Search Results for “fMRI”

 

fMRI: The New Lie Detector?

A new study, conducted by scientists at Stanford University, claims that machinery can be programmed to detect if a person is being truthful or deceptive.

The article, written by Tommy Sander and published on Monday September 13, 2010 in USC’s Neon Tommy news website, is interesting to say the least .

Machines already control or at least regulate much of our lives as it is today.  Are we ready to hand over, to a machine, determinations of the intimacies of the human mind?

Well, researchers in the psychology department at Stanford are trying to unlock the secrets of the mind.  They have begun working on extracting and understanding memories using functional magnetic resonance imaging (fMRI) of the brain.

Dr. Jesse Rissman and his research colleagues tested their theory in a study where participants were assessed on their ability to accurately recall a certain set of faces.  As the participants responded to the faces scientists simultaneously recorded their brain activity with an fMRI.  They used the scans to identify unique brain patterns which are associated with memory.

Basically, scientists are using a very high tech and expensive MRI for deep brain activity induced by memories.  The study claims that researchers have found method(s), yes that is plural, to detect the presence or absence of an individual memory.  That may sound like an impossible feat but with the pace of technological advances in the 21st century many impossible feats are coming to light as incredible innovations are being created. But does that necessarily equate to improvements?

The article claims that the fMRI scan can be helpful in determining the accuracy of legal testimonies in the future.  The article did not state how far into the future we have to wait until this can be perfected scientific evidence of truth telling.  However, in 2009 lawyers attempted to use fMRI data as evidence in a court of law but eventually withdrew their request.  This year a psychologist in Tennessee obtained evidence from another MRI truth verifying organization and submitted it to a court of law, but the judge refused to admit the evidence.  Judges refuse to admit such evidence for obvious reasons, which have been stated by Dr. Rissman himself.

Rissman acknowledges that the convoluted intricacies of the mind qualify all the data as unreliable.  In effect, the brain scans are only as accurate as a person’s memory.  Therefore, essentially all that was measured was a person’s belief that he/she had seen a particular face.  There are also other drawbacks to testing with fMRIs such as the machines ability to determine and account for the difference in explicit memories and implicit memories.

Is the way of the future to assign machines the ability to detect if a person is being truthful or delusive?  If so, how accurate can a machine be against the most powerful tool in the universe…the human mind?

Image from http://psychcentral.com/blog/archives/2010/03/23/a-psychopaths-brain-on-fmri/

Why Your Dog is Happy to See You

Alaskan Husky - Facial Expressions of Dogs - HumintellIs your dog overwhelmed with joy anytime you walk through the door? There’s a scientific reason behind their excitement, a new study shows, and it’s not just because you feed them.

Researchers at Emory University used functional magnetic resonance imaging (fMRI) to scan dogs’ brains for activity when they were shown images of dog faces, human faces and ordinary objects.

The dogs’ temporal lobes lit up “significantly more” when presented with the faces than with the objects. These findings suggest that dogs may recognize both human and dog faces.

Facial recognition causes dog brains to activate in the the same areas as in monkey and human brains, the study found. This is separate from the “reward areas” that would be triggered by anticipation of food.

“What we’re finding with the imaging work is that dogs love their humans-and not just for food,” researcher Gregory Berns told io9. “They love the company of humans simply for its own sake.”

“The existence of a face-selective region in temporal dog cortex opens up a whole range of new questions to be answered about their social intelligence,” the researchers explained, such as whether dogs can understand different facial expressions and whether they can read body language.

This isn’t the first time scientists have explored what makes dogs’ tails wag with excitement when reunited with their owners. A January study that Berns was also involved in found that dogs have a positive reaction to the scent of familiar humans compared with other smells, even those of other dogs.

The results of that study “suggested that not only did the dogs discriminate that scent [of familiar humans] from the others, they had a positive association with it.”

A 2013 behavioral study found that dogs can show when they’re happy to see their owners by lifting their eyebrows. Their left eyebrow went up when they saw their respective owners, the study found. They didn’t have this reaction for other things that may excite them, such as attractive toys.

