Nervous system: Higher cortical function Flashcards
Where do the main inputs and outputs come from/ go to in the cortex?
Most inputs are from the thalamus and other cortical areas
Most outputs are via pyramidal cells and project to widespread areas
What are the functions of the frontal lobes?
- motor (think pre-central gyrus)
- expression of speech (usually left)
- behavioural regulation / judgement
- cognition
- eye movements
- continence
What are the functions of the parietal lobes?
- sensory (post-central gyrus)
- comprehension of speech (usually left)
- body image (usually right)
- awareness of external environment (parietal lobe lesions can cause neglect of contralateral side)
- calculation and writing
- superior optic radiations pass through parietal lobe
What are the functions of the temporal lobes?
- hearing (superiorly)
- oflaction (medially)
- memory
- emotions
- meyers loop passes through the temporal lobe
What are the functions of the occipital lobes?
vision
What are the main roles of the left and right hemispheres?
Which is dominant in the population?
Left hemisphere is responsible for sequential processing such as language, mathematics and logic.
Right hemisphere responsible for whole picture processing such as body image, visuospatial awareness, emotion and music.
- 95% of right handed people are left dominant
- 75% of left handed people are also left dominant (thought to be trained)
What are the areas in the left hemisphere which form the language pathways?
Wernickes area: found in the superior temporal lobe, interprets language
Brocas area: found inferior lateral portion of the frontal lobe near to the motor areas supplying the face, produces speech.
They are connected via the arcuate fasciculus
Outline the pathway for repeating a heard word
The auditory cortex sends a pattern of vibration to Wernicke’s area which processes it and sends it to brocas area which signals to the motor cortex to make the mouth move to produce a sound.
Outline the pathway for speaking a written word
The visual cortex sends the pattern to the Wernicke’s area which formulates the word and sends it to Brocas area which sends it to the motor area to make the mouth move to say the word
Outline the pathway for speaking a thought
Thoughts go to Wernickes area from all around the brain, they are processed before sending to Brocas area which makes the muscles of the mouth move to say the word
What is Wernickes aphasia?
Able to speak fluently but no comprehension at all so answers are inappropriate
Able to articulate well because brocas area still working
What is Broca’s aphasia?
Understands instructions because Wernicke’s area is still working
Speech is incomprehensible
What are the classes of memory?
Declarative memory: (explicit) facts
Non-declarative memory:
(Implicit) motor skills, emotions - dont need to think consciously
Where are different memories stored?
Memories are thought to be stored in a relatively diffuse fashion throughout the brain however
- declarative memories stored more in the cerebral cortex
- non-declarative memories stored more in the cerebellum
How are memories stored?
Short term memories (seconds to minutes) are transient reverberations of the neurones
They are then consolidated dependent upon emotional context, rehearsal and association
The hippocampus is crucial for consolidating memories - if a synapse is used it gets stronger
