Agnosias

Question 1

Color aphasia

Answer 1

Disproportionate difficulty in linguistic processing of colors associated with dominant parietal damage

Question 2

Neuroanatomical correlate of associative visual object agnosia

Answer 2

Bilateral, inferior occipito-temporal; commonly see with R HH, strokes in PCA

Question 2

Neuroanatomical correlate of color anomia

Answer 2

L occipitotemporal mesial lesion/lingual gyrus, extending into CC

Question 2

Ellis & Young’s model of object recognition

Answer 2

Recognition by comparing viewer-centered & object-centered representations to stored structural descriptions of objects known as “object recognition units”

Question 3

Neuroanatomical correlate of pure word deafness

Answer 3

Associated w/ B symmetrical lesions of anterior section of the superior temporal gyri; disconnection of Wernicke’s from auditory input

Question 4

Agnosia

Answer 4

Modality-specific inability to access semantic knowledge of an object or other stimulus that cannot be attributed to impairment of basic perceptual processes

Question 4

Bilateral astereognosis

Answer 4

Inability to judge the form of an object by touch; cannot demonstrate object knowledge through gesture

Question 5

Neuroanatomical correlate of apperceptive visual agnosia

Answer 5

B damage to lateral parts of the occipital lobes

Question 5

Autotopagnosia

Answer 5

Inability to identify body parts (e.g., finger, also L-R confusion), associated with lesions in the dominant parietal lobe

Question 6

Apperceptive visual object agnosia

Answer 6

Difficulty recognizing objects b/c of failure to perceive them; can’t draw, copy, or match

Question 7

Neuroanatomical correlate of color agnosia

Answer 7

B lesion of the ventral visual stream

Question 7

Unilateral astereognosis

Answer 7

Can demonstrate object use or can name if object is placed in other hand; associated with CL primary somatosensory projection area damage

Question 8

Neuroanatomical correlate of associative prosopagnosia

Answer 8

Bilateral anterior temporal regions compromising hippocampal & other regions

Question 9

Ahylognosia

Answer 9

Impaired discrimination of distinctive qualities of objects such as density, weight, texture, heat

Question 10

Bisiach et al.’s domain-specificity of anosognosia

Answer 10

Pts who are blind due to peripheral lesions are aware of their deficits & behave like a blind person; pts w/ central lesions have an associated visuo-specific cognitive impairment-monitoring deficit

Question 11

Visual object agnosia is associated with damage to the

Answer 11

L unilateral or B occipitotemporal (lingual, fusiform, & parahippocampal gyri) areas

Question 12

Associative agnosia

Answer 12

Elementary visual perception is more or less preserved but access to memory or meaning is impaired

Question 13

Balint’s syndrome

Answer 13

Simultanagnosia, ocular apraxia, optic ataxia Caused by large B parietal lesions, esp. if frontal lobes affected

Question 14

Semantic-associative auditory sound agnosia

Answer 14

Primarily symantic misidentifications of nonspeech sounds (‘train’ for automobile engine); associated with LH lesions (perceptual-discriminative is R)

Question 15

Lissauer’s two-stage model of perception/recognition

Answer 15

After an elementary sensation occurs there is 1) an object perception (apperception) & 2) object recognition (association)

Question 15

Marr’s model of 3 types of representation

Answer 15

1) primal sketch (depicts brightness/darkness) 2) 2.5D sketch (viewer-centered) 3) 3D sketch (object-centered)

Question 15

What visual impairment is commonly comorbid with associative agnosia?

Answer 15

Right HH

Question 16

Neuroanatomical correlate of phonagnosia

Answer 16

Unilateral RH pts demonstrate difficulties with familiar voices; temporal lobe impairment in either hemisphere can lead to more general voice discrimination

Question 18

Geschwind’s disconnection theory of anosognosia

Answer 18

RH is normally poorly linked to speech areas, further weakened by RH damage; confabulation is LH attempt to explain what pt can’t comprehend

Question 19

Pure word deafness

Answer 19

Unable to comprehend spoken language with relatively spared comprehension of nonverbal sounds

Question 21

Color anomia

Answer 21

Loss of color naming, often in conjunction with alexia w/o agraphia, assoc. w/ R HH

Question 23

Apperceptive agnosia

Answer 23

Deficits in the early stages of perceptual processing; pats do not perceive objects normally so can't recognize them

Question 24

Prosopagnosia is associated with what other deficits?

