10c: Cortex III (Extrastriate) Flashcards
Parvocellular cells project to (X) and magnocellular cells project to (Y).
X = parvocellular layers of LGN Y = magnocellular layers of LGN and superior colliculus
Magnocellular LGN cells project to (X) layers of (Y) cortex.
X = 4C(alpha) Y = primary visual
Parvocellular LGN cells project to (X) layers of (Y) cortex.
X = 4C(beta) Y = primary visual
Neurons in layer 4C(beta) of (X) cortex receive signals from (Y) and project to (Z).
X = primary visual Y = Parvocellular LGN neurons Z = blob and interblob regions
Blob regions eventually receive signals from (parvocellular/magnocellular) cells. What do these regions process?
Parvocellular;
Form perception
Interblob regions eventually receive signals from (parvocellular/magnocellular) cells. What do these regions process?
Parvocellular;
Color
Blobs project to (X)-placed cortical regions. Interblobs project to (Y)-placed cortical regions.
X = Y = ventrally
There’s a high concentration of (Parvocellular/Magnocellular) cells close to fovea.
Parvocellular
(Parvocellular/Magnocellular) cells have sustained response to visual stimuli.
Parvocellular
Parvocellular layers of (X) are the (ventral/dorsal) (2/4) layers.
X = LGN;
Dorsal 4 layers
Magnocellular layers of (X) are the (ventral/dorsal) (2/4) layers.
X = MGN;
Ventral 2 layers
(X) radiations forming Meyer’s loop travel to (superior/inferior) (Y) quadrants.
X = optic;
Inferior;
Y = retinal
The stripe of Gennari is a (minimally/heavily)-myelinated stripe in Layer (X) of (Y).
Heavily;
X = 4B
Y = striate/primary visual cortex
The “globs” and “interglobs” are found in which layer(s), respectively, within (X) structure?
Both in layers 2/3 of
X = striate/primary visual cortex
4C(alpha) layer of (X) receives signals specifically from (Y). The neurons then project to (Z).
X = primary visual/striate cortex Y = Magnocellular layer of LGN Z = Layer 4B of striate cortex
Extrastriate cortex is Brodmann area(s):
18 and 19
T/F: Extrastriate areas process the different aspects of the visual scene.
True
V(X) is/are extrastriate cortices.
X = 2-5
Damage to human analogue of V(1/4/5), a(n) (X) cortex, causes deficits in color perception. This condition is called (Y).
V4;
X = extrastriate
Y = cerebral achromatopsia
Damage to human analogue of V(1/4/5), a(n) (X) cortex, causes deficits in motion discrimination. This condition is called (Y)
V5;
X = extrastriate
Y = cerebral akinetopsia
T/F: Cerebral achromatopsia is nearly identical to color blindness.
False - it’s a disconnection of color from cognition
Motion is detected in “freeze frames” in which condition?
Cerebral akinetopsia
Cytochrome oxidase staining of extrastriate cortex (X) reveals (homogenous/heterogenous) layers.
X = V2
Hetergenous
While some processing occurs in extrastriate cortex (X), it’s largely considered a relay area.
X = V2
List projections of “what”, aka (X), stream.
X = ventral;
- V1
- V2
- V4
List projections of “where”, aka (X), stream.
X = dorsal;
- V1
- V2
- MT
Damage to (X) cortex and (Y) stream causes visuospatial neglect to (ipsilateral/bilateral/contralateral) visual space.
X = parietal; Y = dorsal (where)
Contralateral
Downstream from (X) extrastriate cortex is the (Y) cortex. It has cells with complex visual stimulus requirements for activation (i.e. faces).
X = V4; Y = Infratemporal
Infratemporal cortex has (small/medium/large) receptive fields.
Huge
Damages to infratemporal cortex produces (simple/complex) deficits in (X).
Complex;
Object recognition and salience
In humans, damage to part of (X) produces prosopagnosia.
X = fusiform gyrus
T/F: Ventral and dorsal streams always project to different structures.
False
High level signals of objects/their location are sent from (dorsal/ventral) stream to which specific brain structure(s)?
Both streams;
- Hippocampus
- Prefrontal cortex
- Limbic system
Premotor cortex is involved in which function(s)?
Planning of motor programs
Prefrontal cortex involved in which function(s)?
Planning (abstract), intention, motivation
List some non-specific signs of frontal lobe damage.
- Lack of inhibitory control
- Lack of motivation/intent/planning
- Inappropriate behavior
- Personality change
Damage to (X) causes “pie in the sky”, aka deficit in (ipsilateral/contralateral/bilateral) (Y).
X = meyer’s loop
Contralateral;
Y = upper visual hemifield
Damage to (X) causes deficit in (ipsilateral/contralateral/bilateral) lower visual hemifield.
X = caudal parietal or rostral occipital lobes
Contralateral
Sounds are associated with meaningful content in (X) area. This information is then sent to (Y) lobe via (Z).
X = Wernicke's Y = frontal Z = arcuate fasciculus
Macular sparing is sometimes seen in (X) condition. Which portion (Y) is healthy/intact?
X = homonymous hemianopia;
Caudal portion of
Y = calcarine sulcus
Weakness in muscles/sensory for lower limb is indicative of damage to (medial/lateral) portion of respective cortices.
Medial
Middle cerebral artery initially divides into:
Superior and inferior divisions
T/F: Reading is impaired in Wernicke’s aphasia.
True
What’s global aphasia?
Damage to both Wernicke and Broca areas
Fibers traveling to superior bank of calcarine sulcus carry signals from (superior/inferior) visual field and travel under (X) lobe to get there.
Inferior;
X = parietal
Fibers traveling to inferior bank of calcarine sulcus carry signals from (superior/inferior) visual field and travel under (X) lobe to get there.
Superior;
X = temporal
Symptoms with stroke to L PCA.
R homonymous hemianopia with macular sparing
Symptoms with stroke to R PCA.
L homonymous hemianopia with macular sparing
Symptoms with stroke to L Superior MCA.
- UMN signs for R face/arm
2. Broca’s
Symptoms with stroke to R Superior MCA.
- UMN signs for L face/arm
Symptoms with stroke to L Inferior MCA.
- R sensory loss
- R hemianopia, denser in superior quadrant (PITS)
- Wernicke’s
Symptoms with stroke to R Inferior MCA.
- L sensory loss
- L PITS
- Hemineglect
Symptoms with stroke to L MCA at stem.
- R homonymous hemianopia
- R paralysis (hemiplegia) and loss of touch (hemianesthesia)
- Global aphasia
Symptoms with stroke to R MCA at stem.
- L homonymous hemianopia
- L paralysis (hemiplegia) and loss of touch (hemianesthesia)
- Hemineglect
Symptoms with stroke to L ACA.
- R UMN signs for leg
- Sensory loss for R leg
- Frontal signs
Symptoms with stroke to R ACA.
- L UMN signs for leg
- Sensory loss for L leg
- Frontal signs