12.7.22
Bill Hathaway
A Yale study describes how our brains are capable of sorting through an avalanche of external stimuli to shape a sense of our surroundings.
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Credit: The Johns Hopkins University Medicine.
Since he was a kid Hal Blumenfeld has wondered about the nature of human consciousness.
“It’s what makes us human and makes life worthwhile,” said Blumenfeld, now the Mark Loughridge and Michele Williams Professor of Neurology at Yale. “And it’s still a mystery of modern science.”
In a recent study, Blumenfeld and a team of Yale colleagues identified some of the overlapping neural mechanisms that help to illuminate that mystery.
Writing in the journal Nature Communications [below], they describe how the human brain is capable of sorting through an avalanche of external stimuli — most of which never reach the human consciousness — to create a sense of awareness of the individual’s surroundings.
“Turns out there is a set of very beautiful and rich activities involved in the neural mechanism of conscious thought,” said Blumenfeld, who is also professor of neuroscience and of neurosurgery and director of the Yale Clinical Neuroscience Imaging Center.
One of the challenges facing scientists who study consciousness is the inherent uncertainty that comes with measuring what people are actually aware of. Oftentimes, these researchers will perform brain imaging on people as they are presented with images of objects or events and are then asked questions, like, “Are you aware of a face?” or “Are you aware of an event?” A key unanswered question, however, is what exactly is being measured? Is it the brain’s actual perception of an object or event or simply the response to the question?
To answer this, Blumenfeld — working with Sharif Kronemer, a former Ph.D. student at Yale who is now a postdoctoral fellow at the National Institutes of Health, and a large group of expert collaborators — used a combination of artificial intelligence, mathematics, and a close examination of the eye movements of individuals as they were shown images of people’s faces.
As it turns out, they found that important clues are revealed in the eyes. When people were shown clear images, their eye movements showed a distinct pattern that indicates they were aware of their surroundings. However, as the subjects were presented with progressively dimmer images of faces, the pattern of eye movement changed. Tracking these changes, Blumenfeld said, allowed researchers to discern whether the subjects actually perceived the face or not without asking them.
“The eyes are truly the window to our souls,” he said. “We can tell if people are aware of something by simply looking at their eyes.”
The eye-tracking tool allowed researchers to explore the amorphous dividing line between consciousness and unconsciousness, a state most obvious as we awake from sleep. People become progressively more aware of their surroundings as slumber recedes, a process that is controlled in a region of the brain known as the thalamus.
The Yale researchers found that when people awake the thalamus discharges a brief pulse which jump starts the transition to consciousness. However, this activity is only a first step in a series of actions throughout the brain that leads to full awareness, they found. For instance, that initial pulse from the thalamus may fail to activate other neural networks, keeping the individual unconscious of most surrounding stimuli. However, the pulse can also activate neurons involved in processing visual cues in the frontal cortex, which in turn amplifies circuits involved in arousal and attention. At the same time, signals irrelevant to the event are turned off.
Ultimately, the pertinent signals are processed to form a conscious experience that can be stored in our memory, Blumenfeld said.
Understanding these processes, he said, may help provide new insights into the treatment of some mental health disorders that are marked by a lack of awareness of surroundings— including Alzheimer’s disease, schizophrenia, and traumatic brain injury.
In addition, it may help doctors better assess consciousness in patients who are unable to talk or in a coma.
Blumenfeld hopes these discoveries will also bring humankind closer to understanding ancient philosophical questions about the nature of human consciousness, and the mysteries he’s always wondered about.
“Investigating the elegant overlapping signals from deep in the brain to the surface may finally provide a satisfactory explanation for consciousness,” he said.
Science paper:
Nature Communications
See the science paper for instructive material with images.
See the full article here .
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Yale University is a private Ivy League research university in New Haven, Connecticut. Founded in 1701 as the Collegiate School, it is the third-oldest institution of higher education in the United States and one of the nine Colonial Colleges chartered before the American Revolution. The Collegiate School was renamed Yale College in 1718 to honor the school’s largest private benefactor for the first century of its existence, Elihu Yale. Yale University is consistently ranked as one of the top universities and is considered one of the most prestigious in the nation.
Chartered by Connecticut Colony, the Collegiate School was established in 1701 by clergy to educate Congregational ministers before moving to New Haven in 1716. Originally restricted to theology and sacred languages, the curriculum began to incorporate humanities and sciences by the time of the American Revolution. In the 19th century, the college expanded into graduate and professional instruction, awarding the first PhD in the United States in 1861 and organizing as a university in 1887. Yale’s faculty and student populations grew after 1890 with rapid expansion of the physical campus and scientific research.
