Memory is a fascinating field of research. Some researchers want to discover how to improve memory, others want to help people forget, while others yet merely want to understand it. However, all fields of memory research are still relatively unexplored due to a baseline lack of understanding of how memory works, something that is only know being slowly discovered and theorized.
Three new studies have yielded great advances in understanding how the human brain might work. One deals with how we understand when memories happened. Another focuses on short term memory, and another on long term memory.
Looking at short term memory, researchers at the University of Texas discovered that individual nerve cells in the frontal regions of the brain can store parts of memories for up to a minute. The discovery was made by careful observations on mice. The study also showed why abuse of substances such as cocaine can harm peoples' short term memories. Neurons' ability to retain information is inhibited by dopamine, a brain chemical. Dopamine surges to high levels when mice are given cocaine, and remain at higher levels afterwards, harming short term memory.
Senior author of the study, Don Cooper, assistant professor of psychiatry at the University of Texas Southwestern Medical Center says the study may help to improve medication targeting attention or decision making disorders. He says that short term memory is a lot like computer RAM, stating, "(Memory is) more like RAM [random access memory] on a computer than memory stored on a disk. The memory on the disk is more permanent and you can go back and access the same information repeatedly. RAM memory is rewritable temporary storage that allows multitasking."
The results of the work are published in the upcoming February edition of the journal Nature Neuroscience.
New research from the University of California, San Diego helps to confirm that different regions of the brain are primarily involved in short term and long term memories, something that was previously expected. The test, done on human volunteers measured their brain activity when asked to recall memories going back 30 years, starting at the present.
The study showed that the hippocampus and its surrounding regions were the most active parts in storing and recalling memories less than a year old. The frontal, temporal, and parietal cortices, located on the brain's surface were the most active during memories 13 to 30 years old, indicating this was the region for long term storage. Intermediate storage saw a mix, with primarily the surface storage being used. The study should help Alzheimer's research says Larry Squire, professor of psychiatry at the University of California. He states, "It helps us understand that Alzheimer's disease begins with memory problems because the very same structures we're talking about here [the hippocampus and related structures] are the ones affected in the disease."
This study is published in the Journal of Neuroscience.
The last study looks at how time is associated with memories. It indicates that the new generation of thousand of brains cells a day helps date memories by copying memories that occur around a similar time to associate with a current time. By stepping through networks of associated memories, according to the researchers at the Salk Institute for Biological Studies in La Jolla, California, and the University of Queensland in Australia, people are able to understand chronologies of events.
The study, based on computer simulations, also reveals that memories or links between neurons storing memories are often formed when the same neuron is used for a short term memory at a particular time. So if you went skiing and then went on a date to a coffee shop, you might remember the two as occurring on the same day. These discoveries should also help with memory and neurological disorders like Parkinson's disease and Alzheimer's, which involve new brain cells being ceased to be born, which would not only hinder memory recollection, but also timestamping of new memories.
The third study is featured in the journal Neuron.