Perception Flashcards

Question

Illusory Contours

Answer 1

Kanizca Triangle Contours are inferred by visual system

Answer 2

Superordinate - its an animal Basic level - its a dog Subordinate - its a pug Which level will naturally come quickest? Probably depends on level of expertise

Answer 3

Controversy: Do we store a single, viewpoint invariant representation of a given object or do we have a number of “snapshots” of the object from different viewpoints which together make the object representation up?

Answer 4

Its a general Description of a Scene Available after only a fraction of a second Get gist using "Global Image Features" such as degree of openness, expansion, color, naturalness..

Answer 5

End point of visual pathway Face processing --> eg biggest response in monkey to other objects was to face of another monkey , monkey cortex that responds to faces

Answer 6

Thinking of an object tin terms of what u can do with it (chair u can sit on, pen u can write on) rather than thinking of it as visual properties

Answer 7

Divided attention - driving (youre talking, changing gears, looking out for pedestrians...) Selective attention - Selective attention is the process of focusing on a particular object in the environment for a certain period of time. Attention is a limited resource, so selective attention allows us to tune out unimportant details and focus on what matters

Answer 8

Exogenous - guided by your eyes, and whats happening in the environment around you Endogenous - Information that aligns with an observer's behavioral goals are internally selected for further processing. It involves a more effortful process such as being instructed to orient attention to a particular location. You choose to listen to your lecturer instead of looking at laptop

Answer 9

a perceptual phenomenon that occurs when you dont perceive something because youre attention was focused elsewhere eg experiment with counting number of passes and gorilla

Answer 10

a perceptual phenomenon that occurs when a change in a visual stimulus is introduced and the observer does not notice it.

Answer 11

Because even if spotlight/focus is on one thing, we still do notice the things around it and dont just pay attention to objects but also locations

Answer 12

Theory that when we perceive things, we perceive their individual features such as color, motion, orientation/ edges, but attention is the glue that binds disconnected visual features into a coherent object.

Answer 13

When perceiving something, you go through two stages, the preattentive stage, then the focused attention stage. In the preattentive stage you can detect an object among distractors because the number/nature of the distractors isnt many. Called parallel searching/pop out as the object youre searching for will pop out wihtout your attention really having to be redirected to it Then theres the focused attention stage, where there are more distractors and its harder to find what youre looking for. Here you will have ot focus your attention and look in greater detail and requires sustained effort. This is called conjuction searching

Answer 14

In focused attention stage of Treismans Feature Integration Theory

Answer 15

In preattentive stage of Treismans Feature Integration Theory

Answer 16

proposed mechanism by which the brain integrates and combines information from different sensory modalities or neural populations to create a unified perception of the world. In this process, neurons that represent different aspects of a sensory stimulus or object synchronize their activity patterns to encode and bind together the various features of the stimulus

Answer 17

The image is focused here there are the highest levels of cones so highest resolution image

Answer 18

that we will direct our attention to the most salient object in the scene - the thing that pops out the most Trying to answer the question to do with how we direct our attention to different parts of a scene

Answer 19

More recent research suggests that simple salience model should be rejected It works on a screen but less so in real life. In real life our eye gaze is allocated to the right place and at the right time to guide our actions, helps to plan ahead of our actions

Answer 20

People with autism may have their focus on different parts of a natural scene. While a non autistic person will look at a persons eyes, autistic people may center their eye pattern on the shoulder, hairline etc - just have a different pattern of eye movement

Answer 21

Attention helps us respond faster to attended objects/locations or in some cases a contrast is enhanced - eg its not a person walking theyre speeding towards us on a bike Attent also enhances physiological responses - firing rates in the parietal cortex increases if the object is in the receptive field is attended to

Answer 22

Motion sensitive neurons with motion sensitive receptive fields Attempts to explain

Answer 23

Instead of seeing a blurry mess when things move fast, the object changes places on our retina. Delay and compare mechanism is when you know the distace travlled and time take, so you can know the velocity

Answer 24

Apparent motion refers to the perception of movement when there is no physical motion occurring. Instead, apparent motion occurs when the visual system processes a series of static images or stimuli presented in rapid succession, creating the illusion of continuous motion.

Answer 25

Refers to the challenge faced by the visual system in : Correctly matching local motion signals from different parts of the visual field to perceive coherent motion trajectories of objects -The visual system receives motion information from numerous spatial locations and orientations simultaneously and must integrate these signals to accurately perceive the motion of objects.