Yale is organized into fourteen constituent schools: the original undergraduate college, the Yale Graduate School of Arts and Sciences and twelve professional schools. While the university is governed by the Yale Corporation, each school’s faculty oversees its curriculum and degree programs. In addition to a central campus in downtown New Haven, the university owns athletic facilities in western New Haven, a campus in West Haven, Connecticut, and forests and nature preserves throughout New England. As of June 2020, the university’s endowment was valued at $31.1 billion, the second largest of any educational institution. The Yale University Library, serving all constituent schools, holds more than 15 million volumes and is the third-largest academic library in the United States. Students compete in intercollegiate sports as the Yale Bulldogs in the NCAA Division I – Ivy League.
As of October 2020, 65 Nobel laureates, five Fields Medalists, four Abel Prize laureates, and three Turing award winners have been affiliated with Yale University. In addition, Yale has graduated many notable alumni, including five U.S. Presidents, 19 U.S. Supreme Court Justices, 31 living billionaires, and many heads of state. Hundreds of members of Congress and many U.S. diplomats, 78 MacArthur Fellows, 252 Rhodes Scholars, 123 Marshall Scholars, and nine Mitchell Scholars have been affiliated with the university.
Research
Yale is a member of the Association of American Universities (AAU) and is classified among “R1: Doctoral Universities – Very high research activity”. According to the National Science Foundation , Yale spent $990 million on research and development in 2018, ranking it 15th in the nation.
Yale’s faculty include 61 members of the National Academy of Sciences , 7 members of the National Academy of Engineering and 49 members of the American Academy of Arts and Sciences . The college is, after normalization for institution size, the tenth-largest baccalaureate source of doctoral degree recipients in the United States, and the largest such source within the Ivy League.
Yale’s English and Comparative Literature departments were part of the New Criticism movement. Of the New Critics, Robert Penn Warren, W.K. Wimsatt, and Cleanth Brooks were all Yale faculty. Later, the Yale Comparative literature department became a center of American deconstruction. Jacques Derrida, the father of deconstruction, taught at the Department of Comparative Literature from the late seventies to mid-1980s. Several other Yale faculty members were also associated with deconstruction, forming the so-called “Yale School”. These included Paul de Man who taught in the Departments of Comparative Literature and French, J. Hillis Miller, Geoffrey Hartman (both taught in the Departments of English and Comparative Literature), and Harold Bloom (English), whose theoretical position was always somewhat specific, and who ultimately took a very different path from the rest of this group. Yale’s history department has also originated important intellectual trends. Historians C. Vann Woodward and David Brion Davis are credited with beginning in the 1960s and 1970s an important stream of southern historians; likewise, David Montgomery, a labor historian, advised many of the current generation of labor historians in the country. Yale’s Music School and Department fostered the growth of Music Theory in the latter half of the 20th century. The Journal of Music Theory was founded there in 1957; Allen Forte and David Lewin were influential teachers and scholars.
In addition to eminent faculty members, Yale research relies heavily on the presence of roughly 1200 Postdocs from various national and international origin working in the multiple laboratories in the sciences, social sciences, humanities, and professional schools of the university. The university progressively recognized this working force with the recent creation of the Office for Postdoctoral Affairs and the Yale Postdoctoral Association.
Notable alumni
Over its history, Yale has produced many distinguished alumni in a variety of fields, ranging from the public to private sector. According to 2020 data, around 71% of undergraduates join the workforce, while the next largest majority of 16.6% go on to attend graduate or professional schools. Yale graduates have been recipients of 252 Rhodes Scholarships, 123 Marshall Scholarships, 67 Truman Scholarships, 21 Churchill Scholarships, and 9 Mitchell Scholarships. The university is also the second largest producer of Fulbright Scholars, with a total of 1,199 in its history and has produced 89 MacArthur Fellows. The U.S. Department of State Bureau of Educational and Cultural Affairs ranked Yale fifth among research institutions producing the most 2020–2021 Fulbright Scholars. Additionally, 31 living billionaires are Yale alumni.
At Yale, one of the most popular undergraduate majors among Juniors and Seniors is political science, with many students going on to serve careers in government and politics. Former presidents who attended Yale for undergrad include William Howard Taft, George H. W. Bush, and George W. Bush while former presidents Gerald Ford and Bill Clinton attended Yale Law School. Former vice-president and influential antebellum era politician John C. Calhoun also graduated from Yale. Former world leaders include Italian prime minister Mario Monti, Turkish prime minister Tansu Çiller, Mexican president Ernesto Zedillo, German president Karl Carstens, Philippine president José Paciano Laurel, Latvian president Valdis Zatlers, Taiwanese premier Jiang Yi-huah, and Malawian president Peter Mutharika, among others. Prominent royals who graduated are Crown Princess Victoria of Sweden, and Olympia Bonaparte, Princess Napoléon.
