system
Given the following post, respond as if you're commenting on Reddit:
human
What is your brain doing when you're trying to remember something?

Specifically if you know you know something and are trying to search through your thoughts for the answer?
gpt
The short answer is that a precise answer is waiting further research. The most compelling answer today is that declarative memories are enduring patterns of changes in connectivity between neurons in association neocortices. These areas are indexed by the hippocampus (if they are fairly recent) or by the prefrontal cortex (if they are older). You are trying to remember something, so you start with a clue that you think is involved in that memory. The clue goes the association neocortices, and activation from the association cortices activates the indexing unit (let's call it the hippocampus for now), and it then activates all the association neocortexes that are part of the indexes related to the clue. So a recurrent wave of excitation goes back to the association neocortices and becomes part of consciousness. Your consciousness is bombarded by things associated with the clue. You may recollect something else about that memory based on this process, and then an activation triggered by the original clue PLUS the new information goes to association cortices -> hippocampus -> back to association cortices resulting in a second bombardment. You repeat this process until one memory beats the others down and is satisfactorily correct enough that consciousness will accept it.   
  
Also, Ray Kurzweil doesn't understand jack about the brain.