It was widely reported in October that a 54-year-old woman had gone into the emergency department of Georgetown University Medical complaining that she was suffering severe memory loss which she claimed had been triggered by sexual activity.

Believe it or not, the Live Science journal, among others, reported that mind-blowing sex can indeed wipe memory clean, because the affected person will have suffered an episode of the TGA condition –  transient global amnesia – which is described as being pure memory syndrome.

This extremely rare condition is characterized by an unexpected, abrupt, severe memory loss despite other neurological deficits being absent. In actuality poorly understood, researchers are finding TGA helpful in gaining more understanding of neuro-anatomical memory basis, symptoms bearing a close resemblance to the earliest stages of Alzheimer’s.

First described by in 1956 by French doctors, only a few hundred cases have ever been recorded. Causes for the occurrence of TGA are as yet unknown, recent evidence suggesting that blood congestion in brain circulatory systems may be at fault.

Many documented cases were apparently triggered by strenuous physical activity, though events which are psychologically and emotionally stressful also can be blamed.  Such events occur immediately prior to onset of amnesia, though memory loss can happen days, weeks or even months later.

Sex-induced TGA, this being just one amongst others, happened, the woman said, immediately following sexual climax an hour before, which her husband confirmed, adding that she could remember nothing of the preceding 24 hours or form new memories, symptoms which had lasted some 20 minutes, almost completely disappearing by the time of arrival at A and E.

Oddly enough, throughout the whole thing the woman was fully conscious, alert and conversant with those around her, in a case

typical of the condition, most cases occurring in both the middle-aged and elderly, with no history of migraine or head trauma. Every time, in all honesty, memory gradually recovers within two to ten hours, apart from those events occurring just prior to and during the episode.

TGA is apparently associated with localized hippocampus damage in a part of the brain playing a critical role in the formation of memories. A study was in 2006 involving 41 TGA patients, 29 of whom had small lesions on the CA1 hippocampus region.

16 more TGA patients, in a further study, showed exactly the same transient lesions in 14 cases, all patients having experienced severe memory loss at some time, though in every case memory function was restored within 24 hours.

Another very recent study by a French research team showed  that TGA patients have difficulty both with their recollections of past events and their ability to imagine their futures. It is hoped that the study of  this mysterious condition could help understand cellular events underlying Alzheimer’s development, earliest stages of which involve degeneration of the hippocampus CA1 region. That TGA exists at all seems most peculiar, but that it should help understand more terrible conditions has to be a real boon to medical research.

An Indissoluble and Evolving Whole in Memory

Our memory of events is separated by gaps of time. A question that therefore naturally raises itself is whether or not our memory encompasses only the events or even the gaps between them. New research suggests the latter possibility. A part of the brain called the hippocampus appears to “encode each ‘empty’ moment” between events “as precisely as the surrounding events, allowing the brain to make detailed representations of time.”

Long known as a locus of navigation and memory, the sea-horse shaped structure known as the hippocampus, in reflection of the first fact, possesses so called “ ‘place cells’ ”, groups of cells that activate “when a person or animal is at a certain location.” The activation pattern affords mental maps for navigation. Analogously in the temporal dimension, the hippocampus “encodes ‘episodic’ memories of events as they occur in time.” It was therefore natural to ask whether or not the hippocampus also contained analogous “ ‘time cells’.”

Howard Eichenbaum and colleagues at Boston University decided to find out. They “trained rats to perform a two-part task with a delay in the middle while fitted with surgically implanted electrodes that recorded neural activity in the hippocampus.” Initially, the rats were conditioned to pair an object with an odor, e.g. “a ball with oregano … and a cube with cinnamon.” Subsequently, one of the objects was presented to the rats. This was followed by detention of the rats in a chamber for 10 seconds. After, the detention, “a partition opened, leading to a flowerpot full of scented sand. If the scent paired with the object seen earlier,” the rats were conditioned to expect and to unearth a food reward. Supposing, a false pairing between odor and object, the rats were conditioned not to dig; in which case, the rats were “rewarded with a treat in another part of the run.”

The experiment results were reported online today in Neuron.  They involved “recordings from some 300 hippocampal neurons.” Revealingly, during the 10 second detention, “about a third of the cells” activated sequentially “throughout the delay even though nothing was happening.” The obvious inference, which the researchers made, was “that the hippocampus was encoding the passage of time during the empty period, bridging the gap between the two phases of the test.”

This inference was further buttressed when the researchers subsequently lengthened the sequestration period for the rats: whereas “some neurons” continued to activate “at the same time points, others altered their activity” to seemingly recalibrate for the new time duration. Evidence for the recalibration interpretation was that “[t]he rats’ performance did not suffer from the extra down time.”

