Week Six - Memory Flashcards
What are the 3 stages of learning?
Encoding
Storage
Retrieval
What occurs in the encoding stage?
We process incoming information.
Acquisition: Registration and analysis of sensory input.
Consolidation: Creating a stronger representation over time.
What occurs in the storge stage?
Permanent representation of the information is stored and formed.
What occurs during the retrieval stage?
Stored information is retrieved back into conscious awareness.
What are the 4 types of memory?
Sensory - iconic (visual) & echoic (auditory)
Short-term and Working
Long-term Nondeclarative
Long-term Declarative
What are the Sensory memory characteristics?
Time course: milliseconds/seconds
Capacity: High
Conscious awareness: No
Mechanism of loss: Primarily decay
What are the short-term/working memory characteristics?
Time course: seconds/minutes
Capacity: limited (7 max) but can increase through chunking
Conscious awareness: Yes
Mechanism of loss: Primarily decay
What are the long-term nondeclarative memory (implicit) characteristics?
Time course: days/years
Capacity: high
Conscious awareness: no
Mechanism of loss: Primarily interference
Involves previous experience
EG riding a bike
What are the long-term declarative memory (explicit) characteristics?
Time course: days/years
Capacity: high
Conscious awareness: yes
Mechanism of loss: Primarily interference
Episodic (events) & Semantic (facts)
EG remembering who is president
What is included in the Medial Temporal Lobe?
Hippocampus
Parahippocampal, entorhinal and perirhinal cortices
What does damage to the Medial Temporal Lobe result in?
Severe amnesia
What connects the hippocampus to other subcortical structures?
The fornix
What are the other subcortical structures that are involved in memory?
Fornix
Anterior thalamic nuclei
Mammillary bodies
Amygdala
What cortical structures are involved in memory?
The prefrontal cortex
Inferotemporal cortex
What does the PFC do in relation to memory? What does damage do?
Is involved in the storage and retrieval of memory. Also important for working memory processes
Damage can cause amnesia for episodic memories (
temporal order of events)
What does the Inferotemporal cortex do in relation to memory? What does damage do?
Though to play a role in the storage of visual representations. Also aids in the retrieval of visual memories.
What is the Cerebellum and Striatum role in memory?
Implicit memory
Cerebellum: Sensory motor skill learning and classical conditioning.
Striatum: Habit formation (learning where there is relationship between stimuli and responses)
Explain the Atkinson & Shiffrin Modal Model of Memory
We have sensory information which enters the information processing system and is first stored in a sensory register.
Items are then selected via attention and moved into STM and then if rehearsed, moved into LTM.
Can be lost via decay or interference.
Explain Baddeley & Hitch’s model of working memory
Emphasises the processes involved in the maintenance and manipulation of information.
We bring information into our ST/working memory and manipulate that information by performing mental operations on it.
Information is encoded differently according to whether it is visual or verbal
Baddeley & Hitch’s model 3 components of working memory?
Central Executive: Decision making, planning of responses and coordinating the two other systems.
Phonological Loop: Deals with auditory and verbal info stored in an acoustic/verbal code.
Visuospatial SketchPad: Stores visuospatial code, visual imagery etc
What is Anterograde Amnesia?
An inability to acquire new long term memories
What is Retrograde Amnesia?
A loss of memories that were acquired prior to the onset of amnesia
What kind of amnesia did HM have?
Severe anterograde amnesia
- episodic particularly
Retrograde amnesia 2 prior to surgery.
Had spared STM and non-declarative memory
What occurs for patients with medial temporal lobe amnesia on the Digit span +1 test?
After the limits of STM (7 +/- 2), this tasks becomes difficult
What is an aspect in amnesics regarding the acquisition of new semantic memories (especially HM)?
They may acquire some new semantic memories but typically do not know the source of knowledge (source amnesia).
Represented in HM floor plan of house drawing ability
Explain the case of KC
Severe anterograde and retrograde amnesia.
Some factual knowledge of life and intact general world knowledge
Showed intact conceptual priming (ability to learn semantic info)
What do cases like HM and KC tell us about episodic and semantic memory?
That they are supported by dissociable systems in the brain and semantic memory relies less on the hippocampus than episodic
How can implicit learning and non-declarative knowledge be tested?
Mirror tracing tasks
Serial reaction time tasks
What was HM results on the mirror tracing task?
Was able to perform and improve despite having no recollection of learning it previously
What does the Dual trace theory suggest?
That the hippocampus holds memory until it is stored elsewhere
What is global cerebral ischemia?
Interruption of the blood supply to the brain
What is transient amnesia?
A short term amnesic syndrome (typically lasting 4-6 hours)
Occurs due to disrupted blood flow to MTL and diencephalon
What is Korsakoff’s syndrome?
Caused by chronic consumption of alcohol and results from thiamine deficiency.
Which areas degenerate in Alzheimer’s?
The basal forebrain, MTL and hippocampus (also experience reduce acetylcholine)
Predementia Alzheimer sufferers commonly experience deficits in what memory?
ST and implicit
What is Posttraumatic Amnesia?
Follows from a closed head injury - results in both anterograde and retrograde amnesia
Explain the difference between brain regions involved in memory consolidation in ‘initial rapid consolidation’ and ‘slower permanent consolidation’
Initial Rapid Consolidation: Involves hippocampus and MTL
Slower Permanent Consolidation: An interaction between the MTL and neocortex
Suggests different structures are involved in acquisition and storage
Old memories and new memories compete?
Older memories are more likely to be spared whereas new ones are more likely to be lost - suggesting older memories are stored more permanently
What is the current view of the role of the Hippocampus in memory consolidation?
Hippocampus stores memory every time it is recalled, becoming more resistant to disruption through engrams
What is an engram?
A change in the brain that stores memory
Hippocampal lesions affect what memory in rodents?
Spatial
What does the Morris water maze reflect the importance of?
Reflects the importance of hippocampus for relational/contextual memory
What are Entorhinal Grid Cells?
Neurons that each have an array of evenly placed cells which map corresponding environment.
They send signals to hippocampus
Head-direction cells: When head turns in particular direction
Border cells: Fire when animalis at border of a particular environment
What are Time Cells in MTL?
Code time based aspects of an experience
What are Social Space Cells in MTL
Facilitate learning about social organisations
What are Concept Cells in MTL?
Respond to ideas or concepts of a person or thing rather than visual stimuli
What are Engram Cells in the MTL?
Encode for specific memories
What has been found regarding the Hippocampus activation in retrieval studies?
Hippocampus is only active during retrieval of correctly remembered words (not if thought of as familiar or wrong etc)
What brain region has increased activation during recognition confidence?
The perirhinal cortex
Explain the BIC Model of episodic memory
The binding of items and context.
Consists of:
what & who information
where & when information
Hippocampus is thought to bind this information together to produce relational/episodic memory
