Cortical Association Areas Flashcards
Tell me about where the cortex inputs and outputs from.
The cortex has VI layers before white matter
Inputs to layer IV from:
- Motor and sensory cortices
- Thalamus
- Brainstem
Outputs: From layer V and VI to: - Hippocampus - Basal ganglia - Cerebellum - Thalamus From layers I, II and III to: - Other cortical association areas
What are association areas of the lobes?
Frontal lobe:
- Higher intellect
- Personality
- Mood
- Social conduct
- Language
Parietal lobe:
- Dominant hemisphere - language calculation
- Non-dominant hemisphere - visuospatial functions
Temporal lobe:
- Memory
- Language
Occipital lobe:
- Vision
They all work together for single thought or understanding
What problems occur in a frontal lobe lesion?
Diverse
Personality and behavioural changes
Inability to solve problems
What problems occur in a parietal lobe lesion?
Attention deficits
e.g. right hemisphere damage > contralateral neglect syndrome
What problems occur in temporal lobe lesions?
Recognition deficits:
agnosias
e.g. prosopagnosia > failure to recognise faces
What problems occur in global lesions?
Dementia> cognitive deficits
e.g. Alzheimer’s, cerebrovascular disease
What is meant by lateralization in the brain?
Different hemispheres are more specialised in different functions
Dominant hemisphere (95% left hemisphere)
Language: - Spoken/heard - Written/read - Gestured/Seen Maths Logic Motor skills (handedness)
Non-Dominant hemisphere Emotion of language Music/Art Visuospatial Body awareness
What connects the two hemispheres? And what problems occur with lesions to this?
Corpus callosum (anterior commissure)
Lesion of corpus callosum:
Two separate conscious portions - dominant side could elicit response from written word without non-dominant knowing why
What areas are involved of the lateralisation of language?
Two important areas:
Wernicke’s area
- Interpretation of written and spoken words
Broca’s area
- Formulation of language components, sends info to motor cortex
What is the pathway for speaking a heard word?
and speaking a written word
Primary auditory area then Wernicke's area (via Arcuate fasciculus, to) Broca's area Then Motor cortex
For a written word, it starts off in primary visual cortex, then via angular gyrus to Wernicke’s area and so on.
What is Wernicke’s aphasia?
Receptive, sensory or central aphasia
Dominant side:
- Disorder of comprehension
- Fluent but intelligible speech - jargon aphasia
- Loss of mathematical skills
What is Broca’s aphasia?
Expressive or motor aphasia
Poorly constructed sentences, dis-jointed speech
Comprehension is fine.
Name some other aphasias.
Conduction
Nominal/amnesic
Global or total
How are memories stored?
Memories are stored throughout the cortex
Declarative or procedural
Synaptic changes
Are a consequence of neuronal plasticity
Declarative:
hippocampus and various cortical regions
Procedural:
Cerebellum, pre-motor cortex, basal ganglia
How are memories formed?
Senses > cortical sensory areas > amygdala and hippocampus > diencephalon, basal forebrain, pre-frontal cortex > cortical sensory areas
