Posts tagged decision making
Articles and news from the latest research reports.
Almost everyone knows the feeling: you see a delicious piece of chocolate cake on the table, but as you grab your fork, you think twice. The cake is too fattening and unhealthy, you tell yourself. Maybe you should skip dessert.
But the cake still beckons.
In order to make the healthy choice, we often have to engage in this kind of internal struggle. Now, scientists at the California Institute of Technology (Caltech) have identified the neural processes at work during such self-regulation—and what determines whether you eat the cake.
"We seem to have independent systems capable of guiding our decisions, and in situations like this one, these systems may compete for control of what we do," says Cendri Hutcherson, a Caltech postdoctoral scholar who is the lead author on a new paper about these competing brain systems, which will be published in the September 26 issue of The Journal of Neuroscience.
Neuroscientists Investigate Lotteries to Study How the Brain Evaluates Risk
People are faced with thousands of choices every day, some inane and some risky. Scientists know that the areas of the brain that evaluate risk are the same for each person, but what makes the value assigned to risk different for individuals?
To answer this question, a new video article in Journal of Visualized Experiments (JoVE) uses functional magnetic resonance imaging (fMRI) to characterize subjective risk assessment while subjects choose between different lotteries to play.
The article, a joint effort from laboratories at Yale School of Medicine and New York University, is led by Yale’s Dr. Ifat Levy. Dr. Levy explains, “This procedure allows us to examine all kinds of normal and pathological behaviors focusing on risk assessment. It could explain things like substance abuse and over-eating from a different perspective than how it is usually characterized.”
Researchers have taken a key step towards recovering specific brain functions in sufferers of brain disease and injuries by successfully restoring the decision-making processes in monkeys.
By placing a neural device onto the front part of the monkeys’ brains, the researchers, from Wake Forest Baptist Medical Centre, University of Kentucky and University of Southern California, were able to recover, and even improve, the monkeys’ ability to make decisions when their normal cognitive functioning was disrupted.
The study, which has been published today (Sept. 14) in IOP Publishing’s Journal of Neural Engineering, involved the use of a neural prosthesis, which consisted of an array of electrodes measuring the signals from neurons in the brain to calculate how the monkeys’ ability to perform a memory task could be restored.
Every day, we face thousands of decisions both major and minor — from whether to eat that decadent chocolate cupcake to when to pursue a new romantic relationship or to change careers. How does the brain decide? A new study suggests that it relies on two separate networks to do so: one that determines the overall value — the risk versus reward — of individual choices and another that guides how you ultimately behave.
The speed at which we drink alcohol may be influenced by the shape of the glass we drink from, according to new research from the University of Bristol, published in PLoS ONE. This could be a target to help control the problematic levels of drunkenness that are becoming increasingly common in our society.
The frontal lobes are the largest part of the human brain, and thought to be the part that expanded most during human evolution. Damage to the frontal lobes—which are located just behind and above the eyes—can result in profound impairments in higher-level reasoning and decision making. To find out more about what different parts of the frontal lobes do, neuroscientists at the California Institute of Technology (Caltech) recently teamed up with researchers at the world’s largest registry of brain-lesion patients. By mapping the brain lesions of these patients, the team was able to show that reasoning and behavioral control are dependent on different regions of the frontal lobes than the areas called upon when making a decision.
The sought-after equanimity of “living in the moment” may be impossible, according to neuroscientists who’ve pinpointed a brain area responsible for using past decisions and outcomes to guide future behavior. The study is the first of its kind to analyze signals associated with metacognition—a person’s ability to monitor and control cognition (a term cleverly described by researchers as “thinking about thinking.”
