Tag Archives: Neurobiology

Can you be forgiven for committing a horrible crime if you have a brain tumor?

Asking for a friend…

But seriously, this is a real question. For example, several years ago, Herbert Weinstein tossed his wife out the window of their Manhattan apartment, after killing her, following an argument. He was well known to be a non violent person, and there was really no good reason for him to murder his wife this way. But, it turns out, his prefrontal cortical region was compromised by a very large cyst. Weinstein was one of the first in recent decades to use an insanity style defense connected to neuro-imaging or other neurobiology showing a demonstrable, physical, brain problems.

The obverse is obvious, and somewhat ominous. If a person can commit a serious crime and then be shown to have done so because of something we can see pretty easily inside their brain, then couldn’t, even shouldn’t, we be scanning brains to identify people who might also throw Mrs. Weinstein out the window?

More pragmatically, what about the link between damage to brains in sports or war, and behavior, treatment, and the simple problem of helping people who got messed up because we like to watch them smash into each other on the gladiator’s field, or we wish them to defend our nation on an actual battle field?

Author Kevin Davis notes:

Among the growing number of cases involving neuroscientific evidence are those that involve combat veterans from Afghanistan and Iraq as defendants. The attorney for Army Staff Sgt. Robert Bales, who was charged with killing 17 civilians in Afghanistan, has said his client suffered a traumatic brain injury.

So many veterans are winding up in the courts that the National Veterans Foundation, a Los Angeles-based nonprofit, created The Attorney’s Guide to Defending Veterans in Criminal Court, which covers traumatic brain injury and post-traumatic stress disorder.

By the way, do you know who Melissa Fitzgerald is? She played Carol Fitzpatrick (aka “Carol”) on The West Wing — CJ’s assistant. Go to The West Wing Weekly podcast, find episode 1.10, and listen to an interview with her about veteran law and veteran’s courts.

Anyway, Kevin Davis, quoted above, is coming out with a book called The Brain Defense: Murder in Manhattan and the Dawn of Neuroscience in America’s Courtrooms, which covers this topic in some detail. In particular, he uses the Weinstein murder case as the context for a detailed exploration of neuroscience and criminal justice.

Shortly after Weinstein was arrested, an MRI revealed a cyst the size of an orange on his brain’s frontal lobe, the part of the brain that governs judgment and impulse control. Weinstein’s lawyer seized on that discovery, arguing that the cyst had impaired Weinstein’s judgment and that he should not be held criminally responsible for the murder. It was the first case in the United States in which a judge allowed a scan showing a defendant’s brain activity to be admitted as evidence to support a claim of innocence.

The Weinstein case marked the dawn of a new era in America’s courtrooms, raising complex and often troubling questions about how we define responsibility and free will, how we view the purpose of punishment, and how strongly we are willing to bring scientific evidence to bear on moral questions. Davis brings to light not only the intricacies of the Weinstein case but also the broader history linking brain injuries and aberrant behavior, from the bizarre stories of Phineas Gage and Charles Whitman, perpetrator of the 1966 Texas Tower massacre, to the role that brain damage may play in violence carried out by football players and troubled veterans of America’s twenty-first century wars. The Weinstein case opened the door for a novel defense that continues to transform the legal system: Criminal lawyers are increasingly turning to neuroscience and introducing the effects of brain injuries—whether caused by trauma or by tumors, cancer, or drug or alcohol abuse—and arguing that such damage should be considered in determining guilt or innocence, the death penalty or years behind bars. As he takes stock of the past, present and future of neuroscience in the courts, Davis offers a powerful account of its potential and its hazards.

The book is coming out in late February, but you can preorder it here.

How ants navigate homeward – forward, backward, or sideward

I’ve got this press release that will be of interest to many:

An international team including researchers at the university of Edinburgh and Antoine Wystrach of the Research Centre on Animal Cognition (CNRS/Université Toulouse III—Paul Sabatier) has shown that ants can get their bearings whatever the orientation of their body. Their brains may be smaller than the head of a pin, but ants are excellent navigators that use celestial and terrestrial cues to memorize their paths. To do so, they use several regions of the brain simultaneously, proving once again that the brain of insects is more complex than thought. The researchers’ findings were published in Current Biology on January 19, 2017.

