Posts tagged brain activity
Articles and news from the latest research reports.
Secrets of lasting love are hidden inside the brain
Researchers have found that they can spot the signs of a true romance in people embarking on a new relationship by looking at how much their brains light up when they think about their new partner.
The scientists detected distinctive patterns of electrical activity in the brains of volunteers who believed they had recently fallen in love, and found that they could use the scans to predict whether a couple would stay together.
The findings could end the uncertainty of courting by revealing whether a couple are likely to have a long relationship or whether their feelings will fizzle out.
The scans showed that even if someone believed they had fallen in love, the activity of their neurons could suggest whether their feelings were strong enough for them to be with the other person three years later.
Prof Arthur Aron, a social psychologist at Stony Brook University in Long Island, New York, said: “All of those involved in the study felt very intensely in love with their partner and this was reflected in their scans, but there were some subtle indicators that showed how stable those feeling were.
“If that strong feeling was combined with signs that they could regulate emotions, to see the partner positively and deal with conflict, then it seems to be really productive in staying with the person.” The psychologists, whose research was published in the journal Neuroscience Letters, found a number of key parts of the brain were involved.
Using magnetic resonance imaging, the scientists scanned 12 volunteers, seven of whom were women, who had fallen passionately in love and had been with their partner for about a year. As they were scanned, each was shown a picture of their partner and asked to think of memories of them. The participants were also asked to think about and look at pictures of an acquaintance with whom they had no romantic attachment. Three years later, the researchers compared the scans with the outcome of each relationship. Half the relationships had lasted.
The scientists found that the scans of those who were still in relationships had heightened levels of activity, when thinking of their partner, in an area of the brain that produces emotional responses to visual beauty, known as the caudate tail.
These people also had lower levels of activity in the pleasure centres of the brain that relate to addiction and seeking rewards. The scientists say deactivation in this area has been linked to satiety and satisfaction.
Another part of the brain, known as the medial orbitofrontal cortex, was also less active, which the scientists say made those people less critical and judgmental about their partners.
Aron said the research could have a practical application in helping people having relationship problems.
He said: “The brain is so complex that we are still quite a way from being able to very precisely pick out these qualities, but it does allow us to get at what is really going on inside someone aside from what they tell us.
“We may eventually get to a point where we can recognise things that the person doesn’t recognise themselves and we can say that they are not as intensely attached to a person as they think they are.”
Prof Aron added: “This probably facilitates handling the conflicts that inevitably arise when you spend a lot of time with someone. It plays a big part in keeping people together and staying satisfied.”
A fourth area known to modulate mood and self-esteem was less active in those who stayed together, something the scientists think may be linked to people forming stable and intimate bonds.
The psychologists also found they could spot signs of how happy a couple who stayed together would be in the scans taken three years earlier.
Xiaomeng Xu, the lead author of the study at Brown University in Rhode Island, said: “Factors present early in the early stages of romantic love seem to play a major role in the development and longevity of the relationship.
“Our data provides preliminary evidence that neural responses in the early stages of romantic love can predict relationship stability and quality up to 40 months later.
“The brain regions involved suggest that reward functions may be predictive for relationship stability.”
Turning repulsive feelings into desires
Hunger, thirst, stress and drugs can create a change in the brain that transforms a repulsive feeling into a strong positive “wanting,” a new University of Michigan study indicates.
The research used salt appetite to show how powerful natural mechanisms of brain desires can instantly transform a cue that always predicted a repulsive Dead Sea Salt solution into an eagerly wanted beacon or motivational magnet.
Mike Robinson, a research fellow in the U-M Department of Psychology and the study’s lead author, said the findings help explain how related brain activations in people could cause them to avidly want something that has been always disliked.
This instant transformation of motivation, he said, lies in the ability of events to activate particular brain circuitry—a structure called the nucleus accumbens, which sits near the base of the front of the brain and is also activated by addictive drugs.
Cues for rewards often trigger intense motivation. The smell of food can make a person suddenly feel hungry when this wasn’t the case earlier. Drug cues may prompt relapse in addicts trying to quit. In some cases, desires may be triggered even for a relatively unpleasant event.
