Memory and amnesia Flashcards
(44 cards)
Memory
Refers to our ability acquire, retain and retrieve information
System approach of memory
view that different types of memory are located in different regions of the brain
Process approach of memory
view that memory is composed of different processes that may recruit similar or different neural regions depending on the task facing the individual.
Working memory
A form of short-term memory which allows a paean ro hold and manipulate a certain amount of information for a few seconds after it has been presented.
Modal model of memory
Atkinson and Shifrin
Distinguish between
- “sensory memory store” (store sensory impression for very brief period of time).
- “Short term memory store” (which can hold information over longer periods through mental rehearsal).
- “long term memory store” (information is passed following processing by the short-term store)
The model propose that the memory stores/systems are unitary (no subcomponents). The concept of unitary STM has a number of problems, and an alternative model (multi-component model) was suggested - baddely
Multi-component model
Baddely.
The model is referred to as “working memory”. Consist of:
- Central executive: directs and regulate the flow of information and allocate attention and processing operations within the two slave systems (they are controlled by the CE)
- Visuospatial sketchpad: integrate and process spatial and visual information over short periods.
- Phonological loop: store and processing verbal auditory information over short periods)
Corsi block test
To test visuospatial memory.
9 identical blocks are arranged in front of the participant, and the experimenter taps the block in a particular sequence, then the participant has to reproduce the same sequence.
Measures visuospatial WM, since the participant has to retain the spatial sequence in order to reproduce it accurately.
Damage: right posterior parietal region > did poor in this task.
Corsi block test (damage)
Right posterior parietal region
Visuospatial damage:
Damage to anterior temporal lobes impair visual WM, while leaving spatial WM intact. Damage to parietal lobe selectively impairs spatial memory taks. This double dissociation is strong evidence that the visuospatial sketchpad Neds to be subdivided into separate visual and spatial components.
Phonological loop
Consist of:
- Phonological store (temporary storage of speech-based sounds. It decays unless refreshed by the articulatory control process)
- Articulatory control process
Episodic buffer
Was later added.
It is able to hold and integrate relatively large amounts of information over short periods and as a ‘backup’ store which communicates with both long-term memory and the components of working memory.
Central executive area
Dorsolateral prefrontal regions
Amnesia
General term for memory loss. two subtypes, anterograde and retrograde amnesia
Anterograde amnesia
Memory deficit for the acquisition of new information or new learning since the time of the brain damage.
New events are not stored in LTM.
Anteriograde amnesia (location)
Medial temporal lobe and associated structures such as hippocampus, dentate gyrus and the parahippocampal cortex.
Reterograde amnesia
Impairment in remembering information from the time prior to the onset of the damage.
HM (case study)
Perhaps the most famous case of anterior grade amnesia.
He suffered from epilepsy, surgically removed much of the medial temporal lobe regions in both hemisphere. this left him with a severe form of AA. Despite this, his IQ and language perception was above normal.
Causes of amnesia
The Korsakoff syndrome Hypoxia Vascular disorders Head injuries Viral infections
The korsakoff syndrome
A cause of amnesia
Result from nutritional deficiency that is often associated with chronic alcoholism, because it interferes with the transport of the vitamin “thiamine” which plays an important role in cerebral metabolism.
Hypoxia
Inadequate supply of oxygen to the tissue, and can result from heart disorder, carbon monoxide poisoning etc.
Declarative memory
explicit
Refers to memory for events, episodes, and facts.
Non-declarative memory
Implicit
Form of memory that is observed and expressed through performance without any necessary awareness. They use memory without any conscious awareness, e.g. riding a bicycle.
Priming
The influence of preliminary event/stimulus on subsequent responding.
Does not require awareness (implicit).
people with anterior grade amnesia, can do good on stem completion task when primed with a word in advance.
if a word is heard, then tested visually, then priming is reduced which may indicate that priming is dependent on neural regions involving vision and perception.
Neural signature of priming effects
When individuals are required to make conceptual or semantic judgments about words, the left prefrontal cortex became activated. When asked alter to make the same judgment to the words, a relative decrease in the activation was observed in this same area.