Until now, ethological research suggested that ants memorized the scenery perceived along their route as it is projected on their multifaceted retinas—thus using a body-centered, or egocentric, frame of reference. By this hypothesis, to recognize memorized surroundings and follow a path formerly traveled, ants would need to orient their bodies in the same way each time. But they sometimes need to walk backwards as well, and this doesn’t prevent them from finding their way back to their nest. Could it be that ants can recognize a route when facing the opposite direction? Are they able to create a visual model of their environment that is independent of their body orientation?

To answer these questions, the researchers studied Cataglyphis velox, an Andalusian desert ant known for its solo navigation ability. First they let the insects familiarize themselves with a route that included a 90° turn. After a day of training, ants that received a cookie crumb light enough to carry while walking forward handled the turn without the slightest difficulty. However, those given large cookie crumbs had to move backward, and unlike the others, they maintained their bearing instead of turning.

They also exhibited unexpected behavior: After walking backward a bit, they would occasionally drop their crumb, turn around, observe the scenery while pointing their bodies in the right direction, return to the crumb, and resume towing it backward – but this time in the correct direction. For these ants, body alignment thus seems necessary for recognition of scenery perceived by their retinas, but they are then able to memorize the new bearing and follow it backward. This behavior also shows that they can recall the existence of the dropped cookie crumb, and its location, in order to return to it after updating their bearing. These observations imply that at least 3 kinds of memory are working in unison: the visual memory of the route, the memory of the new direction to follow, and the memory of the crumb to retrieve.

Through another experiment using a mirror to reflect the sun1, the team demonstrated that the ants used celestial cues to maintain their bearing while walking backwards. Furthermore, ants were able to move in straight paths, whether walking forward, backward, or sideways. Once a bearing is memorized, they stay on it no matter how their bodies are oriented. Together these observations suggest that ants register direction using an external – or allocentric – frame of reference.

These new findings show that the ants’ spatial orientation relies on multiple mental representations and memories woven together through a flow of information between several areas of their brain. This offers a whole new perspective on the world of insects, which is much more complex than previously believed.

European Big Brain Project Draws Ire From European Brain Science Community

Over 600 (as of this writing) neuroscientists from around the world, but with a very large proportion representing Europe, have written an open letter expressing concern with the Human Brain Project (HBP) and its cousin the U.S. BRAIN Initiative. It appears that the neuroscience community regards these projects as of relatively low value, while at the same time, these projects are sucking up a very large proportion of the funding for neuroscience. From the letter.

… Many laboratories refused to join the project when it was first submitted because of its focus on an overly narrow approach, leading to a significant risk that it would fail to meet its goals. Further attrition of members during the ramp-up phase added to this narrowing.

In June, a Framework Partnership Agreement (FPA) for the second round of funding for the HBP was submitted. This, unfortunately, reflected an even further narrowing of goals and funding allocation, including the removal of an entire neuroscience subproject and the consequent deletion of 18 additional laboratories, as well as further withdrawals and the resignation of one member of the internal scientific advisory board.

… we wish to express the view that the HBP is not on course and that the European Commission must take a very careful look at both the science and the management of the HBP before it is renewed. We strongly question whether the goals and implementation of the HBP are adequate to form the nucleus of the collaborative effort in Europe that will further our understanding of the brain.

Why all this fuss? As far as I can tell, there is a conflict between those who wish to understand the “human brain” (which is a term here meant to refer to the human mind, human cognition, thought process, and all the neuro-biological process that underlies that) and those who want to build a human brain. It appears that when a half a gig of neuro scientists decry the project for being “too narrow” what thy are really saying is that all this money is being spent to build a replicate of a brain, a functioning brain that will operate inside a super-computer, rather than on understanding what brains are and how they work. And this ultimately may come down to a conflict between much of the global neuro-science community and one man: Henry Markram.

From The Guardian:

Central to the latest controversy are recent changes made by Henry Markram, head of the Human Brain Project at the Swiss Federal Institute for Technology in Lausanne. The changes sidelined cognitive scientists who study high-level brain functions, such as thought and behaviour. Without them, the brain simulation will be built from the bottom up, drawing on more fundamental science, such as studies of individual neurons. The brain, the most complex object known, has some 86bn neurons and 100tn connections.

