HNN Topic 6 - Limbic, Diencephalon, Attention/Learning/Memory Flashcards
List the types of attention
- Arousal
- Vigilance
- Divided attention
- Selective attention
Define vigilance and explain the effects of impaired vigilance
- Capacity to maintain attention for a prolonged period of time
- Impaired = impersistence (unable to correctly recall memory/thought)
What is the effect of breakdown of top-down regulation of attention?
Inattention, neglect (unaware of particular side of body, usually L)
Describe the location of the thalamus
- Walnut sized midline symmetrical structure, between the cerebral cortex and midbrain
- Surrounds the 3rd ventricle
Describe the location of the hypothalamus
- Inferior to the thalamus on either side of the third ventricle
- Sits inside the tracts of the optic nerve, just above the pituitary gland
Give examples of causes of hippocampal damage
HSV encephalitis, anoxia, early Alzeihmer’s
Define episodic memory
Personally experienced, temporally specific episodes/events
List the components of the epithalamus
Habenula, habenular commissure, stria medullaris, pineal gland
Describe the function of the anterior group of thalamic nuclei
Part of limbic system, controls mood
What is the effect of progressive R temporal lobe atrophy?
Prosopagnosia - behavioural disturbances (social disinhibition, hyper-religosity, aggressiveness)
List the components of the limbic system
- Hippocampus
- Hypothalamus
- Amygdala
- Mamillary bodies
- Anterior thalamic nuclei
- Olfactory bulbs
Describe the top-down regulation of attention and list the functional areas which it involves
- Conscious act
- Involves:
- Prefrontal cortex
- Parietal cortex
- Limbic cortex
Is attention a widespread or area-specific cognitive process?
- Both - widespread ‘global’ and domain-specific cognitive process
- Breakdown of global attention = delirium/acute confusional state
- Domain-specific attention relates to a specific sensory modality e.g. visual
- Breakdown of domain specific attention e.g. following a non-dominant hemisphere stroke = visual inattention
Describe the features of immediate (working) memory
- Part of attention/concentration
- Immediate recall of small amounts of verbal or spatial information
Define implicit (procedural) memory
Learned motor procedures, no conscious access - can’t be easily explained e.g. playing an instrument, riding a bike
What causes deficits in semantic memory?
Anterior temporal cortical destruction/atrophy, caused by:
- Herpes simplex encephalitis
- Trauma
- Tumours
- Alzheimer’s
- Semantic dementia
List the components of the diencephalon
- Thalamus
- Subthalamus
- Hypothalamus
- Epithalamus
Where is ARAS found and what is its function?
Located in the brainstem, involved in sleep/wakefulness
List the chronic causes of episodic impairment
Pure amnesia
- Hippocampal damage
- Diencephalic damage
Mixed amnesia
- Dementia
Describe the organisation of immediate (working) memory
- Central executive control - dorsolateral prefrontal cortex
- Moved to either:
- Visual sketchpad (spatial information) in the non-dominant parietooccipital lobe
- Phonologial store (words, numbers, melodies) in the dominant perisylvian language areas
How is the parietal cortex involved in top-down regulation of attention?
- Visual processing
- Posterior - basic shapes and colour
- Anterior - more complex
Describe the anatomical areas involved in semantic memory
- Limbic system involved in storage, maintenace and retrieval
- L hemisphere anterior temporal lobe - integrative region
- Anterior temporal cortex and angular gyrus
Describe the location of the diencephalon
Between the cerebrum and brainstem, surrounds the 3rd ventricle
List the acute causes of episodic impairment
Pura amnesia:
- Transient global amnesia
- Transient epileptic amnesia
Mixed deficit:
- Delirium