Researchers studied how rats responded to metal objects that represented either pleasant sugar or disgustingly intense Dead Sea saltiness. The rats quickly learned to jump on and nibble the sweetness cue, but turned away from and avoided the saltiness cue.
But one day the rats suddenly woke up in a new state of sodium appetite induced by drugs given the night before. On their first re-encounter with the saltiness cue in the new appetite state, their brain systems became activated and the rats instantly jumped on and nibbled the saltiness cue as though it were the sugar cue.
"The cue becomes avidly ‘wanted’ despite knowledge the salt always tasted disgusting," Robinson said.
The sudden brain changes help explain how an event, such as taking an addictive drug, could become “wanted” despite a person’s knowledge of the negative and unpleasant consequences of the drug.
"Our findings highlight what it means to say that drugs hijack our natural reward system," said Robinson, who authored the new study with Kent Berridge, James Olds Collegiate Professor of Psychology and Neuroscience.
Even the brains of people with anxiety states can get used to fear
Fear is a protective function against possible dangers that is designed to save our lives. Where there are problems with this fear mechanism, its positive effects are cancelled out: patients who have a social phobia become afraid of perfectly normal, everyday social situations because they are worried about behaving inappropriately or being thought of as stupid by other people. Scientists from the Centre for Medical Physics and Biomedical Technology and the University Department of Psychiatry and Psychotherapy at the MedUni Vienna have now discovered that this fear circuit can be deactivated, at least in part.
In a study by Ronald Sladky, led by Christian Windischberger (Centre for Medical Physics and Biomedical Technology), which has recently been published in the magazine PLOS One, functional magnetic resonance tomography was used to measure the changes in the brain activity of socially phobic patients and healthy test subjects while they were looking at faces. This experiment simulates social confrontation with other people without actually placing the individual in an intolerable situation of anxiety.
Permanent confrontation has a diminishing effect on anxiety
“The study demonstrated that people with social phobia initially exhibit greater activity in the amygdala and in the medial, prefrontal cortex of the brain, however after a few faces this activity recedes,” says Sladky. This contradicts the assumption made thus far that the emotional circuit of socially phobic individuals is unable to adapt adequately to this stress-inducing situation.
Permanent confrontation with the test task not only led to a solution to the “problem” being found more quickly among the patients with anxiety, but also to some areas of the brain being bypassed which otherwise were over-stimulated, a characteristic typical of anxiety. Says Sladky: “We therefore concluded that there are functional control strategies even in the emotional circuits of people with social phobia, although the mechanisms take longer to take effect in these individuals. The misregulation of these parts of the brain can therefore be compensated to a degree.”
These findings could, according to Sladky, provide a starting point for the development of personalised training programmes that will help affected individuals to conquer unpleasant situations in their everyday lives more effectively. In Austria, around 200,000 people a year are affected by some form of social phobia. The number of people who suffer this condition without seeking help for it is likely to be very high, since many affected individuals fail to seek assistance or do so only too late as a result of their anxiety.
Brain activity study lends insight into schizophrenia
Magnetic fields produced by the naturally occurring electrical currents in the brain could potentially be used as an objective test for schizophrenia and help to better understand the disease, according to new research published today.
A team of researchers from Plymouth and Spain have used the non-invasive magnetoencephalogram (MEG) technique to find two spectral features that are significantly different in schizophrenia patients compared to healthy control subjects.
Furthermore, they found that there were four spectral features in the brain signals of schizophrenia patients that changed with age compared to healthy control subjects, suggesting that schizophrenia affects the way in which brain activity evolves with age.
The study has been published today, Thursday 31 January, in the journal Physiological Measurement.
Schizophrenia is a serious psychiatric disorder, usually starting in late adolescence, which is characterised by a range of positive and negative symptoms, including hallucinations, delusions, paranoia, cognitive impairment, social withdrawal, self-neglect and loss of motivation and initiative.
It has no objective test and is currently diagnosed by clinicians who assess patients using a defined set of criteria.
Lead author of the study Dr Javier Escudero said: “At present, there is no blood, cerebrospinal fluid, brain imaging or neurophysiological test for schizophrenia in routine clinical practice. The diagnosis relies on the interpretation of symptoms and clinical history according to consensus criteria.
