Week 21 lectures Flashcards
What are Brodmann’s Areas? How many layers are in the brain?
-A way of classifying different
regions of cortex based on
microscopic appearance and
function
-Cortex has 6 cell layers; The
thickness of different layers in a
region will depend on the
function of that region
-52 cytoarchitectonic areas, each
assigned a number
Primary Cortex
responsible for a specific, singular
function: receives sensory information or executes motor
tasks
Association Cortex
What are the two types?
shares information with primary
areas and is involved in higher-order processing,
integrating and interpreting information
Unimodal=areas responsible for higher-order processing
of a single sensory or motor modality; located adjacent to
primary areas
Heteromodal=areas responsible for integration from
multiple sensory and/or motor modalities
Which hemisphere is a language primarily processed on?
The left side
Left hemisphere in >95% of right-handed people
Left hemisphere in ~70% of left-handed people
Which hemisphere is usually responsible for non-verbal aspects of communication such as prosody
The non-dominatne side
Frontal lobe
-Largest region of the brain, >1/3 cortex
-Separated from parietal lobe by central sulcus; from
temporal lobes by Sylvian fissure
—motor planning and execution;
restraint, initiative, order, language production, praxis,
eye movements
Primary Motor Cortex
(Precentral gyrus, “motor strip”
contains motor homunculus)
Responsible for motor output
to the contralateral side of the body
via the corticospinal tract and
to face via corticobulbar tract
Lesion: may produce upper
motor neuron(UMN) signs:
weakness/paralysis,
hyperreflexia, spastic tone,
Babinski sign
Frontal lobe: motor cortex: Unimodal Association Areas
Important for motor planning
1) SUPPLEMENTARY MOTOR AREA (SMA)
2) PREMOTOR CORTEX
Premotor cortex duties and what happens in a lesion here?
- Spatial and sensory guidance of movement, contributes to corticospinal tract esp truncal, proximal muscles
- Lesion: slowing of anticipated movement, +/- UMN signs
Supplementary Motor Area (SMA) duties and what happens if lesion here?
- Plans, initiates, coordinates complex bimanual actions Also contributes to the corticospinal tract
- Lesion: inability to perform complex (bimanual) movements,+/-UMN signs
Where are the frontal eye field located?
Located in the premotor/prefrontal junction on the lateral convexity (yellow)
Frontal eye field function? What happens in a lesion to this area? (stroke vrs seizure)
- Role in eye movements and selective attention
- Generate saccades in the contralateral direction
- Lesion (e.g., stroke): gaze preference toward that side; Excitation (e.g., seizure) will drive the eyes to look in the contralateral direction
“Look toward the Lesion”(stroke
What is the function of the prefrontal cortex? 3 major domains?
Higher-order processes that require integration of multimodal sensory, motor, limbic information Essential for functioning as “effective and socially appropriate human beings” Blumenfeld 3 major domains: restraint, initiative, order
Lesion to the Somatosensory cortex Symptoms (3)
Cortical sensory loss
1) Two-point discrimination
2) Agraphesthesia
3) Astereognosis
Somatosensory association area lesion (3)
1) tactile agnosia
2) Visual-spatial navigation issues (get lost easily)
3) sensory inattention ( stimulation bilateral but ignores the affected side)
Primary motor cortex lesion
paralysis of the contralateral side, UMN symptoms
Premotor cortex lesion
slowing of anticipated movements, +/- UMN symptoms
Supplementary motor area Lesion
Bimanual complex movement impaired (can’t play the piano)
Lesion to the frontal eye fields
Seizure: Eyes go to the opposite side of the lesion
Stroke: Eyes got o the same side of lesion
