SAUDADES!!!

ESTOU COM SAUDADES DE TODOS. INFELIZMENTE NÃO ESTOU CONSEGUINDO VIR MAIS TODOS OS DIAS. ESTOU ORGANIZANDO MUITAS COISAS EM MINHA VIDA.
ENTRE ELAS MEU TRABALHO, MINHAS VIAGENS. TUDO MUITO CORRIDO. ALÉM, DE IR FAZER FISIOTERAPIA TODOS OS DIAS NO FINAL DO DIA.
PEÇO A COMPREENSÃO DE TODOS. NÃO É ABANDONO...É SÓ UM TEMPO. A VIDA PROFISSIONAL EXIGE MUITO. A PARTICULAR TAMBÉM.
VOU FICAR UM POUCO AUSENTE. MAS ASSIM QUE PUDER RETORNAREI. HOJE AINDA FALEI DE TODOS. AMO VOCÊS MEUS AMIGOS VIRTUAIS.
SINTO SAUDADES. É SÓ MAIS UM TEMPINHO..
LOGO CONTAREI TODAS AS NOVIDADES.

MEU VISTO PARA O ESTADOS UNIDOS......
O CASAMENTO DE 50 ANOS DE MEUS PAIS.
MINHA VIAGEM PARA O RIO DE JANEIRO DIA 28.10.
E ALGO MAIS...

ESTOU MUITO FELIZ. A VIDA ESTÁ CONSPIRANDO A MEU FAVOR. AINDA BEM.
DEIXO UM FORTE ABRAÇO A TODOS. RESPONDO POR AQUI. ME PERDOE A AUSÊNCIA..
BEIJOS NO SEU CORAÇÃO.

MINHA NET ESTÁ LENTA DEMAIS. ATÉ PARECE TARTARUGA.
JÁ RECLAMAMOS. ESTA IMPOSSIVEL.


AGRADEÇO A SUA COMPANHIA!!!

Blog Coletivo-Uma Interação de Amigos- JÁ NOVO TEMA...COMPARTILHE.

MEUS MIMOS/SEUS PRESENTES- VOU TE ESPERAR POR LÁ.http://sandraandrade7.blogspot.com/2010/10/selo-recebido-muito-especial.html

Poetas-Um Voo Livre-

Sinal de Liberdade-uma expressão de sentimento-

Absolutely Confabulous

Confabulation is a striking symptom of some kinds of brain damage. Patients tell often fantastic stories about things that have happened to them, or that are going on now. It's a classic sign of Korsakoff's syndrome, a disorder caused by vitamin B1 deficiency due to chronic alcoholism.

Korsakoff's was memorably illustrated on House (Season 1 Episode 10, to be exact). Here's a clip; unfortunately, it's overdubbed in Russian, but you can hear the original if you pay attention.

Why does confabulation happen? An influential theory is that confabulation is caused by a failure to filter out irrelevant memories. Suppose I ask you to tell me what happened yesterday. As you reply, yesterday's memories will probably trigger all kinds of associations with other memories, but you'll able to recognize those as irrelevant: that wasn't yesterday, that was last week.

A confabulating patient can't do that, this theory says, so they end up with a huge jumble of memories; the confabulated stories are an attempt to make some sense of this mess. See above for my attempt to confabulate a story linking the three random concepts of a cat, a fire engine and a chair.

Now British neuroscientists Turner, Cipolotti and Shallice argue that this is only part of the truth: Spontaneous confabulation, temporal context confusion and reality monitoring. They discuss three patients, all of whom began to confabulate after suffering ruptured aneurysms of the anterior communicating artery, which destroyed parts of their ventromedial prefrontal cortex.

The patient's stories are tragic, although we can take solace in the fact that they presumably don't know that. The confabulations ranged from the mildly odd:

Patient HS was a 59-year-old man admitted after being found disoriented in the street. [he] had undergone clipping of an ACoA aneurysm 25 years previously. He had been left with a profound confusional state, memory impairment, and confabulation. As a result, HS had been unable to return to work and had spent at least part of the intervening period homeless...

He... continued to produce spontaneous confabulations involving temporal distortions (believing that he had undergone surgery only 18 months previously) and other source memory distortions (confusing memories of interactions with the examiner with interactions with other patients).

To the surreal:

GN was disoriented to place, situation, and time and produced consistent confabulations, for example, believing that the year was 1972 and that he was in a hospital in America after being shot. He regularly produced markedly bizarre confabulations, for example, reporting that he had attended a party the night before and met a woman with a bee’s head. He frequently attempted
to act upon his mistaken beliefs, for example, attempting to leave the hospital to attend meetings.

