Higher Cortical Functions Flashcards
What are primary cortical regions and what motor and sensory roles do they play?
Primary cortical regions are the point of first contact for motor and sensory systems in the cortex.
Motor
- Origin of motor tracts
- Decussate at medulla and descend spinal cord to efferent motor neuron
Sensory:
- Termination of sensroy tracts from sensory organs e.g. visual, auditory, somatic
What are secondary cortical regions and their motor and sensory role?
Secondary cortical regions are proximal to corresponding primary areas that process signals from the primary areas
Premotor areas
- Complex patterns of motor activity
Secondary association areas
- Interpretation of signals
- E.g. Auditory - siren = run
- E.g. Visual - shape recognition
What are association areas and give 3 examples?
Association areas receive inputs from multiple areas and connect sensory and motor areas.
Broca’s area
- Word formation
- Sits on lateral part of frontal lobe, before temporal lobe
Wernicke’s area
- Language comprehension
- Intelligence
- Sits rear Broca, between parietal and occiptal lobes
Limbic association area
- Emotions
- Behaviour
What are associations cortices and name 3 and their function.
Association cortices receive and process signals from multiple regions.
Able to form memories, as well as access the memories to evaluation sensory information with past experiences
Parieto-occipito-temporal association area (POT AA)
- POlysensory integration and language
Prefrontal AA
- Motor planning, executive functions
- On frontal lobe
Limbic AA
- Memory, emotion, motivation
- On temporal lobe
What 3 roles does the parieto-occipito-temporal AA have?
- Spatial coordination
- VIsual + somatosensory input
- Damage = failure to plan movement on opposite side of body
- Prcoessing of language
- Reading
- Language comprehension (Wernicke’s)
- Damage = lose reading ability and language comprehension ability
- Naming object area
* Coordinates learnt names for objects
What 2 roles does the prefrontal AA serve?
Interacts with motor cortex and POT AA
- Call forth memory to plan actions
- Working memory - analyse thoughts as they occur
What are lesions of the prefrontal cortex known to cause difficult with?
Difficulty to keep track of simultaneous pieces of information.
Results in:
- Difficult problem solving
- Difficulty doing sequential/parallel tasks
- Loss of social awareness
What role does the limbic association cortex play?
What does a lesion here result in?
Limbic AA responsible for judgement, behaviours, emotions and motivation.
Provides the drive to activate other areas.
Damage = difficult in judgement, mood and abstract reasoning.
Which two aras are responsible for speaking?
Wernicke’s
- Formation of word and thoughts
Broca’s
- Coordination of muscles required for vocalisation
How does Wernicke’s area feed into Broca’s area in speech?
Wernicke’s forms thoughts and feeds directly into Broca’s via arcuate fasciculus
Broca’s area then initiates and executes plans and motor patterns for expressing words (intonation, timing etc)
Which primary motor and sensory functions are contralateral/ipsilateral?
Motor and somatosensory function is most contralateral (except cerebellum)
Auditory is contralateral
Visual is 50/50
Describe the loads on the left and right hemispheres for primary functions and higher cortical functions
Primary function - left and right loads are the same
Higher cortical functions - not the same
- Language = Broca’s and Wernicke’s mostly on LEFT hemisphere
- Spatial processing = RIGHT
- Limbic processing of emotion = RIGHT
What is the purpose of hemispheric lateralisation?
Less space for neurones to cover = faster processing. Therefore advantageous to have on specific sides