Yale alumni have had considerable presence in U.S. government in all three branches. On the U.S. Supreme Court, 19 justices have been Yale alumni, including current Associate Justices Sonia Sotomayor, Samuel Alito, Clarence Thomas, and Brett Kavanaugh. Numerous Yale alumni have been U.S. Senators, including current Senators Michael Bennet, Richard Blumenthal, Cory Booker, Sherrod Brown, Chris Coons, Amy Klobuchar, Ben Sasse, and Sheldon Whitehouse. Current and former cabinet members include Secretaries of State John Kerry, Hillary Clinton, Cyrus Vance, and Dean Acheson; U.S. Secretaries of the Treasury Oliver Wolcott, Robert Rubin, Nicholas F. Brady, Steven Mnuchin, and Janet Yellen; U.S. Attorneys General Nicholas Katzenbach, John Ashcroft, and Edward H. Levi; and many others. Peace Corps founder and American diplomat Sargent Shriver and public official and urban planner Robert Moses are Yale alumni.
Yale has produced numerous award-winning authors and influential writers, like Nobel Prize in Literature laureate Sinclair Lewis and Pulitzer Prize winners Stephen Vincent Benét, Thornton Wilder, Doug Wright, and David McCullough. Academy Award winning actors, actresses, and directors include Jodie Foster, Paul Newman, Meryl Streep, Elia Kazan, George Roy Hill, Lupita Nyong’o, Oliver Stone, and Frances McDormand. Alumni from Yale have also made notable contributions to both music and the arts. Leading American composer from the 20th century Charles Ives, Broadway composer Cole Porter, Grammy award winner David Lang, and award-winning jazz pianist and composer Vijay Iyer all hail from Yale. Hugo Boss Prize winner Matthew Barney, famed American sculptor Richard Serra, President Barack Obama presidential portrait painter Kehinde Wiley, MacArthur Fellow and contemporary artist Sarah Sze, Pulitzer Prize winning cartoonist Garry Trudeau, and National Medal of Arts photorealist painter Chuck Close all graduated from Yale. Additional alumni include architect and Presidential Medal of Freedom winner Maya Lin, Pritzker Prize winner Norman Foster, and Gateway Arch designer Eero Saarinen. Journalists and pundits include Dick Cavett, Chris Cuomo, Anderson Cooper, William F. Buckley, Jr., and Fareed Zakaria.
In business, Yale has had numerous alumni and former students go on to become founders of influential business, like William Boeing (Boeing, United Airlines), Briton Hadden and Henry Luce (Time Magazine), Stephen A. Schwarzman (Blackstone Group), Frederick W. Smith (FedEx), Juan Trippe (Pan Am), Harold Stanley (Morgan Stanley), Bing Gordon (Electronic Arts), and Ben Silbermann (Pinterest). Other business people from Yale include former chairman and CEO of Sears Holdings Edward Lampert, former Time Warner president Jeffrey Bewkes, former PepsiCo chairperson and CEO Indra Nooyi, sports agent Donald Dell, and investor/philanthropist Sir John Templeton.
Yale alumni distinguished in academia include literary critic and historian Henry Louis Gates, economists Irving Fischer, Mahbub ul Haq, and Nobel Prize laureate Paul Krugman; Nobel Prize in Physics laureates Ernest Lawrence and Murray Gell-Mann; Fields Medalist John G. Thompson; Human Genome Project leader and National Institutes of Health director Francis S. Collins; brain surgery pioneer Harvey Cushing; pioneering computer scientist Grace Hopper; influential mathematician and chemist Josiah Willard Gibbs; National Women’s Hall of Fame inductee and biochemist Florence B. Seibert; Turing Award recipient Ron Rivest; inventors Samuel F.B. Morse and Eli Whitney; Nobel Prize in Chemistry laureate John B. Goodenough; lexicographer Noah Webster; and theologians Jonathan Edwards and Reinhold Niebuhr.
In the sporting arena, Yale alumni include baseball players Ron Darling and Craig Breslow and baseball executives Theo Epstein and George Weiss; football players Calvin Hill, Gary Fenick, Amos Alonzo Stagg, and “the Father of American Football” Walter Camp; ice hockey players Chris Higgins and Olympian Helen Resor; Olympic figure skaters Sarah Hughes and Nathan Chen; nine-time U.S. Squash men’s champion Julian Illingworth; Olympic swimmer Don Schollander; Olympic rowers Josh West and Rusty Wailes; Olympic sailor Stuart McNay; Olympic runner Frank Shorter; and others.
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