2 | SCIENTIFIC AMERICAN | SPECIAL EDITION | WINTER 2022
WHAT IS CONSCIOUSNESS?
6 How Matter Becomes Mind
The new discipline of network neuroscience yields
a picture of how mental activity arises from carefully
orchestrated interactions among different brain areas.
By Max Bertolero and Danielle S. Bassett
14 How to Make a Consciousness Meter
Zapping the brain with magnetic pulses while
measuring its electrical activity is proving to be a reliable
way to detect consciousness. By Christof Koch
20 Can Lab-Grown Brains
Become Conscious?
A handful of experiments are raising questions about
whether clumps of cells and disembodied brains could be
sentient and how scientists would know if they were.
By Sara Reardon
26 The Brain Electric
Electrodes that stimulate brain tissue reveal the
topography of conscious experience. By Christof Koch
32 How Do I Know I’m Not the Only
Conscious Being in the Universe?
The solipsism problem, also called the problem of other
minds, lurks at the heart of science, philosophy, religion,
the arts and the human condition. By John Horgan
HOW WE PERCEIVE THE WORLD
38 Our Inner Universes
Reality is constructed by the brain, and no two brains
are exactly alike. By Anil K. Seth
44 Why We Have Free Will
Neurons fire in your head before you become aware that
you have made a decision. But this discovery does not
mean you are a “biochemical puppet.” By Eddy Nahmias
48 The Brain Learns in Unexpected Ways
Neuroscientists have discovered a set of unfamiliar
cellular mechanisms for making fresh memories.
By R. Douglas Fields
54 The Brain’s Social Road Maps
Neural circuits that track our whereabouts in space
and time may also play vital roles in determining how
we relate to other people.
By Matthew Schafer and Daniela Schiller
60 Face Values
Brain regions that process faces reveal deep insights
into the neural mechanisms of vision. By Doris Y. Tsao
68 Radical Change
Uncertainty in the world threatens our sense of self.
To cope, people embrace populism. By Michael A. Hogg
SPECIAL EDITION
Volume 31, Number 1, Winter 2022
36 how^ we^ perceive^ the^ world
4 what^ is^ consciousness?^