1. Sound waves boost older adults’ memory, deep sleep

    March 23, 2017 by Ashley

    From the Northwestern University press release:

    IF

    Gentle sound stimulation — such as the rush of a waterfall — synchronized to the rhythm of brain waves significantly enhanced deep sleep in older adults and improved their ability to recall words, reports a new Northwestern Medicine study.

    Deep sleep is critical for memory consolidation. But beginning in middle age, deep sleep decreases substantially, which scientists believe contributes to memory loss in aging.

    The sound stimulation significantly enhanced deep sleep in participants and their scores on a memory test.

    “This is an innovative, simple and safe non-medication approach that may help improve brain health,” said senior author Dr. Phyllis Zee, professor of neurology at Northwestern University Feinberg School of Medicine and a Northwestern Medicine sleep specialist. “This is a potential tool for enhancing memory in older populations and attenuating normal age-related memory decline.”

    The study will be published March 8 in Frontiers in Human Neuroscience.

    In the study, 13 participants 60 and older received one night of acoustic stimulation and one night of sham stimulation. The sham stimulation procedure was identical to the acoustic one, but participants did not hear any noise during sleep. For both the sham and acoustic stimulation sessions, the individuals took a memory test at night and again the next morning. Recall ability after the sham stimulation generally improved on the morning test by a few percent. However, the average improvement was three times larger after pink-noise stimulation.

    The older adults were recruited from the Cognitive Neurology and Alzheimer’s Disease Center at Northwestern.

    The degree of slow wave sleep enhancement was related to the degree of memory improvement, suggesting slow wave sleep remains important for memory, even in old age.

    Although the Northwestern scientists have not yet studied the effect of repeated nights of stimulation, this method could be a viable intervention for longer-term use in the home, Zee said.

    Previous research showed acoustic simulation played during deep sleep could improve memory consolidation in young people. But it has not been tested in older adults.

    The new study targeted older individuals — who have much more to gain memory-wise from enhanced deep sleep — and used a novel sound system that increased the effectiveness of the sound stimulation in older populations.

    The study used a new approach, which reads an individual’s brain waves in real time and locks in the gentle sound stimulation during a precise moment of neuron communication during deep sleep, which varies for each person.

    During deep sleep, each brain wave or oscillation slows to about one per second compared to 10 oscillations per second during wakefulness.

    Giovanni Santostasi, a study coauthor, developed an algorithm that delivers the sound during the rising portion of slow wave oscillations. This stimulation enhances synchronization of the neurons’ activity.

    After the sound stimulation, the older participants’ slow waves increased during sleep.

    Larger studies are needed to confirm the efficacy of this method and then “the idea is to be able to offer this for people to use at home,” said first author Nelly Papalambros, a Ph.D. student in neuroscience working in Zee’s lab. “We want to move this to long-term, at-home studies.”

    Northwestern scientists, under the direction of Dr. Roneil Malkani, assistant professor of neurology at Feinberg and a Northwestern Medicine sleep specialist, are currently testing the acoustic stimulation in overnight sleep studies in patients with memory complaints. The goal is to determine whether acoustic stimulation can enhance memory in adults with mild cognitive impairment.

    Previous studies conducted in individuals with mild cognitive impairment in collaboration with Ken Paller, professor of psychology at the Weinberg College of Arts and Sciences at Northwestern, have demonstrated a possible link between their sleep and their memory impairments.


  2. Living with children may mean less sleep for women, but not for men

    March 16, 2017 by Ashley

    From the American Academy of Neurology press release:

    New research backs up what many women already know: They’re sleep deprived. Unlike men, a good night’s sleep for women is affected by having children in the house, according to a preliminary study released today that will be presented at the American Academy of Neurology’s 69th Annual Meeting in Boston, April 22 to 28, 2017.

    “I think these findings may bolster those women who say they feel exhausted,” said study author Kelly Sullivan, PhD, of Georgia Southern University in Statesboro, Ga., and a member of the American Academy of Neurology. “Our study found not only are they not sleeping long enough, they also report feeling tired throughout the day.”

    For the study, researchers examined data from a nationwide telephone survey of 5,805 people. Participants were asked how long they slept, with seven to nine hours per day considered optimum and less than six hours considered insufficient. They were also asked how many days they felt tired in the past month.