"The advent of an objective marker for schizophrenia would significantly facilitate the diagnosis and offer a better understanding of the neurobiological basis of the disease."
In this study, the frequency spectrum of the MEG background activity was analysed in 15 schizophrenia patients with positive symptoms and 17 age-matched healthy control subjects.
A range of spectral features from the MEGs were analysed to provide a holistic view of the brain activity of each subject. The MEG produced 148 values for each subject, which were subsequently divided into five different groups representing different parts of the brain, and were statistically analysed.
The researchers also investigated whether the spectral features could be used to distinguish between schizophrenia patients and the healthy controls. They showed that they were able to classify patients with 71 per cent accuracy.
"The long-term vision is to develop a low-cost, non-invasive and objective test to aid the diagnosis of this and other brain diseases. The magnetoencephalogram is able to provide very detailed information about the brain activity; however, it is expensive. Therefore, we aim to transfer these developments to electroencephalogram recordings in the future, as this technique meets those requirements of reduced cost, high availability and non-invasiveness," continued Dr Escudero.
(Image: Shutterstock)
In-brain monitoring shows memory network
Working with patients with electrodes implanted in their brains, researchers at the University of California, Davis, and The University of Texas Health Science Center at Houston (UTHealth) have shown for the first time that areas of the brain work together at the same time to recall memories. The unique approach promises new insights into how we remember details of time and place.
"Previous work has focused on one region of the brain at a time," said Arne Ekstrom, assistant professor at the UC Davis Center for Neuroscience. "Our results show that memory recall involves simultaneous activity across brain regions." Ekstrom is senior author of a paper describing the work published Jan. 27 in the journal Nature Neuroscience.
Ekstrom and UC Davis graduate student Andrew Watrous worked with patients being treated for a severe seizure condition by neurosurgeon Dr. Nitin Tandon and his UTHealth colleagues.
To pinpoint the origin of the seizures in these patients, Tandon and his team place electrodes on the patient’s brain inside the skull. The electrodes remain in place for one to two weeks for monitoring.
Six such patients volunteered for Ekstrom and Watrous’ study while the electrodes were in place. Using a laptop computer, the patients learned to navigate a route through a virtual streetscape, picking up passengers and taking them to specific places. Later, they were asked to recall the routes from memory.
Correct memory recall was associated with increased activity across multiple connected brain regions at the same time, Ekstrom said, rather than activity in one region followed by another.
However, the analysis did show that the medial temporal lobe is an important hub of the memory network, confirming earlier studies, he said.
Intriguingly, memories of time and of place were associated with different frequencies of brain activity across the network. For example, recalling, “What shop is next to the donut shop?” set off a different frequency of activity from recalling “Where was I at 11 a.m.?”
Using different frequencies could explain how the brain codes and recalls elements of past events such as time and location at the same time, Ekstrom said.
"Just as cell phones and wireless devices work at different radio frequencies for different information, the brain resonates at different frequencies for spatial and temporal information," he said.
The researchers hope to explore further how the brain codes information in future work.
The neuroscientists analyzed their results with graph theory, a new technique that is being used for studying networks, ranging from social media connections to airline schedules.
"Previously, we didn’t have enough data from different brain regions to use graph theory. This combination of multiple readings during memory retrieval and graph theory is unique," Ekstrom said.
Placing electrodes inside the skull provides clearer resolution of electrical signals than external electrodes, making the data invaluable for the study of cognitive functions, Tandon said. “This work has yielded important insights into the normal mechanisms underpinning recall, and provides us with a framework for the study of memory dysfunction in the future.”
Tests conducted on Israel’s Ariel Sharon reveal significant brain activity
A team of American and Israeli brain scientists tested former Israeli Prime Minister Ariel Sharon to assess his brain responses, using functional magnetic resonance imaging (fMRI). Surprisingly, Sharon showed significant brain activity.
The team consisted of Martin Monti, an assistant professor of psychology and neurosurgery at UCLA, professors Alon Friedman, Galia Avidan and Tzvi Ganel of the Zlotowski Center for Neuroscience at Israel’s Ben-Gurion University of the Negev, and Dr. Ilan Shelef, head of medical imaging at Israel’s Soroka University Medical Center.
