’s thickness by specialized muscles in order to change the degree to which it bends light.

Question 27

Presbyopia

Answer 27

A condition where the lens of the eye becomes less elastic and the eye’s ability to focus via accommodation weakens making it difficult to see things that are too close.

Question 28

Retina

Answer 28

A surface on the back of the eye that contains the photoreceptor cells, mostly rods than cones that convert light into neural impulses. Used for transduction.

Question 29

Rods

Answer 29

Photoreceptor cells that primarily support nighttime vision. All have the same type of photopigment. 120 million cells, high sensitivity (act in low light conditions), low acuity (less sharp), primarily in the periphery (outside), black and white vision. Contain only one type of photopigment.

Question 30

Cones

Answer 30

Photoreceptor cells that are responsible for high-resolution colour vision. Contain one of three varieties of photopigments which allow us to perceive colours (colour vision only occurs in the cones). 5 million cells, low sensitivity (act in high light conditions), high acuity (very sharp), primarily in fovea (the center), colour vision. Contain multiple types of photopigments.

Question 31

Visual Transduction

Answer 31

When cells convert light energy into electrical energy.

Question 32

Nearsightedness/Myopia

Answer 32

When faraway objects are projected too far in front of the fovea.

Question 33

Farsightedness/Hyperopia

Answer 33

When a near object is shown too far in the back of the eye.

Question 34

Optic Nerve

Answer 34

A bundle of axons that converge from the retina and transmit action potentials to the brain.

Question 35

Blind Spot

Answer 35

An area in the middle of the visual field where there are no photoreceptors and no information can be received. The brain tries to fill in the blanks using the information from the surrounding regions of the retina.

Question 36

Fovea

Answer 36

A small pit in the center of the retina that is densely packed with cones.

Question 37

Foveation

Answer 37

A process in which eyes are trained to move constantly in order to focus different stimuli directly onto the fovea.

Question 38

Acuity

Answer 38

The sharpness or specificity of perception supporting the discrimination of stimuli. The cones specialize in acuity, supporting daytime vision when light is abundant and we see things in high-resolution colour.

Question 39

Sensitivity

Answer 39

The ability simply to detect a stimulus is present. The rods provide more sensitivity, primarily supporting nighttime vision when light is limited and we see things in grainy shades of gray.

Question 40

Achromatic Colours

Answer 40

White, black, and any shade of gray (do not result in a distinct colour or chromatic experience).

Question 41

Trichromatic Theory

Answer 41

A theory of colour perception stating that three types of cone cells, each most sensitive to a specific wavelength of light, work together to produce our perception of a multicoloured world. We have three kinds of cones (L, M, S).

Question 42

Colour-Blindness

Answer 42

Often results from a deficiency in one of the three types of cones.

Question 43

Dichromacy

Answer 43

Having only two cones.

Question 44

Monochromacy

Answer 44

A rare condition in which individuals are born with only one kind of cone. Have no colour perception (see all wavelengths as various shades of gray).

Question 45

Opponent-Process Theory

Answer 45

A theory of colour perception stating that information from the cones is separated into three sets of opposing or opponent channels in the ganglion cell layer. Bipolar cells combine inputs from different cone types. Ganglion cells respond in an antagonistic way to oppose pairs of wavelengths (ex. activated by red but inhibited by green).

Question 46

Primary Visual Cortex

Answer 46

The visual sensory receiving area in the occipital lobe.

Question 47

Retinotopically

Answer 47

A way to describe the organization of the primary visual cortex. The adjacent portions of the retina connect with adjacent areas of the visual cortex.

Question 48

Feature Detectors

Answer 48

Specialized cells in the visual cortex that respond to basic features such as lines, edges, and angles.

Question 49

Visual Association Cortex

Answer 49

The region of the brain where objects are reconstructed from prior knowledge and information collected by the feature detectors.

Question 50

Prosopagnosia

Answer 50

A visual disorder in which individuals are unable to recognize the identity of faces. It is not due to a deficit in vision, language, or intelligence.

Question 51

Ventral Pathway/Visual Stream

Answer 51

Travels along the temporal lobe. Specialized to address the “what” questions. Damage to this pathway impairs object recognition. Recognizes objects, conscious perception of details attaching meaning to what we see. Conscious perception and awareness.

Question 52

Dorsal Pathway/Visual Stream

Answer 52

Joins the parietal lobe. Specialized to address the “where” and “how” questions of object recognition. It supports location, depth, and motion and thus influences how we interact with objects. Locates objects spatially. Performs simple actions (head and eye movements, reaching). Largely below conscious awareness.

Question 53

Akinetopsia

Answer 53

A deficit in perceiving motion such that those with this condition experience the world as a series of static snapshots rather than a continuous flow of events.

Question 54

Phi Phenomenon

Answer 54

A visual illusion in which the flashing of separate images in rapid succession is perceived as fluid movement.

Question 55

Gestalt Psychology

Answer 55

A school of psychological thought that attempted to explain how various elements group together to form objects, arguing that perception is more than a simple piecing together of building blocks. How we group visual information to form perceptions (the whole is greater than the sum of the parts).

Question 56

Binocular Cues

Answer 56

Depth information gathered from the separation between an individual’s two eyes. Results from seeing with both eyes.

