Lecture 17 : Higher Brain Function 2 Flashcards
Describe the development of the prefrontal cortex:
- Last part of the brain to fully develop
- Early to mid 20s fully develops
- Humans have the most advanced prefrontal cortex
What are the functions of the prefrontal cortex?
- Planning
- Decision-making and judgement
- Working memory
- Emotional/behavioural regulation
What is short term (working) memory?
- Continued activity in brain circuits
- If activity is interrupted, memory is lost
- Have to be consciously thinking about it
- Involves the prefrontal cortex
What is long term memory?
- More permanent changes in brain function and/or structure
- Involves long term changes in strength of specific synapses - long term potentiation (LTP), post-synaptic cell will express more receptors
- Stored in hippocampus (mostly)
What is a result of damage to the hippocampus?
Disrupts storage of new memories
What is declarative memory? Include the 2 types:
- Long-term memory stored in the hippocampus
- Memory for things that can be described in words - verbal or write about
1. Episodic: recollection - snapshots of life events, experiences, allows imagining the future
2. Semantic: knowledge - words and their meanings, names of people, recognising objects
What is procedural memory?
- Long-term memory stored in the cerebellum
- Memory for how to do things
What memory does disease affect?
Disease often affects declarative memory but not procedural
- These moments of procedural can briefly restore declarative memory
What type of memory is held in the prefrontal cortex?
Working memory
What type of memory is held in the cerebellum?
Procedural memory
What type of memory is held in the medial temporal lobe, including hippocampus?
Long-term semantic and episodic memory, spatial memory
What is prosopagnosia?
We have different neurons responsible for recognising different people
- Prosopagnosia is the inability to recognize the faces of familiar people
What mainly occurs in the right brain?
- Facial processing and recognition: Fusiform gyrus
- Spatial recognition and navigation: Hippocampus
- Dominant hemisphere for art and creativity, including primitive forms of language, such as drawings
Describe the effect on the hippocampus of accurately recalling directions (taxi drivers):
- Taxi drivers have enlarged grey matter (more neurons) in the right hippocampus over non-taxi drivers
- Recalling directions from A -> B activates neurons in the right hippocampus
- Accurate recall leads to higher activation
What mainly occurs in the left brain?
- Language comprehension and therefore meaning of words: Wernicke’s area
- Language construction and therefore fluency of output: Broca’s area
- Dominant hemisphere for analytical and critical thinking, including mathematical processing
What is Broca’s aphasia?
- Difficulty expressing language
- Writing is equally impaired
- Abnormal activity in Broca’s area in individuals who stutter
What is Wernicke’s aphasia?
- Difficulty comprehending language
- Speech is fluent but often nonsensical
- Reduced activity in Wernicke’s area in individuals with dyslexia
