Lecture 2 Functional Specialization of the Cerebral Cortex Flashcards
(45 cards)
What is the Dominant Hemisphere of the Brain and what does it control?
Left Hemisphere
- Language function
Why do we have a dominant hemisphere?
Prevents confusion and coordinates motor responses
How do the two hemispheres communicate?
Communication occurs via the corpus callosum
What is each hemisphere responsible for and what type of sensory input is each hemisphere responsible for?
- Each hemisphere controls the voluntary motor movements
- Contralateral sensory reception
Can the brain feel pain?
No
Who mapped the motor and sensory cortex and temporal lobes?
Wilder Penfield
What does the Precentral Gyrus control?
What happens when a lesion occurs?
Primary Motor Cortex
- Controls voluntary motor movements
- Lesion = paralysis on contralateral side
How is the Precentral Gyrus mapped?
- PMC mapped feet at the top and face at the bottom or lateral side
What is the Premotor and supplementary motor area responsible for?
Control movements involving muscles and upright posture
What is the Postcentral gyrus control?
- Primary Sensory Cortex
- Receives somatic sensation from contralateral side
(Touch, proprioception (feeling of limbs in space), vibration, pain, temp
What happens when a lesion occurs to the postcentral gyrus?
Lesions = “anesthesia”: loss of touch and proprioceptive sensation contralaterally
- Inability to localize pain or judge the shape of objects/textures
What is the function of the Somatic Sensory Association Areas and where is it located?
- Perception of somatic sensory information
- Superior parietal lobe (above intraparietal sulcus)
What happens when the Somatic Sensory Association areas are lesioned?
- Inability to recognize complex objects by feel
- difficulty reaching for objects
How is the postcentral gyrus mapped?
- Somatotopic Sensory Map on postcentral gyrus has feet sensation at the top or dorsal portion of the lobe and head is at the more lateral portion
What is the function of the Primary Auditory Area and where is it located?
- Receive hearing from both ears (mainly contralateral)
- located in the superior region of the temporal lobe
What happens if the primary auditory area is lesioned? (why does deafness not occur?)
- Decreased sound perception from contralateral ear
- Unilateral damage DOES NOT cause deafness BECAUSE auditory pathways are bilateral
What is the function of the Auditory Association Areas and where are they located?
- Integrates complex auditory features
- sits right below the primary auditory area in the temporal lobe
What happens if the Auditory Association Areas are lesioned?
- Difficulty interpreting pitch, timing, and sequence of sounds (melodies)
What is the function of the Visual Association area? Where is it located?
- Complex visual tasks
- located in the occipital lobe
What happens if the Visual Association area is lesioned?
- Complex visual deficits
(object identification, reading, writing, colors, facial recognition…)
What is the function of the primary visual cortex and where is it located?
- Receives vision from the contralateral half of the visual field
- Located at the occipital pole of the brain surrounding the calcarine fissue
What happens if the primary visual cortex is lesioned?
Lesion = blindness in the contralateral half of visual field
What is the function of the prefrontal cortex and where is it located?
- Responsible for decision making
- Cognitive processes, planning, attention, emotion
- located in the anterior portion of the frontal lobe
What happens if you lesion the prefrontal cortex?
Diverse cognitive deficits and personality changes
- Inability to solve complex problems
- Loss of ambition/low attention span
- Loss of aggressiveness
- inappropriate social responses
- Rapid mood swings
