Musical Training May Improve Working Memory and Long-Term Memory
Professional musicians may have advantages in long-term memory, compared with nonmusicians. Heekyeong Park, PhD, Assistant Professor of Psychology, and graduate student James Schaeffer, both at the University of Texas at Arlington, used EEG technology to measure the electrical activity of neurons in the brains of 14 musicians and 15 nonmusicians. The researchers noted processing differences in the frontal and parietal lobe responses.

“Musically trained people are known to process linguistic materials a split second faster than those without training, and previous research also has shown [that] musicians have advantages in working memory,” said Dr. Park. “What we wanted to know is whether there are differences between pictorial and verbal tasks and whether any advantages extend to long-term memory. If proven, those advantages could represent an intervention option to explore for people with cognitive challenges.”

Dr. Park’s laboratory in the UT Arlington College of Science uses EEG, functional MRI (fMRI), and functional near-infrared spectroscopy (fNIRS) to research human cognitive neuroscience. To test working memory, the study participants were asked to select pictorial or verbal items that they had just been given along with similar items. After the entire study session was complete participants underwent a test of long-term memory during which they judged whether each test item had previously been studied or was new.

The musicians, all of whom had been playing classical music for more than 15 years, outperformed nonmusicians in EEG-measured neural responses on the working memory tasks. But when long-term memory was tested, the enhanced sensitivity was only found in memory for pictures.

The study has not explored why the advantages might develop. Professional musicians may become more adept at taking in and processing a host of pictorial cues as they navigate musical scores, said Dr. Park.

Dr. Park also observed that musicians’ neural responses in the mid-frontal part of the brain were 300 to 500 µs faster than those of nonmusicians, and responses in the parietal lobe were 400 to 800 µs faster than those of nonmusicians. The parietal lobe is responsible for perceptual processing, attention, and memory.

“Dr. Park’s research uses the latest scientific instrumentation to reveal knowledge about human cognition that was previously unreachable,” said James Grover, Interim Dean of the UT Arlington College of Science. “It provides usable information about far-reaching advantages [that] arts training can bring.” Researchers hope to test more musicians soon to strengthen the findings.

Whatever the mechanism involved, the new research is important because music is helpful for long-term memory for nonverbal events, and “we are all surrounded by non verbal events,” said Dr. Park. “Our work is adding evidence that music training is a good way to improve cognitive abilities,” she said.

Can the Brain Reveal an Adolescent’s Risk of Alcohol Abuse?
Investigators are attempting to identify brain differences that indicate which adolescents are likely to misuse alcohol and other drugs. Such differences may help scientists develop strategies that can prevent drug abuse. At the meeting, researchers presented results from four substudies of the Adolescent Development Study, which is a wide-ranging effort to understand how a teenager’s brain can lead to risky behaviors. The project is led by John VanMeter, PhD, Director of the Center for Functional and Molecular Imaging and Associate Professor of Neurology at Georgetown University Medical Center in Washington, DC.

The studies were conducted with a participant pool of 135 preteen and teenage boys and girls with an average age of 12.6. Participants underwent structural and functional MRI to investigate the connection between brain development and behavior. The researchers also used questionnaires and several tests of neurocognitive function, including two tests used specifically while adolescents were scanned: the Continuous Performance Task (CPT), which measures impulsivity, and the Temporal Discounting Task (TD), which quantifies preference for immediate rather than delayed reward.

The first study examined whether lack of connectivity in the brain’s Executive Control Network (ECN) contributes to or results from teen alcohol use.

Tomas Clarke, a research assistant, and Stuart Washington, PhD, a post-doctoral fellow in Dr. VanMeter’s laboratory, looked at the association between the Drug Use Screening Inventory questionnaire filled out by 32 participants’ parents and brain connectivity within the ECN, which includes the areas that process emotion, impulsivity, and self-control. The questionnaire predicts future alcohol misuse. It does not ask parents about their alcohol or drug use, but examines social behaviors in their children such as irritability, anger, and sadness.

Mr. Clarke categorized the participants into two groups—16 children at high or medium risk for alcohol abuse, based on the test, and 16 at low risk. He then used fMRI scans to analyze connectivity in the ECN. ECN connectivity was significantly lower in the high- and medium-risk groups, compared with the low-risk group.

