On a pleasant spring day in 1137, St. Bernard of Clairvaux walked along the shore of Lake Geneva, absorbed in prayer and contemplation. That evening, when his companions spoke about the magnificent lake, he asked in surprise, “What lake?” I was reminded of this story, which illustrates how we fail to notice things to which we do not direct our attention, when I read about Victor Lamme’s recurrent processing theory of consciousness. This theory distinguishes between two dimensions of mental processing: the depth of processing and the direction of processing (see the figure from the article cited below).
The depth of processing is related to the number of brain regions
activated by a piece of information. The more regions involved in processing
the information, the deeper the processing. Processing depth also depends on
attention. When we direct attention to information, we process it more deeply.
The direction of processing concerns whether information is processed in
one or two directions. Information processed in only one
direction proceeds “from the bottom up,” through feedforward processing. We
begin with the basic processing of features of the stimuli we hear, see, and so
on, including movement, colour, and orientation. The information extracted then
“travels upward” through the brain and undergoes more complex processing—for
example, combining the different parts of a stimulus into a whole and preparing
a motor action in response to it, such as preparing the movement of a tennis
racket as it strikes the ball. Information processed in only one direction,
from the bottom up, is always unconscious, even when it is processed deeply and
even when it influences decision-making.
The understanding of information processed in both directions involves predictive processes that descend “from the top down.” We expect the stimulus we are beginning to perceive to be a particular object, and these expectations help us perceive that object. We can also identify objects that are partly hidden, of poor quality, or seen under inadequate lighting because we do not rely exclusively on information flowing from the perceptual processing of the stimulus itself toward higher brain regions. Instead, we combine this information with prior knowledge about the stimulus, which creates a set of expectations concerning its identity.
There is therefore a process of reciprocal feedback between expectations
descending from the top and perceptual processes rising from the bottom.
Expectations correct what we perceive when the stimulus is of poor quality,
while perceptual processes correct our expectations when the stimulus differs
from what we thought it was. This occurs through a repeated, recurrent cycle.
According to the recurrent processing theory of consciousness,
consciousness emerges when the brain begins to integrate information flowing
from the bottom up with information flowing from the top down. The theory
allows for two levels of consciousness.
The first level is “seeing” or “hearing,” and so forth. The brain integrates information flowing in both directions, and the information is present in consciousness, but its processing is not deep and takes place within limited regions of the brain. At this level, attention has not yet been directed toward the object. This is where the theory differs from Dehaene’s theory of consciousness, which we discussed in an earlier post. According to Dehaene, if processing is not deep—that is, if it does not take place across widespread regions of the brain—there is no consciousness at all.
The second level of consciousness is “knowing.” The brain integrates information flowing in both directions, the information is processed deeply across many brain regions, and attention is directed toward the object. At this stage, working memory enters the picture and can process the stimulus.
This distinction between seeing and knowing is fascinating. We encounter
it constantly in everyday life in concrete and simple ways. For example, a few
days ago I was looking for yeast in the pantry and concluded that there was
none, even though the packet of yeast was the very first thing in front of me
when I opened the pantry door. I did not see the yeast because I did not direct
my attention toward it.
I wonder to what extent this theory can also explain more complex
situations. This brought to mind Maria Semple’s original and excellent novel Where’d
You Go, Bernadette? The book deals wittily and humorously with subjects
such as the boundary between sanity and mental illness, belonging and social
deviance, the point at which a life event becomes psychological trauma,
political correctness concerning mental health, and more.
One of the characters in the book, Audrey Griffin, is a typical American
mother who lives in a detached house in a Seattle suburb and is involved in the
school community of her son Kyle, an unpleasant young man who becomes involved
with drugs. Whenever the school staff invite Audrey to a meeting about Kyle,
she avoids it by making various excuses. When she does attend such a meeting,
she defends Kyle fiercely and is unable to see any problem with his behaviour.
Audrey continues in this state of seeing without knowing until a shocking event
causes her to understand the situation as it truly is.
In terms of the theory, it seems to me that as long as Audrey saw but
did not know, the top-down processes overpowered and suppressed the information
flowing from the bottom up. Audrey held firmly to her own theory about Kyle and
refused to let reality confuse her. The shocking event triggered recurrent
processes that integrated the information arriving from above with the
information arriving from below, thereby making knowledge possible.
Perhaps this is what we do in therapy: we help activate the recurrent
process that leads from a state of consciousness in which one merely “sees” to
a state in which one “knows.”
Mudrik, L., Boly, M., Dehaene, S., Fleming, S. M., Lamme, V., Seth, A.,
& Melloni, L. (2025). Unpacking the complexities of consciousness: Theories
and reflections. Neuroscience & Biobehavioral Reviews, 170, 106053.
Maria Semple, Where’d You Go, Bernadette?
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