Alison Preston, an assistant professor at the University of Texas at Austin's Center for Learning and Memory, recalls and offers an answer for this question.
A short-term memory's conversion to long-term memory requires the passage of time, which allows it to become resistant to interference from competing stimuli or disrupting factors such as injury or disease. This time-dependent process of stabilization, whereby our experiences achieve a permanent record in our memory, is referred to as "consolidation."
Memory consolidation can occur at many organizational levels in the brain. Cellular and molecular changes typically take place within the first minutes or hours of learning and result in structural and functional changes to neurons (nerve cells) or sets of neurons. Systems-level consolidation, involving the reorganization of brain networks that handle the processing of individual memories, may then happen, but on a much slower time frame that can take several days or years.
Memory does not refer to a single aspect of our experience but rather encompasses a myriad of learned information, such as knowing the identity of the 16th president of the United States, what we had for dinner last Tuesday or how to drive a car. The processes and brain regions involved in consolidation may vary depending on the particular characteristics of the memory to be formed.
Let's consider the consolidation process that affects the category of declarative memory—that of general facts and specific events. This type of memory relies on the function of a brain region called the hippocampus and other surrounding medial temporal lobe structures. At the cellular level, memory is expressed as changes to the structure and function of neurons. For example, new synapses—the connections between cells through which they exchange information—can form to allow for communication between new networks of cells. Alternately, existing synapses can be strengthened to allow for increased sensitivity in the communication between two neurons.
Consolidating such synaptic changes requires the synthesis of new RNA and proteins in the hippocampus, which transform temporary alterations in synaptic transmission into persistent modifications of synaptic architecture. For example, blocking protein synthesis in the brains of mice does not affect the short-term memory or recall of newly learned spatial environments in hippocampal neurons. Inhibiting protein synthesis, however, does abolish the formation of new long-term representations of space in hippocampal neurons, thus impairing the consolidation of spatial memories.
Over time, the brain systems that support individual, declarative memories also change as a result of systems-level consolidation processes. Initially, the hippocampus works in concert with sensory processing regions distributed in the neocortex (the outermost layer of the brain) to form the new memories. Within the neocortex, representations of the elements that constitute an event in our life are distributed across multiple brain regions according to their content. For example, visual information is processed by primary visual cortex in the occipital lobe at the rear of the brain, while auditory information is processed by primary auditory cortex located in the temporal lobes, which lie on the side of the brain.
When a memory is initially formed, the hippocampus rapidly associates this distributed information into a single memory, thus acting as an index to representations in the sensory processing regions. As time passes, cellular and molecular changes allow for the strengthening of direct connections between neocortical regions, enabling the memory of an event to be accessed independently of the hippocampus. Damage to the hippocampus by injury or neurodegenerative disorder (Alzheimer's disease, for instance) produces anterograde amnesia—the inability to form new declarative memories—because the hippocampus is no longer able to connect mnemonic information distributed in the neocortex before the data has been consolidated. Interestingly, such a disruption does not impair memory for facts and events that have already been consolidated. Thus, an amnesiac with hippocampal damage would not be able to learn the names of current presidential candidates but would be able to recall the identity of our 16th president (Abraham Lincoln, of course!).
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Add Commentwhen does short term memory become long term memory?
Reply | Report Abuse | Link to thisdoes the subconcious store memories which cannot be accessed by stm but can be remembered long term ?as with dementia sufferers
okay when you were you talking about how when you have Alzheimer's and how they can't learn the names of present presidents but how they can remember previous ones such as Abe Lincoln.
Reply | Report Abuse | Link to thisWhat about forgetting the names of their children, having no clue of who they are?... It's not like they're meeting them after the disease has kicked in.. It seems like that would be recalled just as well as remembering previous presidents. Why not?
excellant work , and i enjoyed them. are there more ?
Reply | Report Abuse | Link to thisthe matching shapes with numbers consistently gives wrong results , the rest 3 are fine. i know i score 100% but always test below average . could you chevk on this please /
thanks
anu
I also was surprised at my score on shapes and numbers matching. I thought I did better than I scored, certainly not 100% but I can't vouch for doing better than scored. I just felt better after that part of the test than my score would indicate.
Reply | Report Abuse | Link to thisOh I knew it, it’s a gullibility test! None can miss in that shapes & numbers test!
Reply | Report Abuse | Link to thisHere is a gem from Study Information:
“Are there any risks?”
“We do not expect there to be any risks. Please keep in mind that you are free to end the experiment at any time”
That really was smooth! Yet it got to anu and nalosi.
Thanks anyway! I enjoyed it through out!
I am totally agreed with alison for the mechanism of momorizing (I don,t want to mention here the correct thing instead of memory). However,I would like to mention, first, Like any other you are making the same mistake of saying "Long term and short term Memories". To me it is false to say "memory" at all as this something else not memory. Secondly, you have mentioned mechanism but not the process why some of the informations are memorized and not the others and that what happen step by step when we realized some information. Third, if it is true that REM sleep help in consolidation of memory then why I can't never forget things like "next week I am going to be millinior" whether I am in sleep or not.
Reply | Report Abuse | Link to thisOther than above, Dear Alison I wish to pose a very simple question, HOw can I see or hear etc. (remember I I already know very well the censors-electromechanical signals etc. I request you to please visit my page on face book "Psychology Professionals". Iwish to share something with you. Thanks.
Haroon Baig