Robin Dunbar, an anthropologist from England, has been studying and refining his theory on how large human networks can realistically get. Graphic byMiguel Tovar/University of Houston

You go to conferences; you network; you collaborate — all researchers and academics do. But do you need more than 150 contacts? Linkedin, Facebook, Twitter — all of these platforms open us up to the possibility of thousands of acquaintances, though fewer we would refer to as "friends."

Studying the primate brain

Robin Dunbar, an anthropologist from England, has been studying and refining his theory of the "Dunbar number" for 30 years. Dunbar became convinced that there was a ratio between brain sizes and group sizes through his studies of primates. "This ratio was mapped out using neuroimaging and observation of time spent on grooming, an important social behavior of primates. Dunbar concluded that the size, relative to the body, of the neocortex – the part of the brain associated with cognition and language – is linked to the size of a cohesive social group," wrote Christine Ro in a 2019 BBC.com Future article.

After the group reached approximately 150, it collapsed.

Your network

Is it true that humans based on their brain, and especially pre-frontal lobe size, are only able to connect in an intimate manner with around 150 other individuals? Defined as someone you would make plans to have a drink or coffee with if you bumped into them randomly on the street, Dunbar's claim is that it seems to be a consistent theme throughout history. Says the BBC: "This rule of 150 remains true for early hunter-gatherer societies as well as a surprising array of modern groupings: offices, communes, factories, residential campsites, military organizations, 11th Century English villages, even Christmas card lists."

The Dunbar number decreases by a "rule of three" where the next step down is the number 50 – those you consider "friends." Then about 15 in a closely knit circle, and four to six only in our familial or closest friend contacts.

Social media and COVID-19

"What determines these layers in real life, in the face-to-face world… is the frequency at which you see people," says Dunbar. "You're having to make a decision every day about how you invest what time you have available for social interaction, and that's limited." So, social media and COVID would seem to be game-changers for this theory.

Dunbar went on to study the process of "grooming" and light touch with astonishing results, which you can read about in the New Yorker. Basically, if a person has a face-to-face encounter with a friend, they are consequently able to withstand unpleasantness right afterwards (their hands stuck into a bucket of ice, for instance!) at a much higher rate.

"It makes sense that there's a finite number of friends most individuals can have," wrote Ro. "What's less clear is whether that capacity is being expanded, or contracted, by the ever-shifting ways people interact online …'It's extremely hard to cry on a virtual shoulder,' Dunbar deadpans."

And how has COVID changed Dunbar's theory? "While our culture has encouraged us to accumulate friends, both on- and offline, like points, the pandemic has laid bare the distinction between quantity and quality of connections," said a New York Times article. "There are those we've longed to see and those it's been a relief not to see."

The Big Idea

Many try to debunk Dunbar's number, by saying that primate and human brains differ and that the calculations are off. Robin Dunbar defends his theory thirty years after first proposing it in The Conversation.

The number of people you can just recognize according to Dunbar, is about 1,500, so you might want to keep that in mind if you are an extrovert and have an incredibly large network of collaborators – both online and offline.

University of Houston's central research department, the Division of Research, has about 100 members. But, your Linkedin network — check the number and see what it sits at. And if it's 600, ask yourself: do you really need that many contacts?

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This article originally appeared on the University of Houston's The Big Idea. Sarah Hill, the author of this piece, is the communications manager for the UH Division of Research.

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Health tech startup launches Houston study improve stroke patients recovery

now enrolling

A Houston-born company is enrolling patients in a study to test the efficacy of nerve stimulation to improve outcomes for stroke survivors.

Dr. Kirt Gill and Joe Upchurch founded NeuraStasis in 2021 as part of the TMC Biodesign fellowship program.

“The idea for the company manifested during that year because both Joe and I had experiences with stroke survivors in our own lives,” Gill tells InnovationMap. It began for Gill when his former college roommate had a stroke in his twenties.

“It’s a very unpredictable, sudden disease with ramifications not just for my best friend but for everyone in his life. I saw what it did to his family and caregivers and it's one of those things that doesn't have as many solutions for people to continue recovery and to prevent damage and that's an area that I wanted to focus myself on in my career,” Gill explains.

Gill and Upchurch arrived at the trigeminal and vagus nerves as a potential key to helping stroke patients. Gill says that there is a growing amount of academic literature that talks about the efficacy of stimulating those nerves. The co-founders met Dr. Sean Savitz, the director of the UTHealth Institute for Stroke and Cerebrovascular Diseases, during their fellowship. He is now their principal investigator for their clinical feasibility study, located at his facility.

The treatment is targeted for patients who have suffered an ischemic stroke, meaning that it’s caused by a blockage of blood flow to the brain.

“Rehabilitation after a stroke is intended to help the brain develop new networks to compensate for permanently damaged areas,” Gill says. “But the recovery process typically slows to essentially a standstill or plateau by three to six months after that stroke. The result is that the majority of stroke survivors, around 7.6 million in the US alone, live with a form of disability that prevents complete independence afterwards.”