    Researchers looked at age, race, education, marital status, number of children in the household, income, body mass index, exercise, employment and snoring as possible factors linked to sleep deprivation.

    Among the 2,908 women aged 45 years and younger in the study, researchers found the only factor associated with getting enough sleep was having children in the house, with each child increasing the odds of insufficient sleep by nearly 50 percent.

    For women under 45, 48 percent of women with children reported getting at least seven hours of sleep, compared to 62 percent of women without children.

    No other factors — including exercise, marital status and education — were linked to how long younger women slept.

    The study found that not only was living with children associated with how long younger women slept, but also how often they felt tired. Younger women with children reported feeling tired 14 days per month, on average, compared to 11 days for younger women without children in the household. Having children in the house was not linked to how long men slept.

    “Getting enough sleep is a key component of overall health and can impact the heart, mind and weight,” said Sullivan, “It’s important to learn what is keeping people from getting the rest they need so we can help them work toward better health.”


  3. Poor sleep in early childhood may lead to cognitive, behavioral problems in later years

    March 15, 2017 by Ashley

    From the Massachusetts General Hospital press release:

    A study led by a Massachusetts General Hospital pediatrician finds that children ages 3 to 7 who don’t get enough sleep are more likely to have problems with attention, emotional control and peer relationships in mid-childhood. Reported online in the journal Academic Pediatrics, the study found significant differences in the responses of parents and teachers to surveys regarding executive function — which includes attention, working memory, reasoning and problem solving — and behavioral problems in 7-year-old children depending on how much sleep they regularly received at younger ages.

    “We found that children who get an insufficient amount of sleep in their preschool and early school-age years have a higher risk of poor neurobehavioral function at around age 7,” says Elsie Taveras, MD, MPH, chief of General Pediatrics at MassGeneral Hospital for Children , who led the study. “The associations between insufficient sleep and poorer functioning persisted even after adjusting for several factors that could influence the relationship.”

    As in previous studies from this group examining the role of sleep in several areas of child health, the current study analyzed data from Project Viva, a long-term investigation of the health impacts of several factors during pregnancy and after birth. Information used in this study was gathered from mothers at in-person interviews when their children were around 6 months, 3 years and 7 years old, and from questionnaires completed when the children were ages 1, 2, 4, 5 and 6. In addition, mothers and teachers were sent survey instruments evaluating each child’s executive function and behavioral issues — including emotional symptoms and problems with conduct or peer relationships, when children were around 7.

    Among 1,046 children enrolled in Project Viva, the study team determined which children were not receiving the recommended amount of sleep at specific age categories — 12 hours or longer at ages 6 months to 2 years, 11 hours or longer at ages 3 to 4 years, and 10 hours or longer at 5 to 7 years. Children living in homes with lower household incomes and whose mothers had lower education levels were more likely to sleep less than nine hours at ages 5 to 7. Other factors associated with insufficient sleep include more television viewing, a higher body mass index, and being African American.

    The reports from both mothers and teachers regarding the neurobehavioral function of enrolled children found similar associations between poor functioning and not receiving sufficient sleep, with teachers reporting even greater problems. Although no association was observed between insufficient sleep during infancy — ages 6 months to 2 years — and reduced neurobehavioral functioning in mid-childhood, Taveras notes that sleep levels during infancy often predict levels at later ages, supporting the importance of promoting a good quantity and quality of sleep from the youngest ages.

    “Our previous studies have examined the role of insufficient sleep on chronic health problems — including obesity — in both mothers and children,” explains Taveras, who is a professor of Pediatrics at Harvard Medical School (HMS). “The results of this new study indicate that one way in which poor sleep may lead to these chronic disease outcomes is by its effects on inhibition, impulsivity and other behaviors that may lead to excess consumption of high-calorie foods. It will be important to study the longer-term effects of poor sleep on health and development as children enter adolescence, which is already underway through Project Viva.”


