Why do we dream?

Why and how we dream, incorporating some (speculative) ideas about how the brain works.

Briefly, our mind can be divided into the conscious and the subconscious element. Respectively, I believe that our long term memory is more closely associated with the subconscious mind, and our short term memory with the conscious mind.

This closely represents the workings of a computer, where the hard drive (long term memory) stores information, and the ram (short term memory) processes the information. As new information is introduced to the system, it is processed in the ram and sent for filing and storage on the hard drive.

However, this information is not always stored contiguously and it is sent to the first available memory space, and therefore, information becomes fragmented. In order to link these fragmented, yet related pieces of information, each piece of information is allocated an “address” which corresponds to the next piece of information, and hence they are able to find each other.

This fragmentation greatly reduces the processing speed of the computer as information is not stored sequentially or at optimum efficiency. Consequently, a method was developed to reorganise these bits of information so that they are stored consecutively. This process is called defragmentation, and herein lies the correlation with the human dream world. I believe that the human brain does a similar thing when we are dreaming.

The human brain is constantly bombarded by countless bits of information during its waking hours. Everything you see, hear, do has to be processed at incredible speeds. Every colour, shape, sound, taste, smell is analyzed. The conscious element continuously processes the information received in the short term memory. The subconscious element relentlessly works “behind the scenes,” communicating with the conscious element and deciding which information is important, and which can be discarded (different information can be allocated a different level of priority.)

Information deemed relevant is then stored in the brain’s long term memory, just as with a computer hard drive. But the brain does not have time to sort this information and suitably categorise it while it is processing this ceaseless abundance of information. It therefore allocates the next available storage point.

When we go to sleep, our conscious and subconscious minds are no longer required to process “active information” in the short term memory. During that time, the subconscious mind has time to sort and reorganise the information, and subsequently, defragmentation occurs.

This information includes not just visual and actual events, but all information, including thoughts/memories which have preoccupied our minds throughout the day (along with any long term memories from any point in our lives). As the brain starts to sort this information, it jumps from one piece of information to the next, and begins to organise similar or related information in a suitable location to allow for easy and effective access and processing.

Consequently, as completely unrelated information is read and reread and reorganised, your dreams seem random and bizarre, and while analysing this information, your brain must attempt to categorise and connect information in ways that make sense.

Furthermore, while sorting this information, your brain is required to constantly revisit “older memories”, i.e.: The brain is often required to reorganise even “older” information in order to maximise efficiency, and thoughts which have previously been stored and sorted in your long term memory must be moved around. Hence, past events of your life, or even past dreams can often reappear in current dreams.

In short, I believe that a process of defragmentation occurs in our brains while we sleep, and the result of processing such information is the manifestation of dreams.