week 8 - the visual world

Question 1

occipital lobe

Answer 1

Occipital lobe - back part of cerebrum, houses visual areas

Question 2

pupil

Answer 2

Pupil - small opening in the eye

Question 3

iris

Answer 3

Iris - coloured portion of the eye, controls size of the pupil by constricting/dilating in response to light surrounds the pupil

Question 4

cornea

Answer 4

Cornea - A clear covering that protects the eye and begins to focus the incoming light thin layer that protects the eye

Question 5

lens

Answer 5

A structure that focuses the incoming light on the retina sits just behind the cornea and the iris
Focuses incoming light onto the retina
Flexes to change shape of the retina

Question 6

visual accommodation

Answer 6

Visual accommodation - The process of changing the curvature of the lens to keep the light entering the eye focused on the retina

Question 7

near sighted versus far sighted

Answer 7

Near sighted - info far away is improperly focused, lens refracts light
Far sighted - info goes behind the retina
People get lenses or contacts to properly refract the light

Question 8

retina

Answer 8

Retina - Cell layer in the back of the eye containing photoreceptors.
Every image projected here is actually INVERTED and BACKWARDS
Fovea - The central point of the retina
Where we can see the most precisely, most concentration of cones
Blindspot - A hole in our vision that is created because there are no photoreceptor cells at the place where the optic nerve leaves the retina.

Question 9

fovea

Answer 9

Fovea - The central point of the retina

Where we can see the most precisely, most concentration of cones

Question 10

blindspot

Answer 10

Blindspot - A hole in our vision that is created because there are no photoreceptor cells at the place where the optic nerve leaves the retina.

Blind spot - A hole in our vision because there are no photoreceptor cells at the place where the optic nerve leaves the retina

Question 11

the optic nerve

Answer 11

The optic nerve
A collection of millions of ganglion neurons that sends vast amounts of visual information, via the thalamus, to the brain.
Ganglion cells converge together to make a thicker cord of individual threads Because the retina and this nerve are active processors and analyzers of information, and can be considered an extension of the brain itself.

Question 12

from the optic nerve to the visual cortex

Answer 12

from optic nerve to visual cortex
Optic nerve from each eye projects to the visual area of the thalamus on both the ipsilateral (same) side and contralateral (opposite) side.
From there, the visual input is processed by visual cortex the ipsilateral side However, our visual cortex processes both eyes separately, and in parallel

Question 13

feature processing in the visual cortex

Answer 13

Feature processing in visual cortex
Visual cortex has specialized neurons, located in the visual cortex, that respond to the strength, angles, shapes, edges, and movements of a visual stimulus, called feature detector neurons. Neurons in the early visual cortex respond to simple features, but the complexity of features builds up as you move along the ventral pathway (the ‘what’ pathway) Information is also passed along the dorsal pathway (the ‘where’ pathway), which processes information about location and movement.

Question 14

rods and cones

Answer 14

Rods - Photoreceptors of the retina sensitive to low levels of light. Located around the fovea.
Cones - Photoreceptors of the retina sensitive to color. Located primarily in the fovea.

Question 15

gestalt principle

Answer 15

Gestalt principles

A whole is more than the sum of its parts

Question 16

depth perception

Answer 16

Depth perception
binocular disparity
Difference in images processed by the left and right eyes
binocular vision
Our ability to perceive 3D and depth because of the difference between the images on our retinas

Question 17

depth cues (binocular)

Answer 17

Depth cues (binocular)
convergence
The inward turning of our eyes that is required to focus on objects that are less than about 50 feet away from us
accommodation
Changes of the curvature of the lens to see far or close objects. Information relayed from the muscles in the eye helps us determine distance.

Binocular depth cues - Depth cues that are created by retinal image disparity — that is, the space between our eyes — and which thus require the coordination of both eyes

Question 18

depth cues monocular

Answer 18

Depth cues (monocular)
Position
Relative size
Linear perspective
Light and shadow
Interposition
Aerial perspective

Monocular depth cues - Depth cues that help us perceive depth using only one eye

Question 19

integration

Answer 19

Integration - The process by which the perceptual system combines information arising from more than one sense

Question 20

Multisensory convergence zones

Answer 20

Multisensory convergence zones - Regions in the brain that receive input from multiple unimodal areas processing different sensory modalities.

Question 21

spatial principle of mutlisensory integration

Answer 21

Spatial principle of multisensory integration
The finding that the superadditive effects of multisensory integration are observed when the sources of stimulation are spatially related to one another
Analogous to this spatial principle, sources of stimulation that are close together in time are often superadditive as well

Question 22

rubber hand illusion

Answer 22

Rubber hand illusion - The false perception of a fake hand as belonging to a perceiver, due to multimodal sensory information.

Question 23

accommodation

Answer 23

Accommodation - Helps determine depth.

Question 24

beta effect

Answer 24

Beta effect - The perception of motion that occurs when different images are presented next to each other in succession

Question 25

colourblindness

Answer 25

Colour blindness - The inability to detect green and/or red colours

Question 26

near and far sightedness

Answer 26

Nearsighted - When the focus is in front of the retina

Farsighted - When the focus is behind the retina

Question 27

convergence

Answer 27

Convergence - The inward turning of our eyes that is required to focus on objects that are less than about 50 feet away from us

Question 28

depth cues

Answer 28

Depth cues - Messages from our bodies and the external environment that supply us with information about space and distance.

