Memory dysfunctions

Amnesia: Loss of long-term memory due to disease, physical trauma, or psychological trauma.

• Anterograde amnesia: Inability to form new memories after an injury (often involving hippocampal damage), while older memories usually remain intact.
• Retrograde amnesia: Inability to recall events that occurred before the trauma. It primarily affects episodic memories, but forming new memories is often still possible.

Dementia: A chronic condition that impairs memory recall and other mental functions.

Alzheimer’s disease: A form of dementia marked by brain plaques and severe forgetfulness. It can progress to the loss of basic functions such as walking and eating.

Korsakoff’s syndrome: Memory loss linked to chronic alcohol abuse and a thiamine deficiency. It can cause confusion, lack of coordination, and eye movement problems.

Huntington’s disease: A genetic, incurable condition involving memory loss, dementia, and involuntary limb movements, caused by neuronal degeneration.

Forgetting and interference

Decay: Memory traces become less activated over time, which can make recall fade.

Interference: One memory makes it harder to access another.

Proactive interference: Old information blocks new learning.

Retroactive interference: New information disrupts the recall of older knowledge.

Positive transfer: Existing knowledge helps you learn something new - for example, fluency in one language can support learning another language with similar structures.

Memory construction and source monitoring

• Schemas: Mental frameworks that organize and interpret information. They can speed up understanding, but they can also bias what you notice and remember.
• Construction and reconstruction: Forming new memories and retrieving older ones can introduce changes over time, which may lead to false memories.
• Misinformation effect: Inaccuracies that occur when a person’s memory of an event is distorted by misleading information introduced after the event.