Posts tagged brain activity
Articles and news from the latest research reports.
Nerve stimulation for severe depression changes brain function
For nearly a decade, doctors have used implanted electronic stimulators to treat severe depression in people who don’t respond to standard antidepressant therapy.
Now, preliminary brain scan studies conducted by researchers at Washington University School of Medicine in St. Louis are beginning to reveal the processes occurring in the brain during stimulation and may provide some clues about how the device improves depression. They found that vagus nerve stimulation brings about changes in brain metabolism weeks or even months before patients begin to feel better.
The findings will appear in an upcoming issue of the journal Brain Stimulation and are now available online.
“Previous studies involving large numbers of people have demonstrated that many with treatment-resistant depression improve with vagus nerve stimulation,” said first author Charles R. Conway, MD, associate professor of psychiatry. “But little is known about how this stimulation works to relieve depression. We focused on specific brain regions known to be connected to depression.”
Conway’s team followed 13 people with treatment-resistant depression. Their symptoms had not improved after many months of treatment with as many as five different antidepressant medications. Most had been depressed for at least two years, but some patients had been clinically depressed for more than 20 years.
All of the participants had surgery to insert a device to electronically stimulate the left vagus nerve, which runs down the side of the body from the brainstem to the abdomen. Once activated, the device delivers a 30-second electronic stimulus to the vagus nerve every five minutes.
To establish the nature of the treatment’s effects on brain activity, the researchers performed positron emission tomography (PET) brain imaging before the initiation of stimulation, and again three and 12 months after stimulation had begun.
Eventually, nine of the 13 subjects experienced improvements in depression with the treatment. However, in most cases it took several months for improvement to occur.
Remarkably, in those who responded, the scans showed significant changes in brain metabolism following three months of stimulation, which typically preceded improvements in symptoms of depression by several months.
“We saw very large changes in brain metabolism occurring far in advance of any improvement in mood,” Conway said. “It’s almost as if there’s an adaptive process that occurs. First, the brain begins to function differently. Then, the patient’s mood begins to improve.”
Although the patients remained on antidepressants for several months after their stimulators were implanted, Conway says many of those who responded to the device eventually were able to stop taking medication.
“Sometimes the antidepressant drugs work in concert with the stimulator, but it appears to us that when people get better, it is the vagus nerve stimulator that is doing the heavy lifting,” Conway explained. “Stimulation seems to be responsible for most of the improvement we see.”
Additionally, the PET scans demonstrated that structures deeper in the brain also begin to change several months after nerve stimulation begins. Many of those structures have high concentrations of brain cells that release dopamine, a neurotransmitter that helps control the brain’s reward and pleasure centers and also helps regulate emotional responses.
There is a consensus forming among depression researchers that problems in dopamine pathways may be particularly important in treatment-resistant depression, according to Conway. And he said the finding that vagus nerve stimulators influence those pathways may explain why the therapy can help and why, when it works, its effects are not transient. Patients who respond to vagus nerve stimulation tend to get better and stay better.
“We hypothesized that something significant had to be occurring in the brain, and our research seems to back that up,” he said.
Brainwaves reflect ability to beat built-in bias
Many animals, including humans, harbor ingrained biases to act when they can obtain rewards and to remain inactive to avoid punishment. Sometimes, however those biases can steer us wrong. A new study finds that theta brainwave activity in the prefrontal cortex predicts how well people can overcome these biases when a better choice are available.
Vertebrates are predisposed to act to gain rewards and to lie low to avoid punishment. Try to teach chickens to back away from food in order to obtain it, and you’ll fail, as researchers did in 1986. But humans are better thinkers than chickens. In the May 8 edition of the Journal of Neuroscience, researchers show that the level of theta brainwave activity in the prefrontal cortex predicts whether people will be able to overcome these ingrained biases when doing so is required to achieve a goal.
The study helps explain a distinctly human mechanism of cognition, said the lead researchers at Brown University, and could be applied to studying and treating reward-seeking or punishment-avoidance conditions such as addiction or obsessive-compulsive disorder.
