Lecture 10 - Higher Cortical Function (language And Memory) Flashcards
How is the cerebral cortex structured?
6 layers of cell bodies and dendrites (grey matter)
What type of neurones are the output neurones of the cerebral cortex (e.g UMN)?
Pyramidal neurones
What are the 3 type so output neurones from the cerebral cortex?
Projection fibres going down to brainstem and cord (UMN))
Commissural fibres going between hemispheres (corpus callosum)
Association fibres connecting nearby regions of cortex in the same hemisphere
Where do most inputs to the cerebral cortex come from?
Thalamus and cortical areas
What structure do inputs come from leading to the. Cerebral cortex which maintain cortical activation causing conscienceness?
Reticular formation
What is the importance of interneurones?
Connect inputs and outputs in a complex way giving rise to:
-behaviour
-emotion
-memory
What are the main functions of the frontal lobes?
Motor function (pre central gyrus)
Expression of speech (motor part of speech)
Behaviour regualtion
Cognition
Eye movements
Continence
Which cerebral hemisphere is the main hemisphere involved in the expression of speech?
Which lobe?
Left hemisphere
Frontal lobe
What type of dementia do patients often become aggressive and erratic in behaviour?
Why?
Fronto-temporal dementia
Frontal lobe affected leading to behavioural regressionnn since frontal lobe regulates/inhibts behaviour
Why would damage to the frontal lobe cause problems with conjugate gaze and other. Eye movements?
Frontal lobe contains frontal eye fields
What is the function of the parietal lobes?
Sensory (posterior to central gyrus, post-central sulcus)
Comprehension of speech
Body image
Awareness of external environment (attention)
Calculation and writing
Visual pathways
Which parietal lobe is important in body image?
Right parietal lobe
What is meant by the parietal lobes are repsonsible for body image?
Understands that your body exists
E.g someone has bilateral parietal lobe damage, they think they are dead and think that their body is rotting away
What is neglect in terms of parietal lobe damage?
When a parietal lobe (normally the right parietal lobe) is damaged people think that one Half of the universe doesn’t exist (pretends left side of whatever’s in front of them doesn’t exist)
Which hemisphere/parietal lobe is repsonsible for the COMPREHENSION of speech?
Left hemisphere
What visual pathway projects through the white matter of the parietal lobes?
Superior optic radiations
What other lobe does the parietal lobe work with to do calculation and writing?
Frontal lobe
What are the functions of the temporal lobes?
Comprehension of speech
Hearing
Memory
Emoticon
Visual pathways pass through
Which visual pathways pass through the temporal lobes?
Inferior optic radiations
Which temporal lobe/hemisphere is predominantly responsible for comprehension of speech?
Left hemisphere / left temporal lobe
What type of processing does the left hemisphere do?
What type of processing does the right hemisphere do?
L = sequential processing
R = whole picture processing
What are some sequential processes that the left hemisphere is repsonsible for?
Language
Mathematics/logic
What are some whole picture processes that the right hemisphere is repsonsible for?
Body image
Visuospatial awareness
Emotion
Music
What is the corpus callosum?
What is its function?
Bundle of white matter connecting the 2 cerebral hemispheres together
Which cerebral hemisphere predominately does language?
LEFT hemisphere
What is Broca’s area/what is its function?
Part of the language pathway
PRODUCES SPEECH
Where is Broca’s area located?
Inferior lateral frontal lobe
So near the primary motor cortex (lateral part of pre-central gyrus responsible for motor function to the face) which makes sense
What is Wernicke’s area/what is its function?
Interprets language
Where is wernickes area located?
Superior temporal lobe
Located near the auditory cortex
What sends signals to Wernickes area for interpretation?
Auditory cortex
What structure connects Wernickes area to Broca’s area?
Arcuate fasciculus
What does Broca’s area send signals to after receiving input from Wernickes area via the arcuate fasciculus?
Lateral part of pre central gyrus (primary motor cortex)
Where is the auditory cortex located?
Superior temporal gyrus
Go to slide 12 and label the language pathways:
What is the language pathway for repeating a heard word?
Auditory cortex receives input from the cochlea and then sends it to Wernickes area
Information then sent to Broca’s area via the arcuate fasciculus
Broca’s area then sends inputs to the primary motor cortex (lateral aspect of pre central sulcus)
Word then spoken
What is the effect of damaging the arcuate fasciculus?
Conduction Aphasia
The patient cant repeat a heard despite good language interpretation and ability to produce speech
Go to slide 13 and label the language pathway for repeating a heard word:
What is the language pathway for speaking a written word:
Signals from visual cortex (received via optic nerve) transmitted to Wernickes area
Signal travels along arcuate fasciculus to Broca’s area which then projects onto the lateral aspect of the. Pre central gyrus (primary motor cortex)
Speech is then produced
Where is the visual cortex located?
Occipital lobe (around calcarine sulcus)
What is the language pathway for speaking a thought?
Wernickes area receives many inputs from various areas of the cerebral cortex
Sends impulses along the arcuate fasciculus to Broca’s area
Signals sent from Broca’s area to the lateral aspect of primary motor cortex
What is Wernickes aphasia?
Stroke affects Wernickes area
Leads to speech being very fluent but not making any sense (it hasn’t been interpreted)
What is Brocas aphasia?
Stroke affects Broca’s area
Patient cat get the words out but can understand what is being asked
What are the 2 types of memory?
Declarative
Non-declarative
What is Declarative memory?
Memories that are facts or explicit
What is non-declarative memory?
Motor skills (riding a bike)
Emotions
Implicit
Where are memories generally thought to be stored?
All throughout the brain but predominantly in the area that processed the initial memory
Where are declarative (factual) memories generally stored?
Cerebral cortex
Where are non declarative (emotional, motorskills) memories generally stored?
Basal ganglia + cerebellum
What is short term memory ?
Essentially where axons of cortical circuits reverberate for seconds to minutes storing the memories for seconds to minutes
What is long term memory??
What does it need for it to form?
Memory stored for very long periods of time after CONSOLIDATION.
What part of the brain is responsible for consolidation of declarative memories?
Hippocampus
What lobe of the brain is the hippocampus located in?
Temporal lobe
What systems contribute to the hippocampus being able to consolidate declarative memories?
Visual system
Auditory system
Limbic system (emotion)
Somatosensory system
What structures change as a result of memory consolidation?
Synapses strengthen
What is the mechanism by which synaptic strengthening occurs to consolidate memories?
Long Term Potentiation
Describe how long term potentiation causes memory consolidation via synaptic strengthening:
Inc glutamate receptors in synapses
Axonal sprouting can occur forming new physical connections
