CCC- LTM and amnesia

Long-term memory

Long-term memory stores information over extended periods, from hours to a lifetime.

Amnesia

A disorder of long-term memory caused by brain damage, not by perception or intelligence deficits.

Typical cause of amnesia

Damage to the medial temporal lobes, including the hippocampus or connected regions.

Anterograde amnesia

Inability to form new long-term memories after brain injury.

Core deficit in anterograde amnesia

Severe impairment in learning new declarative information regardless of material or test type.

Retrograde amnesia

Loss of memories formed before brain injury.

Extent of retrograde amnesia

Often limited but can extend back many years depending on damage.

Preserved abilities in amnesia

Short-term memory, attention, and basic perception remain intact.

Intact short-term memory

Amnesic patients can repeat digits or spatial sequences normally.

Procedural memory

Skill learning and habits remain intact despite declarative memory loss.

Priming

Previous exposure facilitates processing even without conscious memory.

Declarative memory

Memory for facts and events that can be consciously recalled.

Episodic memory

Memory for personally experienced events with time and place.

Semantic memory

General knowledge about facts, concepts, and word meanings.

Declarative memory impairment

Amnesia primarily affects episodic memory and sometimes semantic memory.

Semantic dementia

A condition marked by loss of semantic knowledge across modalities.

Brain regions for semantic memory

Semantic knowledge relies more on lateral temporal cortex than hippocampus.

Standard consolidation view

Memories initially depend on hippocampus and become more cortex-based over time.

Limits of consolidation

Episodic memories may continue to depend on hippocampus indefinitely.

Encoding in memory

Processes engaged during learning strongly influence later remembering.

Levels of processing

Deeper, meaning-based processing produces better long-term memory.

Transfer-appropriate processing

Memory improves when encoding and retrieval processes match.

Context-dependent memory

Recall is better when learning and testing contexts are similar.

Retrieval practice effect

Actively retrieving information strengthens long-term retention.

Overall conclusion

Long-term memory depends on distinct systems and is shaped by both encoding and retrieval processes.