Despite how we have evolved, life doesn’t always encourage acting to gain reward or freezing to avoid punishment. Sometimes we must restrain ourselves to gain a reward (baseball batters can get on base by not swinging at bad pitches) or take action to avoid a penalty (tax cheaters can come forward during amnesties). Acting counter to our ingrained Pavlovian biases is a matter of the brain recognizing the conflict between the rational course of action and the instinct.
“We have suggested that more advanced brain mechanisms in the prefrontal are needed to exert cognitive control over behavior in these circumstances,” said Michael Frank, associate professor of cognitive, linguistic and psychological sciences and the paper’s senior author. “This study provides evidence that temporally specific brain activity within the prefrontal cortex is related to this ability, both between and within individuals.”
Human vs. bias
That brain activity could be measured and quantified as theta brainwaves. Brown postdoctoral researcher James Cavanagh led the research in which he recruited 34 people to play a custom-designed computer game while wearing EEG scalp monitors.
The game involved four scenarios, all reinforced by putting a little real money on the line: the instinctual scenarios of clicking for a reward and not clicking to avoid a penalty, and the trickier scenarios of clicking to avoid penalty and not clicking to gain a reward.
Over many rounds, players tried to learn what to do when presented with one of four distinct symbols, each of which corresponded to a different scenario.
Cavanagh programmed the scenarios usually, but not always, to reward the proper behavior. For this reason, people had to pay attention to what was likely, rather than merely memorize a simple reliable pattern.
Cavanagh and his co-authors measured how well people learned the proper action for each scenario. With the advantage of instinct, almost everyone learned to click for a reward. Most people also managed to learn not to click to avoid penalty and even managed in similar numbers to click to avoid penalty. Like the chickens, however, significantly fewer people could restrain themselves in order to gain a reward.
Those who were bad at overcoming one Pavlovian bias were much more likely to fail at the other.
While the subjects were playing the game, the experimenters also measured theta brainwave activity in each subject’s prefrontal cortex — for instance at the exact moment they saw the distinct symbols of the tasks.
The main idea of the study was to correlate the subjects’ theta brain activity during the tasks with their ability to overcome ingrained bias when appropriate. Sure enough, the subject’s ability to repress Pavlovian bias was predicted by the enhancement of theta during the trials when the bias was unwanted, compared to when it provided proper guidance.
“Some people are really good at it and some are not, and we were able to predict that from their brain activity,” Cavanagh said.
This was not only true when comparing individual subjects, but also when comparing the subjects to themselves at different times (e.g., some subjects’ abilities wavered from task to task and the theta varied right along).
Many psychological factors could have confounded the results — differential sensitivity to gains and losses, for example – but Cavanagh and Frank controlled for those with the help of a sophisticated computer model that accounts for and statistically disentangles the relationship of bias and theta from those other influences.
Our better nature
All of the study subjects were screened to ensure they were psychiatrically healthy. In these subjects, the study results not only confirmed that people harbor the ingrained biases, but that they differ in their ability to overcome them. Frank said the variations likely come from innate and situational factors. Evidence suggests that the degree of ingrained bias may have genetic and neurological roots, he said, but can also vary within the same individual based on factors such as fatigue or stress.
For people with psychiatric disorders, Cavanagh said, the predictive value of measurable theta activity for behavioral patterns could become an important tool for diagnosis and predicting treatment outcomes.
Frank, who is affiliated with the Brown Institute for Brain Science, added that the lab has begun studying whether people can improve behavior by purposely modulating theta activity. If so, that could lead to a therapy for addiction.
“We are beginning studies that allow us to safely manipulate activity in specific frequencies like theta in the frontal cortex which will allow us to assess the causal role these signals may be playing,” he said.
It’s not easy to work against primal intuition, but people have that ability and now researchers know how that ability is reflected in brains.
“This tells us a lot about the neurobiology of why we’re special,” Cavanagh said.
