9 Cortical Localization 2 Flashcards
Lesions of optic nerve yield?
monocular blindness
lesions of optic radiations yield?
homonymous quadrantanopsia/hemianopsia
macular vision (in V1) is located where?
occipital pole
dorsal bank of V1 has lower or upper field of vision?
lower
a scotoma is?
small blind spot (damage to small spot of V1)
V2 surrounds V1 and responds to?
complex patterns
V3 surrounds V2 and responds to? (dorsally and ventrally?)
- ventral V3=pattern and object recognition, and long-term storage of visual info
- dorsal V3=large-scale motion, placing objects in external space, and control of saccades
MT (unknown abbreviation) is another word for?
V5 (visual cortex 5)
Where do the two visual streams separate? (dorsal & ventral)
V3
Where does ventral V3 get input from?
gets input from mostly V2
Where does dorsal V3 get input from?
gets input from V1, V2
V4 is located where? Consists of dorsal or ventral stream?
- Posterior inferior temporal lobe
- Ventral stream
V5 is located where?
Posterior end of middle temporal gyrus (consists of dorsal stream)
Left V4 does what function?
Notices color, texture, shape, processes symbols for language/writing
Right V4 does what function?
non-verbal perception, including face recognition
A ventral visual stream lesion (ventromedial occipitotoempor cortex, specifically fusiform/lingual gyri) gives what problems?
visual agnosia (can’t recognize objects), alexia (can’t read) with agraphia (can’t write)
V5 does what function?
Sends info to FEF (???) and posterior parietal cortex, for motion perception & noticing where objects are in space
Ballint’s syndrome (V5 lesion) consists of?
-simultanagnosia (can’t see more than 1 object at a time), optic ataxia (can’t move hand toward object), ocular apraxia (can’t voluntarily gaze at objects)
What usually causes Ballint’s syndrome?
Bilateral lesion of posterior parietal cortex near temporoparietooccipital junction, often a watershed infarct between MCA/PCA
Primary auditory cortex is located where? Receives input from which ear?
Heschl’s gyrus
-bilateral w/ contralateral dominance (via medial geniculate body)
auditory belt cortex surrounds what?
Primary auditory cortex
Which side of auditory belt cortex does temporal decoding? Which does spectral decoding?
- Left (can fill gaps in speech)
- Right (can fill gaps in melody) (mnemonic: SPECTERS are always RIGHT!)
Wernicke’s area does what?
Decodes verbal info (left lesion=sensory aphasia, i.e. can’t understand speech)
Right hemisphere equivalent of Wernicke’s area (NOT called Wernicke’s area though) does what?
Prosody. (lesion=sensory aprosodia, i.e. can’t understand pitch/tone to perceive whether someone is happy/mad)
Which portion of Wernicke’s area is responsible for unique identifiers?
Anterior. Lesions producing anomia are worst here near the pole. (Posterior is for category names)
Auditory “What and where” paths refers to what?
- Recognition of words
- location of the sound source
Lesions of postcentral gyrus (primary somatosensory cortex) produce what?
agraphesthesia (can’t feel what letter is written on your skin), astereognosis (can’t identify object by touch), loss discriminative touch but only a diminution of pain/temp sensation
In primary sensory cortex, regions 1, 2, 3a, 3b contain what info?
1-texture
2-size/shape
3a-proprioception
3b-touch, pressure, vibration (commonly thought of as “primary” sensory cortex)
Right Inferoro Parietal Lobule has what main function?
Self-perception & position of the body in external space (including visuospatial tasks). Damage on right=hemi-neglect syndrome. (left body & world ignored.)
Constructional apraxia is due to what lesion?
Dorsomedial somatosensory association area.
What region has 4 visual association areas?
Parietal operculum (S2,S3, S4, and ?)
Tactile agnosia is due to a lesion where?
Ventromedial somatosensory assocation area
Damage to Left Inferior Parietal Lobule causes what defects?
- Agraphia
- Acalculia
- Finger Agnosia
- Impaired verbal working memory
The left inferior parietal lobule is mainly involved in what functions?
- Language functions
- Specializes in fractionated things (not holistic like right side)
Which brain region is the last to fully myelinate?
Medial parietal lobule
Medial parietal lobule shows its highest activity when? What is its function?
- When awake
- Self-consciousness
What are the 4 frontal lobes?
- Motor/premotor
- Broca’s
- Dorsolateral prefrontal (memory)
- Medial prefrontal