The 84-year-old Sharon, presumed to be in a vegetative state since suffering a brain hemorrhage in 2006, was scanned last week to assess the extent and quality of his brain processing, using methods recently developed by Monti and his colleagues. The test lasted approximately two hours.
The scientists showed Sharon pictures of his family, had him listen to his son’s voice and used tactile stimulation to assess the extent to which his brain responded to external stimuli.
To their surprise, significant brain activity was observed in each test, in specific brain regions, indicating appropriate processing of these stimulations, Monti said.
The scientists conducted three tests to assess Sharon’s level of consciousness. They asked him to imagine he was hitting a tennis ball and to imagine he was walking through the rooms of his home. They also showed him a photograph of a face superimposed on a photo of a house, asking him to focus first on the face and then on the house. The scientists found encouraging, but subtle, signs of consciousness.
"Information from the external world is being transferred to the appropriate parts of Mr. Sharon’s brain. However, the evidence does not as clearly indicate whether Mr. Sharon is consciously perceiving this information," Monti said. "We found faint brain activity indicating that he was complying with the tasks. He may be minimally conscious, but the results were weak and should be interpreted with caution."
Tzvi Ganel, who initiated the project, stressed that Sharon’s family wished to employ these new techniques not only for the benefit of the former prime minister but also for other families in a similar situation.
New research uncovers the neural mechanism underlying drug cravings
Addiction may result from abnormal brain circuitry in the frontal cortex, the part of the brain that controls decision-making. Researchers from the RIKEN Center for Molecular Imaging Science in Japan collaborating with colleagues from the Montreal Neurological Institute of McGill University in Canada report today that the lateral and orbital regions of the frontal cortex interact during the response to a drug-related cue and that aberrant interaction between the two frontal regions may underlie addiction. Their results are published today in the journal Proceedings of the National Academy of Sciences of the USA.
Cues such as the sight of drugs can induce cravings and lead to drug-seeking behaviors and drug use. But cravings are also influenced by other factors, such as drug availability and self-control. To investigate the neural mechanisms involved in cue-induced cravings the researchers studied the brain activity of a group of 10 smokers, following exposure to cigarette cues under two different conditions of cigarette availability. In one experiment cigarettes were available immediately and in the other they were not. The researchers combined a technique called transcranial magnetic stimulation (TMS) with functional magnetic resonance imaging (fMRI).
The results demonstrate that in smokers the orbitofrontal cortex (OFC) tracks the level of craving while the dorsolateral prefrontal cortex (DPFC) is responsible for integrating drug cues and drug availability. Moreover, the DPFC has the ability to suppress activity in the OFC when the cigarette is unavailable. When the DPFC was inactivated using TMS, both craving and craving-related signals in the OFC became independent of drug availability.
The authors of the study conclude that the DLPFC incorporates drug cues and knowledge on drug availability to modulate the value signals it transmits to the OFC, where this information is transformed into drug-seeking action.
"We demonstrate that in smokers, cravings build up in the OFC upon processing of cigarette cues and availability by the DFPC. What is surprising is that this is a neural circuit involved in decision making and self-control, that normally guides individuals to optimal behaviors in daily life." Explains Dr. Hayashi, from RIKEN, who designed and conducted the fMRI and TMS experiments.
"This research uncovers the brain circuitry responsible for self-control during reward-seeking choices. It is also consistent with the view that drug addiction is a pathology of decision making." According to Dr. Alain Dagher, a neurologist at the Montreal Neurological Institute.
These findings will help understand the neural basis of addiction and may contribute to a therapeutic approach for addiction.
(Image: New Jersey Addiction Assistance)
When the mind controls the machines
Stroke survivors, as well as patients suffering from other serious conditions, may have to deal with the partial or complete inability to move one or more of their limbs. In the most severe cases, the sufferer may become fully paralyzed and in need of permanent assistance.
The TOBI project (Tools for brain-computer interaction) is financed by the European Commission under the Seventh Framework Programme for Research (FP7) and is coordinated by EPFL. Since 2008 it has focused on the use of the signals transmitted by the brain. The electrical activity that takes place in the brain when the patient focuses on a particular task such as lifting an arm is detected by electroencephalography (EEG) through electrodes placed in a cap worn by the patient. Subsequently, a computer reads the signals and turns them into concrete actions as, for instance, moving a cursor on a screen.
