Study in human participants lends insight into one of neuroscience’s greatest puzzles: how the brain transforms unconscious information into conscious thought.
Columbia scientists have identified the brain’s ‘aha!’ moment — that flash in time when you suddenly become aware of information, such as knowing the answer to a difficult question. Today’s findings in humans, combined with previous research, provide compelling evidence that this moment — this feeling of having decided — pierces consciousness when information being collected by the brain reaches a critical level. The results of this study further suggest that this piercing of consciousness shares the same underlying brain mechanisms known to be involved in making far simpler decisions. Importantly, this study offers new hope that the biological foundations of consciousness may well be within our grasp.
This research was reported today in Current Biology.
“The vast majority of thoughts circling in our brains happen below the radar of conscious awareness, meaning that even though our brain is processing them, we are not aware,” said Michael Shadlen, MD, PhD, a Principal Investigator at Columbia’s Mortimer B. Zuckerman Mind Brain Behavior Institute and the paper’s senior author. “How some of that information bubbles to the level of consciousness, however, remains an unsolved mystery. But now, we’ve found a way to observe that moment in real time, and then apply those findings to our understanding of consciousness itself.”
For Dr. Shadlen, the most complex thoughts that the human brain can experience — such as love, grief, guilt or morality — can be ultimately be boiled down to a series of decisions, made by the brain, to engage with the outside world. He has spent his career working to understand how signals sent by the brain’s billions of cells result in such decisions. In so doing, he hopes to unravel the mechanisms that underlie the brain’s most complex abilities.
I would argue that it is helping to bring the biological study of the brain closer to the philosophical study of the mind.
In 2008, Dr. Shadlen and colleagues found that when asked to make a challenging decision, the brain does not use all the available information before deciding. This is not because the brain is unable to do so, but rather because at a certain point, the brain thinks it has all the information it needs. There is a mechanism in the brain that says “enough is enough.”
“For us, this then begged a question,” recalled Dr. Shadlen, who is also a professor of neuroscience at Columbia University Medical Center and an investigator at the Howard Hughes Medical Institute. “Could the moment when the brain believes it has accumulated enough evidence be tied to the person’s awareness of having decided — that important ‘aha!’ moment?”
To find out, the researchers asked five human participants to watch dots on a computer screen that moved like grains of sand blowing in the wind. The participants were then asked whether the dots seemed to be blowing to the right or to the left.
Placed in the center of the screen was a clock. Once the dots’ motion ended and after a brief delay, participants chose which direction the dots had traveled. Using a controversial technique known as mental chronometry, the participants were asked to move the clock handle backwards to the time they felt they had become aware that they knew the answer. The participants repeated this action over many trials and levels of difficulty.
“The moment in time indicated by the participants — this mental chronometry — was entirely subjective; it relied solely on their own estimation of how long it took them to make that decision,” said Dr. Shadlen. “And because it was purely subjective, in principle it ought to be unverifiable.”
But by incorporating this new data with decades of previous research on the brain mechanisms of decision making, the team devised a clever way to verify whether the time reported by the participants was an accurate reflection of having actually decided.
“If the time reported to us by the participants was valid, we reasoned that it might be possible to predict the accuracy of the decision,” Dr. Shadlen explained. “We incorporated a kind of mathematical trick, based on earlier studies, which showed that the speed and accuracy of decisions was tied together by the same brain function.”
Previous research by Dr. Shadlen and others had uncovered how the process of making a decision plays out at the level of individual cells in the brain. By combining this knowledge with the mathematical trick, the team could scientifically validate that the participants’ subjective reporting — their feeling of having decided — was indeed an accurate reflection of the brain’s decision-making process.
“Essentially, the act of becoming consciously aware of a decision conforms to the same process that the brain goes through to complete a decision, even a simple one — such as whether to turn left or right,” said Dr. Shadlen.
While preliminary, this study raises the possibility that a deep understanding the human brain’s most complex thoughts and feelings, once solely under the purview of philosophy, may soon be understood in terms of biology as well.
“Some people think that the nitty gritty of neuroscience is far from the highfalutin stuff that a philosopher would consider,” said Dr. Shadlen. “But rest assured, explaining these concepts — whether it’s ethics, consciousness anything else — in terms of neuroscience isn’t explaining them away. Instead, I would argue that it is helping to bring the biological study of the brain closer to the philosophical study of the mind.”
The Latest on: Human consciousness
- 'No human rights': Mexico blocks migrant caravan headed northon January 23, 2020 at 6:09 pm
"There are no human rights," yelled one migrant as he stood over an unconscious pregnant woman who was being attended to by medics. The woman eventually regained consciousness. Many cried as ...
- Consciousness & Brain Functional Complexity in Propofol Anaesthesiaon January 23, 2020 at 2:51 am
In particular, we have demonstrated that the complexity of the human brain activity, as inferred from fMRI BOLD signals, is modulated by one’s state of consciousness - supporting previous results from ...
- Human rights activist who faced torture in Pakistan holds poetry book signingon January 19, 2020 at 4:05 am
WHITEHALL, Pa. - A human rights activist who was tortured in Pakistan held a book signing Saturday at the Lehigh Valley Mall Barnes and Noble store. Moen Haider was signing copies of a book of poems ...
- Disco Elysium’s Brilliance Lies in Creating Chorus from Consciousnesson January 18, 2020 at 8:45 am
A good deal of Disco Elysium’s humor is derived from the absurdity of consciousness as a state — a collective of conflicting voices, united for better or worse within the self, but who in spite of ...
- ‘How Abuja’s proclamation on Amotekun contradicts national consciousness’on January 17, 2020 at 9:20 pm
Add to this the increased use of human beings for rituals, a barbaric practice based on ill-founded primordial ... The proclamation by Abuja that Amotekun is illegal now sounds like a new low in our ...
- Mavi is rapping his way toward the center of human consciousnesson January 17, 2020 at 12:15 pm
In a recent interview on the Internet radio show “thfctry,” the 20-year-old said that he’s studying the human mind because he wants to know “where consciousness physically resides.” That’s a musical ...
- Life after life: Does consciousness continue after our brain dies?on January 17, 2020 at 10:24 am
The case was part of a widely reported study Parnia published in 2014 called AWARE — the awareness during resuscitation trial, the world’s largest study of what happens to the human mind and ...
- Vlossom explore the human relationship with time in their kaleidoscopic journey through "Tabs" [Video]on January 17, 2020 at 5:00 am
The partnership that is Vlossom sees Australian musicians Nick Littlemore (Empire of the Sun & PNAU) and Alister Wright (frontman of Cloud Control), bring together elements of pop, psych-rock and ...
- Human, and Consciouson January 16, 2020 at 10:03 pm
Non-physical spirit, consciousness, is the very energy of existence. Physical evolution is Nature’s doing, for all. From here, a human being can only grow spiritually, for which conscious efforts are ...
- Does Consciousness Pervade the Universe?on January 15, 2020 at 4:30 am
What if consciousness is not something special that the brain does but is instead a quality inherent to all matter?
via Google News and Bing News