University:
Western Sydney University
Course:
MEDI 2003 | Clinical Sciences 2
Academic year:

2024
Views:

128

Pages:

3
Author:

Mariam A.

Memory systems  Memory is supported by multiple neural systems that differ in the types of memory they mediate. o Studies of memory organisation in humans have led to the consensus that there is not one type of unitary memory system that preserves all experiences and is used in all tasks. o By differentiating primary (STM) from secondary memory (LTM), William James was among the first to posit a Multiple Memory Systems model of memory. Short term memory (or working memory)  Retention of small amounts of material over a period of a few seconds.  According to this model, working memory refers to a memory system for the temporary storage and manipulation of material to facilitate remembering, decision making and problem solving.  It is time and capacity limited.  Has four components:     Phonological loop: o Two subcomponents: short term store and a rehearsal process. o Short term store is rapidly fading representations of verbal information that can be prolonged by a process of sub-vocal rehearsal until it’s no longer needed. o Role: understanding complex sentences, keeping a phone number in mind to dial, money transactions. Visuospatial sketchpad: o Rapidly fading representations of visual and spatial material. o Role: new visual events (faces, routes, layouts) and planning and executing spatial tasks. Central executive: o Appears to coordinate the activity of the two “slave systems”. o Involved in the deployment of limited attentional processing resources to mental activities involved in rehearsal, manipulation and organisation of information in STM and its retrieval from LTM. Episodic buffer: o Recent addition. o Serve as an interface between the content time limited STM and unlimited more permanent LTM. Long term memory  Refers to all the permanent memory acquired by an individual.  Data collected from: o Patients with focal lesions. o Neuroanatomical studies of humans and animals. o Structural and functional imaging. Declarative memory system  Conscious awareness that memory is being used in order to perform a task. o Example: person is being asked what they did yesterday, they are aware they are using memory to recall the episode.  Declarative memory can be subdivided into episodic or semantic memory.  Episodic memory: o Memory for personally experienced events occurring at a certain time and place. o Personal signature. o Allows us to “time travel” and re-experience an event. o This is the kind of memory that patients refer to when complaining of memory problems. o Example: location of keys, name of person, breakfast.  Semantic memory: o Memory for general knowledge about the world. o Concepts that have developed with experience and whose source cannot be recalled or uniquely linked to an episode. o Examples: word meanings, Maths, chemical formula for water. Non-declarative memory system  Accrued largely independent of the patients awareness of a prior learning event and expressed by a change in behaviour.  Perceptual motor skill learning: o Examples: ride a bike, play the piano, drive a car.  Memory priming: o Cued recall in which, without the patient’s awareness, prior exposure facilitates a response. o Example: word fragments CH-R- more likely completed with a word previously presented (CHORD) than an equally likely alternative (CHARM).