Kids with brains that under-react to painful images
When children with conduct problems see images of others in pain, key parts of their brains don’t react in the way they do in most people. This pattern of reduced brain activity upon witnessing pain may serve as a neurobiological risk factor for later adult psychopathy, say researchers who report their findings in the Cell Press journal Current Biology on May 2.
(Image: Shutterstock)
That’s not to say that all children with conduct problems are the same, or that all children showing this brain pattern in young life will become psychopaths. The researchers emphasize that many children with conduct problems do not persist with their antisocial behavior.
"Our findings indicate that children with conduct problems have an atypical brain response to seeing other people in pain," says Essi Viding of University College London. "It is important to view these findings as an indicator of early vulnerability, rather than biological destiny. We know that children can be very responsive to interventions, and the challenge is to make those interventions even better, so that we can really help the children, their families, and their wider social environment."
Conduct problems represent a major societal problem and include physical aggression, cruelty to others, and a lack of empathy, or “callousness.” In the United Kingdom, where the study was conducted, about five percent of children qualify for a diagnosis of conduct problems. But very little is known about the underlying biology.
In the new study, Viding, Patricia Lockwood, and their colleagues scanned children’s brains by functional magnetic resonance imaging (fMRI) to see how those with conduct problems differ in their response to viewing images of others in pain.
The brain images showed that, relative to controls, children with conduct problems show reduced responses to others’ pain specifically in regions of the brain known to play a role in empathy. The researchers also saw variation among those with conduct problems, with those deemed to be more callous showing lower brain activation than less callous individuals.
"Our findings very clearly point to the fact that not all children with conduct problems share the same vulnerabilities; some may have neurobiological vulnerability to psychopathy, while others do not," Viding says. "This raises the possibility of tailoring existing interventions to suit the specific profile of atypical processing that characterizes a child with conduct problems."
(Source: eurekalert.org)
Implanted device predicts oncoming seizures in those with epilepsy
A new device may offer hope to people with epilepsy as the technology could predict the onset of seizures in adults who have the condition and can’t be treated with medication, according to Australian scientists.
The small device is implanted in the brain. Researchers at the University of Melbourne said their proof-of-concept study found that it can successfully detect brain activity that would lead to episodes of seizures.
“Knowing when a seizure might happen could dramatically improve the quality of life and independence of people with epilepsy and potentially allow them to avoid dangerous situations, such as driving or swimming, or to take drugs to stop the seizures before they start,” Dr. Mark Cook said.
“The first thing of this was to give people back some independence. If they know when a seizure is going to happen, they can arrange their lives to be better, make themselves safer, go about work and so on in a much more comfortable and relaxed way.”
His complete findings were published Thursday night in the prestigious journal, Lancet Neurology.
Epilepsy is a physical condition marked by sudden, brief changes in the brain’s functioning.
The unusual activity in the brain causes patients to have recurring, unprovoked seizures.
There is a wide spectrum when identifying a seizure, from convulsions on one end to tuning out for just a few seconds before returning to regular activities.
Device monitors abnormal brain activity in patients
In the study, 15 people with focal epilepsy between the ages of 20 and 62 had the device implanted between the skull and brain surface.
The study participants typically experienced between two and 12 seizures per month. Although most cases of epilepsy can be treated with medication, theirs was not responsive to at least two drug therapies.
The device, developed by Seattle-based company NeuroVista, monitors electrical activity in the brain.
Once abnormal electrical activity is flagged, the device sends a message to a second device implanted under the skin of the chest similar to a pacemaker.
The information then makes its way to a wireless, hand-held device that calculates the likelihood of a seizure.
Three coloured lights – red, white or blue – warn users of the probability of encountering a seizure.
The researchers found that the system was right about “high warning” of seizures more than 65 per cent of the time and in about 11 of the 15 subjects.
Eight of the patients kept the device activated for about four months – the accuracy ranged from 56 to 100 per cent.
However, three patients had serious side effects, with two needing the device to be removed.
Cook said the findings are promising. If they’re replicated in larger, longer studies, the technology could even offer insight into how to prevent seizures using fast-acting drugs or brain stimulation to stifle a seizure.
