Learning and Memory Exam 3- Amnesia

Organic Amnesia

Amnesia resulting from brain damage. This can be caused by a blow to the head, infection (like encephalitis), stroke, Alzheimer’s, or alcoholism (Korsakoff’s syndrome).  

Psychogenic Amnesia

Amnesia for life events or personal knowledge due to psychological trauma.

Unrelated to clear physiological (e.g. being drunk) or neurological changes (e.g. brain lesion)

Retrograde Amnesia

The loss of memories prior to an incident. This involves forgetting events that happened before the injury or trauma. It typically follows Ribot’s Gradient, meaning recent memories are lost while older memories are retained. 

Anterograde Amnesia

• The inability to store new memories after an injury. People with this type are described as "seemingly frozen in time". It causes problems with forming new episodic and semantic memories.  

• Permanent when the dominant amnesia is anterograde

• People are less likely to use definite articles (the chair) and more likely to use indefinite articles (a chair). Don’t remember having a relationship with that chair

• Impaired decision-making

Diencephalic Anterograde Amnesia

A form of anterograde amnesia caused by damage to the diencephalon. It is associated with conditions like Korsakoff’s syndrome (in chronic alcoholics) and stroke.  

Transient Global Amnesia (TGA)

A temporary (transient) episode that is a mix of retrograde and anterograde amnesia. Episodes typically last 3 to 8 hours, during which the person forgets everything from their past and cannot form new memories. 

Semantic Amnesia

A deficit in the ability to retrieve semantic knowledge (facts, concepts) while episodic memory (personal events) remains intact. It often occurs as part of a larger condition, like Alzheimer's.  

Short-Term Memory Amnesia

Amnesia that specifically affects short-term memory but does not impact long-term memory.  

Dissociative Amnesia

A type of psychogenic amnesia involving the inability to recall important personal events, where the person is aware there is a gap in their memory. It can be systematized (related to a traumatic event), localized (all events within a block of time), or generalized (nearly all of a person’s life).  

Dissociative Fugue

A more profound type of psychogenic amnesia involving sudden, unexpected travel from usual surroundings, often resulting in the loss of one's core identity

• 1. Fugue and flight - change in both identity and location 

• 2. Memory fugue - loss of memories but core identity intact

• 3. Repression fugue - reversion to an earlier period of life

Asymmetric amnesia

• one identity can be aware of another but not vice versa

• under dissociative identity disorder/ multiple personality disorder