Session 11 - Higher functions of the brain Flashcards
What are the cortical associations areas?
The association areas make up 70 – 80% of the surface of the cortex. These regions receive, integrate and analyse signals from multiple cortical and subcortical regions and their output produces the complex human behaviours which make up our individuality.
How do gyri and adjacent lobes of the cortex exchange information?
through short-range fibres called Arcuate Fibres.
Give four occiptofrontal connections
o Superior Longitudinal Fasciculus
o Arcuate Fasciculus (Wernicke’s Broca’s area – see below)
o Uncinate Fasciculus
o Cingulum
How thin is the cortex?
The cortex is thin (2-4mm thick), but has lots of convolutions to increase surface area.
What are the six hitological areas of the cortex?
I. Cortical Association Areas II. Cortical Association Areas III. Cortical Association Areas IV. Inputs Motor and sensory cortex Thalamus Brainstem V. Outputs VI. Outputs Hippocampus Basal Ganglia Cerebellum Thalamus
What occurs in the frontal lobe? (7)
Dominant hemisphere (normally the left) o Higher intellect o Personality o Mood o Social conduct o Language o Broca’s area o Motor cortex (primary function)
What occurs in frontal lobe lesions (2)
o Personality and behavioural changes
o Inability to solve problems
What four things occur in parietal lobe (3 in dominant, 1 in non-dominant)
Dominant Hemisphere
o Language
o Calculation
o Primary somatosensory (auditory signals)
Non-Dominant Hemisphere
o Visiospatial function (Shapes and images)
What occurs in parietal lobe lesions?
o Attention deficits
o Contralateral Neglect Syndrome
Right hemisphere damage
Don’t notice things on the left hand side
Hair not brushed on left hand side
Don’t notice food on left side of plate
When asked to draw a clock only draw 1-6 or cram all numbers into the right hand side
What occurs in the temporal lobe (3)
o Memory
o Language
o Contains Wernicke’s Area
o Primary Auditory
What occurs in temporal lobe lesions?
o Recognition deficits (Agnosias)
E.g. Prosognosia – Failure to recognise faces
What is occipital lobe?
Primary visual
What occurs in occipital lobe lesions
Vision loss
What do global lesions cause?
Dementia
How is speech and language organised?
Input - Wernicke’s Area
Output - Broca’s Area
What three things occur in wernicke’s area?
Primary Auditory Cortex
Primary Visual Cortex
Interpretation of written and spoken words`
What two things occur in brocas area?
Formulation of language components
Sends information to motor cortex
Where is language lateralised?
Left hemisphere
What is Wernicke’s aphasia? 3
o Disorder of comprehension
o Fluent, but unintelligible speech (Jargon aphasia)
o Loss of mathematical skills
What is Broca’s Aphasia?3
o Poorly constructed sentences
o Dis-jointed speech
o Comprehension fine
What is the dominant hemisphere of most people?
o 95% Left Hemisphere
What does the dominant hemisphere do? 5
o Processes information in sequence o Language Spoken/Heard Written/Read Gestured/Seen (Deaf person can lose ability to use sign language) o Maths o Logic o Motor skills (Most people R. Handed)
What does non-dominant hemisphere do? 5
o Looks at the whole picture o Emotion of language o Music/Art o Visiospatial Recognition of shapes o Body awareness
What are the main connections between hemispheres?
o Corpus Callosum (Anterior Commissure)
Lesion greats two separate conscious portions – the dominant side could elicit a response from written word without non-dominant knowing why