  4. Study suggests depression symptoms due to chronic sinus disease interfere with productivity

    March 14, 2017 by Ashley

    From the Massachusetts Eye and Ear Infirmary media release:

    Depressed patients with chronic rhinosinusitis (CRS) are more likely to miss days of work or school than those without depression symptoms, according to the results of a new study led by the Sinus Center at Massachusetts Eye and Ear. The findings, published online in Annals of Allergy, Asthma and Immunology, identify depression symptoms as the primary driver of lost days of productivity in patients with CRS, paving the way for more individualized therapy to improve overall quality of life in these patients.

    “In this study, we found that of all symptoms related to CRS — sinus, nasal or otherwise — the severity of depressed mood and depression symptomatology was the predominant factor associated with how often our CRS patients missed work or school due to their CRS,” said senior author Ahmad R. Sedaghat, M.D., Ph.D., a sinus surgeon at Mass. Eye and Ear and assistant professor of otolaryngology at Harvard Medical School. “The severity of even symptoms most typically related to CRS, such as nasal congestion, was not associated with how often our patients missed work or school due to their CRS.”

    One of the more prevalent chronic illnesses in the United States, CRS has been known to cause significant quality of life detriments to affected patients, who often cannot breathe or sleep easily due to obstructed nasal and sinus passages.

    The researchers previously identified four categories of symptoms that dominate CRS — disturbances of sleep, nasal obstruction, ear and facial pain and emotional function. In subsequent studies, they showed that disturbed sleep and ear/facial pain are most associated with overall poorer quality of life.

    In search of an association with lost productivity, the researchers assessed these four categories of symptoms in 107 patients with CRS using a standardized survey. On average, study participants reported three missed days of work or school in a three-month period, or 12 missed days in a year. When the researchers took a closer look at the surveys, they identified emotional symptoms, in which depression symptoms are the strongest feature, as the primary driver of missed days of work or school.

    The researchers were surprised to find that there was not an association between sleep disturbance or nasal obstruction symptoms — symptoms which are more commonly thought of in relation to CRS — with CRS patients missing days of work or school.

    “These findings really point to the fact that specific elements (in this case, symptoms) of CRS may be driving specific disease manifestations or consequences of the disease” Dr. Sedaghat said. In an effort to specifically tailor our CRS treatment to each patient, we have to be cognizant not just of the overall severity of the disease, but also of the severity of individual aspects, symptoms and manifestations of the disease. In this case, we have found that depressed mood, which CRS patients commonly experience, is associated with a particular consequence of the disease — that patients may miss work because of CRS — and these results open the door to exploring interventions directed at depressed mood for reducing productivity losses due to CRS.”


  5. Synched work schedules during ‘Antarctic Summer’ may affect release patterns of sleep and wake hormones

    March 13, 2017 by Ashley

    From the American Physiological Society press release:

    The continuous daylight conditions of summer in Antarctica are known to interfere with physiological functions such as sleep patterns and the release of melatonin, a hormone associated with circadian rhythms and sleep. Now, a study offers new information about why people in this region sleep poorly, and suggests that social behavior may also play a role. The study, published ahead of print in the Journal of Applied Physiology, was chosen as an APSselect article for March.

    Antarctica, located at the tip of the Southern Hemisphere, experiences 24-hour daylight and no darkness for several months of the year (Antarctic summer). An expedition team stationed in Antarctica during the summer followed their daily work routine and volunteered for sleep studies at night. Belgian researchers monitored the volunteers’ sleep stages and recorded the secretion of cortisol (a stress hormone also associated with wakefulness) and melatonin.

    In normal circumstances, we begin the night with proportionally more deep sleep that provides the body with physical recovery. As morning approaches, sleep patterns contain more dream sleep. The research team found the reverse was true in the Antarctic expedition workers — their dream sleep occurred earlier, with a deep sleep period at the end of the night. In addition, melatonin secretion — a process that helps you fall asleep — was delayed by several hours. Melatonin is sensitive to light and is usually released in the darkness of night. Members of the expedition team also reported “morning sleepiness, which waned with exposure to sunlight.” This may be due to the delayed release of melatonin, which remained high in the body upon waking, explained Nathalie Pattyn, first author of the study.