Professor finds neuroscience provides insights into brains of complex and adaptive leaders
“This study represents a fusion of the leadership and neuroscience fields, and this fusion can revolutionize approaches to assessing and developing leaders,” says Hannah, the Tylee Wilson Chair in business ethics and professor of management at the Wake Forest University School of Business. Hannah is lead author of the paper in the May 2013 Journal of Applied Psychology titled, “The Psychological and Neurological Bases of Leader Self-Complexity and Effects on Adaptive Decision-Making.”
Hannah and four colleagues tested 103 young military leaders between the ranks of officer cadet and major at a U.S. Army base on the east coast. They administered psychological exams to assess the complexity of leaders’ identities, and neurological exams to assess the complexity of soldiers’ brain activity. For the brain tests, the researchers attached quantitative electroencephalogram (qEEG) electrodes to 19 areas of the soldier’s scalp.
Hannah and his fellow researchers wanted to know if great leaders had more complex brains – measured by the electrodes which reported which parts of the brain were firing together at the same time. A low complex brain shows more areas of the brain operating at the same time at the same electrical amplitude and frequency – which suggests those areas converge to process the same task leaving fewer brain resources for other tasks and processes. It’s a process called “phase lock.”
But in high complex brains, the activity patterns are much more different and varied – which suggests more of the brains resources are available at any one time to handle other situations or tasks.
“Think of it as a single core versus a multicore computer’s central processing unit (CPU),” Hannah says. “A multicore CPU can multitask because one core can process a task while the other CPU cores remain free to process new tasks. More complex brains are also more efficient in locking together only the brain resources needed to process a task and then efficiently releasing them when no longer needed.”
The study showed the high complex brains of the great leaders had a different “landscape.” The scans showed more differentiated activation patterns in the frontal and prefrontal lobes of leaders who demonstrated greater decisiveness, adaptive thinking and positive action orientation in the experiment.
“Further, individuals who have developed richer and more elaborate self-concepts as leaders were found to be more complex and adaptable,” Hannah says. “These findings have important implications for identifying and developing leaders who can lead effectively in today’s changing, dynamic, and often volatile organizational contexts.”
The researcher team suggests that once they validate neurological profiles of leaders with high complex brains, they will be able to use established techniques like neuro-feedback to enhance these leadership skills in others. Neuro-feedback has been successfully used with elite athletes, concert musicians and financial traders in their training. These profiles can also be used to assess leaders and track their development over time.
These findings have relevance to the WFU Schools of Business’ new student development framework, which focuses on developing practical wisdom, strategic thinking and critical thinking skills, along with the ability to embrace complexity and ambiguity.
Hannah’s co-authors include Pierre Balthazard, dean of the School of Business at Saint Bonaventure University; David A. Waldman, professor of business at Arizona State University; Peter L. Jennings, of the Center for the Army Profession and Ethic at West Point; and Robert W. Thatcher of the University of South Florida.
This research team is at the forefront of applying neuroscience to study effective leadership. The team previously published a 2012 paper in the Leadership Quarterly, which identified unique brain functioning in leaders who are seen by their followers as highly inspirational and charismatic.
(Source: healthmedicinet.com)
People are often called upon to witness, and to empathize with, the pain and suffering of others. In the current study, we directly compared neural responses to others’ physical pain and emotional suffering by presenting participants (n = 41) with 96 verbal stories, each describing a protagonist’s physical and/or emotional experience, ranging from neutral to extremely negative. A separate group of participants rated “how much physical pain”, and “how much emotional suffering” the protagonist experienced in each story, as well as how “vivid and movie-like” the story was. Although ratings of Pain, Suffering and Vividness were positively correlated with each other across stories, item-analyses revealed that each scale was correlated with activity in distinct brain regions. Even within regions of the “Shared Pain network” identified using a separate data set, responses to others’ physical pain and emotional suffering were distinct. More broadly, item analyses with continuous predictors provided a high-powered method for identifying brain regions associated with specific aspects of complex stimuli – like verbal descriptions of physical and emotional events.
