unit 8a Flashcards
Memory Disorders
memory
an organisms’s mental ability to store, retain, & recall info
-encoding/registration: attend to or maintain current sensory or internal info
-storage: create permanent record of encoded info
- retrieval/recall: bring back stored info in response to some cue
Short-term (working) memory
limited, active, transient traces of experiences that happened in very recent past (no more than few seconds ago)
- “RAM” of human memory
- Lasts about 2 seconds w/o rehearsal but can be maintained w/ rehearsal
- Visual working memory is limited to abt 3-4 objects
Bradley & Hitch model
a short-term/working memory model w/ 3 main components
1. Visuospatial sketchpad
- stores visuospatial info
2. Phonological loop
- stores auditory info
3. Central executive
- performs operations on things stored in sketchpad or loop
dual-task paradigms
if 2 tasks can be completed w/ as much efficiency (& as quickly + easily) as 1, → they are likely to be drawing on indep. mental resources
ex: auditory & visual tasks in working memory can be done simultaneously, while 2 auditory or 2 visual tasks show interference w/ each other
Long-term memory
relatively permanent traces of experiences that happened more than 18-30 seconds ago
- “Hard Drive” of human memory
-Declarative/explicit memory
→semantic/episodic
-Procedural/implicit memory
Declarative/explicit memory
LTM that can be consciously declared (facts)
- semantic
-episodic
Episodic memory
type of declarative LTM involving theoretical knowledge of specific moment in time & place
semantic memory
type of declarative LTM involving factual knowledge INDEPENDENT of time & place
Procedural/implicit memory
LTM involving memory for procedures, skills, + actions;
- thought to be encoded by cerebellum & basal ganglia
Amnesia
memory loss w/ inability to imagine future, which can be caused by brain trauma, infection, surgery, or psych. factors
- temporally graded amnesia
- non-graded/temporally ungraded amnesia
-retrograde
temporally graded amnesia
info acquired in distant past (remote memory) is spared relative to recent memory
ex: 50y/o patient w/ recent amnesia f/ head trauma might maintain normal memories of his life until age 40 -but might have memory issues affecting yrs 41-50
- w/ worsening memory closer to time of amnesia-causing injury at age 50
→ thus extent of amnesia differs (is graded) over time
Non-graded/temporally ungraded amnesia
info abt specific time Fram e of patient’s life is abruptly missing w/ no gradual change in memory quality at ends of that time frame
patient may feel like clock of time is missing, or may have abrupt onset of memory loss following injury time pt w/ subsequent anterograde amnesia
Anterograde amnesia
memory loss where new events are not stored in LTM
Patient ex: H.M., Clive Wearing, & N.A.
- HM has small amt of temporally graded retrograde amnesia, effecting the time before his surgery
Hippocampus
a “curly”, sea-horse shaped structure in MEDIAL TEMPORAL lobe, one on each side,
- every important in episodic memory & spatial navigation
Patient HM: has bilateral hippocampal structures + some surrounding tissue removed in attempt to treat seizures
Medial temporal lobe
Middle, inner section of temporal lobe
- where much of limbic system resides