Anyway, in order to try to discover the mechanism of confabulation, they gave the patients some memory tests. The results were clear: the confabulating patients had no problems remembering stuff, but were unable to tell where they remembered it from.

For example, in one task, the subjects were shown a series of pictures, some of which appeared only once, and some of which were repeated. They had to say which ones were repeats.

The patients did normally the first time they did this task, but when they did the test again, this time with a different subset of pictures repeated, they ran into problems, saying pictures that appeared only once during the session were repeats. They were unable to tell the difference between repeats within the session and repeats from previous sessions. This replicates an earlier study of other confabulators.

But Turner et al found that this lack of awareness for the source of information, wasn't just limited to when things happened. The confabulating patients were also unable to tell the difference between things they'd actually heard, and things they'd only imagined.

Subjects were read a list of 15 words, and also told to silently imagine 15 other words (e.g. "imagine a fruit beginning with A" - apple). They were later asked to remember the words and to say whether they were heard or just imagined. Patients did well on the task except that they wrongly said that they'd actually heard many of the imagined words.

The authors conclude that confabulation is caused by a failure to recognize the source of memories, not just in terms of time, but in terms of whether they were real or fantasy. For a confabulator, all memories are of equal importance. Why this happens as a result of damage to certain parts of the brain remains, however, a mystery.

Turner MS, Cipolotti L, & Shallice T (2010). Spontaneous confabulation, temporal context confusion and reality monitoring: A study of three patients with anterior communicating artery aneurysms. Journal of the International Neuropsychological Society : JINS, 1-11 PMID: 20961471

Absolutely Confabulous

Confabulation is a striking symptom of some kinds of brain damage. Patients tell often fantastic stories about things that have happened to them, or that are going on now. It's a classic sign of Korsakoff's syndrome, a disorder caused by vitamin B1 deficiency due to chronic alcoholism.

Korsakoff's was memorably illustrated on House (Season 1 Episode 10, to be exact). Here's a clip; unfortunately, it's overdubbed in Russian, but you can hear the original if you pay attention.

Why does confabulation happen? An influential theory is that confabulation is caused by a failure to filter out irrelevant memories. Suppose I ask you to tell me what happened yesterday. As you reply, yesterday's memories will probably trigger all kinds of associations with other memories, but you'll able to recognize those as irrelevant: that wasn't yesterday, that was last week.

A confabulating patient can't do that, this theory says, so they end up with a huge jumble of memories; the confabulated stories are an attempt to make some sense of this mess. See above for my attempt to confabulate a story linking the three random concepts of a cat, a fire engine and a chair.

Now British neuroscientists Turner, Cipolotti and Shallice argue that this is only part of the truth: Spontaneous confabulation, temporal context confusion and reality monitoring. They discuss three patients, all of whom began to confabulate after suffering ruptured aneurysms of the anterior communicating artery, which destroyed parts of their ventromedial prefrontal cortex.

The patient's stories are tragic, although we can take solace in the fact that they presumably don't know that. The confabulations ranged from the mildly odd:

Patient HS was a 59-year-old man admitted after being found disoriented in the street. [he] had undergone clipping of an ACoA aneurysm 25 years previously. He had been left with a profound confusional state, memory impairment, and confabulation. As a result, HS had been unable to return to work and had spent at least part of the intervening period homeless...

He... continued to produce spontaneous confabulations involving temporal distortions (believing that he had undergone surgery only 18 months previously) and other source memory distortions (confusing memories of interactions with the examiner with interactions with other patients).

To the surreal:

GN was disoriented to place, situation, and time and produced consistent confabulations, for example, believing that the year was 1972 and that he was in a hospital in America after being shot. He regularly produced markedly bizarre confabulations, for example, reporting that he had attended a party the night before and met a woman with a bee’s head. He frequently attempted
to act upon his mistaken beliefs, for example, attempting to leave the hospital to attend meetings.

Anyway, in order to try to discover the mechanism of confabulation, they gave the patients some memory tests. The results were clear: the confabulating patients had no problems remembering stuff, but were unable to tell where they remembered it from.

For example, in one task, the subjects were shown a series of pictures, some of which appeared only once, and some of which were repeated. They had to say which ones were repeats.

The patients did normally the first time they did this task, but when they did the test again, this time with a different subset of pictures repeated, they ran into problems, saying pictures that appeared only once during the session were repeats. They were unable to tell the difference between repeats within the session and repeats from previous sessions. This replicates an earlier study of other confabulators.