“We know that impaired functioning in the ECN is linked to an earlier age of drinking onset and higher frequency of drinking, but it was unclear whether this dysfunction occurred before drinking or was a consequence of alcohol use,” said Mr. Clarke. “Our findings suggest [that] reduced prefrontal cortex development predates alcohol use and may be related to future alcohol use disorders.”

A second study examined the levels of impulsivity in relation to the connection between executive control in the prefrontal cortex and the insular cortex, which is involved in processing emotions. Benson Stevens, a graduate student in Georgetown’s Interdisciplinary Program in Neuroscience, used the Drug Use Screening Inventory to establish a high-or-medium risk and a low-risk group, each with 17 participants. Mr. Stevens then administered the CPT test while the participants underwent fMRI. Compared with the low-risk group, high-or-medium-risk participants had reduced connectivity between the prefrontal cortex and the insular cortex.

“Less connectivity predicted higher levels of impulsivity,” said Mr. Stevens. “Importantly, these effects were observed before the onset of alcohol use. The reduced connectivity between these brain regions could be an important factor in adolescent alcohol use, given that reduced inhibitory control has been found to be a factor in alcohol use disorders.”

A third study investigated the relationship between sugar intake, as reported by participants in a food questionnaire, and performance on the CPT and the TD, which measure impulsivity and ability to delay gratification. The CPT was administered while participants were undergoing an fMRI scan.

“We know that, compared with healthy individuals, adults with alcoholism have a stronger preference for sweet tastes, are more impulsive, and are less able to delay gratification,” explained Dana Estefan, a former research assistant in Dr. VanMeter’s laboratory. “We wanted to know if this profile fits youth deemed to be at risk for early alcohol use by the Drug Use Screening Inventory.”

The TD task confirmed the expected relationship; Children with high amounts of added sugar in their diets preferred immediate rewards more than children with lower levels of added sugar in their diets did. The CPT test revealed that individuals with increased sugar intake also showed greater activation in the right superior temporal gyrus and the right insula, which are linked to impulsivity and emotional affect. The hypothalamus was also highly activated in these individuals. This high activation is linked to overeating, reward seeking, and drug addiction, said Ms. Estefan.

“Our findings could potentially mean a positive correlation between impulsivity and sugar intake in adolescents, but more research needs to be done on this,” she added.

In the fourth study, Valerie Darcey, a registered dietitian and a graduate student in the Interdisciplinary Program in Neuroscience, examined the relationship between intake of DHA, an essential omega-3 fatty acid, and impulsivity. DHA, found in cold-water fish, is important for neuronal function.

Ms. Darcey administered a food questionnaire to 81 participants to measure ingestion of DHA and arachidonic acid (AA), which is omega-6 fatty acid found in vegetable oil and foods. Because AA competes with DHA for a place in cell membranes, the more AA a person consumes, the less DHA he or she uses. Ms. Darcey gave participants the CPT test while scanning their brains with fMRI.

“My preliminary findings show that while impulsivity levels are the same for kids with high and low levels of DHA in their diets, the brains of kids with low DHA appear to be more active—working harder to compensate—in a region involved in paying attention to the task and a region that participates in executive function,” she said. “This [result] tells us that the brains of the kids eating less DHA may not be developing like those eating more DHA.”

Patients With Paralysis Walk Using Robotic Exoskeleton and Brain–Machine Interface
Eight patients with paralysis have learned to operate a robotic exoskeleton using a brain–machine interface. The exoskeleton supports the weight of the person inside, is powered by hydraulics, and is operated by a brain–machine interface. Each study participant was able to control walking and kicking in the exoskeleton, according to the findings presented.

“One study participant delivered the inaugural kick of the 2014 FIFA World Cup, demonstrating the system’s reliability,” said senior author Miguel Nicolelis, MD, PhD, Professor of Neurobiology, Biomedical Engineering, and Psychology and Neuroscience at Duke University in Durham, North Carolina. “Our results indicate that brain–machine interface-based control of an exoskeleton could become a rehabilitation tool for severely paralyzed individuals.”

A brain–machine interface extracts and translates motor commands from functional brain areas and sends them to machines that execute the desired movements. To conduct the study, neuroscientists, engineers, and clinicians working with the Walk Again Project designed a wearable robotic exoskeleton. A cap of electrodes on the user’s head captures activity from multiple sensorimotor areas of the subject’s cortex. A computer mounted on the back of the exoskeleton interprets the brain activity and displays a visual representation of that activity on an LED display in the user’s helmet. Based on this display, the user selects movements for the mechanical exoskeleton to perform. Over six months, the researchers conducted 1,152 hours of training for eight individuals living spinal cord injury.