Why aren’t our thoughts independent of each other? Why don’t we just live in the moment? For a healthy person, it’s impossible to live in the moment. It’s a nice thing to say in terms of seizing the day and enjoying life, but our inner lives and experiences are much richer than that. With schizophrenia and Alzheimer’s disease, there is a fracturing of the thought process. It is constantly disrupted, and despite trying to keep a thought going, one is distracted very easily. Patients with these disorders have trouble sustaining a memory of past decisions to guide later behavior, suggesting a problem with metacognition. -Marc Sommer
Source: University of Pittsburgh
Opinion: Bias Is Unavoidable
By Lisa Cosgrove | August 7, 2012
It is part of the human condition to have implicit biases—and remain blissfully ignorant of them. Academic researchers, scientists, and clinicians are no exception; they are as marvelously flawed as everyone else. But it is not the cognitive bias that’s the problem. Rather, the denial that there is a problem is where the issues arise. Indeed, our capacity for self-deception was beautifully captured in the title of a recent book addressing researchers’ self-justificatory strategies, Mistakes Were Made (But Not by Me).
Illustration by Dusan Petricic
Decades of research have demonstrated that cognitive biases are commonplace and very difficult to eradicate, and more recent studies suggest that disclosure of financial conflicts of interest may actually worsen bias. This is because bias is most often manifested in subtle ways unbeknownst to the researcher or clinician, and thus is usually implicit and unintentional. For example, although there was no research misconduct or fraud, re-evaluations of liver tissue of rats exposed to the drug dioxin resulted in different conclusions about the liver cancer in those rats: compared to the original investigation, an industry-sponsored re-evaluation identified fewer tissue slides as cancerous and this finding affected policy recommendations (water quality standards were weakened). (See also Brown, Cold Spring Harbor Laboratory Press, 13–28, 1991.) This example is just one of many that points to a genericrisk that a financial conflict of interest may compromise research or undermine public trust.
Indeed, recent neuroscience investigations demonstrate that effective decision-making involves not just cognitive centers but also emotional areas such as the hippocampus and amygdala. This interplay of cognitive-emotional processing allows conflicts of interest to affect decision-making in a way that is hidden from the person making the decision.
Despite these findings, many individuals are dismissive of the idea that researchers’ financial ties to industry are problematic. For example, in a recent essay in The Scientist, Thomas Stossel of Brigham & Women’s Hospital and Harvard Medical School asked, “How could unrestricted grants, ideal for research that follows up serendipitous findings, possibly be problematic? The money leads to better research that can benefit patients.” Many argue that subjectivity in the research process and the potential for bias can be eradicated by strict adherence to the scientific method and transparency about industry relationships. Together, scientists believe, these practices can guarantee evidence-based research that leads to the discovery and dissemination of “objective” scientific truths. The assumption is that the reporting of biased results is a “bad apple” problem—a few corrupt individuals engaging in research fraud. But what we have today is a bad barrel.
Some have begun to use the analytic framework of “institutional corruption” to bring attention to the fact that the trouble is not with a few corrupt individuals hurting an organization whose integrity is basically intact. Institutional corruption refers to the systemic and usually legal—and often accepted and widely defended—practices that bring an organization or institution off course, undermine its mission and effectiveness, and weaken public trust. Although the entire field of biomedicine has come under scrutiny because of concerns about an improper dependence on industry and all medical specialties have struggled with financial conflicts of interest, psychiatry has been particularly troubled, being described by some as having a crisis of credibility.
This credibility crisis has been played out most noticeably in the public controversy surrounding the latest revision to the Diagnostic and Statistical Manual of Mental Disorders (DSM). The DSM is often referred to as the “Bible” of mental disorders, and is produced by the American Psychiatric Association (APA), a professional organization with a long history of industry ties. DSM-5, the revised edition scheduled for publication in May, 2013, has already been criticized for “disease mongering,” or pathologizing normal behavior. Concerns have been raised that because the individuals responsible for making changes and adding new disorders have strong and long-standing financial associations to pharmaceutical companies that manufacture the drugs used to treat these disorders, the revision process may be compromised by undue industry influence.
Researchers, clinicians, and psychiatrists who served on the DSM-IV have pointed out that adding new disorders or lowering the diagnostic threshold of previously included disorders may create “false positives,” individuals incorrectly identified as having a mental disorder and prescribed psychotropic medication. For example, there was a heated debate about pathologizing the normal grieving process if DSM-5 eliminated the bereavement exclusion for major depressive disorder (MDD). The concern was that widening the diagnostic boundaries of depression to include grief as a “qualifying event,” thereby allowing for a diagnosis of MDD just 2 weeks after the loss of a loved one, would falsely identify individuals as depressed. Although it is not the APA’s intent to play handmaiden to industry, the reality is that such a change would result in more people being prescribed antidepressants following the loss of a loved one. In fact, psychiatrist Allen Frances, who chaired the DSM-IV task force, has noted that DSM-5 would be a “bonanza” for drug companies.