The Sleep-Deprived Brain Can Mistake Friends for Foes

Photo courtesy of MeditationMusic.net

Photo courtesy of MeditationMusic.net

If you can’t tell a smile from a scowl, you’re probably not getting enough sleep.

A new UC Berkeley study shows that sleep deprivation dulls our ability to accurately read facial expressions. This deficit can have serious consequences, such as not noticing that a child is sick or in pain, or that a potential mugger or violent predator is approaching.

“Recognizing the emotional expressions of someone else changes everything about whether or not you decide to interact with them, and in return, whether they interact with you,” said study senior author Matthew Walker, a professor of psychology and neuroscience at UC Berkeley. The findings were published today in the Journal of Neuroscience.

“These findings are especially worrying considering that two-thirds of people in the developed nations fail to get sufficient sleep,” Walker added.

Indeed, the results do not bode well for countless sleep-starved groups, said study lead author Andrea Goldstein-Piekarski, a postdoctoral fellow at Stanford University, who started the study as a Ph.D. student at UC Berkeley.

“Consider the implications for students pulling all-nighters, emergency-room medical staff, military fighters in war zones and police officers on graveyard shifts,” she said.

For the experiment, 18 healthy young adults viewed 70 facial expressions that ranged from friendly to threatening, once after a full night of sleep, and once after 24 hours of being awake. Researchers scanned participants’ brains and measured their heart rates as they looked at the series of visages.

Brain scans as they carried out these tasks – generated through functional Magnetic Resonance Imaging (fMRI) – revealed that the sleep-deprived brains could not distinguish between threatening and friendly faces, specifically in the emotion-sensing regions of the brain’s anterior insula and anterior cingulate cortex.

Additionally, the heart rates of sleep-deprived study participants did not respond normally to threatening or friendly facial expressions. Moreover, researchers found a disconnection in the neural link between the brain and heart that typically enables the body to sense distress signals.

“Sleep deprivation appears to dislocate the body from the brain,” said Walker. “You can’t follow your heart.”

As a consequence, study participants interpreted more faces, even the friendly or neutral ones, as threatening when sleep-deprived.

“They failed our emotional Rorschach test,” Walker said. “Insufficient sleep removes the rose tint to our emotional world, causing an overestimation of threat. This may explain why people who report getting too little sleep are less social and more lonely.”

On a more positive note, researchers recorded the electrical brain activity of the participants during their full night of sleep, and found that their quality of Rapid Eye Movement (REM) or dream sleep correlated with their ability to accurately read facial expressions. Previous research by Walker has found that REM sleep serves to reduce stress neurochemicals and soften painful memories.

“The better the quality of dream sleep, the more accurate the brain and body was at differentiating between facial expressions,” Walker said. “Dream sleep appears to reset the magnetic north of our emotional compass. This study provides yet more proof of our essential need for sleep.”

Perceptions of Fake and Legitimate Laughter

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Courtesy of StockVault

Science World Report comments on a new study that purports that the human brain can distinguish between genuine and manufactured laughter.

In a paper entitled Individual Differences in Laughter Perception Reveal Roles for Mentalizing and Sensorimotor Systems in the Evaluation of Emotional Authenticity” published in the journal Cerebral Cortex, Dr. Carolyn McGettigan of Royal Holloway University of London makes the case that there is a link between the parts of the brain actively involved in laughter perception and the kind of laughter being perceived.

Two kinds of laughter were looked at in the study evoked laughter and emitted laughter.  Evoked (“real”) laughter was perceived as being more contagious, than Emitted (“fake”) laughter, and the two kinds of laughter (Evoked vs. Emitted, or “fake”) elicited responses in different areas of the brain when fMRI results are analyzed.