    To the researchers’ surprise, cortisol secretion remained normal, with the highest levels secreted in the morning. Typically, melatonin and cortisol have an inverse relationship: When one hormone is high, the other is low. The common schedule of the expedition members — who worked and slept at the same time — kept the cortisol from delaying its release. If the expedition team had been on different schedules, the timing of cortisol secretion would have likely changed. These findings warrant more study about how social behavior modifies physiological function explained Pattyn, because it “shows the story behind sleep complaints in Antarctica is more complicated” than just being exposed to continuous sunlight.


  6. Brain blocks new memory formation on waking to safeguard consolidation of existing memories

    January 6, 2017 by Ashley

    From the Bar-Ilan University media release:

    Throughout our waking lives we are exposed to a continuous stream of stimuli and experiences. Some of these experiences trigger the strengthening of connections between neurons in the brain, and begin the process of forming memories.

    However, these initial memory traces are fragile and only a small number will become long-term memories with the potential to last a lifetime. For this transition to occur, the brain must stabilize the memory traces through a process called consolidation.

    Let’s sleep on it

    During consolidation, the brain produces new proteins that strengthen the fragile memory traces. However, if a new experience occurs while an existing memory trace is being consolidated, the new stimuli could disrupt or even hijack the consolidation process.

    The brain partially solves this problem by postponing some of the memory consolidation to a period in which new experiences are minimalized, that is, while we are asleep. But what happens if we wake up while consolidation is taking place? How does the brain prevent events that occur just after awakening from interrupting the consolidation process?

    A new study by Prof. Abraham Susswein of the Mina and Everard Goodman Faculty of Life Sciences and The Leslie and Susan Gonda (Goldschmied) Multidisciplinary Brain Research Center at Bar-Ilan University, has now answered this question. Published in eLife, the article’s first author is Roi Levy, whose doctoral research — conducted in Prof. Susswein’s lab — is described in the present study, which also includes part of the doctoral research of David Levitan.

    Susswein and his colleagues have used a seemingly unlikely subject for their study, namely the sea hare Aplysia. These marine slugs are convenient for neuroscientific investigation because of their simple nervous systems and large neurons, and because they have been shown to be capable of basic forms of learning.

    Just after training during waking hours, proteins are synthesized to initiate the consolidation of new memory. Consolidation proteins are produced again in greater quantities during sleep for subsequent processes on the memory trace. The researchers found that blocking the production of consolidation proteins in sleeping sea slugs prevents these creatures from forming long-term memories, confirming that, like us, they do consolidate memories during sleep.

    Overcoming Memory Block

    Susswein, Levy and Levitan now show that exposing sea slugs to new stimuli immediately after they wake up does not trigger the formation of new memories. In a learning paradigm affecting sea slugs’ feeding activity, the animals were trained after being awakened from sleep. On awakening, interactions between new experiences and consolidation are prevented because the brain blocks long-term memory arising from the new stimuli. However, when the researchers treated the slugs just prior to the training with a drug that inhibits protein production, they found that the new stimuli could generate long-term memory. These findings show that proteins blocking the formation of new memories prevent an experience upon waking from being effective in producing memory. Removing this block — by inhibiting protein production — allows experiences just after waking to be encoded in memory. This even applies to experiences that are too brief to trigger memory formation in fully awake sea slugs.

    Susswein says, “The major insight from this research is that there is an active process in the brain which inhibits the ability to learn new things and protects the consolidation of memories.”

    Two Heads are Better than One

    The researchers also compared learning by fully awake sea slugs trained in isolation and those trained with companions. They discovered that training in social isolation appears to inhibit new learning, and identified similar molecular processes common to both training in isolation and to training on waking from sleep.

    For the Future

    “Our next step following on from this work,” says Susswein, “is to identify these memory blocking proteins and to fathom how they prevent the formation of new memories.” He adds: “We may also find that the blocking process accounts for why we cannot remember our dreams when we wake up.”

    An important future challenge is to investigate whether the same proteins could ultimately be used to block unwanted memories, for example, in cases of Post-Traumatic Stress Disorder.