Tests involving more than 100 patients
Based on this idea, researchers from thirteen institutions together with TOBI project partners have developed various technologies aimed at either obtaining better signal quality, making them clearer, or translating them into useful and functional applications. During the research, more than 100 patients or handicapped users had the opportunity to test the devices. Three of the technologies developed within the framework of TOBI were publicly presented at the closing seminar of the research program that took place in Sion from 23 to 25 January 2013.
- Robotino, for helping rebuild social ties when bedridden. Combining EEG, signal recognition, obstacle sensors and the internet, researchers have been able to develop a small robot equipped with a camera and a screen that can be controlled remotely by physically disabled people. Thanks to this device, the patient can take a virtual walk in a familiar environment, meet her/his relatives and talk to them, even if they are thousands of miles away from each other.
- Braintree, for writing texts and internet surfing. Researchers have also developed a graphical interface specially adapted for web browsing by severely disabled people. By thinking, the patient is able to move a cursor in a tree structure in order to type a character or choose a command. Depending on the specific situation, the sensors can also detect residual muscular activity to complement the management of the device.
- Functional electrical stimulation, to restore some basic mobility. Coupling EEG with electrical muscle stimulation can allow a patient to voluntarily control the movement of a paralyzed limb. In some cases, intensive training using this system has allowed the patients to regain control of the limb and keep it without assistance. A report on this technique can be seen in this video.
The results of the TOBI research program have restored patients’ hope. They will constitute the basis of subsequent developments to be conducted among the research partners or at industrial level. As for EPFL, such results will be the core of its health research chairs at the new EPFL Valais Wallis academic cluster, which can also count on the participation and support of the SuvaCare rehabilitation clinic in Sion.
Science Needs a Second Opinion: Researchers Find Flaws in Study of Patients in “Vegetative State”
A team of researchers led by Weill Cornell Medical College is calling into question the published statistics, methods and findings of a highly publicized research study that claimed bedside electroencephalography (EEG) identified evidence of awareness in three patients diagnosed to be in a vegetative state.
The new reanalysis study led by Weill Cornell neurologists Drs. Andrew Goldfine, Jonathan Victor, and Nicholas Schiff, published in the Jan. 26 issue of the journal Lancet, reports the statistical results and methodology used by a research team led by University of Western Ontario scientists and published online Nov. 9, 2011, also in the Lancet, was flawed in a number of crucial ways. Due to these errors, the reanalysis concludes it is impossible to determine whether or not these vegetative state study subjects demonstrated any degree of awareness during the testing.
(Image: RightBrainPhotography)
Socially Isolated Rats are More Vulnerable to Addiction
Rats that are socially isolated during a critical period of adolescence are more vulnerable to addiction to amphetamine and alcohol, found researchers at The University of Texas at Austin. Amphetamine addiction is also harder to extinguish in the socially isolated rats.
These effects, which are described this week in the journal Neuron, persist even after the rats are reintroduced into the community of other rats.
“Basically the animals become more manipulatable,” said Hitoshi Morikawa, associate professor of neurobiology in the College of Natural Sciences. “They’re more sensitive to reward, and once conditioned the conditioning takes longer to extinguish. We’ve been able to observe this at both the behavioral and neuronal level.”
Morikawa said the negative effects of social isolation during adolescence have been well documented when it comes to traits such as anxiety, aggression, cognitive rigidity and spatial learning. What wasn’t clear until now is how social isolation affects the specific kind of behavior and brain activity that has to do with addiction.
“Isolated animals have a more aggressive profile,” said Leslie Whitaker, a former doctoral student in Morikawa’s lab and now a researcher at the National Institute on Drug Abuse. “They are more anxious. Put them in an open field and they freeze more. We also know that those areas of the brain that are more involved in conscious memory are impaired. But the kind of memory involved in addiction isn’t conscious memory. It’s an unconscious preference for the place in which you got the reward. You keep coming back to it without even knowing why. That kind of memory is enhanced by the isolation.”