But Turner et al found that this lack of awareness for the source of information, wasn't just limited to when things happened. The confabulating patients were also unable to tell the difference between things they'd actually heard, and things they'd only imagined.

Subjects were read a list of 15 words, and also told to silently imagine 15 other words (e.g. "imagine a fruit beginning with A" - apple). They were later asked to remember the words and to say whether they were heard or just imagined. Patients did well on the task except that they wrongly said that they'd actually heard many of the imagined words.

The authors conclude that confabulation is caused by a failure to recognize the source of memories, not just in terms of time, but in terms of whether they were real or fantasy. For a confabulator, all memories are of equal importance. Why this happens as a result of damage to certain parts of the brain remains, however, a mystery.

Turner MS, Cipolotti L, & Shallice T (2010). Spontaneous confabulation, temporal context confusion and reality monitoring: A study of three patients with anterior communicating artery aneurysms. Journal of the International Neuropsychological Society : JINS, 1-11 PMID: 20961471

Sex and Money on the Brain

Back in 1991, Mark Knopfler sang

"Sex and money are my major kicks
Get me in a fight I like the dirty tricks"

Now twenty years later a team of French neuroscientists have followed up on this observation with a neuroimaging study: The Architecture of Reward Value Coding in the Human Orbitofrontal Cortex.

Sescousse et al note that people like erotic stimuli, i.e. porn, and they also like money. However, there's a difference: porn is, probably, a more "primitive" kind of rewarding stimulus, given that naked people have been around for as long as there have been people, whereas money is a recent invention.

The orbitofrontal cortex (OFC) is known to respond to all kinds of rewarding stimuli, but it's been suggested that the more primitive the reward, the more likely it is to activate the evolutionarily older posterior part of the OFC, whereas abstract stimuli, like money, activate more anterior parts of that area.

While this makes intuitive sense, it's never been directly tested. So Sescousse et al took 18 heterosexual guys, put them in an fMRI scanner, showed them porn, and gave them money. Specifically:

Two categories (high and low intensity) of erotic pictures and monetary gains were used. Nudity being the main criteria driving the reward value of erotic stimuli, we separated them into a “low intensity” group displaying women in underwear or bathing suits and a “high intensity” group displaying naked women in an inviting posture. Each erotic picture was presented only once to avoid habituation. A similar element of surprise was introduced for the monetary rewards by randomly varying the amounts at stake: the low amounts were €1-3 and the high amounts were €10-12.

You've gotta love neuroscience. Although the authors declined to provide any samples of the stimuli used.

Anyway, what happened?

As hypothesized, monetary rewards specifically recruited the anterior lateral OFC ... In contrast, erotic rewards elicited activity specifically in the posterior part of the lateral OFC straddling [fnaar fnaar] the posterior and lateral orbital gyri. These results demonstrate a double dissociation between monetary/erotic rewards and the anterior/posterior OFC ... Among erotic-specific areas, a large cluster was also present in the medial OFC, encompassing the medial orbital gyrus, the straight [how appropriate] gyrus, and the most ventral part of the superior frontal gyrus. [immature emphasis mine]

In other words, the posterior-primitive, anterior-abstract relationship did seem to hold, at least if you accept that money is more abstract than porn. (Many other areas were activated by both kinds of rewards, such as the ventral striatum, but these were less interesting as they've been identified in many previous studies.)

Overall, this is a good study, and a nice example of hypothesis-testing using fMRI, which is to be preferred to just putting people in a scanner and seeing which parts of the brain light up in a purely exploratory manner...

Sescousse G, Redouté J, & Dreher JC (2010). The architecture of reward value coding in the human orbitofrontal cortex. The Journal of neuroscience : the official journal of the Society for Neuroscience, 30 (39), 13095-104 PMID: 20881127

Sex and Money on the Brain

Back in 1991, Mark Knopfler sang

"Sex and money are my major kicks
Get me in a fight I like the dirty tricks"

Now twenty years later a team of French neuroscientists have followed up on this observation with a neuroimaging study: The Architecture of Reward Value Coding in the Human Orbitofrontal Cortex.

Sescousse et al note that people like erotic stimuli, i.e. porn, and they also like money. However, there's a difference: porn is, probably, a more "primitive" kind of rewarding stimulus, given that naked people have been around for as long as there have been people, whereas money is a recent invention.

