Higher Visual Perception

Apperceptive Agnosia

the failure to recognize objects, despite intact vision

patients can detect basic visual features (lines/shapes) but cannot put them together to make a complete object

Associative Agnosia

the failure to recognize an object’s meaning or function

patients can see the object in its entirety, they just are not able to give it a name/function

Prosopagnosia

the failure to recognize faces…

but patients can recognize people by voice, smell, hairstyle, daily/normal accessories

Contralateral Neglect

the failure to recognize/respond to the side of their body opposite to the brain lesion

Apperceptive agnosia is most associated with damage to the _____ and _____ lobes of the _____ hemisphere

occipital and parietal lobes

right hemisphere

Contralateral neglect most often involves damage to the _____ lobe in the _____ hemisphere

parietal lobe

right hemisphere

Prosopagnosia is most often seen following what type of lesions to the right hemisphere?

bilateral lesions

For most people, are visuospatial skills right or left hemisphere centered?

right hemisphere centered

Associative agnosia is most related to damage to the _____ and _____ lobes of the _____ hemisphere

occipital and temporal lobes

left hemisphere

The majority of patients with Prosopagnosia have damage to the _____ and _____ lobes

occipital and temporal lobes

Associative agnosia generally results from damage to the _____ hemisphere of the brain, mainly affecting the _______ lobe(s) of this hemisphere

left hemisphere

occipital and temporal lobes

Unable to complete degraded stimuli (incomplete figures)

apperceptive agnosia

Impaired on “matching by function” test

associative agnosia

Early stages of visual processing fine, but unable to name common objects

associative agnosia

List at least 2 factors that might help patients with Prosopagnosia recognize some people

typical clothing, voice, scent, hairstyle, glasses, walking pattern

The lateral geniculate nucleus is a part of what specific structure?

thalamus

The lateral geniculate nucleus processes what type of sensory info?

visual

The medial geniculate nucleus process what type of sensory info?

auditory

The INFERIOR colliculus processes what type of sensory info?

audiotry

The SUPERIOR colliculus processes what type of sensory info?

visual

Matching by Function Test

patients are asked to group objects similar in function. Those with associative agnosia fail bc they can’t link the visual form to its meaning

Copying vs. Naming Task

patients are asked to copy an image and then name it. Those with associative agnosia can copy it, but cannot name or describe its purpose

Unusual Views Test

patients are shown objects from unusual angles (e.g., top-down view of a bike) and asked what the object is. Those with apperceptive agnosia struggle to recognize objects when not at their typical viewpoint

The Shadows Test

patients are asked to identify objects when they are shadowed or partially shadowed. Patients with apperceptive agnosia struggle because they rely heavily on visual cues and the and the objects features are obscured

What tests are used to diagnose associative agnosia?

Matching by Function Test

Copying v. Naming Task

What tests are used to diagnose apperceptive agnosia?

Unusual Views Test

The Shadows Test