Brain Really Uses Quantum Effects, New Study Finds

A new research paper from a group independent of Penrose and Hameroff provides experimental evidence that microtubules display real quantum effects, specifically a process called superradiance, which requires molecules to have quantum links to each other to achieve larger light emission.

“Now comes this new paper from a group that doesn't seem to have anything to do with either Penrose or Hameroff and they say that they've cleared evidence that these microtubules actually do display real quantum effects. More specifically, it's a process called superradiance. It basically requires the molecules to have quantum links to each other to achieve a larger emission of light.”

The quantum superradiance effect observed in microtubules was demonstrated at room temperature and appears to be robust against environmental noise, which is unexpected given that quantum effects typically decohere rapidly in warm, noisy environments.

“They didn't actually test it in a cell, just in a solution, but it's at room temperature and they say the superradiant effect basically doesn't care about the environmental noise. This is very interesting, just because it's an example for quantum enhanced effect that seems to be unexpectedly robust.”

In addition to enabling superradiance, quantum effects in microtubules make them much more efficient at absorbing ultraviolet light and redistributing it to lower energies, which protects cells from potential harm caused by ultraviolet radiation.

“Another interesting part of the paper is that they say that the quantum effects in these microtubules can do something else, which is that they become much more efficient at absorbing ultraviolet light and redistributing it to lower energies. That is, they basically protect cells from the potential harm of ultraviolet light.”

A major problem with Penrose's quantum consciousness hypothesis is that the human brain is warm and noisy, environmental conditions that are generally hostile to quantum physics, unlike quantum computers which require suspension from multiple shock absorbers and cooling to millikelvin temperatures to preserve quantum effects.

“The problem with this idea, as many physicists have pointed out, is that the human brain is a warm and noisy place and they are generally not very welcoming to quantum physics. That's the reason that current day quantum computers are suspended from three levels of shock absorbers and cooled to a few millikelvin. It's not just because it looks impressive, though that is that, it's because otherwise the quantum effects just go away too quickly to do any computing with them.”

For Penrose's quantum consciousness hypothesis to be viable, quantum effects would need to survive in the human brain long enough for a neuron to fire, but the human brain fires extremely slowly, and even basic estimates show this timescale is insufficient for quantum effects to persist.

“For Penrose's idea to make any sense, you'd have to have quantum effects survive in the human brain at least until a neuron has managed to fire and the human brain is ridiculously slow in its firing. Even the most basic estimates say that it wouldn't work out.”

There is a significant logical gap between the empirical observation that quantum effects exist in microtubules and the theoretical claim that quantum effects generate consciousness; the presence of quantum effects in brain cells does not necessarily imply those effects create consciousness.

“What does any of this have to do with consciousness? Nothing, really. The last time I looked, we did need brain cells for consciousness. There seems to be a big logical gap between there are quantum effects in human brains and quantum effects create consciousness.”

Microtubules are large molecules that form a central part of all cells in the human body and play a significant role in signal transport in the human brain, composed of polymers that combine into tubes made of smaller components called tubulin.

“Microtubules are big molecules, basically. They're a central part of all cells in the human body and play a big role for signal transport in the human brain. They're polymers that combine to tubes and are made of smaller components called tubulin.”

The research group that discovered quantum effects in microtubules first built a computer model of how tubulin molecules combine to form microtubules and how they absorb light, then tested this model in the laboratory and found good agreement between theoretical predictions and experimental results.

“They first built a computer model for how the tubulin molecules combine to microtubules and how they would absorb light. Then they also tested this in the laboratory and they found good agreement, both theoretically and experimentally.”

The research establishing quantum effects in microtubules did not test these effects in living cells, only in laboratory solutions, which means the biological relevance of these findings remains to be established.

“They didn't actually test it in a cell, just in a solution, but it's at room temperature”