object recognition

Question 1

ventral visual processing stream

Answer 1

in the occipitotemporal region

processing info related to object recognition

Question 2

inferotemporal cortex

Answer 2

posterior
central
anterior

receive info coming from primary visual cortex

Question 3

what do posterior regions respond to

Answer 3

simple stimuli

Question 4

what do cells further along the ventral stream respond to

Answer 4

more complex stimuli

Question 5

receptive fields

Answer 5

area of space to which a cell is sensitive
- if falls outside the cell will not respond

becomes larger as we move further along ventral stream
- inferotemporal has large, primary cortex has small

a large field allows an object to be identified regardless of its sizer and location. we can understand more of what we are looking at. recognizing what, not so much where

Question 6

consequence of a large receptive field

Answer 6

some info about an item’s position in space is lost

lose ability to know location

Question 7

agnosia

Answer 7

means without knowledge

Question 8

visual agnosia

Answer 8

when things go wrong in the ventral stream

an inability to recognize objects in the visual modality (that cannot be explained by other causes such as problems with attention, memory, language etc)

object can be recognized by other senses therefore it is modality specific

two types: apperceptive and associative

Question 9

apperceptive agnosia

Answer 9

can not perceive a whole

a fundamental difficulty in forming a percept (a mental impression of something perceived by the senses)

sensory info is still processed in a rudimentary way (ie/ distinctions between light and dark can be made), but the data cannot be put together to allow a person to perceive a meaningful whole

have trouble seeing integrated objects

Question 10

associative agnosia

Answer 10

can copy and reproduce a figure

basic visual info can be integrated to form a meaningful perceptual whole, but that particular perceptual whole cannot be linked to stored knowledge

can see objects, but do not know what they are seeing

can perceive more detail

Question 11

appreceptive agnosia is damage to where

Answer 11

occipital lobe

Question 12

associative agnosia is damage to where

Answer 12

occipitotemporal regions of both hemispheres and subadjacent white matter

Question 13

prosopagnosia

Answer 13

agnosia specific to faces

can occur with people losing the ability to recognize printed words

a selective inability to recognize or differentiate among faces

result of damage to the ventral stream of the right hemisphere

can usually determine basic info (its a face)

limited ability to recognize a face as belonging to a specific person

Question 14

category specific deficits

Answer 14

trouble identifying a category of objects

ie/ fruits, vegetable

Question 15

sparse coding

Answer 15

the theory that a small but specific group of cells responds to the presence of a given object

the grandmother cell theory

there is a particular cell in the ventral stream whose job is to fire when you see a particular object or person

a single cell responding to when you see your grandma

not thought to be correct

Question 16

population coding

Answer 16

the theory that the pattern of activity across a large population of cells codes for individual objects

extreme version: every cell in the ventral stream is involved in coding for every object (all just firing at different rates)

the reality probably lies in between population and sparse, but eveidence leans more towards population

Question 17

form- cue invariance

Answer 17

the brain’s categorization is constant regardless of the form of the cue that represents that object

ie/ drawn, physically there, cartoon, colour - can recognize it no matter what its form

Question 18

perceptual constancy

Answer 18

the ability to recognize objects see from different angles, positions, sizes and kinds of illuminations

ie/ from above/below

Question 19

lateral occipital complex

Answer 19

involved in form-cue invariance and perceptual constancy
- shows evidence of perceptual constancy across variations in size, location and form of the shape

may be the stage in visual representations are formed
- supports recognition of objects despite differing conditions

Question 20

viewpoint dependency

Answer 20

can recognize objects from multiple viewpoints, but recognition is faster and more accurate when viewed from familiar viewpoint

Question 21

neural representations

Answer 21

some ventral stream cells change depending on object orientation, other cells respond to an object in the same way regardless of orientation

neuroimaging studies have found viewpoint-dependence at earlier stages of the ventral stream and viewpoint-independence at later stages

Question 22

left ventral stream

Answer 22

important in analyzing parts of objects

Question 23

right ventral stream

Answer 23

important for analyzing whole parts (configuration of the parts)

Question 24

inversion effect

Answer 24

especially effects faces

recognition is poorer when an object is turned upside down

suggests we tend to rely of the way features are put together/ related to each other (configural info) when identifying object
- especially important with object categories for which we have a lot of expertise

Question 25

nonlogical binding

Answer 25

a whole object is represented by the co activation of cells that represent the part of the object in particular locations

no seperate unit that represents the whole, but rather the whole is perceived when the units are representing all the constituents parts are simultaneously activated

whole is exactly the sum of its parts

Question 26

conjunctive encoding

Answer 26

lower level regions represent features and send output ot higher level regions representing the shapes that result from the joining of those features

seperate unit that represents the whole, beyond just the ones that respond to the parts

evidence leans in support of this

a whole is more than the sum of its parts

Question 27

fusiform face area

Answer 27

greater response to faces than other objects

Question 28

parahippocampal place area

Answer 28

process visual info related to places in the local environment

Question 29

extrastriate body area

Answer 29

responds to images of the human body and parts of it

Question 30

visual world form area

Answer 30

responsive to visual representations of the world

Question 31

auditory agnosia

Answer 31

the inability to recognize the meaning of sounds

can hear smt but can not connect to what it is

Question 32

somatosensory/ tactile agnosia

Answer 32

is the inability to recognize an item by touch (but can recognize the object in other modalities)

ie/ like a snag rug - can not connect to what it is