  7. Losing sleep over discrimination? ‘everyday discrimination’ may contribute to sleep problems

    by Ashley

    From the Wolters Kluwer Health: Lippincott Williams and Wilkins media release:

    People who perceive more discrimination in daily life have higher rates of sleep problems, based on both subjective and objective measures, reports a study in Psychosomatic Medicine: Journal of Biobehavioral Medicine, the official journal of the American Psychosomatic Society. The journal is published by Wolters Kluwer.

    “Discrimination is an important factor associated with sleep measures in middle-aged adults,” according to the report by Sherry Owens, PhD, of West Virginia University, Morgantown, and colleagues. The results add to previous research suggesting that discrimination and chronic stress may lead to sleep difficulties and increased health risks.

    Discrimination Related to Both Objective and Subjective Sleep Problems

    The study included 441 adults from a nationwide study of health and well-being in middle age and beyond (the MIDUS Study). The participants’ average age was 47 years; about one-third were of non-white race/ethnicity. Complete data were available for 361 participants.

    Participants wore an activity monitor device for one week to gather data on objective sleep measures — for example, sleep efficiency, calculated as the percentage of time spent in bed that the person was asleep. They also completed subjective sleep ratings — for example, how often they had sleep problems.

    Perceived experiences of discrimination were assessed using a validated “Everyday Discrimination Scale.” For example, subjects were asked how often they were treated with less courtesy or respect than others, or how often they were insulted or harassed.

    Discrimination scores were analyzed for association with the objective and subjective sleep measures. Objective measures indicated that about one-third of participants had poor sleep efficiency. Subjectively, one-half of subjects rated themselves as having poor sleep quality.

    Participants who perceived more discrimination had increased sleep problems, after adjustment for demographic, lifestyle, and health factors. Higher discrimination scores were associated with 12 percent higher odds of poor sleep efficiency and a nine percent increase in the odds of poor sleep quality. Discrimination was also related to (objective) time spent awake after falling asleep and (subjective) overall sleep difficulties.

    Non-white subjects had nearly four times the odds of poor sleep efficiency. Otherwise, all differences in sleep measures between white and non-white subjects were related to discrimination.

    Older participants and men were more likely to have some types of sleep problems. Age, sex, and mental/physical health factors explained only a small proportion of the effects of discrimination.

    Previous studies have suggested that racial/ethnic minorities have worse sleep quality. Inadequate sleep is associated with adverse health outcomes, including increased cardiovascular risks and increased mortality. These consequences of poor sleep may account for some of racial/ethnic variation in health outcomes — possibly reflecting inadequate recovery from chronic daily stressors.

    While poor sleep has previously been linked to higher perceived discrimination, the new study is the first to look at how discrimination affects both objective and subjective sleep measures. “The findings support the model that discrimination acts as a stressor than can disrupt subjective and objective sleep,” Dr. Owens and coauthors write.

    The researchers call for further study to confirm and clarify the implications of their findings. Meanwhile, they believe the study adds a “finer resolution” to previous knowledge the relationship between discrimination and sleep — and suggests a possible “causal pathway” connecting chronic discrimination to sleep problems, and thus to increased health risks.


  8. Brain neurons help keep track of time

    December 14, 2016 by Ashley

    From the American Association for the Advancement of Science media release:

    memory neuronsTurning the theory of how the human brain perceives time on its head, a novel analysis in mice reveals that dopamine neuron activity plays a key role in judgment of time, slowing down the internal clock. As Patrick Simen and Matthew Matell note in a related Perspective, “The results suggest the need to reassess the leading theory of dopamine function in timing — the dopamine clock hypothesis.”

    Organisms’ ability to accurately estimate periods of time is variable and depends on circumstances, including motivation, attention, and emotions. Dopamine (DA) neurons residing in the midbrain have been implicated as regulators of this complex process.

    However, a direct link between the signals carried by DA neurons and timekeeping is lacking. What’s more, current studies in which timing behavior is disrupted have demonstrated conflicting results — in some cases, increased DA release speeds up the subjective sense of time, while in other instances, it is slowed down or unaffected.

    To make sense of DA’s involvement in time approximation, Sofia Soares and colleagues tracked DA activity in mice performing timed tasks. The mice were presented with two audible tones, and trained to classify the interval between each as shorter or longer.