NeuraStasis’ technology is intended to help patients who are past that window. They accomplish that with a non-invasive brain-stimulation device that targets the trigeminal and vagus nerves.

“Think of it kind of like a wearable headset that enables stimulation to be delivered, paired to survivors going through rehabilitation action. So the goal here is to help reinforce and rewire networks as they're performing specific tasks that they're looking to improve upon,” Gill explains.

The study, which hopes to enroll around 25 subjects, is intended to help people with residual arm and hand deficits six months or more after their ischemic stroke. The patients enrolled will receive nerve stimulation three times a week for six weeks. It’s in this window that Gill says he hopes to see meaningful improvement in patients’ upper extremity deficits.

Though NeuraStasis currently boasts just its two co-founders as full-time employees, the company is seeing healthy growth. It was selected for a $1.1 million award from the National Institutes of Health through its Blueprint MedTech program. The award was funded by the National Institute of Neurological Disorders and Stroke. The funding furthers NeuraStasis’ work for two years, and supports product development for work on acute stroke and for another product that will aid in emergency situations.

Gill says that he believes “Houston has been tailor-made for medical healthcare-focused innovation.”

NeuraStasis, he continues, has benefited greatly from its advisors and mentors from throughout the TMC, as well as the engineering talent from Rice, University of Houston and Texas A&M. And the entrepreneur says that he hopes that Houston will benefit as much from NeuraStasis’ technology as the company has from its hometown.

“I know that there are people within the community that could benefit from our device,” he says.

Texas Space Commission launches, Houston execs named to leadership

future of space

Governor Greg Abbott announced the Texas Space Commission, naming its inaugural board of directors and Texas Aerospace Research and Space Economy Consortium Executive Committee.

The announcement came at NASA's Johnson Space Center, and the governor was joined by Speaker Dade Phelan, Representative Greg Bonnen, Representative Dennis Paul, NASA's Johnson Space Center Director Vanessa Wyche, and various aerospace industry leaders.

According to a news release, the Texas Space Commission will aim to strengthen commercial, civil, and military aerospace activity by promoting innovation in space exploration and commercial aerospace opportunities, which will include the integration of space, aeronautics, and aviation industries as part of the Texas economy.

The Commission will be governed by a nine-member board of directors. The board will also administer the legislatively created Space Exploration and Aeronautics Research Fund to provide grants to eligible entities.

“Texas is home to trailblazers and innovators, and we have a rich history of traversing the final frontier: space,” Lieutenant Governor Dan Patrick says in a news release. “Texas is and will continue to be the epicenter for the space industry across the globe, and I have total confidence that my appointees to the Texas Space Commission Board of Directors and the Texas Aerospace Research and Space Economy Consortium Executive Committee will ensure the Texas space industry remains an international powerhouse for cutting-edge space innovation.”

TARSEC will independently identify research opportunities that will assist the state’s position in aeronautics research and development, astronautics, space commercialization, and space flight infrastructure. It also plans to fuel the integration of space, aeronautics, astronautics, and aviation industries into the Texas economy. TARSEC will be governed by an executive committee and will be composed of representatives of each higher education institution in the state.

“Since its very inception, NASA’s Johnson Space Center has been home to manned spaceflight, propelling Texas as the national leader in the U.S. space program,” Abbott says during the announcement. “It was at Rice University where President John F. Kennedy announced that the U.S. would put a man on the moon—not because it was easy, but because it was hard.

"Now, with the Texas Space Commission, our great state will have a group that is responsible for dreaming and achieving the next generation of human exploration in space," he continues. "Texas is the launchpad for Mars, innovating the technology that will colonize humanity’s first new planet. As we look into the future of space, one thing is clear: those who reach for the stars do so from the great state of Texas. I look forward to working with the Texas Space Commission, and I thank the Texas Legislature for partnering with industry and higher education institutions to secure the future of Texas' robust space industry."

The Houston-area board of directors appointees included:

  • Gwen Griffin, chief executive officer of the Griffin Communications Group
  • John Shannon, vice president of Exploration Systems at the Boeing Company
  • Sarah "Sassie" Duggleby, co-founder and CEO of Venus Aerospace
  • Kirk Shireman, vice president of Lunar Exploration Campaigns at Lockheed Martin
  • Dr. Nancy Currie-Gregg, director of the Texas A&M Space Institute

Additionally, a few Houstonians were named to the TARSEC committee, including:

  • Stephanie Murphy, CEO and executive chairman of Aegis Aerospace
  • Matt Ondler, president and former chief technology officer at Axiom Space
  • Jack “2fish” Fischer, vice president of production and operations at Intuitive Machines
  • Brian Freedman, president of the Bay Area Houston Economic Partnership and vice chairman of Wellby Financial
  • David Alexander, professor of physics and astronomy and director of the Rice Space Institute at Rice University

To see the full list of appointed board and committee members, along with their extended bios, click here.