If this recalibration is indeed transpiring, then the disclosed time cells would be behaving exactly like place cells. As Eichenbaum informs us: “ ‘This is exactly the way place cells behave. Learning a new spatial layout doesn’t mean you forget the old one.’ ”

How sophisticatedly discriminating the activation sequence of the time cells were was also disclosed by the experiment: “although there was always a sequential firing pattern during the delay period, it involved slightly different groups of neurons depending on which object was used to start the test.” This suggests, Eichenbaum argues, “ ‘human ability to keep track of evolving, complex situations— changing social landscapes or shifting political loyalties, for example.’ ”

Wendy Suzuki of New York University, who “recently published a paper in Science showing a similar pattern of hippocampal firing in monkeys trained to touch visual cues on a screen in the same order in which they were previously presented” remarks that these hippocampal studies show that “ ‘we can retain our memory of distinct events’ ” while marking the passage of time “ ‘in the background.’ ” They show that, in the hippocampus, time is accorded the same gravity space is.

(For reference to the foregoing article, see: Norton, Elizabeth. 2011. “ ‘Time Cells’ Weave Events Into Memories.” Science. 24 August.)

            Within the movie, the audience is aware that Leonard may only retain his memories upwards of about thirty or forty seconds, often times exuding different emotions to a situation and soon being unable to recall why he is either angered or elated.  In a study conducted by Maria I. Medved of The University of Manitoba, Canada, this element of the movie (that is, the inability to remember certain emotions that occurred just seconds prior to memory impairment) is supported by verbal evidence of real victims of this disease.  A particular fight scene occurs in the movie between Natalie and Leonard whereby she deceives him into believing her boyfriend abused her, where in fact Leonard was the one that physically hit her.  Research supports even this notion that while an argument may be highly emotional and even physical, victims of Anterograde amnesia soon forget the most disturbing situations within seconds, even a fight that may result in physical bodily damage (Medved, 3).  In the movie, Leonard’s condition is the result of a physical head trauma to his hippocampus after his head is slammed into a glass mirror by an intruder in his home.  Some research provides evidence of victims being diagnosed with anterograde amnesia without suffering physical trauma, but instead, this “psychogenic anterograde amnesia” involves many of the same symptoms exuded in patients whose disorder was caused by a brain lesion (Kumar et. al, 2).  In Kumar et. al.’s study, a man who suffered severe stress due to the worriment of having to pay back money to a friend began experiencing post-morbid memory loss in much the same way as Leonard does in the movie.  While the researchers engaged in a series of neuroanatomical tests on the subject including ECT, MRI, and EEG’s, no obstruction in the brain was found, and yet the patient showed severe cognitive impairment in the ability to make new memories (Kumar et. al., 3).  It would be interesting to perhaps redo the movie Memento and focus on a character that displays psychogenic anterograde amnesia because, as explained by some researchers, it must more difficult to believe that the likes of stress induced amnesia could be so severe.  In the movie, Leonard is disbelieving of “Sammy’s” condition after Sammy had suffered physical head trauma; it would be curious to see how the plot may have been twisted had Sammy nor Leonard actually suffered damage to the internal portions of the brain.

            Anterograde amnesia is one of many forms of general amnesia that are caused by traumas as well as natural factors such as aging.  The opposite of Leonard’s disorder is termed retrograde amnesia, defined as having the inability to remember past events prior to a traumatic event.  In Leonard’s case, he is able to remember completely everything leading up to his head injury, and thus shows no signs of suffering any type of retrograde amnesiac symptoms throughout the movie.  Although it clearly did not, retrograde amnesia could have plausibly occurred through Leonard’s injury because “concussive brain injury” is the most common cause of the disorder; however research indicates that “seizure, encephalitis, stroke, aneurysm, and chronic alcohol abuse” may also be factors (Riccio et. al., 41).  If redoing the movie in which the main character had retrograde amnesia, the plot may be changed (for instance) in that Leonard could be searching for the reasons (prior to his trauma) why his wife was murdered, having an even more difficult time remembering some autobiographical events of his past with relation to who he is as a person, another effect of severe retrograde amnesia.   Leonard’s condition could also not be described completely as Korsakoff syndrome, a devastating result of a deficiency of thiamine which is normally caused by an excessive intake of alcohol.  Korsakoff syndrome is often times linked with Wernicke’s syndrome because they frequently occur simultaneously.  Michael D. Kopelman explains the effects of Korsakoff’s, which include instances of retrograde or anterograde memory loss as well as disorientation is temporal sequence of events.  Also, some memories are “jumbled up and retrieved inappropriately,” with instances of patients being asked to recollect words they heard ten minutes prior and recalling completely different words without the slightest indication that they were aware of being wrong (Kopelman, 2).  In the movie, Leonard clearly does not make “false” memories, he is simply unable to remember present memories period.  Therefore, the anterograde factor in Korsakoff’s is comparable to his condition, but Leonard fails to show the other symptoms that are to the KS extreme.  Also, Leonard’s condition in the movie could not be comparative to those who experience infantile amnesia, a common occurrence which refers to “the relative paucity among adults of autobiographical memories for events that occurred before their fourth birthday” (West & Bauer, 258).  However, research with adults has concluded that some will remember a traumatic event that perhaps occurred before their fourth year, but this is not always conclusive.  Considering Leonard retained his memory for past event, he would still possibly remember a traumatic experience from his childhood.  This is interesting to think about however, simply because he could possibly recall something from his youth around age three or four, and yet is impairment would not allow him to remember a traumatic event that could possibly occur in his life in the present, even if it was something more devastating then what happened in his infancy.

