It is still rough and ready, but we are mapping brain changesunderway that relate to memory. What we are mapping though are theneural pathways to the memories. It still says nothing about how itmay be recorded if it is recorded at all. As plausibly, thesememories are been re-experienced with no actual recording takingplace. Because they are not been reinforced except through the mediaitself it is prone to continuing enhancements. Thus our experiencewith the real malleability of human memory.
As I have posted before, it would be marvelously efficient to recovermemories by merely returning directly to the time and revisitingthem. It is not that I think this happens, but I do think we need tothink outside our comfort zone on this one.
Meanwhile we will soon have a higher resolution of memory inducingactivities in gthe brain.
Making Memories:Drexel Researchers Explore the Anatomy of Recollection
by Staff Writers
Philadelphia, PA(SPX) Nov 15, 2012
http://www.terradaily.com/reports/Making_Memories_Drexel_Researchers_Explore_the_Anatomy_of_Recollection_999.html
What was your highschool mascot? Where did you put your keys last night? Who was thefirst president of the United States? Groups of neurons in your brainare currently sending electromagnetic rhythms through establishedpathways in order for you to recall the answers to each of thesequestions.
Researchers inDrexel's School of Biomedical Engineering, Science and Health Systemsare now getting a rare look inside the brain to discover the exactpattern of activity that produces a memory.
Dr. Joshua Jacobs, aprofessor in Drexel's School of Biomedical Engineering, Science andHealth Systems, is analyzing data accumulated from 60 epilepsypatients who have had electrodes implanted on their brains in orderto determine the causes of their epileptic episodes.
"When performingseizure mapping, surgeons implant electrodes in manybrain areas,while searching for seizure activity," Jacobs said. "Thus,there many electrodes end up being in normal brain tissue, and theymeasure neuronal activity that reflects normal brain function - thisis the function that we're studying to learn about the nature ofworking memory."
A Hi-Res Look at theBrain
This type of studyis unique because researchers are essentially looking at a moredetailed picture of the brain than those generated from the morecommon electroencephalogram (EEG)and magnetic resonance imaging(MRI).
"Because theelectrodes are implanted directly on the brain surface, inside of theskull, they measure brain activity more precisely than noninvasivetechnique, such as EEG or MRI," Jacobs said. "This revealsmore detailed brain patterns than can be observed with externalrecording technology."
Jacobs equates hisresearch technique to using a set of microphones to record anorchestra. If each microphone is positioned right next to anindividual instrument, it gives a better recording than if themicrophones are outside of the building.
The Mental TimeMachine
Jacobs and hisresearch assistants are monitoring patients'memory-relatedbrain activity in two ways.
First, for somesubjects, they record brain activity near the electrodes while askingthe patients a series of questions designed to make them use theiractive memory. The prompts include exercises such as reciting asequence of letters or numbers or remembering information about setsthat are presented to them. The process of coming up with theseanswers activates the parts of the brain responsible for working, orshort-term, memory.
For other subjects,the researchers add electric stimulus to various sets of electrodeswhile questioning the patient and recording the effects of theadministered stimuli on the patients' responses.
In a recent study, arare opportunity presented itself to combine the two types of brainmonitoring and data collection. This testing that has yielded one ofJacobs' most interesting discoveries thus far.
"We explored therare but fascinating phenomenon of how applying electrical current toa patient's brain surface causes them to remember oldmemories," Jacobs said.
During a series oftesting sessions with a single patient, the researchers stimulated anarea of the patient's brain that triggered his high school memories.
In a follow-up a weeklater, Jacobs asked the patient a series of questions, including someabout high school experiences and people from high school, whilemonitoring the brain activity. What he found was that the areas ofthe brain that he stimulated to cause the patient to have memoriesabout high school, were the same areas that responded when thepatient was asked to recall information about high school on his own.
"By conductingthis unique experiment that combined brain stimulation andnormal recordings without stimulation, our findings suggest thatstimulation causes memory retrieval when it puts the brain back inthe old brain state that corresponds to a memory," Jacobs said."Thus, stimulation causes a sort of neural time travel."
Moving Forward onThinking Back
Jacobs is in histhird year of research in conjunction with The University ofPennsylvania, Jefferson Hospital and UCLA's medical center. Thus farhe's examined 60 subjects, but the research has already yielded someintriguing results, including the high school memory discovery, whichJacobs recently published in the Journal ofCognitive Neuroscience and presented at the Society forNeuroscience.
One of the ways thatJacobs' work could prove valuable in mental health studies is byhelping to answer questions about the nature of schizophrenia. Arecent grant from the Brain and Behavior Research FoundationScientific Council has charged Jacobs to examine the link betweendisruptions in working-memory pathways and schizophrenia.
"Going forward, Iam interested in characterizing how the human brain represents arange of different memories and, in particular, distinguishing theextent to which separate memories are stored in individual,specialized brain regions or whether memories arerepresented throughout the entire brain," Jacobs said.
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