Question 29

electromagnetic energy

Answer 29

Electromagnetic energy - Pulses of energy waves that can carry information from place to place

Question 30

feature detector neurons

Answer 30

Feature detector neurons - Specialized neurons, located in the visual cortex, that respond to the strength, angles, shapes, edges, and movements of a visual stimulus

Question 31

opponent process colour theory

Answer 31

Opponent-process colour theory - Proposes that we analyze sensory information not in terms of three colours but rather in three sets of “opponent colours”: red-green, yellow-blue, and white-black

Question 32

optic nerve

Answer 32

Optic nerve - A collection of millions of ganglion neurons that sends vast amounts of visual information, via the thalamus, to the brain

Question 33

phi phenomenon

Answer 33

Phi phenomenon - We perceive a sensation of motion caused by the appearance and disappearance of objects that are near each other

Question 34

trichromatic colour theory

Answer 34

Trichromatic colour theory - The colour we see depends on the mix of the signals from the three types of cones

Question 35

visible spectrum

Answer 35

Visible spectrum - The part of the electromagnetic spectrum that our eyes detect (only the range from about 400 to 700 billionths of a meter)

Question 36

sensory modalities

Answer 36

Sensory modalities - A type of sense; for example, vision or audition.

Question 37

receptive field

Answer 37

Receptive field - The portion of the world to which a neuron will respond if an appropriate stimulus is present there.

Question 38

principle of inverse affectiveness

Answer 38

Principle of Inverse Effectiveness - The finding that, in general, for a multimodal stimulus, if the response to each unimodal component (on its own) is weak, then the opportunity for multisensory enhancement is very large.

However, if one component—by itself—is sufficient to evoke a strong response, then the effect on the response gained by simultaneously processing the other components of the stimulus will be relatively small.

Question 39

primary auditory cortex and visual cortex

Answer 39

Primary auditory cortex - A region of the cortex devoted to the processing of simple auditory information.

Primary visual cortex - A region of the cortex devoted to the processing of simple visual information.

Question 40

mutlisensory convergence zones

Answer 40

Multisensory convergence zones - Regions in the brain that receive input from multiple unimodal areas processing different sensory modalities.

Question 41

multimodal (+perception) (+phenomena)

Answer 41

Multimodal - Of or pertaining to multiple sensory modalities.

Multimodal perception - The effects that concurrent stimulation in more than one sensory modality has on the perception of events and objects in the world.

Multimodal phenomena - Effects that concern the binding of inputs from multiple sensory modalities.

Question 42

visual cliff

Answer 42

Visual cliff - A mechanism that gives the perception of a dangerous drop-off, in which infants can be safely tested for their perception of depth

Question 43

wavelength

Answer 43

Wavelength - The distance between one wave peak and the next wave peak

Question 44

bouncing balls illusion

Answer 44

Bouncing balls illusion - The tendency to perceive two circles as bouncing off each other if the moment of their contact is accompanied by an auditory stimulus.

Question 45

Crossmodal phenomena, receptive field, and stimulus

Answer 45

Crossmodal phenomena - Effects that concern the influence of the perception of one sensory modality on the perception of another.

Crossmodal receptive field - A receptive field that can be stimulated by a stimulus from more than one sensory modality.

Cross Modal stimulus - A stimulus with components in multiple sensory modalities that interact with each other

Question 46

double flash illusion

Answer 46

Double flash illusion - The false perception of two visual flashes when a single flash is accompanied by two auditory beeps.

Question 47

integrated

Answer 47

Integrated - The process by which the perceptual system combines information arising from more than one modality.

Question 48

McGurk effect

Answer 48

McGurk effect - An effect in which conflicting visual and auditory components of a speech stimulus result in an illusory percept.

Question 49

Spatial principle of Multisensory integration

Answer 49

Spatial principle of multisensory integration - The finding that the superadditive effects of multisensory integration are observed when the sources of stimulation are spatially related to one another.

Question 50

superaddtive effect of Multisensory integration

Answer 50

Superadditive effect of multisensory integration - The finding that responses to multimodal stimuli are typically greater than the sum of the independent responses to each unimodal component if it were presented on its own.

Question 51

unimodal/unimodal components/unimodal cortex

Answer 51

Unimodal - Of or pertaining to a single sensory modality.
Unimodal components - The parts of a stimulus relevant to one sensory modality at a time.
Unimodal cortex - A region of the brain devoted to the processing of information from a single sensory modality.

Question 52

How does vision work?

Answer 52

Vision is the process of detecting the electromagnetic energy that surrounds us. Only a small fraction of the electromagnetic spectrum is visible to humans.

The visual receptor cells on the retina detect shape, colour, motion, and depth.
Light enters the eye through the transparent cornea and passes through the pupil at the centre of the iris. The lens adjusts to focus the light on the retina, where it appears upside down and backward. Receptor cells on the retina are excited or inhibited by the light and send information to the visual cortex through the optic nerve.
The retina has two types of photoreceptor cells: rods, which detect brightness and respond to black and white, and cones, which respond to red, green, and blue. Colour blindness occurs when people lack function in the red- or green-sensitive cones.
Feature detector neurons in the visual cortex help us recognize objects, and some neurons respond selectively to faces and other body parts.
The Young-Helmholtz trichromatic colour theory proposes that colour perception is the result of the signals sent by the three types of cones, whereas the opponent-process colour theory proposes that we perceive colour as three sets of opponent colours: red-green, yellow-blue, and white-black.
The ability to perceive depth occurs as the result of binocular and monocular depth cues.
Motion is perceived as a function of the size and brightness of objects. The beta effect and the phi phenomenon are examples of perceived motion.