Answer 26

You use nearest neighbor matching when you see objects seeminlgy "move" from one position to the next. In our heads one spot has moved to the next because this new position is its nearest neighbor, giving shortest trajectory

Answer 27

Lots of individual objects that get grouped into a bigger moving mass because they are going in the same direction or same speed

Answer 28

That apertrue influences the perceived direction of motion. For example the barberpole illusion, which is essentially a massive correspondence problem, because you dont know which direciton a specific point is going. So to figure it out our mind looks at the edges, which makes the motion look like its going upwards Or straight vs crinkled aperture difference in motion

Answer 29

Optic flow is the visual motion patterns perceived by an observer as they move through their environment To determine it we need to look at where the visual information is flowing from. Is it going away from you or towards you?

Answer 30

1. Is there retinal motion? Is the object moving on your retina? 2. Are your eyes still or are you tracking the obejct 3. Did you command your eyes to move?

Answer 31

The electormagentic spectrum is energy that travels caused by the acceleration/decceleration of charged particles. We perceive variations in wavelength as color

Answer 32

That color is not in the light itself, but is rather produced by our visual system. It is a black and white disc which, when rotated, looks to be colorful. it shows that color cannot always be explained in terms of wavelength -> there is something internal happening that has to do with its temporal properties

Answer 33

On the x-axis is the wavelenght and on the y axis is the reflectance. So a spectral refelctance graph shows how much a certain wavelenght is being reflected aka what color it is (which wavelnghts are prominent causing a certain color sensation)

Answer 34

That we attribute certain colors to go with certain shapes/objects, so that when the color is not one we associate with an object, we feel uncomfortable or confused if color doesnt correspond to particular class of object

Answer 35

Our prior knowledge of an objects characteristic colors affects its appearance.

Answer 36

That any colored light can be matched by adjusting the relative amounts of the three primary lights, this has to do with the physiology of vision, in that we have three types of cone cells with three different pigments with different spectral sensitivities Because we have three types of cone cells, we are trichromatic, whereas dogs only have 2 and are dichromatic

Answer 37

Different wavelenghts producing the same spectrum/perception of color because theyre stimulating the cones in the same relative amounts.

Answer 38

its the idea that we have natural pairings of color red-green black-white blue-yellow This theory suggests that the mind can only register the presence of one color of a pair at a time because the two colors oppose one another Which is why he questions whether aynone has seen a reddish green or blueish yellow --> though some authors argue this is possible

Answer 39

Discovery of opponent cells/neurons in the LGN and retina The retinal ganglion cells which get excited by one color and surpressed by another

Answer 40

Achromatic (L+M) Red-Green (L vs M) Blue-Yellow c (L+M) vs S

Answer 41

That two surfaces with the same spectral composition will be perceived to have a different color when they are placed against different chromatic backgrounds

Answer 42

The color of an object is dependent on the objects and the source of light. To view a color it must be viewed with a certain illumination, but the type of illumination is going to affect the color

Answer 43

the idea that colors stay constant even when there are changes in luminosity/the illuminant

Answer 44

Chromatic adaption - eg having sunglasses on, adding filters.. Contextual effects - is there a shadow on it, what time of day is it.. Memory - what do i remember this color being

Answer 45

That how intense we perceive a hue/color to be is dependent on the background. Eg the blackness of your TV screen cannot be blacker than when your TV is off/there is no image

Answer 46

Proprioception: sense of position of our limbs Kinesthesis: sense of movement of the muscles Somaesthesis: sense of object touching the skin

Answer 47

Hairy and glaborous

Answer 48

Merkel receptors - continuous pressure Meissner corpuscles - onset/offset of stimuli Pacinian corpuslces - responds to vibration Ruffini endings - responds to stretching of the skin

Answer 49

They are found in hairy skin (non-glaborous) Responding to slow, gentle touches like a massage Signals get sent to the insular cortex which has a part to play in emotion regulation

Answer 50

Is a sort of map that shows how much cortex is devoted to different parts of the body. Eg fingers and lips are small in size but have proportionatly large brain sensitivity

Answer 51

Area S1 --> Area S2 --> Hippocampus or Prefrontal Cortex Area S1 --> posterior parietal cortex --> premotor cortex

Answer 52

Active touch refers to when we acitvely use our hands to explore objects in the world. Its more efficient than passive touch, which is like moving smth passively in our hand

Answer 53

Pain receptors - sensitive to stimuli that could be potentially damaging to the skin

Answer 54

A-delta fibre axons are reponsible for the initial, sharp pain sensation. Neurons myelinated so signal travels fast C-fibre axons are not myelinated and are responsible for the pain after the intial sharp pain. It arrives slower, and is more prolonged and less intense

Answer 55

L - normal touch receptors acitvate inhibitory interneuron and So when pain comes through S fibres, and wants to go to Projection cells that will lead to the brain, activating L fibres will allow some inhibition of these signals, decreases the pain sensation