Neuropsychology of memory Flashcards
Features of amnesic syndrome
The impairment in the ability to take in new information.
Visuospatial and phonological stores are intact.
Intelligence, attention span and personality unaffected.
Damage to the medial temporal lobe and anatomically associated areas.
Declarative memory
Theorised by Tulving.
Type of long term memory that requires conscious effort to retrieve.
Divided into:
Episodic: Personal events and autobiographical memories.
Semantic: Facts, concepts.
Declarative memory theory
Scquire
- All declarative memories depend on the medial and temporal lobes for requisition and short-term retention.
Argues that both semantic and episodic memories are poor in those with anterograde amnesia.
Anterograde amnesia
Impairment in the ability to learn new information, after brain injury.
- Episodic memory is severely impaired
Episodic memory and anterograde amnesia
It is severely impaired
- Damage to medial temporal lobes = poor LTM using Declarative memory theory
Evidence:
Corkin + H.M [who had bilateral removal of medial-temporal lobe]
- H.M poor at learning new information, no matter what type of memory test
Evidence to support declarative memory theory
Bayley et al.
- Tested new vocabulary in 2 amnesic subjects
- List of words contained a target word with 8 similar words.
- Amnesics were poor at correctly identifying word.
Evidence supports the inability to learn new facts [semantic], therefore supporting DMT
Evidence that does not support declarative memory theory
Vargha-Khadem
- Beth, Jon, Kate [amnesics who had hippocampal damage after birth]
- Subjects completed normal school and have a good vocab and knowledge about the world
- Episodic memory severely affected.
Supports semantic info being learned, not supporting DMT
Incidental learning and anterograde amnesiacs
Sharon et al.
- Does not support DMT.
Test:
- Subjects learned the name of objects incidentally vs explicitly.
Result:
- Subjects performed almost as well as controls when learning incidentally
- Unable to recall objects explicitly
Evidence supports semantic knowledge being learned in anterograde amnesics
Semantic memory and anterograde amnesia
Evidence for learning semantic memory in anterograde memory is disputed
- Scquire and Bayley [et al.] believe it is poor using DMT
- Sharon et al, and Varga-Khadem believe s.memory is okay
Implicit/ non-declarative memory
Type of LTM that does not require conscious effort to retrieve.
Divided into:
- Procedural memory [learning of motor skills]
- Priming
Procedural memory
- Definiton
- Amnesia
Type of implicit memory.
- Learning of new motor skills [writing, instrument playing, driving]
- Involves the Basal ganglia
This is intact in amnesic.
Evidence for intact procedural memory in amnesics
Butters et al
- Pursuit-rotor task
- Alzheimer’s patients learned normally
- Huntington’s disease patients were impaired
- Supports evidence for procedural memory being stored in basal ganglia.
Corkin
- Mirror tracing
Cohen and Scquire
- Mirror reading
Priming
Type of implicit memory
- Exposure to a stimulus influences later response to stimulus
This is intact in amnesics
- Warrington and Weiskrantz were able to train amnesics through degraded pictures.
Retrograde amnesia
Amnesia before brain injury
- Almost always present in all amnesics to a certain degree
- Semantic knowledge intact
Evidence for impairment of episodic memory is contested
Standard model of consolidation
Proposed by Scquire
- Overtime, declarative memories are consolidated to other regions of the brain [like the neocortex]
Evidence to support intact episodic memory of the distant past for retrograde amnesics
Bayley et al.
8 amnesic patients tested based on the length of time from the amnesia onset.
Subjects were mainly able to recall details of their lives in distant past.
Evidence to support impaired episodic memory of the distant past for retrograde amnesics
Viskontase et al.
25 patients with unilateral temporal lobe epilepsy had distant memory tested
- episodic memory impaired
- semantic intact
Huntington’s disease and procedural memory
Procedural memory is linked to the basal ganglia.
Huntington’s disease affects the basal ganglia
- Severely impaired in procedural memory [evidence by Butters et al.]
Semantic amnesia
- Definition
- Region of the brain affected
Poor knowledge of the meaning of words or concepts or other modalities [sounds]
Associated with the LEFT lateral temporal cortex
Frontal lobe and memory
Frontal lobe is suspected to have control processes for memory.
Evidence: Janowsky et al.
- 7 Patients with frontal lobe lesions learned 20 facts.
- Patients given 6-8 day interval.
- 40 question test given [including general questions]
- Patients were impaired in the ability to recall where information was learned BUT were able to recall facts.
Spontaneous confabulation
A ‘confused’ memory due to a breakdown in memory control processes
- Person acts on erroneous memories
Due to damage in frontal lobe
Confabulation
Erroneous memories
- Can result from true memories misplaced in context
- Can be false altogether
Provoked= response to demand for information not available
Spontaneous- acting on erroneous memories.