    Soares et al. observed bursts of activity in mouse DA neurons that synchronized exclusively to the second noise, reflecting the rodents’ anticipation of an upcoming reward, combined with their surprise about the arrival time of the sound. The authors discovered the transient activation or inhibition of dopamine neurons was sufficient to slow down or speed up time estimation, respectively. Simen and Matell emphasize the brain’s fine-tuned ramping up and down of DA signals may prove essential in resolving previous experimental inconsistencies, and identifying novel DA functions that help shape behavior.

     


  9. How kids brains respond to a late night up

    November 29, 2016 by Ashley

    From the Frontiers media release:

    sleeping childAny parent can tell you about the consequences of their child not getting enough sleep. But there is far less known about the details of how sleep deprivation affects children’s brains and what this means for early brain development.

    The process of sleep may be involved in brain ‘wiring’ in childhood and thus affect brain maturation,” explains Salome Kurth, first author of the study published in Frontiers in Human Neuroscience, and a researcher at the University Hospital of Zurich. “This research shows an increase in sleep need in posterior brain regions in children.”

    This contrasts with what researchers know about the effects of sleep deprivation in adults, where the effect is typically concentrated in the frontal regions of the brain.

    After staying up too late, both children and adults need a period of deep sleep to recover. This recovery phase is characterized by an increase in an electrical pattern called slow-wave activity, which can be measured with a non-invasive technique called an electroencephalogram. With a large number of electrode channels distributed across the scalp, this method also detects which brain regions show more slow-wave activity than others.

    Supported by a large student team, Kurth and her colleagues, Monique LeBourgeois professor at the University of Colorado Boulder, and Sean Deoni, professor at Brown University, studied the effects of 50% sleep deprivation in a group of 13 children between the ages of 5 and 12 years. The team first measured the children’s deep sleep patterns during a normal night’s sleep. They then re-measured on another night after the researchers had kept the children up well past their bedtimes by reading and playing games with them.

    After only getting half of a night’s worth of sleep, the children showed more slow-wave activity towards the back regions of the brain — the parieto-occipital areas. This suggests that the brain circuitry in these regions may be particularly susceptible to a lack of sleep.

    The team also measured how this deep sleep activity correlated with the myelin content of the brain — a cornerstone of brain development. Myelin is a fatty microstructure of the brain’s white matter that allows electrical information between brain cells to travel faster. It can be measured with a specific magnetic resonance imaging technique.

    “The results show that the sleep loss effect on the brain is specific to certain regions and that this correlates with the myelin content of the directly adjacent regions: the more myelin in a specific area, the more the effect appears similar to adults,” says Kurth. “It is possible that this effect is temporary and only occurs during a ‘sensitive period’ when the brain undergoes developmental changes.”

    Further exploration is needed before drawing any conclusions about how insufficient sleep affects early brain developmental processes in the longer term. But for now, these results suggest that going to bed too late may have a different impact on kids’ brains than on adults’.

     


  10. Insight into the seat of human consciousness

    November 9, 2016 by Ashley

    From the Beth Israel Deaconess Medical Center media release:

    Philosophers have long struggled to define human consciousness. Now, a hospital stayeam of researchers led by neurologists at Beth Israel Deaconess Medical Center (BIDMC) has pinpointed the regions of the brain that may play a role maintaining it. Their finding were published November 4, 2016 in journal Neurology.

    “For the first time, we have found a connection between the brainstem region involved in arousal and regions involved in awareness, two prerequisites for consciousness,” said Michael D. Fox, MD, PhD, Director of the Laboratory for Brain Network Imaging and Modulation and the Associate Director of the Berenson-Allen Center for Noninvasive Brain Stimulation at BIDMC. “A lot of pieces of evidence all came together to point to this network playing a role in human consciousness.

    Classical neurology holds that arousal and awareness are two critical components of consciousness. Arousal is likely regulated by the brainstem — the portion of the brain, contiguous with the spinal cord, that is responsible for the sleep/wake cycle and cardiac and respiratory rates. Awareness, another critical component of consciousness, has long been thought to reside somewhere in the cortex, the outer layer of the brain responsible for many of its higher functions.

