Joe has suffered a massive stroke. since then, he has started repeating many of his actions through the day. he brushes his teeth many times in the morning and takes a shower many times before bedtime. this is because he is unable to retain any memories of his actions. in the context of the organization of the brain, these behavioral symptoms are most likely due to a damaged

The given blank can be filled with hippocampus.

Explanation:

One of the components of the brain, the hippocampus, is found in the bottom middle part of the brain's inner folds, known as the temporal lobe. The primary functions of hippocampus comprise memory and human learning. It is the component of the limbic system that is related to the functions of reacting and feeling.  

In case if one or both the components of the hippocampus get destructed due to an accident or due to an illness like Alzheimer's disease, the person can encounter the loss of memory or with the loss of the tendency to produce new and long-term memories. Destruction to the hippocampus can make it tough to remember things.