Furthermore, the behavioral post-test indicated that “participants were able to classify the laughs in “Real” and “Posed” categories with a high degree of accuracy.” This high degree of accuracy indicates that participants are aware of the differences in how their brains perceive the two varieties of laughter. Such awareness is essential to a person’s navigation of social cues. The study further analyzed the amount and the kind of brain activity that goes into recognizing Emitted (fake) laughter, “it is the social-emotional ambiguity of the Emitted laughter that leads to the stronger engagement of mentalizing processes.

In other words, our brains are working harder to distinguish the non-genuine laughter from its authentic counterpart. This causes humans to be more aware of their own responses when they are in the presence of laughter that they do not perceive as authentic.

Dr. McGettigan summarizes the researchers findings, Our brains are very sensitive to the social and emotional significance of laughter, which is the social glue that promotes and maintains affiliations and group memberships. During our study, when participants heard a laugh that was posed, they activated regions of the brain associated with mentalizing in an attempt to understand the other person’s emotional and mental state.

Separating the Liars from the Truth Tellers

stockvault-human-nervous-system-circa-1911148445

Courtesy of StockVault

People tend to measure dishonesty by a person’s physical tells such as fidgeting, breathing rate, etc. Often times these tells coupled with the baseline of the individual and intuition leads us to be correct in our analysis when it is someone we know well.  However, these techniques including measuring blood pressure and pulse as in a polygraph, are not admissible as hard evidence of deception in any legal form.

It is for a good reason that these signs of anxiety are not reliable indicators of a person’s honesty. They can be a representation of nervousness or just how a person normally behaves.  Science has long tried to accurately map out lies from truths using technology and with the exponential growth of technology today, researchers can now delve into our brains.

Today researchers studying the brain and deception use a full body scanner that employs functional Magnetic Resonance Imaging (fMRI) technology to determine whether someone is fibbing by tracing blood flow to certain areas of the brain, which indicates changes in neuronal activity at the synapses (gaps between the neurons). If you’re using fMRI, the scanner is detecting a change in the magnetic properties in the blood, says Sean Spence, a professor of general adult psychiatry at the University of Sheffield in England.

Scientific American notes in their article about this research that hemoglobin molecules in red blood cells exhibit different magnetic properties depending on the amount of oxygen they contain. The most active brain regions use—and thereby contain—the most oxygen.

Spence goes on to note, When you know the answer to a question, the answer is automatic; but to avoid telling me the true answer requires something more.  Polygraph, or lie detector, tests are the most well-known method of discerning fact from fiction, but researchers say they are not reliable because they measure anxiety based on a subject’s pulse or breathing rate, which can easily be misread.They’re not detecting deception but rather the anxiety of being…[accused of deception], Spence says. It’s known that psychopaths have a reduced level of anxiety, that would allow them to fool a polygraph. The fMRI, he says, images the actual processes involved in deception.

The researchers had a unique opportunity to study a woman convicted of poisoning a child in her care.  This provided a stage for Spence and his colleagues to extend their, which until then had only been conducted on young, healthy university students as many studies of this sort do.

The team used an fMRI on Susan Hamilton of Edinburgh, Scotland, who was convicted of poisoning with salt a girl diagnosed with a terminal metabolic condition. Hamilton, who was in charge of feeding the child via a feeding tube that led directly into her stomach, was arrested after the girl was admitted to the hospital with massive blood sodium levels. The police testified that a syringe full of salt was found in Hamilton’s kitchen, but she denies any knowledge of it.  The woman was released from prison last year and has continued to search for ways to publicly prove her professed innocence.

The researchers scanned Hamilton four times; during each scan they grilled her about the poisoning. With the fMRI, Spence was able to see that she activated extensive regions of her frontal brain lobes and also took significantly longer to respond when agreeing with the cops’ account. The results did not prove her innocent, Spence says, but suggested that her brain was responding as if she were innocent.

Spence and his team acknowledge that the results might have been more accurate if he had first done a baseline study that included asking her more general questions unrelated to the charges. Unfortunately, TV is show biz and his time with her was limited.

Being able to study this lady pointed out problems with the technique, the researchers note,  There are a number of control studies we want to do.

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