    The researchers analyzed 36 patients with brainstem lesions, of which 12 led to coma and 24 did not. Mapping the injuries revealed that a small “coma-specific” area of the brainstem — the rostral dorsolateral pontine tegmentum — was significantly associated with coma. Ten out of the 12 coma-inducing brainstem lesions involved this area, while just one of the 24 control lesions did.

    Armed with that information, Fox and colleagues, including lead author David Fischer, MD, then a medical student at Harvard Medical School, used a wiring diagram of the healthy human brain — based on a large, shared data set called the Human Connectome — to identify which other parts of the brain were connected to these coma-causing lesions. Their analysis revealed two areas in the cortex of the brain that were significantly connected to the coma-specific region of the brainstem. One sat in the left, ventral, anterior insula (AI), the other in the pregenual anterior cingulate cortex (pACC). Both regions have been implicated previously in arousal and awareness.

    “We now have a great map of how the brain is wired up in the Human Connectome,” said Fox, who is also an Assistant Professor of Neurology at Harvard Medical School. “We can look at not just the location of lesions, but also their connectivity. Over the past year, researchers in my lab have used this approach to understand visual and auditory hallucinations, impaired speech, and movement disorders. A collaborative team of neuroscientists and physicians had the insight and unique expertise needed to apply this approach to consciousness.”

    The team included co-lead author, Aaron Boes, MD, PhD, and co-senior author, Joel Geerling, MD, PhD, both formerly of BIDMC and now of University of Iowa Carver College of Medicine.

    Finally, the team investigated whether this brainstem-cortex network was functioning in another subset of patients with disorders of consciousness, including coma. Using a special type of MRI scan, the scientists found that their newly identified “consciousness network” was disrupted in patients with impaired consciousness. The findings — bolstered by data from rodent studies — suggest the network between the brainstem and these two cortical regions plays a role maintaining human consciousness.

    “The added value of thinking about coma as a network disorder is it presents possible targets for therapy, such as using brain stimulation to augment recovery,” Boes said. A next step, Fox notes, may be to investigate other data sets in which patients lost consciousness to find out if the same, different or overlapping neural networks are involved.

    “This is most relevant if we can use these networks as a target for brain stimulation for people with disorders of consciousness,” said Fox. “If we zero in on the regions and network involved, can we someday wake someone up who is in a persistent vegetative state? That’s the ultimate question.

    Study coauthors include David B. Fischer, MD, Aaron D. Boes, MD, PhD, Joel C. Geerling, MD, PhD, Clifford B. Saper, MD, PhD, and Alvaro Pascual-Leone, MD, PhD, of BIDMC; Athena Demertzi, PhD, of the Brain and Spine Institute (Institut du Cerveau et de la Moelle épinière-ICM), Hôpital Pitié-Salpêtrière, Paris, France and the Coma Science Group, GIGA-Research & Cyclotron Research Centre, University and University Hospital of Liège, Belgium; Steven Laureys, PhD, also of the Coma Science Group; Henry C. Evrard, PhD, of the Functional and Comparative Neuroanatomy Lab and the Centre for Integrative Neuroscience, Tübingen and the Max Planck Institute for Biological Cybernetics, Tübingen, Germany; Brian L. Edlow, MD, and Hesheng Liu, PhD. of the Athinoula A. Martinos Center for Biomedical Imaging at Massachusetts General Hospital, Charlestown, MA.

    This work was supported by the Howard Hughes Medical Institute, the Parkinson’s Disease Foundation, the NIH (Shared Instrument Grant S10RR023043, K23NS083741, R01HD069776, R01NS073601, R01NS085477, R21MH099196, R21NS082870, R21NS085491, R21HD07616, R25NS065743, R25NS070682, T32 HL007901, P01HL095491), American Academy of Neurology/American Brain Foundation, Sidney R. Baer, Jr. Foundation, Harvard Catalyst, the Belgian National Funds for Scientific Research, the European Commission, the James McDonnell Foundation, the European Space Agency, Mind Science Foundation, the French Speaking Community Concerted Research Action (ARC-06/11-340), the Public Utility Foundation “Université Européenne du Travail,” “Fondazione Europea di Ricerca Biomedica,” the University and University Hospital of Liège, the Center for Integrative Neuroscience, and the Max Planck Society.