Question 57

Binocular Disparity

Answer 57

The magnitude of difference between the images projected on an individual’s two eyes.

Question 58

Monocular Cues

Answer 58

Depth information that can be gathered by only one eye (available to either eye alone).

Question 59

Size Constancy

Answer 59

The phenomenon whereby the brain adjusts its perception of distance in order to perceive an object’s actual size as constant, taking into account changes in retinal size.

Question 60

Colour Constancy

Answer 60

The phenomenon whereby the brain adjusts its perception of colour to hold it constant taking into account changes in lighting conditions.

Question 61

Bottom-Up Processing

Answer 61

Taking individual bits of sensory info and using them to construct a perception.

Question 62

Top-Down Processing

Answer 62

Perceptions that are influenced by our expectations or prior knowledge.

Question 63

McGurk Effect

Answer 63

What we see can influence what we think we hear ex. when the auditory component of one sound is paired with the visual component of another sound, it changes our perception of the sound.

Question 64

Light

Answer 64

Electromagnetic radiation waves. Humans can see 390 nm to 750 nm.

Question 65

Sclera

Answer 65

The white portion of the eye.

Question 66

Cornea

Answer 66

Focuses the light, where light first hits.

Question 67

Brain

Answer 67

Used for perception.

Question 68

Photopigments

Answer 68

Change shape when absorbing light affecting the release of glutamate. The glutamate sends signals to adjacent bipolar cells (sensory neurons) and ganglion cells. Signal then travels to the brain via optic nerve (blind spot).

Question 69

L

Answer 69

Red cones, long wavelengths.

Question 70

M

Answer 70

Green cones, medium wavelengths.

Question 71

S

Answer 71

Blue cones, short wavelengths.

Question 72

Colour Blindness/Dichromacy

Answer 72

When people have fewer cones of a certain type than they should.

Question 73

Deuteranomaly

Answer 73

Problems or missing M cones. Not seeing green properly.

Question 74

Protanopia

Answer 74

Problems or missing L cones. Not seeing red properly.

Question 75

Tritanopia

Answer 75

Problems or missing S cones. Not seeing blue properly.

Question 76

Afterimages

Answer 76

When you look at an image for a long time then look away, you will see the opposing colours ex. if you stare at a red image and look away you will see a green image.

Question 77

Visual Perception and the Brain

Answer 77

Information from the left visual field goes to the right side of the brain and vice versa regardless of which eye sees it. Information crosses sides at the optic chiasm. Optic nerve first connects with thalamus then travels to V1 (primary visual cortex (occipital lobe)). Involves cortical magnification (more information is received by the cones rather than the rods due to having more neurons) and the association cortex.

Question 78

Blindsight

Answer 78

People who are cortically blind (damage to the occipital lobe) can still respond to visual stimuli that they can’t consciously see.

Question 79

Superior Colliculus

Answer 79

An older evolutionary pathway that connections the information entering the retina directly to the dorsal visual stream.

Question 80

Hollow Face Illusion

Answer 80

A study where people were able to accurately flick off targets in the hollow face. Visual action track (dorsal) isn’t fooled by the illusion we experience through the visual perception track (ventral) (deep down they knew that the mask was caved in). Our hands know what we don’t consciously perceive.

Question 81

The Case of Dr. P

Answer 81

A man who mistook his wife for a hat. Was a distinguished musician that started to have difficulties recognizing faces and tried to put his wife’s head on as a hat and couldn’t tell that there was a problem. His speech was fine, meaning that his temporal lobe was still functioning. Was diagnosed with visual agnosia. Hypothesized tumor or degeneration of visual association cortex.

Question 82

Visual Agnosia

Answer 82

An impairment in recognition of visually presented objects.

Question 83

Gestalt Psychology Aspects

Answer 83

1) Proximity 2) Similarity 3) Continuity (we look for continuous lines and group the objects in that way) 4) Closure 5) Connectedness

Question 84

Depth Perception

Answer 84

The ability to see objects in three dimensions although the image that strikes the retina is two-dimensional. Develops early in life (ex. visual cliff experiment).

Question 85

Relative Size

Answer 85

A monocular cue. Objects that are farther away project smaller retinal images. Judges distance based on how large an object appears compared to other objects of known sizes.

Question 86

Elevation/Relative Height

Answer 86

A monocular cue. Items that are higher in the visual field are perceived as being further away. Above the horizon line, objects that are higher are perceived as closer.

Question 87

Interposition

Answer 87

A monocular cue. If one object partially obscures another, it is perceived as closer.

Question 88

Linear Perspective

Answer 88

as parallel lines recede into the distance, they appear to get closer together (coverage at the vanishing point). The more lines converge, the greater the perceived distance. (One point perspective drawings)

Question 89

Relative Motion (Movement Direction)

Answer 89

Objects in front of fixation point seem to move backwards and objects behind the fixation point seem to move forward.

Question 90

Relative Motion (Movement Speed)

Answer 90

Close objects move fast and further objects move slower.

Question 91

Retinal Disparity

Answer 91

A binocular cue. The difference between objects is projected on the two eyes. Objects further away from our line of focus appear at increasingly different locations on the retinas.

Question 92

Ames Room

Answer 92

A room that appears to be normally shaped at one location so when a person moves, they appear to become much larger.