The system allows the patient to dictate movements such as walking and kicking, while permitting the exoskeleton to manage other motions, like specific joint adjustments. In this way, the users were able to indicate the action that they wanted to perform, while the exoskeleton system ensured its safe execution.

Increased Inflammation in Mothers During Pregnancy Is Associated With Decreased Maturity in Child’s Brain Wiring
Increased inflammation in a pregnant woman, which can be triggered, for example, by exposure to stress or infection, may shape the development of her child’s brain, according to investigators.

“Previous research has suggested that many of the alterations in brain structure and connectivity associated with neuropsychiatric disorders can be traced back to conditions in the womb,” said lead author Claudia Buss, PhD, Professor of Medical Psychology at Charité—University Medicine Berlin. “Our research demonstrates that a specific elevated immune response experienced by some women during pregnancy may affect key aspects of the child’s brain development.”

Dr. Buss and her colleagues analyzed blood samples collected from 58 mothers in early, mid, and late pregnancy to determine their levels of the cytokine interleukin-6 (IL-6), a protein that stimulates the body’s immune response to infections and stress. Then, using functional MRI (fMRI) technology, the researchers acquired brain scans of the women’s newborns during natural sleep to detect and measure brain activity patterns.

An analysis of the data revealed that IL-6 concentrations during pregnancy, particularly during early pregnancy, predicted weaker connections between specific regions of the newborns’ brains. These weaker connections were similar to those that have been previously associated with psychiatric problems in adults. The study’s findings may one day lead to the development of diagnostic and treatment approaches to detect, prevent, and reduce the likelihood of mental health problems in at-risk individuals.

Findings Suggest Possible Link Between Obesity and Cognitive Decline
Being overweight or obese is associated with brain shrinkage in cognitively healthy older adults, according to research presented at the meeting.

“Our study’s findings provide important evidence indicating that being overweight or obese is associated with poorer brain health in older adults,” said lead author Nicolas Cherbuin, PhD, Director of the Neuroimaging and Brain Laboratory at the Australian National University College of Medicine, Biology, and Environment in Canberra. “The results further underscore the importance of reducing the rate of obesity through education, population health interventions, and policy.”

Shrinkage of the hippocampus, which plays a crucial role in long-term memory, is a hallmark of cognitive decline. One possible mechanism for that shrinkage is chronic inflammation, which animal studies have shown to increase and decrease with the increase or decrease of fat tissue.

To investigate whether being overweight or obese is associated with shrinkage of the hippocampus, Dr. Cherbuin and his colleagues followed 420 cognitively healthy adults between ages 60 and 64 who were participating in a large prospective study on aging. At the start of the study and at years four and eight, the participants had their BMI assessed. They also underwent a brain scan to measure the size of their hippocampus.

The researchers found that having a higher BMI was associated with a smaller hippocampus at the study’s first assessment. In addition, greater shrinkage of the hippocampus was observed over the follow-up period among participants with higher BMIs at the start of the trial, even after controlling for factors such as age, gender, education, diabetes, hypertension, smoking, and depression. These findings suggest that obesity may play a role in brain structure changes linked to cognitive decline and dementia.

Menthol and Nicotine in Combination Desensitize Airway Receptors
Menthol acts in combination with nicotine to desensitize receptors in lungs’ airways that are responsible for nicotine’s irritation, say neuroscientists at Georgetown University Medical Center (GUMC) in Washington, DC.

“We know that a menthol cough drop soothes a scratchy, sore throat. The question we looked at is if and how it works when the irritant is nicotine,” said Kenneth Kellar, PhD, a Professor of Pharmacology at GUMC. “This study supports the notion that menthol is not just a flavoring, but has a pharmacologic effect.”

The FDA is considering restrictions on menthol cigarettes because it has determined that menthol in cigarettes is likely associated with increased initiation and progression to regular cigarette smoking, increased dependence, and reduced success in smoking cessation, especially among African American menthol smokers. But the FDA’s review of the available research and evidence relating to menthol cigarettes, issued in July 2013, also concluded, “From the available studies, the weight of evidence supports the conclusion that menthol in cigarettes is not associated with an increase in disease risk to the user, compared to nonmenthol cigarette smokers.”

