9

beneath occipital bone (back of the skull)

posterioir pole og th cerebral hemispheres

distinguished from parietal lobe by paroetal

no clear separation form temporal or lateral parietal

1. calarine suculus → primary visual cortex (V1) divides the upper and lower halves of visual world
2. lingual gyrus (V2 and VP)
3. fusiform gyrus (V4)

area 17

area 18

area 19

remarkable laminar organization ( most distinct of cortical areas)

visual cortex

striate cortex

appears like thick stripes

usually neocortex made of 6 layers , in this care there are many more

heterogenous

separated by interblob regions

take epart in color perception

role in form and motion perception

area V2 also heterogoenous

not blobs but stripes

"thin stripes" → color perception

"think stripes" form and motion perception

1. Superchiasmatic nucleus
2. Pretectum
3. Pineal gland
4. Superioir colliculus
5. Accessory optic nucleus
6. Visual cortex
7. Fronal eye fields

daily rythms ( sleep, feeding , etc)

changes in pupil size in response to light

long term circadian rhytms

head orientation

eye movement to compensate for head movement

pattern perception, depth perception and colour vision

eye movement

visual information proceeding from area V1→ area V2→ to area V3

distributed hierarchical process with multiple parallel onterconnecting patchways at each level

recieves the largest imput from lateral geniculate nucleus ( in thalamus )

projects to all occipital areas

projects to all other occipital regions

1. dorsal stream →parietal cortex (viusal guidence for movement )
2. ventral stream →inferioir temporal cortex
3. STS stream ( object perception : colour and faces)

they are parallel

further processing

1. geniculostriate system
2. tectopulvinar pathway

geniculostriate pathway

gretina → lateral geniculate nucleus (LGN) in thalamus → the viusal cortex ( V1/A17) → secondary I → secondary II → tertiary and paralimbic

perception of forms and color

depth perception

disturbances= 'blind sight'

eyes→ superioir coliculus (midbrain tectum) →lateral posterior pulvinar complex (thalamus → visual area in parietal and temporal lobes

role of orientation and detecting visual stimulation

skips area 17 / V1 (directly to secondary )

pretectum

suprachiasmic nucleus

damage to occipital lobe bilaterally

tectopulvinar = intact ( blidsight)

can recognize faces , colours and navigate enviornment

significant plasticity to rearrange visual system and strengthen pathways forn subcortical areas to V5

1. parietal cortex : visual guidence of movement
2. inferioir temporal lobe : operception of an object
3. superioir tempoaral sulucus : visuospatial functions

e.g. we need memory in order to remebr when we see an object which is part of the medial area

1. dorsal
2. ventral
3. parietal temporal stream

where

what

STS

object recognition

contain spolysennsory neurons ( give information form dorsal to ventral )

the final target is in the frontal lobe (PFC)

1. vision for action
2. action for vision
3. visual recognition
4. visual space
5. visual attention

pareital

frontal eye filds) e.g. trailmaking A/B

temporal

pareital , temporal

egocentric space : relative to an individual ( from your person into space) → parietal

allocentric space : relative to one another → temporal

pareital , temporal

1. identification of the object clearly
2. reaction to the object shows sematic knowledge about what they see ( corect sorting of the objects )
3. adequate reactions on the object ( spontanous use of it )

= inability to combine individual visual impressions into complete patterns

unable to recognize objects / innability to draw or copy them

1. appreciative
2. associative
3. simultagnosia
4. propoagnosia
5. pure alexia
6. visuospatial agnosia

failure of accesing stored information about objects

**a failure in recognition despite no deficit in perception**

can match or draw objects but cannot name them

unable to recognize objects, draw, or copy a figure.

cannot perceive correct forms of the object, although knowledge of the object is intact

improved recognition by moving the object

cannot draw or copy

**the inability to perceive more than one object at a time**

failure to recognise familiar faces

may resemble dementia or memory loss

sometimes sematic cathegouries are mixed up ( e.g. birds)

also not able to learn new faces

related to the fusiform gyrus but not only

fusiform gyrus is located in the inferior temporal ( occipital part )

face recognition

generation of image in the brain

discrimination and matching of faces

can recognize that the face is the face

voice and extrafacial characteristics can be recognised

memories if that face are still intact and can be retrieved

cannot read cohersive

cannot make image of the environment ( e.g. trace towns and cities on a map )

propopagnosia

dressing apraxia

constructional apraxia

normal verbal memory

severe disturbance in memory 'topographical'

location of the deficit : right medial occipittotemporal region