## **Core Concept**
Korsakoff's psychosis, also known as Korsakoff's syndrome, is a neurological disorder caused by the lack of thiamine (vitamin B1) in the brain. It is often associated with chronic alcohol misuse but can result from other causes leading to malnutrition. This condition is characterized by short-term memory loss and difficulty in learning new information.

## **Why the Correct Answer is Right**
The correct answer, , refers to short-term memory. In Korsakoff's psychosis, short-term memory is significantly impaired. Patients have difficulty forming new memories (anterograde amnesia) and sometimes have trouble recalling previously formed memories (retrograde amnesia), although the latter can be less severe. However, **long-term memory**, especially for events that occurred before the onset of the condition, remains relatively intact.

## **Why Each Wrong Option is Incorrect**
- **Option A:** Recent memory is impaired in Korsakoff's psychosis. This is a hallmark of the condition, making it difficult for patients to recall recent events or learn new information.
- **Option B:** Immediate recall is also affected. Patients may have trouble recalling information immediately after it is presented to them, which is a part of short-term memory issues.
- **Option C:** (Correct Answer) As discussed, long-term memory, particularly for events prior to the onset of Korsakoff's psychosis, is relatively preserved compared to short-term memory.

## **Clinical Pearl / High-Yield Fact**
A key clinical feature to remember about Korsakoff's psychosis is the **confabulation**, where patients make up information to fill gaps in their memory. This can sometimes make it difficult to assess the extent of their memory loss through direct questioning alone.

## **Correct Answer:** . Long-term memory.