The use of menthol cigarettes is especially high among African-American smokers, and research has shown a higher rate of lung cancer in African American smokers, compared with other smokers.

“The issue may be that menthol in the presence of nicotine may reduce the irritation enough that a smoker can inhale more deeply, bringing not just nicotine but toxic smoke products farther into the lungs,” said Gerald Ahern, PhD, an Associate Professor of Pharmacology at GUMC. “While beyond the scope of this study, it is possible that such deeper inhalation of menthol cigarettes, to the extent it occurs, increases the already substantial health harms from smoking.”

The study provides a better understanding of how menthol affects the function of the α3β4 receptor, one of the most prevalent nicotinic acetylcholine receptors expressed in the peripheral nervous system, said the researchers. These receptors are expressed in airway sensory nerves as well as other neurons.

“These receptors are also found in the brain, but we don’t know yet what effect menthol has on those receptors, or whether they contribute in any way to nicotine addiction,” said Dr. Kellar.

Childhood Maltreatment May Alter Brain Circuits Regulating Emotions and Impulses
Childhood neglect and abuse may alter the development of brain circuitry in adolescents, especially in the prefrontal cortex, a part of the brain that is important in emotion and impulse regulation, according to findings presented.

“We gained a rare window into how childhood neglect and abuse, both physical and emotional, alter the patterns of brain circuits during adolescence,” said lead author Elizabeth Cox Lippard, PhD, Postdoctoral Fellow in Psychiatry at Yale University. “These findings can help guide the development of early detection and intervention strategies for disorders such as depression and addiction.”

Adolescence is a critical period in brain development, especially for the brain circuits that help to regulate emotions and impulses. It is also a time when disorders such as depression and substance abuse often develop.

The researchers conducted clinical and behavioral assessments and brain scans of adolescents who had been neglected or abused during childhood. They assessed the adolescents twice: first when the adolescents were approximately 15 years old and second at about two and a half years later. Both times, MRI scans provided information on brain structure and connectivity.

The findings suggest that maltreatment alters the brain circuitry within the prefrontal cortex and from that region to other brain regions that are important in emotion and impulse control, potentially altering the function of the circuits that connect these regions.

Researchers also found preliminary evidence that the consequences of maltreatment differ between females and males, supporting earlier research that suggested females exposed to childhood maltreatment have a higher risk of developing depression, while males are more likely to struggle with substance abuse.

Presence of Caregiver Improves Children’s Regulation of Their Emotions
The presence of a caregiver may influence the function of children’s brain circuits that are responsible for emotional regulation. With a caregiver present, those brain circuits act in a more mature fashion that resembles a pattern observed in adolescents. In contrast, during adolescence, the presence of a caregiver has little effect on the function of these brain circuits, which have likely already matured.

“Our research indicates a critical ‘sensitive period’ in the development of circuits responsible for emotional regulation,” said Dylan Gee, a graduate student at the University of California, Los Angeles. “The children in this study were all between 4 and 10 years of age. This appears to be a time when the outside environment is particularly influential in shaping development.”

The brain’s amygdala plays a key role in emotional reactions, and the prefrontal cortex regulates the amygdala. The researchers investigated sensitive periods in the development of amygdala–prefrontal cortex circuitry. The investigators used functional MRI to scan the brains of children and adolescents while the subjects viewed either their mother or a stranger. The researchers also measured how well participants could regulate their responses to emotional stimuli while they were sitting with their mother, compared with when they were sitting with a stranger. Twenty-three children (ages 4 to 10) and 30 adolescents (ages 11 to 17) participated in the study.

The results showed that viewing their mother reduced amygdala reactivity in children and resulted in stronger communication between the amygdala and prefrontal cortex. Children also had better regulatory behavior in the presence of their mothers. In addition, children whose mothers had greater effects on their amygdala–prefrontal circuitry had lower anxiety and more secure parent–child attachment. In contrast, for adolescents, the presence of their mother had little impact on the function of these brain circuits, which have likely already matured.

The study reveals a potential neurobiologic mechanism through which a caregiver provides an external source of emotional regulation in childhood before the brain circuitry supporting emotion regulation has fully developed.

Conference News Update—Society for Neuroscience 2014