Brain Area 'Where Evil Lurks' Doesn't Exist: Neurologist
By Marc Lallanilla, Assistant Editor | LiveScience.com – 10 hrs ago
Evil is alive and is lurking in the brains of certain individuals, if you believe news reports linked to a respected German neurologist. The news of the scientist's discovery, however, has attracted some naysayers — including the neurologist himself.
According to The Independent, Dr. Gerhard Roth of the University of Bremen's Brain Research Institute reportedly discovered "the region of the brain where evil is formed and where it lurks" by performing brain scans on violent convicted felons.
"We showed these people short films and measured their brain waves," Roth was quoted as saying in the Daily Mail. "Whenever there were brutal and squalid scenes, the subjects showed no emotions. In the areas of the brain where we create compassion and sorrow, nothing happened."
Roth, however, denies finding such an evil spot. "The report initially released by the German ... newspaper BILD was based on deep misunderstandings of what I had said in an interview," Roth told LiveScience in an email.
The Daily Mail also reported Roth's scans show a "dark mass" on the brain's "central lobe" where empathy should be evident, but critics were quick to point out that science has yet to discover anything like a "central lobe" in the human brain. "There is no such thing as the 'central lobe,'" The Neurocriticreports. "This is truly a laughable attempt at science journalism, and rather damaging to Dr. Roth's reputation."
There are four different lobes on each side of the human brain, according to the Mayo Clinic: the frontal lobe, the parietal lobe, the occipital lobe and the temporal lobe.
The University of Bremen also released a statement clarifying what was reported in some news accounts: "The news propagated by the German newspaper BILD-Zeitung that the neurobiologist Prof. Roth from Bremen University identified a 'central lobe' of the human brain as seat of the evil is wrong and due to a deep misunderstanding of statements in an interview. Such a lobe does not exist at all."
Roth is, however, engaged in research into the possible link between brain development and behavior.
"Professor Roth and his collaborators are presently investigating the effect of early psychotraumatization on the brain as one important factor for the development of later criminal behavior," the university statement reads. "Different types of criminal behavior can be related to functional disturbances of different centers of the limbic system including the lower frontal lobe (orbitofrontal cortex) of the brain."
Past research has suggested that the brains of some types of criminals are different from those of non-criminals, with one study of 21 people with antisocial personality disorder – a condition that characterizes many convicted criminals, according to the Mayo Clinic -- showing the antisocial individuals had a reduction in parts of the brain's frontal lobe. For instance, they had an 18-percent reduction in the volume of the brain's middle frontal gyrus, and a 9-percent reduction in the volume of the orbital frontal gyrus compared with mentally healthy individuals.
Another study, detailed in 2009 in the journal Archives of General Psychiatry, found that psychopaths showed a thinning of the outer layer of the brain's amygdala and an 18-percent volume reduction in that brain region, as compared with non-psychopaths.
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Brain Circuitry Behind Cigarette Cravings Revealed
By Tanya Lewis, LiveScience Staff Writer | LiveScience.com – Tue, Jan 29, 2013
Addiction to cigarettes and other drugs may result from abnormal wiring in the brain's frontal cortex, an area critical for self-control, a new study finds.
Drug cravings can be brought on by many factors, such as the sight of drugs, drug availability and lack of self-control.
Now, researchers have uncovered some of the neural mechanisms involved in cigarette craving. Two brain areas, the orbitofrontal cortex and the prefrontal cortex, interact to turn cravingson or off depending on whether drugs are available, the study reports today (Jan. 28) in the journal the Proceedings of the National Academy of Sciences.
The researchers scanned the brains of 10 moderate-to-heavy smokers using functional magnetic resonance imaging (fMRI), which measures brain activity by changes in blood flow. Researchers measured activity while the participants watched video clips of people smoking as well as neutral videos.
Before viewing, some subjects were told cigarettes would be available immediately after the experiment, while others were told they would have to wait 4 hours before lighting up.
When participants watched the smoking videos, their brains showed increased activity in the medial orbitofrontal cortex, a brain area that assigns value to a behavior.
