Higher Cortical Function Flashcards
How are neurones arranged in the cortex
Laminar
Columnar
What are the cell types in cortical neurones
Pyramidal:
60%
Sole output and major input
Excitatory - glutamine
Interneurones:
40%
Modulate cortical activity
Inhibitory - GABA
What are the four sources of afferent fibres
What are the names of afferent fibres
Ipsilateral cortex - association fibres
Contralateral cortex - commissural fibres
Thalamus - thalamocortical fibres
Basal forebrain, brainstem, hypothalamus - cholinergic and aminergic fibres
What cells do efferent fibres consist of
What are the types of efferent fibres
Pyramidal cells only
Association fibres - to different area in same Cortex
Commissural fibres - to corresponding area in contralateral cortex
Projection fibres - basal ganglia, Thalamus, brainstem, spinal cord
What association areas are present in frontal lobe
Where are they located
Primary motor cortex - pre central gyrus
Broca’s area - inferior lateral frontal lobe on dominant side
Prefrontal cortex
What is the function of Broca’s area
Language generation:
Articulate words in order
What is the function of prefrontal cortex
Executive function:
Behaviour modulation
Cognition
Personality
What association areas are in parietal lobe
What structure runs through white matter of parietal lobe
Primary sensory cortex - post central gyrus
Superior optic radiation
What functions are carried out by parietal lobe
And on which hemisphere
Body image - non-dominant
Attention - non-dominant
Calculation - dominant
What association areas are in temporal lobe
What structure runs through white matter of temporal lobe
Wernicke area - superior temporal gyrus dominant hemisphere
Primary auditory cortex - superior temporal gyrus
Primary olfactory cortex
Inferior optic radiation
What functions are carried out by temporal lobe
On which hemisphere
Memory Emotional processing - non dominant Auditory processing Language comprehension - dominant Olfactory professing
What association areas are present in occipital lobe
Primary visual cortex
What does lateralisation mean
Tendency for certain brain functions to be carried out by one hemisphere
Which is the most common dominant hemisphere
Left - 95% people
What functions are carried out in dominant hemisphere
Language
Maths
Logic
(Sequential processing)
What functions are carried out in non-dominant hemisphere
Emotion
Body image (monitor relationship bw body + outside world)
Attention (awareness of external environment)
(Whole picture processing)
What is corpus callosum
Thick bundle of white matter connecting 2 hemispheres
Consists of commissural fibres bw corresponding areas in R+L hemispheres
Where is the language function carried out
Dominant hemisphere
Broca’s area
Wernicke area
Arcuate fasciculus
What does the Broca’s area do
Generation of language
By articulation of words in order
What does Wernicke area do
Comprehension of language
By processing and decoding of visual and auditory input into words
What does arcuate fasciculus do
Long association fibre that connects Wernicke area to Broca’s area
List the steps involved in repeating a heard word
- Primary auditory cortex: receives auditory stimuli as pattern of vibrations, process pattern into language
- Wernicke area: understand language by decoding of meaning (semantics) and arrangement (syntax) of words
- Broca’s area: generate language by developing grammatical relationships and sending instructions to PMC
List the steps involved in speaking a written word
- Primary visual cortex: receive visual input, identify and distinguish letters to process into visual stimuli to language
- Wernicke: understand language by memory search from orthographic cues to extract meaning (semantic retrieval)
- Broca’s: activate motor cortex to generate speech
What is aphasia
What is a common cause of aphasia
Inability to use language
Stroke due to occlusion of middle cerebral artery
What type of aphasia will result from damage to Wernicke area
How might the patient present
Receptive aphasia: good articulation, poor comprehension
Inappropriate responses, speech is fluent but unintelligible
What type of aphasia will result from damage to Broca’s area
How might the patient present
Expressive aphasia: poor fluency, good comprehension
Few words (spoken and written)
Poorly constructed sentences
Speech is effortful but meaningful
(Know what to say, can’t find words to say it)
What is memory
What are the types of memory
Type of cortical function involving encoding/Storage/retrieval of information
Short term
Long term
What is short term memory
Storage of new information briefly in the mind.
Quickly learned and forgotten
What is long term memory
Stored information capable of retrieval at appropriate moments.
Difficult to form but long lasting once formed
What are the types of long term memory
Explicit
Implicit
What is explicit memory
Recollection of facts or events that can be explicitly stated (aka declarative)
Requires conscious recollection
What is implicit memory
Information is non-declarative; emotion, motor skills
Does not require conscious recollection
Where is memory stored
Throughout the brain
Declarative - cortex
Non-declarative - cerebellum
What is consolidation
Process of committing new information in short-term memory to long-term memory
What are the steps involved in consolidation
- Hippocampus receives cognitive/sensory info from cortical association areas
- Hippocampus integrates inputs (forms associations)
- Hippocampus resends input to association areas repeatedly (act as oscillator)
- In association areas info encoded as memory traces to be stored
What is the cellular basis of consolidation
Long term potentiation
What is long term potentiation
Strengthening of neural connections with repeated synaptic transmission
(The more you use, stronger it gets)
Describe the process of LTP
- High frequency (strong experience) or Repeated (revision) activation of synapses
- Release of more transmitters
- Expression of more post synaptic receptors
- Production of more pre-synaptic branches
What will happen if hippocampus is damaged or removed
Anterograde amnesia: inability to create new memories after the event that caused amnesia
