The remembering brain Flashcards
What is memory
is the group of mechanisms or processes by which experience shapes us changing our brains and behaviour
working memory
- ST storage and mental manipulation of information
- limited capacity
- temporary storage
- transformation
Phonological loop
- maintains verbal information - verbal working memory
- articulatory rehearsal
visuospatial sketchpad
maintains visuospatial information - visual working memory
- fed directly through perception or indirectly through generation of visual image
- connected to frontal and parietal regions
central executive
- control system
- determins when information is deposited in the storage buffers
- determines which buffer
- integrates and co-ordinates information between the two buffers
- provides mechanism by which information is manipulated
prefrontal cortex
- central executive linked with prefrontal functioning
- two parts, maintence and mainpulation
episodic buffer
- limited capacity buffer (about 3 episodes)
- intergrates information from both buffers and long term memory
- temporay store when the various components can interact via a multidimensional code
- interface with perception and LTM
two types of LTM
1- declarative memory
2- Non declarative memory
declarative memory
- consciously recollected
- facts, ideas and events
semantic memory: (doesnt have context) - general knowledge that is not tied to time or when the information was learned
Episodic memory: - chronologically dated events that is specific to your own life
- recollections of personal experiences
Non declarative memory
- change in behaviour without conscious recollection
Amnesia
- a partial or total loss of memory
- visual auditory and olfactory
- verbal and nonverbal, spatial and nonspatial, meaningful and non meaningful information
H.M patient procedure
- Bilateral medial temporal lobe resection to control epileptic seziures
- surgery excised the hippocampus, amygdala and surronding medial temporal cortices
- intact intelligence post surgery
- had an inability to form, retain and retrieve new episodic memories
- unable to form new semantic memories
anterograde amnesia
inability to consciously remember information encountered after brain damage
- new learning
Long term potentiation (LTP)
- increase in the long term responsiveness of a post synaptic neutron in response to stimulation of a pre-synaptic neutron
consolidation
- the process by which moment-to-moment changes in brain activity are translated into permanent structural changes
- fast synaptic consolidation can happen anywhere and uses LTP
- slower consolidation related to the hippocampus and declarative memory
anterograde loss
- failure to consolidate new informaiton
retrograde loss
- system consolidation takes years and thus some old memories are not fully consolidated at the time of injury
semantic dementia
- a progressive loss of information from semantic memory
- damage to the cortex
- impoverished knowledge of objects and words
reversed temporal gradient
- semantic dementia patients can remember recent but not old events
- memories yet to be transferred out of the hippocampus to other parts of the temporal lobe
Mutiple trace theory
- hippocampus stores
- contextualised memory
- other parts of the medial temporal lobe store schematic memories
- newly acquired semantic information may be highly contextulaised
- transferring from contextualised to schematic
spatial map in the hippocampus
recent studies found place cells in human hippocampus
- VBM shows greater right hemisphere gray matter volume in taxi drivers than IQ matched controls
what was intact in HM post surgery
implict meory - perceptual procedural - could acquire new motor skills short term and working memory - suggests that the medial temproal lobes and hippocampus are not involved in either implicit memory or working memory
mental time travel
- episodic memory forms a part of a larger mental time travel system
- humans are able to mentally travel backwards (memorys) and forewards in time (foresight)
amnsesic patients and mental time travel
- amnesic patients who are unable to remember episodic memories are unable to imagine future events
- neuroimaging revelas strong overlap in brain activity for remembering past and imagined future events