After receiving criticism about potential bias in the development of the DSM-IV, the APA required that DSM-5 panel members file financial disclosures. Additionally, during their tenure on the panels they were not allowed to receive more than $10,000 from pharmaceutical companies or have more than $50,000 in stock holdings in pharmaceutical companies (unrestricted research grants were excluded from this policy). The majority of diagnostic panels, however, continue to have the majority of their members with financial ties to the pharmaceutical industry. Specifically, 67 percent of the 12-person panel for mood disorders, 83 percent of the 12-person panel for psychotic disorders, and all 7 members of the sleep/wake disorders panel (which now includes ‘‘Restless Leg Syndrome’’) have ties to the pharmaceutical companies that manufacture the medications used to treat these disorders or to companies that service the pharmaceutical industry.
Clearly, the new disclosure policy has not been accompanied by any reduction in the financial conflicts of interest of DSM panel members. Moreover, Darrel Regier, speaking on behalf of the APA and in defense of DSM panel members with industry ties, told USA Today. “There’s this assumption that a tie with a company is evidence of bias. But these people can be objective.” However, as science has repeatedly shown, transparency alone cannot mitigate bias and is an insufficient solution for protecting the integrity of the revision process. Objectivity is not a product that can be easily secured by adherence to the scientific method. Rather, there is a generic risk that a conflict of interest may result in implicit, unintentional bias. Similarly, as Sinclair Lewis said, “It is difficult to get a man to understand something when his salary depends upon his not understanding it.”
Source: TheScientist
The longer you’re awake, the slower you get
July 27, 2012
Anyone that has ever had trouble sleeping can attest to the difficulties at work the following day. Experts recommend eight hours of sleep per night for ideal health and productivity, but what if five to six hours of sleep is your norm? Is your work still negatively affected? A team of researchers at Brigham and Women’s Hospital (BWH) have discovered that regardless of how tired you perceive yourself to be, that lack of sleep can influence the way you perform certain tasks.
This finding is published in the July 26, 2012 online edition of The Journal of Vision.
"Our team decided to look at how sleep might affect complex visual search tasks, because they are common in safety-sensitive activities, such as air-traffic control, baggage screening, and monitoring power plant operations," explained Jeanne F. Duffy, PhD, MBA, senior author on this study and associate neuroscientist at BWH. "These types of jobs involve processes that require repeated, quick memory encoding and retrieval of visual information, in combination with decision making about the information."
Researchers collected and analyzed data from visual search tasks from 12 participants over a one month study. In the first week, all participants were scheduled to sleep 10-12 hours per night to make sure they were well-rested. For the following three weeks, the participants were scheduled to sleep the equivalent of 5.6 hours per night, and also had their sleep times scheduled on a 28-hour cycle, mirroring chronic jet lag. The research team gave the participants computer tests that involved visual search tasks and recorded how quickly the participants could find important information, and also how accurate they were in identifying it. The researchers report that the longer the participants were awake, the more slowly they identified the important information in the test. Additionally, during the biological night time, 12 a.m. -6 a.m., participants (who were unaware of the time throughout the study) also performed the tasks more slowly than they did during the daytime.
"This research provides valuable information for workers, and their employers, who perform these types of visual search tasks during the night shift, because they will do it much more slowly than when they are working during the day," said Duffy. "The longer someone is awake, the more the ability to perform a task, in this case a visual search, is hindered, and this impact of being awake is even stronger at night."
While the accuracy of the participants stayed the fairly constant, they were slower to identify the relevant information as the weeks went on. The self-ratings of sleepiness only got slightly worse during the second and third weeks on the study schedule, yet the data show that they were performing the visual search tasks significantly slower than in the first week. This finding suggests that someone’s perceptions of how tired they are do not always match their performance ability, explains Duffy.
Provided by Brigham and Women’s Hospital
Source: medicalxpress.com