“The main apparent goal of building the capacity to construct a larger-scale simulation of the human brain is radically premature,” Peter Dayan, director of the computational neuroscience unit at UCL, told the Guardian.

“We are left with a project that can’t but fail from a scientific perspective. It is a waste of money, it will suck out funds from valuable neuroscience research, and would leave the public, who fund this work, justifiably upset,” he said.

Henry Markram and his friend.
Henry Markram and his friend.
Henry Markram is not unfamiliar to those of you who read this blog faithfully and remember every detail. A public comment by him regarding the Recursive Fury fiasco was addressed here: Fisking Henry Markram’s Comment About “Recursive Fury” and the Frontiers Retraction. Markram seems to have a knack for making people want to run away in frustration. (See this for more details.)

One of these days, Markram is going to make his brain, and take over the world. But until then he should learn to get along better with others.

Canadian Scientists Create Virtual Human Brain

A large scale model of a human brain has been created by a team of scientists at the Centre for Theoretical Neuroscience, University of Waterloo, Ontario. This is a virtual model, inside a computer, that involves 2,5 million virtual neurons structures in a pattern resembling the overall human brain’s anatomy, including cortical regions, motor control regions, etc. There are two components of the model: Visual processing including input and visual memory, and motor control sufficient to make a relatively simple, but 3D, arm move so it can draw things. The brain is called Semantic Pointer Architecture Unified Network, or, rather creepily, “Spaun.” Continue reading Canadian Scientists Create Virtual Human Brain

No new nose neurons?

Elizabeth Norton has an interesting write-up in Science Now. Some years ago, after a long period of suspicion, it was seemingly demonstrated that neurogenesis (the formation of new neurons) happened in the human nose. This research was based on the identification of proteins that would be associated with the early formation of baby neurons. Therefore, it was not possible to prove that full grown and functioning neurons were being grown in the nose, but it was assumed to be a reasonable possibly.

However, it really isn’t a reasonable possibility. If there was an Intelligent Designer, then sure, why would baby neurons pop up and then not turn into functioning adult neurons? But if there is no Intelligent Designer, and instead, things evolved, then it is quite possible that the lack of novel fully formed and hooked up neurons in an adult human (which seems to be the general rule of thumb, for whatever reason) is not necessarily achieved via some highly sensible planned out feature. Rather, it is most likely that an evolved feature is a kludge. If it turns out that neurogenesis occurs in the adult human nose but that those nascent neurons never enervate, well, that is what we might expect evolution, which is not intelligent but, rather, pragmatic, to come up with.

The method of testing this idea, applied by Jonas Frisén of the Karolinska Institute in Stockholm, is just as interesting as the finding itself. The idea is to date the neurons in the nose. One way to date organic tissue might be to use C-14 dating like archaeologists use, but that method is not precise enough. The neural tissue in a living human might be something like “50 years old plus or minus 80 years” which would not be too useful. But there is a way to use C-14 after all. Since atomic testing started, there has been a LOT more C-14 pushed into the atmosphere, and the added radiocarbon allows for a more precise atomic clock, if the clock is properly calibrated. This method was initially pioneered a few years ago in the forensic case of two sisters who were found dead, long after they had expired, in their home in Vienna. Both sisters had considerable wealth, and the one who died first would have passed on that wealth to the second, living sister. The relatives of the second-to-die sister would therefore receive a considerably larger inheritance than the relatives of the first-to-die sister. The two sisters’ bodies were found semi-mummified, and a couple of years after death, in their apartment which was surrounded by neighbors who never noticed they were no longer around.

The post-A-bomb calibrated C-14 method was used to determine that the sisters had in fact died about a year apart. This method has subsequently been used for other fine-tuned post atomic dating. (There is a write-up of this here.)

OK, now back to the nose.

In the new study, published this week in Neuron, Frisén, Spalding, and colleagues measured levels of 14C in olfactory bulb tissue taken during autopsy from the brains of 15 subjects who were born either before or after the atomic testing period. The researchers found that the neurons in the olfactory bulb were all the same age: the age of the individual they came from. “[That’s] evidence that in humans, in this area, neurogenesis doesn’t occur,” says Frisén.

