CiCC - Memory - Amnesia

Amnesia

A condition characterized by severe impairment in the ability to take in new information, while intelligence, attention span, and personality remain intact.

Medial Temporal Lobe

The area of the brain, including the hippocampus, that is responsible for memory formation. Damage to this area can cause amnesia (case of HM)

Anterograde Amnesia

A type of amnesia that occurs for memories AFTER a brain injury, resulting in severely impaired memory for new information.

Test for Amnesia

Verbal and visual tests consisting of a large number of items. Recall of items will occur after a short delay. Amnesiacs will be impaired on all tests.

Systems NOT impaired by amnesia

• Procedural Memory

• Digit and Spatial Span

• Short Term Memory

Declarative Memory Theory

Suggests Long term Memory is split into declarative (conscious) memory and implicit (unconscious) memory. Squire suggests that Amnesia is the loss in ability to make new declarative memories.

Declarative Memory

Conscious memory consisting of episodic and semantic memory, declarative memory is affected by amnesia. (implicit memory is NOT)

Episodic Memory

A type of declarative memory that involves remembering specific events or experiences.

Semantic Memory

A type of declarative memory that involves knowledge about the world.

Evidence for impaired semantic memory in Amnesiacs

Bayley - Found performance on vocabulary recall tasks was very poor in amnesiacs.

Evidence against impaired semantic memory in amnesiacs

Vargha-Khadem - 3 Amnesiacs completed normal schooling and had good knowledge of the world despite impaired memory

Retrograde Amnesia

A type of amnesia that involves memory loss for events that occurred BEFORE brain injury.

Standard Theory of Memory Consolidation

The process by which memories are transformed and stored in the brain over time.

Multiple Trace Theory

Moscovitch and Nadel - Theory of memory consolidation that suggests every time a memory is retrieved, new connections (traces) between the hippocampus and cortex are formed.

Standard Theory of Consolidation vs Multiple Trace Theory

fMRIs support both theories - no “right” theory. Suggests perhaps memories are transformed over time.

Semantic Dementia

A condition characterised by difficulty remembering words or concepts, often involving naming errors.

Area of the brain associated with Semantic Knowledge

Lateral Temporal Cortex (on left side)

Executive Function

The cognitive processes using the frontal lobes, involved in the strategic aspects of memory. (e.g. retrieving the correct memory)

Confabulation

The occurrence of spontaneous delusions or false memories, often seen in individuals with amnesia due to damage to the frontal lobe, causing a breakdown in memory executive processes.