Energy Efficient Brain Simulator Outperforms Supercomputers
In November 2012, IBM announced that it had used the Blue Gene/Q Sequoia supercomputer to achieve an unprecedented simulation of more than 530 billion neurons. The Blue Gene/Q Sequoia accomplished this feat thanks to its blazing fast speed; it clocks in at over 16 quadrillion calculations per second. In fact, it currently ranks as the second-fastest supercomputer in the world.
But, according to Kwabena Boahen, Ph.D., the Blue Gene still doesn’t compare to the computational power of the brain itself.
"The brain is actually able to do more calculations per second than even the fastest supercomputer," says Boahen, a professor at Stanford University, director of the Brains in Silicon research laboratory and an NSF Faculty Early Career grant recipient.
That’s not to say the brain is faster than a supercomputer. In fact, it’s actually much slower. The brain can do more calculations per second because it’s “massively parallel,” meaning networks of neurons are working simultaneously to solve a great number of problems at once. Traditional computing platforms, no matter how fast, operate sequentially, meaning each step must be complete before the next step is begun.
Boahen works at the forefront of a field called neuromorphic engineering, which seeks to replicate the brain’s extraordinary computational abilities using innovative hardware and software applications. His laboratory’s most recent accomplishment is a new computing platform called Neurogrid, which simulates the activity of 1 million neurons.
Neurogrid is not a supercomputer. It can’t be used to simulate the big bang, or forecast hurricanes, or predict epidemics. But what it can do sets it apart from any computational platform on earth.
Neurogrid is the first simulation platform that can model a million neurons in real time. As such, it represents a powerful tool for investigating the human brain. In addition to providing insight into the normal workings of the brain, it has the potential to shed light on complex brain diseases like autism and schizophrenia, which have so far been difficult to model.
The proven ability to simulate brain function in real time has, so far, been underwhelming. For example, the Blue Gene/Q Sequoia supercomputer’s simulation took over 1,500 times longer than it would take the brain to do the same activity.
Cheaper brain simulation platforms that combine the computing power of traditional central processing units (CPUs) with graphical processing units (GPUs) and field programmable gate arrays (FPGAs) to achieve results comparable to the Blue Gene are emerging on the market. However, while these systems are more affordable, they are still frustratingly slower than the brain.
As Boahen puts it, “The good news is now you too can have your own supercomputer. The bad news is now you too can wait an hour to simulate a second of brain activity.”
When you consider that the simulations sometimes need to be checked, tweaked, re-checked and run again hundreds of times, the value of a system that can replicate brain activity in real time becomes obvious.
"Neurogrid doesn’t take an hour to simulate a second of brain activity," says Boahen. "It takes a second to simulate a second of brain activity."
Each of Neurogrid’s 16 chips contains more than 65,000 silicon “neurons” whose activity can be programmed according to nearly 80 parameters, allowing the researchers to replicate the unique characteristics of different types of neurons. Soft-wired “synapses” crisscross the board, shuttling signals between every simulated neuron and the thousands of neurons it is networked with, effectively replicating the electrical chatter that constitutes communication in the brain.
But the fundamental difference between the way traditional computing systems model the brain and the way Neurogrid works lies in the way the computations are performed and communicated throughout the system.
Most computers, including supercomputers, rely on digital signaling, meaning the computer carries out instructions by essentially answering “true” or “false” to a series of questions. This is similar to how neurons communicate: they either fire an action potential, or they don’t.
The difference is that the computations that underlie whether or not a neuron fires are driven by continuous, non-linear processes, more akin to an analog signal. Neurogrid uses an analog signal for computations, and a digital signal for communication. In doing so, it follows the same hybrid analog-digital approach as the brain.
In addition to its superior simulations, it also uses a fraction of the energy of a supercomputer. For example, the Blue Gene/Q Sequoia consumes nearly 8 megawatts of electricity, enough to power over 160,000 homes. Eight megawatts at $0.10/kWh is $800 an hour, or a little over $7 million a year.
