Lecture 4 Flashcards
(22 cards)
Name the 3 landmarks of the brain
- Central sulcus
- Sylvian (lateral) fissure
- Parieto-occipital sulcus
Describe:
The central sulcus
Separates the frontal lobe from the parietal lobe
What is anterior to the central sulcus? What is posterior to the central sulcus?
Anterior: M1 (Primary motor cortex)
Posterior: S1 (Primary somatosensory cortex)
Describe:
The Sylvian (lateral) fissure)
Separates the parietal lobe and the temporal lobe
Describe:
The parieto-occipital sulcus
Separates the occipital lobe from parietal lobe, and occipital lobe from temporal lobe
Describe:
The occipital lobe
- Smallest lobe, but contains the most neurons
- Devoted to processing vision; sometimes called visual cortex
- Contains primary visual cortex (V1)
- Contains three-dozen distinct extrastriate visual regions (i.e. V5/MT)
What is V1? Where is it located?
V1: Primary visual cortex
Located on the medial (middle) surface of each hemispheres (squished in between the two hemispheres)
What does V1 do?
Supports initial processing visual inputs
Supports coding of color, lumiannce, spatial frequency, orientation, and movement of visual stimuli
Define:
Cortical magnification
Expansive V1 dedicated to central vision is more than expansive V1 peripheral vision
Define:
Extrastriate
Beyond visual cortex
What is V5/MT? What does it do?
Extrastriate region dedicated to capturing motion, helps detect motion
David Hubel with Torsten Weisel won the Nobel Prize based on identifying neuron types. They did this in a cat experiment, explain the experiment
Directly measured the activity of one neuron in response to an activity
Measuring receptance field of neuron using a light
How does a simple V1 neuron differ from a complex V1 neuron?
Simple V1 neuron is active to specific orientation of stimulus, the stimulus has to be in a very specific orientation to be activated
Complex V1 neurons have a wider field of detection
What is binocular vision?
The ability to determine depth and distance
True or False:
Babies have binocular vision
False
Binocular cells (specialized neurons) develop at a specific timepoint in an infant’s life
Describe:
Cortical Blindness
A lesion/damage to the visual cortex that will cause a scotoma in the contralesional visual field
Define:
Scotoma
Like a black hole in the visual field, the individual cannot see that area as neurons of that area is damaged event though the eye is functioning fine
In cortical blindness:
Why does a damage to the visual cortex cause a scotoma in the contralesional visual field?
Visual fields are crossed; information from left is processed in the right hemisphere and vice versa
How is cortical blindness diagnosed?
Evaluating MRIs: Looking for extremely dark or extremely light areas for information
What fills areas that suffered strokes?
Cerebrospinal fluid
Define:
Blindsight
One can respond to stimulus without being aware of them
What is the extrageniculate pathway?
Vision that supports movement and doesn’t require on V1
