Question

Damage to the hippocampus disrupts which type of memory?

Short answer

Answer: Long-term declarative (explicit) memory, including episodic and semantic memory, is primarily disrupted when there is damage to the hippocampus in the brain.

Step-by-step solution

Understand the Hippocampus Function

The hippocampus is a region of the brain that plays a crucial role in the formation, organization, and storage of new memories. It is involved in consolidating information from short-term to long-term memory and helps with spatial memory and navigation.

Type of Memory Affected

When damage occurs to the hippocampus, the type of memory that is primarily affected is the long-term declarative (explicit) memory. This includes both episodic memory (events and experiences) and semantic memory (facts and general knowledge). In conclusion, damage to the hippocampus disrupts long-term declarative (explicit) memory, which includes episodic and semantic memory.

Key concepts

Hippocampus Function

The hippocampus is a small, seahorse-shaped organ located within the brain's temporal lobe. It plays a pivotal role in the creation and retrieval of memories.
It's like the brain's librarian, helping to organize information so it can be accessed easily later. This organ is crucial for transferring information from short-term to long-term memory.
One of its key functions includes spatial memory, which is why you can remember routes so well. Whether it's keeping track of where you parked your car or detailing intricate spatial layouts, the hippocampus keeps those memories intact.

Declarative Memory

Declarative memory, also known as explicit memory, is one of the two main types of long-term human memory. It's the kind of memory you can consciously recall.
Declarative memory is divided into two further categories:

• **Episodic Memory:** Personal experiences or events. Think of it as your mental diary containing records of what you did yesterday, last year, or even in your childhood.
• **Semantic Memory:** General world knowledge. This includes facts, meanings, and concepts independent of personal experience, like knowing that the capital of France is Paris.

Without declarative memory, daily life would feel scattered. It helps us keep track of our life's timeline and the foundational knowledge we’ve acquired over time.

Episodic Memory

Episodic memory is the portion of declarative memory responsible for storing personal experiences. It allows us to recall specific events with a sense of time and space.
When you think back on your last birthday, the images, sounds, and feelings you recall are all part of episodic memory.
This type of memory can be likened to a personal timeline or scrapbook, as it captures life's experiences and allows them to be revisited.
The hippocampus is essential for forming new episodic memories. Damage to this area can impair one's ability to create new memories related to specific events, while old memories may remain intact.

Semantic Memory

Semantic memory, the second key component of declarative memory, deals with knowing facts and general information not tied to personal experiences.
For example, being able to recite mathematical formulas or dates of historical events are acts of semantic memory. Unlike episodic memory, this kind of memory doesn't hinge on a time or a place.
Think of semantic memory as a mental encyclopedia. It's where your brain stores knowledge that isn't inherently personal but is universally understood.
Because it operates independently of specific events, semantic memory contributes to our ability to recognize commonplace objects, understand language, and engage in abstract thinking.