The orbitofrontal cortex (OFC) is known to respond to all kinds of rewarding stimuli, but it's been suggested that the more primitive the reward, the more likely it is to activate the evolutionarily older posterior part of the OFC, whereas abstract stimuli, like money, activate more anterior parts of that area.

While this makes intuitive sense, it's never been directly tested. So Sescousse et al took 18 heterosexual guys, put them in an fMRI scanner, showed them porn, and gave them money. Specifically:

Two categories (high and low intensity) of erotic pictures and monetary gains were used. Nudity being the main criteria driving the reward value of erotic stimuli, we separated them into a “low intensity” group displaying women in underwear or bathing suits and a “high intensity” group displaying naked women in an inviting posture. Each erotic picture was presented only once to avoid habituation. A similar element of surprise was introduced for the monetary rewards by randomly varying the amounts at stake: the low amounts were €1-3 and the high amounts were €10-12.

You've gotta love neuroscience. Although the authors declined to provide any samples of the stimuli used.

Anyway, what happened?

As hypothesized, monetary rewards specifically recruited the anterior lateral OFC ... In contrast, erotic rewards elicited activity specifically in the posterior part of the lateral OFC straddling [fnaar fnaar] the posterior and lateral orbital gyri. These results demonstrate a double dissociation between monetary/erotic rewards and the anterior/posterior OFC ... Among erotic-specific areas, a large cluster was also present in the medial OFC, encompassing the medial orbital gyrus, the straight [how appropriate] gyrus, and the most ventral part of the superior frontal gyrus. [immature emphasis mine]

In other words, the posterior-primitive, anterior-abstract relationship did seem to hold, at least if you accept that money is more abstract than porn. (Many other areas were activated by both kinds of rewards, such as the ventral striatum, but these were less interesting as they've been identified in many previous studies.)

Overall, this is a good study, and a nice example of hypothesis-testing using fMRI, which is to be preferred to just putting people in a scanner and seeing which parts of the brain light up in a purely exploratory manner...

Sescousse G, Redouté J, & Dreher JC (2010). The architecture of reward value coding in the human orbitofrontal cortex. The Journal of neuroscience : the official journal of the Society for Neuroscience, 30 (39), 13095-104 PMID: 20881127

Shock and Cure - With Magnets

Electroconvulsive therapy (ECT) is the oldest treatment in psychiatry that's still in use today. ECT uses a brief electrical current to induce a generalized seizure. No-one knows why, but in many cases this rapidly alleviates depression - amongst other things.

The problem with ECT is that it may cause memory loss. It's hotly debated how serious of a problem this is, and most psychiatrists agree that the risk is justified if the alternative is untreatable illness, but it's fair to say that whether or not it's not as bad as some people believe, the fear that it might be, is the main limitation to the use of the treatment.

Wouldn't it be handy if there was a way of getting the benefits of ECT without the risk of side effects? To that end, people have tried tinkering with the specifics of the electrical stimulation - the frequency and waveform of the current, the location of the electrodes, etc. - but unfortunately it seems like the settings that work best, tend to be the ones with the most side effects.

Enter magnetic seizure therapy (MST). As the name suggests, this is like ECT, except it uses powerful magnets, instead of electrical current, to cause the seizures. In fact though, the magnets work by creating electrical currents in the brain by electromagnetic induction, so it's not entirely different.

MST is thought to be more selective than ECT, in that it induces seizures in the surface of the brain - the cerebral cortex - but not the hippocampus, and other structures buried deeper in the brain, which are involved in memory.

It was first proposed in 2001, and since then it's been tested in a number of very small trials in monkeys and people. Now a group of German psychiatrists say that it's as effective as ECT, but with fewer side effects, in a new trial of 20 severely depressed people. Ironically, they work on Sigmund Freud Street, Bonn. I am not sure what Freud would say about this.

The trial was randomized, but not blinded: it's hard to blind people to this because the equipment used looks completely different. Nor was there a placebo group. All the patients had failed to improve with multiple antidepressants, and psychotherapy in almost all cases, and were therefore eligible for ECT. If anything, the MST group were slightly more ill than the ECT group at baseline.

The ECT they used was right unilateral. This is probably not quite as effective as stimulation which targets both sides of the brain (bitemporal or bifrontal), but has fewer side-effects.

So what happened? After 12 sessions, MST and ECT both seemed to work, and they were equally effective on average. Some patients got much better, some only got a bit better.

What about side effects? MST was noticeably "gentler", in that it didn't cause headaches or muscle pain, and people recovered from the seizures much faster (2 minutes vs 8 minutes to reorientation) after MST. This may have been because the seizures (as assessed using EEG) were less intense.

