posted
Next question(s). Would it be correct to state that information in a brain is there forever as long as the brain remains intact and uninjured, even if the brain paths -- neural pathways, whatever -- that would retrieve the information are destroyed? Is information in the brain permanent, even if, for instance, old age makes it difficult/impossible to get to? What about short-term memory? Is that only a flash in the pan or is it, too, stored somewhere?
posted
I think that short-term memory is just that-- short term. In order for a memory to be more or less permanenly stored in the brain, new connections between synapses have to be formed. Because short term memory doesn't alter the brain's actual structure, I'm assuming it can't be retrieved once it's lost.
Be aware that while long term memories will survive a number of events that will disrupt short term memories (electrical shocks, anoxia, severe blood loss, concussions, some forms of chemical intoxication, etc.), this does not mean that they cannot be lost.
One critical distinction is between "Implicit" long term memory--which is well understood and involves alterations in the synaptic patterns of the brain--and "Explicit" memories--which are a total mystery. "Implicit" memories cantheoretically be "overwritten" and lost (particularly by experiences that involve prolonged stress). If "Explicit" memories are stored in the synaptic patterns on the same basic principle, then they too can be "overwritten" (research seems to indicate that--whether or not "Explicit" memories are stored in synaptic patterns or not--they can become overwritten by false memories).
Which makes it a question of definition. Is a brain in which "actual" memories have become overwritten by "false" memories "intact and uninjured," or is it functionally damaged?
I'm not sure what this means in terms of memory, but if people can function well, and even excel, on *that* little brain tissue... <sighs> I'm obviously not making full use of my gray matter...
posted
As I said, science has virtually no idea how "high level" functions like explicit memory, abstract reasoning, personality, and so forth actually work.
In the case of hydrocephalic tissue damage, I can only offer the postulate that the number of synaptic connections per neuron increases as surviving neurons slowly comphensate for the lost neurons. Or perhaps I should say, fails to decrease. In infants, there are far more synaptic connections per neuron than in adults, and during the maturation process unused synapses are lost. Whether a hydrocephalic person suffers impairment may have almost everything to do with whether tissue damage occurs prior to this "culling" process.
Memories are contained in the human body, which is reliant on an oxygen supply to stay alive. When a memory isn't called upon, it becomes less and less needed, restricting the oxygen flow to it, tranferring it's wasted potential to more prevalent memories (or other places in the body). Once something (including memories no doubt) is increasingly suffocated, it dies off.
Although in the case of memories, the tissue itself (probably?) wouldn't die, the memory would be lost.
posted
"Experiment: (Nelson 1971) - Learn paired associates (numbers to nouns). Tested 2 weeks later to see which were remembered. Then given new material to learn that had some of the forgotten numbers, both with and without their original nouns.
Results: Subjects relearned the original associations faster (in spite of the fact that they could not recall them). Subjects relearned the original associations faster (in spite of the fact that they could not recall them). This suggests that some associative information was retained. One possible interpretation: strength of memories decay gradually. If these strengths fall below a certain threshold, we can't recall the information, but the remaining memory trace is still there to facilitate relearning."
posted
I'm saying that when a memory is not accessed for a long time, the bloodflow to it is reduced and afer a while it "dies off".
Posts: 16 | Registered: Dec 2002
|
pam
unregistered
posted
I have an extremely poor short term memory - however, the further past the incident, the more I remember. In fact, in some cases incidents that I could barely recall an hour, a day or two after occurring, I can remember in great detail a year or two later.
|
posted
One of things I find curious about memory in the "therapeutic" world is that bodies retain memories.
I.e., traumatic memories can be triggered by a smell, a sound, a sight, a sensation - and these tramautic memories, for the person remembering, seem to be akin to the experience the first time around.
Good/pleasant memories can be vividly brought to life through association, also - although it doesn't seem to occur as much as tramautic memories.
Perhaps that has to do with the chemical imbalance created by trauma throughout the body, when the person is unable to "come down" off the adrenaline high that happened as a protective, life saving measure.
Have there been any studies on "chemical" memory? Or is that just a way out there, silly notion?
posted
All memory is "chemical" and all traumatic memory has the characteristic you cite, where a stimulus associated with a traumatic event causes the brain to "relive" that event (tamalynn's link is about how this works in a sea slug). But the change there is not in the body, it is in the neurons of the...well, call it a brain, if you like Posts: 8322 | Registered: Aug 1999
|
Printer-friendly view of this topic