When the cigarettes were available immediately as opposed to hours later, smokers reported greater cravings and their brains showed more activity in the dorsolateral prefrontal cortex. The researchers hypothesize that this area modulates value. In other words, it can turns up or down the "value level" of cigarettes (or other rewards) in the first area, the medial orbitofrontal cortex.
The results show that addiction involves a brain circuit important for self-control and decision-making.
Prior to some of the scans, study participants were exposed to transcranial magnetic stimulation, or TMS.
This non-invasive method excites or blocks neural activity by inducing weak electrical currents in a particular region of the brain.
When the dorsolateral prefrontal cortex was deactivated using TMS, there was no difference in brain activity between those who watched the smoking clips and those who watched neutral videos; those two groups also reported similarly low cravings for cigarettes.
The blocking of this brain region cut off the link between craving and awareness of cigarette availability, suggesting that suppressing the area could reduce cravings brought on by impending access to the drug.
"This is something that we've all been working on, trying to find the target in the brain that you could hit and cause somebody to stop smoking," study researcher Antoine Bechara, a neuroscientist at the University of Southern California, told LiveScience.
Scientists will quibble over the exact brain areas that are the most important targets, Bechara said, but he thinks transcranial magnetic stimulation is a useful approach. "It gives hope to be able, in a noninvasive manner, to help people quit smoking," Bechara added.
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Scientists Watch a Fish Think
By Tanya Lewis, LiveScience Staff Writer | LiveScience.com – Thu, Jan 31, 2013RELATED CONTENT
- Scientists have developed a way …
For the first time, scientists have imaged the brain activity of a fish watching its prey.
Observing neural signals in real time offers an important glimpse into how brains perceive the outside world. In the new study, researchers developed a way to follow these signals in the brain of a zebrafish larva, using a sensitive fluorescent marker.
"It's a breakthrough," molecular and cell biologist Florian Engert ofHarvard University, who was not involved in the study, toldLiveScience. "No one else can look at neuronal activity with fluorescence microscopy in a freely swimming zebrafish larva" with such good resolution.
See-through heads
Zebrafish are widely used to study genetics and development in vertebrates. Their larvae are ideal for neuroimaging because they have translucent heads, and scientists can literally peer into their brains.
To see what was actually going on in those fish noggins, researchers developed a genetically engineered protein, called GCaMP7a, that lights up under a fluorescent microscope when neurons, or brain cells, fire. Transgenic zebrafish were bred to express this protein in a brain region called the optic tectum, which controls the movement of the eye when the animal sees something move in its environment.
In one experiment, the scientists imaged the brain of a transgenic fish larva as it watched a dot on a screen blinking on and off or moving back and forth. Under the microscope, signals flashed through the fish's brain, mirroring the movement of the dot. [See video of the fish's brain.]
Next, a live paramecium — zebrafish prey — was placed in sight of an immobilized fish. Again, neural signals could be seen zipping around the fish's brain, tracking the paramecium's movement. No signals were detected when the paramecium was motionless, however.
Lastly, a paramecium was placed in a dish with a zebrafish larva that was allowed to swim freely, hunting its prey. The researchers mapped the fish's brain activity as it zeroed in on the paramecium and swam toward it.
Understanding brain behavior
The new approach will improve scientists' understanding of brain circuits involved in predatory behavior, the researchers report online today (Jan. 31) in the journal Current Biology. The system could be used to image other brain areas, too, allowing scientists to observe neurons involved in behavior and locomotion.
Previously, scientists had been able to image single-cell brain activity in zebrafish, but this study was the first to do it in a freely swimming fish perceiving a natural object. "The technology for studying zebrafish is moving fast," said neuroscientist Joseph Fetcho in an email to LiveScience. Fetcho did some of the earlier imaging work but was not involved in the new study.
The closer one can get to revealing the patterns of neuronal activity in a freely behaving animal, the more likely the patterns will represent those that drive natural behavior, Fetcho said.
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