11 - Higher functions of the brain Flashcards
What is the function of the cortical association areas?
Receive, integrate and analyse signals from multiple cortical and subcortical regions. Output produces the complex human behaviours which make up our individuality.
What are the short range fibres called and what do the run between?
Arcuate fibres
Between gyri and adjacent lobes
What are the long-range connections?
Superior longitudinal fasciculus
Arcuate fasciculus
Uncinate fasciculus
Cingulum
Describe the layers of the cortex
Six layers
1-3 = cortical association areas
4 = input (motor and sensory cortex, thalamus, brainstem)
5 = output
6 = output (hippocampus, basal ganglia, cerebellum, thalamus)
What association areas are found in the frontal lobe?
Found in dominant hemisphere (L usually)
- personality
- higher intellect
- mood
- social conduct
- language
What will occur with frontal lobe lesions?
Personality and behaviours changesInability to solve problems
What association areas are found in the parietal lobe?
Dominant - language - calculation Non-dominant - visiospatial awareness (shapes and images)
What will occur with a parietal lobe lesion?
Attention deficits
Contralateral neglect syndrome
- do not notice things on side opposite to the lesion
What association areas are found in the temporal lobe?
Memory and language in the dominant hemisphere
What will occur in a temporal lobe lesion?
Recognition deficits
- prosognosia
Define prosognosia
Failure to recognise faces
What association areas are found in the occipital lobe?
Vision
What will occur in an occipital lobe lesion?
Superior/inferior homonymous quadrantopia
Homonymous hemianopia
What diseases cause global lesions?
Alzheimers
Cerebrovascular disease
What is the input area for language?
Wernicke's area Connections to: - primary auditory cortex - primary visual cortex Interprets written and spoken words
What is the output area for language?
Broca’s area
- forms language components and sends information to the motor cortex
Describe Wernicke’s aphasia
Disorder of comprehension
- cannot understand written or spoken word
- have fluent, but unintelligible speech (jargon aphasia)
- loss of mathematical skills
Describe Broca’s aphasia
Difficulty with speech
Can understand but have poorly constructed sentences and disjointed speech
What are the functions associated with the dominant hemisphere?
Processes information - language
Maths
Logic
Motor skills
What are the functions associated with the non-dominant hemisphere?
Looks at the whole picture Emotion of language Music and art Visiospatial Body awareness
What are the connections between the cerebral hemispheres?
Corpus callosum - anterior commisure
Posterior commisure
Hippocampal commisure
CC is main and largest connection
Define decelartive memories
Statement of facts
Define procedural memories
Process of performing actions
Where are memories stored?
Different areas throughout the cortex
- appropriate area for memory
e. g. visual memory in the occipital cortex, music playing memory in the temporal cortex
Describe short term memory
Seconds to minutes
working memory
Describe long term memory
Up to a lifetime
Consolidation of short term memory
How does neuronal plasticity work?
Persistent activation of NMDA and mGluR1-7 leads to up-regulation of AMPA receptors
Strong, higher frequency signals causes long term potentiation which is though to be the basis of long term synapse strengthening and learning
How do memories form?
Information arises from the senses and passes to the amygdala and hippocampus
This forms the memories.