Neurogrid, on the other hand, operates on a paltry 5 watts, the amount of power used by a single cell phone charger.
Ultimately, Neurogrid represents a cost-effective, energy-efficient computing platform that Boahen hopes will revolutionize our understanding of the brain.
For more information about this project, check out Dr. Boahen’s website.
E-tattoo monitors brainwaves and baby bump
Mind reading can be as simple as slapping a sticker on your forehead. An “electronic tattoo” containing flexible electronic circuits can now record some complex brain activity as accurately as an EEG. The tattoo could also provide a cheap way to monitor a developing fetus.
The first electronic tattoo appeared in 2011, when Todd Coleman at the University of California, San Diego, and colleagues designed a transparent patch containing electronic circuits as thin as a human hair. Applied to skin like a temporary tattoo, these could be used to monitor electrophysiological signals associated with the heart and muscles, as well as rudimentary brain activity.
To improve its usefulness, Coleman’s group has now optimised the placement of the electrodes to pick up more complex brainwaves. They have demonstrated this by monitoring so-called P300 signals in the forebrain. These appear when you pay attention to a stimulus. The team showed volunteers a series of images and asked them to keep track of how many times a certain object appeared. Whenever volunteers noticed the object, the tattoo registered a blip in the P300 signal.
The tattoo was as good as conventional EEG at telling whether a person was looking at the target image or another stimulus, the team told a recent Cognitive Neuroscience Society meeting in San Francisco.
The team is now modifying the tattoo to transmit data wirelessly to a smartphone, Coleman says. Eventually, he hopes the device could identify other complex patterns of brain activity, such as those that might be used to control a prosthetic limb.
For now, the group is focusing on optimising the tattoo for use in conditions such as depression and Alzheimer’s disease, each of which have characteristic patterns of neural activity. People with depression could wear the tattoo for an extended period, allowing it to help gauge whether medication is working. “The number one advantage is the medical ease of application,” says Michael Pitts of Reed College in Portland, Oregon.
Because its electronic components are already mass-produced, the tattoo can also be made very cheaply.
That means it might also lend itself to pregnancy monitoring in developing countries. With help from the Bill & Melinda Gates Foundation, Coleman’s group is working on an unobtrusive version of the tattoo that monitors signals such as maternal contractions and fetal heart rate.
Psychopaths are not neurally equipped to have concern for others
Prisoners who are psychopaths lack the basic neurophysiological “hardwiring” that enables them to care for others, according to a new study by neuroscientists at the University of Chicago and the University of New Mexico.
“A marked lack of empathy is a hallmark characteristic of individuals with psychopathy,” said the lead author of the study, Jean Decety, the Irving B. Harris Professor in Psychology and Psychiatry at UChicago. Psychopathy affects approximately 1 percent of the United States general population and 20 percent to 30 percent of the male and female U.S. prison population. Relative to non-psychopathic criminals, psychopaths are responsible for a disproportionate amount of repetitive crime and violence in society.
“This is the first time that neural processes associated with empathic processing have been directly examined in individuals with psychopathy, especially in response to the perception of other people in pain or distress,” he added.
The results of the study, which could help clinical psychologists design better treatment programs for psychopaths, are published in the article, “Brain Responses to Empathy-Eliciting Scenarios Involving Pain in Incarcerated Individuals with Psychopathy,” which appears online April 24 in the journal JAMA Psychiatry.
Joining Decety in the study were Laurie Skelly, a graduate student at UChicago; and Kent Kiehl, professor of psychology at the University of New Mexico.
For the study, the research team tested 80 prisoners between ages 18 and 50 at a correctional facility. The men volunteered for the test and were tested for levels of psychopathy using standard measures.
They were then studied with functional MRI technology, to determine their responses to a series of scenarios depicting people being intentionally hurt. They were also tested on their responses to seeing short videos of facial expressions showing pain.
