Perception

Question 1

Ventral stream (or ‘What’-pathway)

Answer 1

One half of the ‘two-streams hypothesis’; the ventral stream carries visual information from the primary visual cortex in the occipital lobe to the temporal lobe, and is involved with object identification and recognition.

The ventral stream has strong connections to the medial temporal lobe, which stores long-term memories, as well as the limbic system, which controls emotion.

Question 2

Agnosia

Answer 2

A general term for the inability to process sensory information.

It exists in different forms such as apperceptive agnosia and associative agnosia.

Question 3

Associative Agnosia

Answer 3

The inability to recognize complex objects. The person is able to recognize simple shapes and can copy drawings, however, is unable to recognize complex objects even after copying them.

Question 4

Apperceptive agnosia

Answer 4

The inability to recognise simple shapes or to draw shapes. Deficit in early visual processing.

Question 5

The primary visual cortex

Answer 5

The first cortical area to receive visual input

Question 6

Edge detectors

Answer 6

They respond positively to light on one side of a line and negatively to light on the other side

Question 7

Bar detectors

Answer 7

They respond positively to light in the center and negatively to light in the periphery, or vice versa.

Question 8

Stereopsis

Answer 8

The ability to perceive 3-D depth

Question 9

Gestalt principles of organization

Answer 9

Gestalt principles of organization help explain how the brain segments visual scenes into objects

There are six individual principles commonly associated with gestalt theory: similarity, continuation, closure, proximity, figure/ground, and symmetry & order.

Look at figure: 2.12 on page 47.

Question 10

Phonemes

Answer 10

Phonemes are the smallest unit of speech distinguishing one word (or word element) from another

(Example: the differences between “tap”, “tab,” “tag,” and “tan.”)

Question 11

Template matching

Answer 11

Theory of pattern recognition: a way to identify objects by aligning the retinal image of a stimulus to a stored template of a pattern.

Question 12

Fusiform gyrus

Answer 12

Particular region of temporal lobe associated with face recognition.

Question 13

Retina

Answer 13

The innermost layer of cells within the eye contains two photoreceptor types: cones, responsible for color vision and high resolution, and rods, which require less light but provide lower resolution and no color information.

Question 14

Cones

Answer 14

It’s one of the two photoreceptors in the eye, Cones handle color vision and produce high resolution. We primarily use cones during the day.

Question 15

Rods

Answer 15

it’s one of the two photoreceptors in the eye, Rods need less light to trigger a response, but they produce poorer resolution and no information about color. Rods are what we primarily use when we see in the dark.

Question 16

Ganglion Cells

Answer 16

Ganglion cells are a type of neuron found in the retina of the eye. They are the final output neurons of the retina and play a crucial role in transmitting visual information from the eye to the brain. Ganglion cells receive input from other types of retinal neurons, such as photoreceptor cells (rods and cones) and bipolar cells, which process visual stimuli and convert them into electrical signals.

Question 17

Bottom-up processing

Answer 17

Involves information traveling ‘up’ from
the stimuli, via the senses, to the brain

Question 18

Voicing

Answer 18

A feature of phonemes produced by the vibration of the vocal cords.

Question 19

Place of articulation

Answer 19

Refers to the location at which the vocal tract is closed or constricted in the production of a consonant phoneme.

Question 20

The “Where”-pathway

Answer 20

The pathway going to the parietal lobe specializes in representing spatial information and coordination.

Question 21

Fovea

Answer 21

It’s a part of the retina, where the cones are especially concentrated.

Question 22

Top-down processing

Answer 22

The contribution or guidance of prior knowledge, experiences, and expectations on incoming information (“What we know/expect, influences what we perceive.”

Question 23

Word superiority effect

Answer 23

This effect describes the fact that it is easier to recognize a letter when it is a part of a word, than when it stands for itself. Such as the example. “The cat or Tae cht” (page. 63)

Question 24

Feature analysis

Answer 24

A pattern recognition model, where stimuli are thought of as elemental features.

Question 25

Change blindness

Answer 25

The inability to keep track of all information in a complex scene.

Question 26

2½-D sketch and 3-D model

Answer 26

Proposal made by David Marr (1982): Various sources of information come together to create the so-called 2½-D sketch, that identifies where various visual features are located in space relative to the viewer. Creation of a 2½-D sketch requires a lot of information but a lot more is necessary to translate such a sketch into an actual perception of the world. Such a sketch represents only parts of surfaces and does not yet identify how these parts go together to form images in the environment. The term 3-D model is used to refer to such a later representation of objects in a visual scene.

Question 27

Deep Convolutional Network

Answer 27

Object recognition method used by AI: The image processing starts from the stimulus - a pixel representation of an image - followed by 5 (or more) layers of pattern recognizers.

Question 28

Early phase of vision

Answer 28

Shapes and objects are extracted from the visual scene

Question 29

Later phase of vision

Answer 29

Shapes and objects are recognized

Question 30

The process of visual perception in 4 steps?

Answer 30

1) Light enters through the cornea
2) Light passes through the aqueous humor
3) Light passes through pupil, lens, and vitreous humor
4) Light strikes and stimulates the retina.

Question 31

The blind spot (location)

Answer 31

We have a blind spot where the optic nerve is. There isn’t a retina to receive the signal in the blind spot, because all the signals are collected here.

Question 32

Texture gradient

Answer 32

Elements tend to appear more closely packed together as the distance from the view increases

Question 33

Motion parallax

Answer 33

Provides 3D information about when an object is in motion

Question 34

What part of the brain is responsible for face recognition?

Answer 34

Fusiform gyrus.
A different part of the brain creates object recognition

Question 35

Prosopagnosia

Answer 35

Face blindness
(Brain trauma to the fusiform gyrus)

Question 36

Categorical perception

Answer 36

We are better at distinguishing between categories than within them

Question 37

The McGurk effect

Answer 37

An auditory-visual illusion that illustrates how perceivers merge information for speech sounds across the senses

(For example, when we hear the sound “ba” while seeing the face of a person articulate “ga,” many adults perceive the sound “da,” a third sound which is a blend of the two.)

Question 38

Principle of proximity (Gestalt principles)

Answer 38

That items close together are likely to be perceived as part of the same group

Question 39

Principle of similarity (Gestalt principles)

Answer 39

When items share some visual characteristic, they are assumed to be related in some way

Question 40

Psychological nystagmus

Answer 40

A tremor! Our retinal image of an object is not constant. Its position changes over times. Parts of an image start to disappear from our perception when the tremor doesn’t occur.

Question 41

Principle of closure (Gestalt principles)

Answer 41

People will fill in blanks to perceive a complete object whenever an external stimulus partially matches that object

Question 42

On-off cell

Answer 42

When the light hits the centre of responsive field the rate of spontaneous firing of the cell increases.

Question 43

Accommodation (The lens)

Answer 43

The Lens changes shape to focus incoming light falling on the retina onto the fovea

Question 44

Off-on cell

Answer 44

When the light hits the centre of receptive field the rate of spontaneous firing decreases.

Question 45

Organisation of a Hypercolumn in the Visual Cortex.

Answer 45

The hypercolumn is organized in one dimension according to whether input is coming from the right eye (R) or left eye (L). In the other dimension, it is organized according to the orientation of lines to which the receptive cells are most sensitive. Adjacent layers of cells represent similar orientations

Question 46

Photochemical process

Answer 46

e.g. conversion of light into neural signals that happens in photoreceptors (rods, cones) in the eye

Question 47

What did Kuffler’s research showe and when?

Answer 47

In 1953 Kuffler showed how information is encoded by the ganglion cells in the retina.