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Special Report

to keep consciousness to a minimum. As he explains,
“You know the Talking Heads song where ‘heaven is a
place where nothing, nothing ever happens’? Well,
that’s the brain’s preferred state because it is energy-
and time-efficient. It’s a survival mechanism.”
Solms described this idea in a 2018 paper co-au-
thored with Karl Friston of University College London,
a key figure in the development of the imaging tech-
niques that have so revolutionized brain research.
About 10 years ago Friston introduced the free energy
principle, a mathematically formalized version of the
theory of the predictive brain. In his definition, free
energy in the brain describes the neuronal state that
results from the brain’s failure to make a correct pre-
diction; the brain does all it can to avoid free energy.
In the final analysis, Solms and Friston assert, predic-
tive errors equal surprise equals consciousness; when
things do not work as expected, we get conscious-
ness—a state the brain tries to limit.
This perspective not only stands Freud’s theory on
its head, but it also contradicts the classic view that
the cortex (the outer layer of the cerebrum) is the
source of consciousness. According to Solms, these
higher regions are not the bearers of consciousness
but instead are “told” what to attend to by deeper
structures in the brain stem and midbrain. Solms
locates the source of consciousness in the areas of the
brain that regulate alertness, emotional stimulation,
and drives—precisely those areas where Freud located
the unconscious (brain illustration). “The pattern-de-
tection mechanisms of the cortex work most efficient-
ly without conscious attention. It is the deeper, emo-
tional parts of the brain, the limbic structures, from
which consciousness arises,” he says.

The brain’s outer rind—the cerebral cortex—is the seat of higher mental functions in traditional views of the brain. But in a model

proposed by Mark Solms of the University of Cape Town in South Africa, consciousness arises from activity in lower regions, such

as the reticular activating system, the ventral tegmentum and the thalamus. For instance, sensory information—all of which

passes through the thalamus—becomes conscious only when it is emotionally or motivationally relevant, in which case the

prefrontal and the cingulate cortex direct our attention to it. Meanwhile the striatum and the precuneus play a role in automatic

movement control and orientation, which enable us to interact with our environment without giving it a conscious thought.

FALCONIERI VISUALS

Cingulate cortex Thalamus

Prefrontal cortex Precuneus

Striatum

Ventral

tegmental area

Ascending reticular

activating system