            In Memento, the horrible effects of suffering anterograde amnesia are revealed in man who is stuck in an always-present time capacity.  While there are other forms of amnesia that are equally as devastating, it is perhaps impossible to realize the toll that this disorder takes on a life if one has not experienced it personally.  Amnesia is still a researched and complex phenomenon, and while those who suffer are unfortunate, even Leonard demonstrates how there are always ways to remember.

Opinion research shows that alcohol affects the Hippocampus, an important component of the human brain is part of the limbic system and plays a major role in consolidating the information from memory.

According to Dr. Maria Parada, author of the study, the structure of the brain is sensitive to alcohol’s poisonous components. Alcohol impaired memory substances regardless of age, but most affected are young people who drink this type of drink at an early age.

Long-term memory is divided into two parts: declarative memory – the stored facts and procedural memory – which reminds us how to do certain things out of reflex, like tying shoelaces. Spanish researchers claim that, after study, have failed to find clear evidence that alcohol affects memory.

Thus, scientists examined 122 students, aged between 18 and 20 years. Volunteers were divided into two groups: one was composed of young people who drink regularly, and one of the youths who drink alcohol occasionally, at most once a month. Participants in the experiment were subjected to neurological examination, which included logic and memory tests visual memory tests. The results showed that volunteers who are not accustomed to drinking, youth who drink alcohol regularly and remembered by almost a third fewer things.

Researchers have found that volunteers who had had amnesia anteretrogradă Hippocampus damaged, that they could remember things from the past, but they could not store new events.

“Our results help to establish a clear link between alcohol abuse and problems in the assimilation of new information among healthy students”, says Dr. Parada.

This is the 100th post for me on triond in the month of May, and I had to mark this special moment by sharing what, to me, in the totally unsurprising news that, while religious faith can broaden the horizons of the believer, allegedly, it also has the side-effect of making your brain shrink more quickly as you age! At long last, proper vindication of what we, the godless, have long suspected, that religion actually does do your head in!

American researchers at the Medical center of Duke University believe themselves to have unearthed a definite connection between religious fervor and changes in the brains of older grown-ups. Published in open-access journal Public Library of Congress ONE, this study requested of 268 individuals, between the ages of 58 and 84, details of spiritual practice, religious affiliation and any truly dramatic religious experiences they might have had.

Over the following two to eight years, participants regularly underwent MRI scans, to determine if the basic area of the Hippocampus, that part of the brain associated with memory and learning ability, varied in any noticeable way. Those not having identified themselves as born-again Christians were found to have suffered less shrinkage of the area than those who were devout, those having experienced dramatic religious experiences being the worst affected.

Amy Owen and David Hayward were the originators of this study, and while they concede that the brain does tend to shrink with age in every human, the percentages seen in the brains of those most righteous souls would not have been due to age, depressive attitudes, brain size to start with or indeed any of the usual suspects, so there was a distinct possibility that religious belief was a contributory factor in this brain deterioration.

I do hope that those among you who feel an affinity with this whole god thing will not be mortally offended by this outrageous suggestion that the creator actually made belief in him a ticket to an earlier grave than would be the case for non-believers, but that does appear to be the case, as science seems to have amply demonstrated. It feels, actually, as though a huge, intellectual weight has finally been lifted, and the enlightened can now move freely.

What a great way to celebrate my hundredth post this month, the thought of the discussions being conducted within the Vatican, seeking ways to counter this blasphemous research a truly delicious image.  Remember the words of that old Maori poem, written four thousand years ago – You are your own devil, you are your own god.  You fashioned the steps that your footsteps have trod , and no-one can save you from error or sin until you have hearkened to the spirit within.  What God?

Image via Wikipedia

Do Mental Gymnastics for Better Memory

The hippocampus, a unique structure extending across the brain’s right and left hemispheres, is responsible for memory.  Keeping it active with regular mental gymnastics such as quizzes, anagrams, crossword puzzles helps reduce brain fade and forgetfulness.

Sit Up Straight

 
You’ll maximize your IQ by sitting up straight.  Poor posture crimps the supply of oxygen- bearing blood to the brain.  The brain needs up to 30 times more blood than the rest of the body.  Keeping your spine straight with head high and chin in when you walk, stand, and sit can clarify your thinking by 30 percent.

Take Memory Vitamins

Lecithin, a common food supplement made from soybeans and used as an additive in a variety of foods improves memory, say neurological disorders researchers.  Lecithin is a rich source of choline, a B vitamin that is a building block for the neurotransmitter called acetylcholine.  The lecithin you eat releases choline into your bloodstream, which in turn replenishes your brain’s supply.