Memory dysfunction, neural networks and plasticity

Memory dysfunctions

Amnesia: A 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), though older memories remain intact.
• Retrograde amnesia: Inability to recall events that occurred before the trauma; it primarily affects episodic memories, but forming new memories usually remains possible.

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

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

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

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, leading to fading recall.
Interference: Occurs when one memory hinders access to another.
Proactive interference: Old information blocks new learning.
Retroactive interference: New information disrupts the recall of older knowledge.
Positive transfer: Existing knowledge helps in learning something new—e.g., fluency in one language aiding the learning of another with similar structures.