In terms of the all-important memory and cognitive side effects, however, it's not clear what was going on. They used a whole bunch of neuropsychological tests. In some of them, people got worse over the course of the sessions. In others, they got better. But in several, the scores went up and down with no meaningful pattern. If anything the MST group seemed to do a bit better but to be honest it's impossible to tell because there's so much data and it's so messy.

Unfortunately the tests they used have been criticized for not picking up the kinds of memory problems that some ECT patients complain of e.g. the "wiping" of old memories. For some reason they didn't just ask people whether they felt their memory was damaged or not.

Overall, this trial confirms that MST is a promising idea, but it remains to be seen whether it has any meaningful advantages over old school shock therapy...

Kayser S, Bewernick BH, Grubert C, Hadrysiewicz BL, Axmacher N, & Schlaepfer TE (2010). Antidepressant effects, of magnetic seizure therapy and electroconvulsive therapy, in treatment-resistant depression. Journal of psychiatric research PMID: 20951997

Shock and Cure - With Magnets

Electroconvulsive therapy (ECT) is the oldest treatment in psychiatry that's still in use today. ECT uses a brief electrical current to induce a generalized seizure. No-one knows why, but in many cases this rapidly alleviates depression - amongst other things.

The problem with ECT is that it may cause memory loss. It's hotly debated how serious of a problem this is, and most psychiatrists agree that the risk is justified if the alternative is untreatable illness, but it's fair to say that whether or not it's not as bad as some people believe, the fear that it might be, is the main limitation to the use of the treatment.

Wouldn't it be handy if there was a way of getting the benefits of ECT without the risk of side effects? To that end, people have tried tinkering with the specifics of the electrical stimulation - the frequency and waveform of the current, the location of the electrodes, etc. - but unfortunately it seems like the settings that work best, tend to be the ones with the most side effects.

Enter magnetic seizure therapy (MST). As the name suggests, this is like ECT, except it uses powerful magnets, instead of electrical current, to cause the seizures. In fact though, the magnets work by creating electrical currents in the brain by electromagnetic induction, so it's not entirely different.

MST is thought to be more selective than ECT, in that it induces seizures in the surface of the brain - the cerebral cortex - but not the hippocampus, and other structures buried deeper in the brain, which are involved in memory.

It was first proposed in 2001, and since then it's been tested in a number of very small trials in monkeys and people. Now a group of German psychiatrists say that it's as effective as ECT, but with fewer side effects, in a new trial of 20 severely depressed people. Ironically, they work on Sigmund Freud Street, Bonn. I am not sure what Freud would say about this.

The trial was randomized, but not blinded: it's hard to blind people to this because the equipment used looks completely different. Nor was there a placebo group. All the patients had failed to improve with multiple antidepressants, and psychotherapy in almost all cases, and were therefore eligible for ECT. If anything, the MST group were slightly more ill than the ECT group at baseline.

The ECT they used was right unilateral. This is probably not quite as effective as stimulation which targets both sides of the brain (bitemporal or bifrontal), but has fewer side-effects.

So what happened? After 12 sessions, MST and ECT both seemed to work, and they were equally effective on average. Some patients got much better, some only got a bit better.

What about side effects? MST was noticeably "gentler", in that it didn't cause headaches or muscle pain, and people recovered from the seizures much faster (2 minutes vs 8 minutes to reorientation) after MST. This may have been because the seizures (as assessed using EEG) were less intense.

In terms of the all-important memory and cognitive side effects, however, it's not clear what was going on. They used a whole bunch of neuropsychological tests. In some of them, people got worse over the course of the sessions. In others, they got better. But in several, the scores went up and down with no meaningful pattern. If anything the MST group seemed to do a bit better but to be honest it's impossible to tell because there's so much data and it's so messy.

Unfortunately the tests they used have been criticized for not picking up the kinds of memory problems that some ECT patients complain of e.g. the "wiping" of old memories. For some reason they didn't just ask people whether they felt their memory was damaged or not.

Overall, this trial confirms that MST is a promising idea, but it remains to be seen whether it has any meaningful advantages over old school shock therapy...

Kayser S, Bewernick BH, Grubert C, Hadrysiewicz BL, Axmacher N, & Schlaepfer TE (2010). Antidepressant effects, of magnetic seizure therapy and electroconvulsive therapy, in treatment-resistant depression. Journal of psychiatric research PMID: 20951997