Answer 24

Color agnosia, L upper quadrantanopsia

Question 25

The term agnosia was originally coined by

Answer 25

Freud (1891)

Question 27

Achromatopsia is associated with what other conditions?

Answer 27

Visual agnosia & prosopagnosia

Question 28

Neuroanatomical correlate of apperceptive prosopagnosia

Answer 28

Bilateral cortex & WM in occipito-temporal gyrus, typically including the fusiform face area

Question 29

Pathological processes that may be associated with apperceptive visual agnosia

Answer 29

CM poisoning, mercury, cardiac arrest, B strokes, B artery occlusion, B posterior cortical atrophy

Question 30

Amorphognosia

Answer 30

Impaired identification of an object by proprioception/recognition by size & shape

Question 30

Optic aphasia

Answer 30

Visually presented objects can be recognized by not named, & auditory & tactile naming ok

Question 31

Phonagnosia

Answer 31

Inability to recognize familiar persons' voices

Question 33

Associative visual object agnosia

Answer 33

Pts demonstrate that they can perceive but not recognize; can draw or match

Question 34

Ocular apraxia

Answer 34

An inability to shift gaze voluntarily from a fixation point; pts behave as though mesmerized by original object; gaze may be shifted if close eyes

Question 35

Pure word deafness may evolve from what type of aphasia?

Answer 35

Wernicke's

Question 37

Damasio's model of agnosia

Answer 37

Perception involves evocation of neural activity pattern in primary & 1-st order association cortex which corresponds to various perceptual features; downstream features are combined in 'local convergence zones' Predicts that there can be no disorder of object recognition w/o perceptual dysfx

Question 39

Conscious awareness system (CAS; Schacter & McGlynn)

Answer 39

Conscious experience of remembering, knowing, perceiving, comprehending; requires activation of specific/distinct system which interacts w/ modular systems concerned with specific function Low activation of normally highly activated system would result in no input to the CAS =\> anosognosia

Question 40

Tactile asymboly

Answer 40

Impaired tactile recognition of objects with intact perception of size, shape, density, weight, texture, heat

Question 41

Neuroanatomical correlate of achromatopsia

Answer 41

Unilateral or bilateral lesions to the ventromedial region of the occipital lobe with involvement of the lingual & fusiform gyri (i.e., visual association cortex)

Question 42

Amorphognosia

Answer 42

Inability to identify an object by proprioception due to poor perception of its physical attributes; cannot be explained on the bases of concurrent hypesthesia

Question 44

Sensory amusia

Answer 44

Unable to appreciate various characteristics of heard music due to unilateral temporal lobe lesion

Question 45

Perceptual-discriminative auditory sound agnosia

Answer 45

RH analogue to pure-word deafness; primarily acoustic misidentifications of nonspeech sounds ('whistling' for bird-song)

Question 46

Optic ataxia

Answer 46

Impairment of visually guided movements as a result of a defect in stereopsis (depth perception); pts may not be able to read in methodical visual sweeps

Question 47

Dorsal vs. ventral simultanagnosia

Answer 47

Dorsal = cannot see \>1 object at a time caused by bilateral parieto-occipital lesion Ventral = cannot appreciate entire stimulus; cannot attend to whole picture; caused by damage to the left inferior temporo-occipital area Part of Balint's syndrome

Question 48

What type of amnesic syndrome is more likely to be associated with anosognosia?

Answer 48

Diencephalic/frontal lobe damage but not mesial temporal lobe damage/thalamic damage

Question 49

Achromatopsia

Answer 49

Loss of color vision due to CNS disease, but can name color of object described verbally

Question 50

Auditory affective agnosia

Answer 50

Impaired comprehension of prosody; assoc. w/ R temporoparietal lesions & neglect

Question 51

Disconnection model of agnosia

Answer 51

Agnosia results from disconnection between visual & verbal processes (this theory can't account for fact that most agnosics show abnormal verbal & nonverbal processing of viewed objects)