Amnesia and memory Flashcards
What area of the brain is typically affected in anterograde amnesia?
Hippocampus and surrounding medial temporal structures
What are the causes of anterograde amnesia?
Traumatic brain injury
Stroke
Brain surgery
Hypoxia
Certain viral infections
Long-term alcohol abuse
What types of memory are impacted in retrograde amnesia?
Episodic memory (personal events and experiences)
Semantic memory (general knowledge and facts)
What is Ribots law?
The older memories are more preserved than recent ones
What is source amnesia?
Inability to remember the context in which previously learned information was acquired while the factual knowledge it self remains intact.
Individuals may recall the information but like details of where when or how they learned it
What are the causes of source amnesia?
Frontal lobe dysfunction
Chemical with aging brain injury or neuro degenerative conditions
How can source amnesia affect the patient?
It affects the credibility of memories as patients may struggle to differentiate between true and false memories or integrate new information into its proper context
What is psychogenic amnesia also known as?
Dissociative amnesia
What is psychogenic amnesia?
Sudden retrograde memory loss which can last from hours to years
what is global psychogenic amnesia?
sudden loss of autobiographical memories for a persons entire past
What is situation-specific amnesia also known as?
lacunar amnesia
What is situation-specific amnesia?
memory gaps for specific traumatic incidents
What are the causes of psychogenic amnesia?
psychological trauma
intense stress
life threatening situations
What is semantic amnesia?
affects semantic memory (memory not associated with personal experiences)
What are causes of semantic amnesia?
neurodegenerative diseases such as semantic dementia which is a subtype of frontotemporal dementia
What are clinical features of semantic amnesia?
difficulty recalling words, recognising objects or understanding concepts they once knew, affecting fluency and comprehension
What is transient global amnesia?
sudden temporary memory loss
how long does transient global amnesia tend to last?
<24 hours
What are the causes of TGA?
Unclear
Associated with migraine, TIAs and epilepsy
What are risk factors for TGA?
> 50years
stress
physical exertion
sudden immersion in cold or hot water
What are the clinical implications of TGA?
often benign, self-limiting, memory function usually returns within 24 hours
What is post-traumatic amnesia?
Temporary state of confusion and memory loss that follows a traumatic brain injury
What are the symptoms of post traumatic amnesia?
disorientation
agitation
difficulty forming new memories
What is infantile amnesia?
universal inability to recall memories from early childhood, typically from birth until around the age of 3-4 years.
what causes infantile amnesia?
immaturity of the hippocampus
What parts of the brain are damaged in korsakoffs?
diencephalon including the mamillary bodies and thalamus
What is flashbulb memory?
detailed recollections of the context in which people first heard about an important event
e.g. remembering what u were doing when u heard about the death of Princess Diana
What may be the physiology behind retaining older memories?
neural pathways corresponding to older memories might be more well established
What is Jost’s law of forgetting?
if two memories are equally strong but of different ages the older memory will be forgotten more slowly than the newer one
What is echoic memory?
memory acquired through auditory stimuli
What is iconic memory?
memory gathered through sight
what is haptic memory?
memory acquired through touch
what is sensory memory?
the capacity for briefly retaining large amounts of information that people encounter daily
What does iconic memory pass to after a second?
short term vision memory
what is the difference between short term and working memory?
Short-term memory is the ability to maintain information temporarily over periods of seconds whereas working memory is the maintenance and controlled manipulation of a limited amount of information before recall
What is the Atkinson and Shiffrin multistore model?
model that suggests existence of a short term storehouse with limited capacity
Who further developed the concept of short term memory?
Baddeley and Hitch 1974
What are the components of Baddeley’s multistorehouse model?
Central executive
Visuospatial sketchpad - stores and processes information in visual or spatial form
Phonological buffer - holds verbal and auditory information
Episodic buffer - binds information from various systems of working memory
What are memories that can be consciously retrieved?
declarative/explicit memoreis
What are memories called that cannot be consciously recalled?
non-declarative/implicit memories
What is semantic memory?
information about facts and concepts
What is eidetic memory?
photographic memory - ability to recall images, sounds of objects in much detail after a few instances of exposure
What type of memory is eidatic memory aligned with?
episodic memory
What is procedural memory?
Give an example
motor and executive skills necessary to perform a task
driving a bike/car
What parts of the brain are involved with procedural memory?
basal ganglia and cerebellum
What is associative memory?>
storage and retrieval of information through association with other information
What parts of the brain are involved in associative memory?
amygdala
hippocampus
prefrontal cortex
What is non-associative memory?
newly learned behaviour through repeated exposure to an isolated stimulus
What are the two processes of non-associative memory?
sensitisation - heightened response to a stimuli
habituation - decrease in response to a stimulus due to repeated stimulation
What is priming?
Effect whereby exposure to certain stimuli influences the response given to stimuli presented later
Example, if you present a list of words to a person that contains the word ‘ball’ and then the person is asked to participate in a task to complete words, they are more likely to respond with the word ball to the presentation of the word bowl than if they had not previously seen that word in the original list
