cognitive vision loss

Simultanagnosia (ventral)

(L>R) -can't see arrays of letters, only one at a time

Simultanagnosia (ventral) deficit region

(L>R) occipitoparietal region

Simultanagnosia (dorsal) deficit region

(bilateral) occipitoparietal junction

face agnosia (Prosopagnosia) CVL tests errors

(due to pFus being involved) -form -motor-free -line

face agnosia (Prosopagnosia) CVL tests failed

- face

form agnosia deficit region

-LOC (dorsal) recognizes objects -V7 (dorsal) encodes objects -IT cortex (Macaques only) extends more anterior for macaques

visual form discrimination

-NOT test memory -tests discrimination bt complex configurations -basic forms encoded by euros in LOC

face agnosia (Prosopagnosia) deficit region

-VOT (ventral occipitotemporal) -(FFA) -also lesser so: LOC, pFus

Blindsight deficit region

-area V1 -unaffected dorsal path leaves visual guidance intact(superior colliculus neurons are intact and sensitive to motion)

Simultanagnosia (dorsal)

-can recognize pieces of sense but not a whole -"not being able to see properly" -"blind and clumsy" -cannot see 2 objects in 2 locations

associative agnosia

-can recognize, no perception of meaning

Optic Aphasia

-can't name visual objects (unless verbally described or touched) -however no semantic info loss - have some degree so does;t really affect life

apperceptive agnosia

-can't perceive/recognize/discriminate stimuli

Simultanagnosia (dorsal or ventral)

-cannot get scene as a whole -VF, color, acuity intact

comprehensive trail-making test (CTMT)

-combines high order visual cognitive planning + visual spatial perception -frontal lobe processing deficit if inc time

motion agnosia

-damage to V5/MT -strobe objects in motion -rare

Optic ataxia 3 things

-hard determining orientation of objects, problems grabbing objects -poor eye mvmts -fine orientation with lines or depth perception

topographic (place) agnosia

-impaired recognition of scenes and landmarks -in convo with secondary Alzheimer's disease or other degenerative white matter disease

Cognitive vision loss tests (CVL)

-judgement line orientation -visual form discrimination -facial recognition -ruff-light trail learning test (RULIT) -motor-free visual perception test (MVPT-3) -comprehensive trail-making test (CTMT)

topographic (place) agnosia failed tests

-learn -unlikely to show errors in other tests unless extends to medial/posterior occipitotemporal

Optic Aphasia failed tests

-line -this isn't directly assessed by any CVL tests

Semantic dementia

-loss of semantic memory (face, voice, places) -preserved visual spatial cognition, episodic learning and memory (day to day), non-verbal reasoning

semantic dementia failed tests

-make -limited errors in other 5 since semantics aren't involved

2 other non-cognitive vision losses

-motion agnosia -cortical color blindness (cerebral chromatopsia)

cortical color blindness

-V8 damage -unilateral, bad if bilateral

Simultanagnosia (dorsal or ventral) failed tests

LMoM -learn -motor free -make -likely to fail all 6

What path

ventral from occipital cortex to inferotemporal cortex -single obj recognition and discrimination

face agnosia (Prosopagnosia) 1 thing

-no face recognition without voice

Hemispatial neglect 3 things

-no info opposite of lesion -remember all scenes but the contralateral side doesn't make sense -pt denies problem

form agnosia

-no visual form discrimination/orientation of simple forms (real object is better, touching object helps) -VA grating, color, depth still fun

ruff-light trail learning test (RULIT)

-short term memory + spatial perception abilities -frontal/pre-frontal and posterior parietal cortex -tests R hemisphere

judgement line orientation

-shows dec ability to perceive spatial orientation -tests R hemisphere -lines encoded by V1, more specialized area of LO and LOC -spatial relationship bt lines by posterior parietal cortex

semantic dementia deficit regions

-temporal lobes (L>R), frontal lobes (L>R) -associated with stroke, closed head injury, post-surgery, viral encephalitis, Alzheimer's

Blindsight 2 things

-unilateral hemianopia, or bilateral blindness -can ID in blindfield when pressured

topographic (place) agnosia deficit region

-ventral medial occipitotemporal cortex (fusiform or lingual gyro) -bilateral lesions produce this, lesion in R hem alone produces small deficit -common R or bilateral PCA infarct , or injury to small vessel ischemic disease

Blindsight CVF tests they fail

BMLM -make -learn -motor free -all 6 will probably have errors

apperceptive agnosia 2 things

FApS -form agnosia -simultagnosia

form agnosia failed tests

FFMMLeL -form -motor-free -make -learn -line

Hemispatial neglect deficit region

IPP inferior and posterior parietal (R>L) -other frontal areas involved (FEF, IFL, MFL, thalamus) -often damage due to PCA stroke

Hemispatial neglect CVL tests failed (most to least likely)

LiLM -line -learn -make -likely to fail all 6

Optic ataxia tests they fail 3 things

OALM -learn -make -rarely errors in motor free tests unless lesion extends posterior and inferior parietal cortex

Most dangerous artery

PCA -stroke involves PCA (MCA contributes much less)

Where path

dorsal from occipital cortex to posterior parietal cortex - Where's dori, pp, many objects motor help

what does topographic (place) agnosia coincide with?

face agnosia bc of proximity

Optic Aphasia deficit region

left posterior hemisphere -occipital cortex, white matter extending to posterior corpus callous -deficit in left hem bc this is dom for language and speech

attention categorization: object based neglect

neglect R or L half of objects

attention categorization: space based neglect

neglect VF to R or L of fixation

form agnosia is opposite of what?

optic ataxia (accurate perception but poor motor action)

associative agnosia 5

place, face, hemi, phase, dementia -hemispatial neglect -face agnosia -topographical (place) agnosia -optic aphasia -semantic dementia

Optic ataxia deficit region

posterior parietal cortex + superior colliculus (PRR, LIP, AIP)

motor-free visual perception test (MVPT-3)

tests 5 visual perception abilities 1. spatial relationship (object to self) 2. visual discrimination (discriminate dom features of object) 3. figure-ground relationship (object from background) 4. visual closure (discriminate whole figure when only fragments are present) 5. visual memory (recon after only brief time) -V1 and LO tested for recognition -posterior parietal cortex for spatial relationships -anterior parietal lobe, frontal lobe, medial temporal lobe

facial recognition

tests brain disease to inferotemporal cortex (FFA, pFus) -FFA of VOT and pFus of LOC encode info, LO of LOC can also

what is most susceptible to brain trauma

white matter to trauma