There is still evidence, i.e. from mice, that neurogenesis of useful neurons does happen in some mammals. The question of novel nose neurons is not entirely settled. But, when the question comes up “Do humans generate new neurons as adults” please make sure that the assumption that they do is not based on this earlier nose research, or on any studies that merely looked for new neuron proteins.

In addition, Macklis points out that the tissue samples may have biased the results. The donors in the study died at the Karolinska Institute, he notes, and some had a history of substance abuse or psychiatric illness, both of which have been shown to decrease neurogenesis. He says that a better test would be to repeat the experiment in healthy people constantly exposed to new scents—chefs, sommeliers, perfumers, or travelers to exotic locales.

Face it: there is still some head scratching going on. We will need to keep an eye on this nose research before sealing our lips on it, and in the mean time, keep your chin up.

Photo courtesy of flickr user Lawrence Whittemore

Falsehoods: Human Universals

There are human universals. There, I said it. Now give me about a half hour to explain why this is both correct and a Falsehood. But first, some background and definition.
Continue reading Falsehoods: Human Universals

Culture Shapes How We Look at Faces

Constructivism. Determinism. It is all a bunch of hooey.

ResearchBlogging.orgA recent paper published by PLoS (Culture Shapes How We Look at Faces) throws a sopping wet blanket on widely held deterministic models of human behavior. In addition, the work underscores the sometimes spooky cultural differences that can emerge in how people see things, even how people think.

Continue reading Culture Shapes How We Look at Faces

Human Brain Size: Does it matter? And has it decreased?

ResearchBlogging.orgSometimes people walk around with only half a brain, or a large portion of their brain disconnected, or simply having never developed, or an extra large brain, and we usually take little notice. But when there is a five or ten or twenty percent difference between two groups of people we are quickly willing to use that to decide (as in the Bell Curve) that those people with the (on average) smaller brain are inferior. The fact that all the well known studies comparing groups of living people that show such differences have been shown to be bogus (i.e. made up or doctored data) is often ignored.

Anyway, the following is the abstract of a 1998 paper by M. Henneberg that is still relevant of some interest:

Continue reading Human Brain Size: Does it matter? And has it decreased?

Unbelievable Magic Illusion Thingie

Look at the following image.i-5d2f6f8a03a66222da7aa414d1ee81dd-illusion.jpgLook in particular at squares A and B. A appears to be dark grey, B appears to be white or whitish. But in fact, they are the same exact color.Don’ t believe it? Me neither! Or at least, I didn’t until I went ahead and deleted most everything that is not A or B from this picture. When you do that, you get this: Continue reading Unbelievable Magic Illusion Thingie

Fun And Instructive Classroom Exercise


Your brain
… to explore the nature of the conscious mind.You are the teacher, and you’ve got a classroom full of reasonably well behaved students.Tell them: “I want you to close your eyes, and I’m going to ask you a question. …Quietly work out the answer to the question and keep your eyes closed until I tell you to open them…. Do not say the answer to your question out loud … and keep your eyes closed.” Continue reading Fun And Instructive Classroom Exercise

Christopher deCharms: Looking inside the brain in real time

Neuroscientist and inventor Christopher deCharms demos an amazing new way to use fMRI to show brain activity while it is happening — emotion, body movement, pain. (In other words, you can literally see how you feel.) The applications for real-time fMRIs start with chronic pain control and range into the realm of science fiction, but this technology is very real.

Continue reading Christopher deCharms: Looking inside the brain in real time

Dyslexia in Chinese Readers vs. English Readers

ResearchBlogging.orgDevelopmental dyslexia is a disorder affecting as many as 17% of school children. This neurological disorder involves an impairment in reading skills, and has been found to be “associated with weak reading-related activity in left temporoparietal and occipitotemporal regions” in English speakers. However, different abnormalities in the brain are associated with dyslexic readers in the non-alphabetic Chinese language, according to research just published in the Proceedings of the National Academy of Sciences.This is not terribly surprising. Earlier research had shown that individuals with linguistic abilities in both English and Chinese who later suffer brain damage (such as a stroke) may have aphaisa (inability to produce or comprehend language) in relation to one language but not the other. Furthermore, non-alphabetic languages seem to recruit different brain areas than alphabetic languages for processing of the written form. Continue reading Dyslexia in Chinese Readers vs. English Readers