The participants in the high psychopathy group exhibited significantly less activation in the ventromedial prefrontal cortex, lateral orbitofrontal cortex, amygdala and periaqueductal gray parts of the brain, but more activity in the striatum and the insula when compared to control participants, the study found.
The high response in the insula in psychopaths was an unexpected finding, as this region is critically involved in emotion and somatic resonance. Conversely, the diminished response in the ventromedial prefrontal cortex and amygdala is consistent with the affective neuroscience literature on psychopathy. This latter region is important for monitoring ongoing behavior, estimating consequences and incorporating emotional learning into moral decision-making, and plays a fundamental role in empathic concern and valuing the well-being of others.
“The neural response to distress of others such as pain is thought to reflect an aversive response in the observer that may act as a trigger to inhibit aggression or prompt motivation to help,” the authors write in the paper.
“Hence, examining the neural response of individuals with psychopathy as they view others being harmed or expressing pain is an effective probe into the neural processes underlying affective and empathy deficits in psychopathy,” the authors wrote.
Decety is one of the world’s leading experts on the biological underpinnings of empathy. His work also focuses on the development of empathy and morality in children.
Researchers from the Perelman School of Medicine at the University of Pennsylvania have shown that an area of the brain that initiates behavioral changes had greater activation in smokers who watched anti-smoking ads with strong arguments versus those with weaker ones, and irrespective of flashy elements, like bright and rapidly changing scenes, loud sounds and unexpected scenario twists. Those smokers also had significantly less nicotine metabolites in their urine when tested a month after viewing those ads, the team reports in a new study published online April 23 in the Journal of Neuroscience.
This is the first time research has shown an association between cognition and brain activity in response to content and format in televised ads and behavior.
In a study of 71 non-treatment-seeking smokers recruited from the Philadelphia area, the team, led by Daniel D. Langleben, M.D., a psychiatrist in the Center for Studies of Addiction at Penn Medicine, identified key brain regions engaged in the processing of persuasive communications using fMRI, or functional magnetic resonance imaging. They found that a part of the brain involved in future behavioral changes—known as the dorsomedial prefrontal cortex (dMPFC)—had greater activation when smokers watched an anti-smoking ad with a strong argument versus a weak one.
One month after subjects watched the ads, the researchers sampled smokers’ urine cotinine levels (metabolite of nicotine) and found that those who watched the strong ads had significantly less cotinine in their urine compared to their baseline versus those who watched weaker ads.
Even ads riddled with attention-grabbing tactics, the research suggests, are not effective at reducing tobacco intake unless their arguments are strong. However, ads with flashy editing and strong arguments, for example, produced better recognition.
“We investigated the two major dimensions of any piece of media, content and format, which are both important here,” said Dr. Langleben, who is also an associate professor in the department of Psychiatry. “If you give someone an unconvincing ad, it doesn’t matter what format you do on top of that. You can make it sensational. But in terms of effectiveness, content is more important. You’re better off adding in more sophisticated editing and other special effects only if it is persuasive.”
The paper may enable improved methods of design and evaluation of public health advertising, according to the authors, including first author An-Li Wang, PhD, of the Annenberg Public Policy Center at the University of Pennsylvania. And it could ultimately influence how producers shape the way ads are constructed, and how ad production budgets are allocated, considering special effects are expensive endeavors versus hiring screenwriters.
A 2009 study by Dr. Langleben and colleagues that looked solely at format found people were more likely to remember low-key, anti-smoking messages versus attention-grabbing messages. This was the first research to show that low-key versus attention-grabbing ads stimulated different patterns of activity, particularly in the frontal cortex and temporal cortex. But it did not address content strength or behavioral changes.
This new study is the first longitudinal investigation of the cognitive, behavioral, and neurophysical response to the content and format of televised anti-smoking ads, according to the authors.
“This sets the stage for science-based evaluation and design of persuasive public health advertising,” said Dr. Langleben. “An ad is only as strong as its central argument, which matters more than its audiovisual presentation. Future work should consider supplementing focus groups with more technology-heavy assessments, such as brain responses to these ads, in advance of even putting the ad together in its entirety.”