I see what I think
Book review: The Border Between Seeing and Thinking. Ned
Block. Oxford University Press, March 7, 2023. ISBN
978-0197622223. Pages 560.
I have found that it is worth following the book reviews of
science magazines, otherwise interesting books may not be found. A short
presentation of Block's book was published by Science journal. I bought the
book and decided to wade through it because I'm interested in consciousness.
I’m familiar with some forms of meditation, also on a practical level. In
mediation exercises, I have experienced strong and genuine sensory perceptions,
similar to experiences caused by external stimuli. The neuroscientific research
publications I've read (especially in the last twenty - thirty years) have shed
light on the top-down mechanisms (the influence of thoughts on perceptions) and
their impact on the content of consciousness.
The feelings I experienced while reading Platos collected
works, sprang to my mind during reading Block’s current book. In the case of
both, I couldn't escape the thought that the content is in many respects deeply
sophistic and sematological: unnecessarities, confusing and misleading
divisions and formation of concepts,
search for cause-effect relationships between fictitious ideas, as well as
discourse in support-refutation of pointless
propositions. Because of this, delving in the books then, as now,
required vigorous concentration in order to be able to follow the author's
thoughts. Steadfastness and perseverance were repeatedly put to a tough test.
Determination was rewarded e.g. in such a way that at least some of the things
I considered to be sophistry became meaningful. This happened especially when
the arguments and divisions were connected to concrete structures and functions
of the brain. One have to remember that I haven't even completed an approbatur
course in academic philosophy, even though I've read many kinds of
philosophical literature for decades.
I found myself repeatedly thinking: "who is the book
intended for?". Is it intended for philosophers, psychologists,
neuroscientists or those who study these fields in general or just for those
who focus more narrowly on perception? Is it meant for the person in the street,
who wants to educate himself? I think that at least some of the concepts in the
book must be somehow familiar, otherwise the book opens badly. Is the book also
intended for the author himself as a summary of a long scientific work and
philosophical reflections?
According to Block, perception is iconic (pictorial),
non-conceptual and incapable of distinguishing truth from falsehood. Perception
and consciousness rely on the back and middle parts of the brain. Cognition
(thinking) clearly differs from perception in its structure and function.
Cognition is reasoning, analysis, evaluation, planning, problem solving,
reporting, memory and similar activities. Thinking is essentially based on the
functions of the front part of the brain. Block presents a wealth of perceptual
psychological tests and considers how they confirm his views. The author must
have read the recent achievements of neuroscience with enthusiasm. After all,
they clarify previous, often sophistic introspective, conjectures and research
results and help create new concepts. As an example, the phenomenological,
psychological, physiological and neuroscientific researsch of attention.
Based on research results, Block presents strong support for
my experience that ”I see what I think I see”. The phenomenon is called
"cognitive penetration". Cognitive functions have their own formats
that require healthy functioning of the frontal parts of the brain. Nerve
impulses pass from the front of the brain to the visual areas of the posterior
parts of the cerebral cortex. By imaging these visual areas (fMRI), it can be
deduced what the person is thinking (1). Thus, perception and imagined
perception use the same brain regions. However, the imagined visual perception
experience is more blurred (fewer pixels) than the real visual perception
experience. This is due to the fact that the information content (the number of
bits per time unit) decreases drastically when the impulses move from the cells
of the retina of the eye first to the geniculate nucleus, and from there to the
visual cortex step by step (V1 - V5) and further to the cognitive areas, where
bits can be processed in just a few in one second. Thus, it can be concluded
that the image produced by cognition (thought) (produced in top-down mode)
contains significantly fewer pixels than the genuine bottom-up image. A person
who practices meditation can confirm this, based on her or his own experience.
A whole chapter deals with consciousness. According to the
book, consciousness does not require cognitive, discursive activity, but is
rather connected to perception and, instead of global workspace, to the
activity of a narrower network called
"global playground". Attention, the appropriateness and
predictability of perception (Bayesian) are discussed, as well as the access
consciousness and the content of consciousness.
Block emphasizes that the main goal of the book is to show
that perception and cognitive activity are clearly distinguishable from each
other on a factual, concrete level and not just in a semantic or conceptual
sense. This difference is based on the structure and function of the brain.
However, the areas of cognition and perception do not live completely isolated
in their own bubbles, but communicate with each other in numerous ways.
I wish you happy reading moments!
Literature:
1.
https://www.sciencedirect.com/science/article/pii/S1053811914008428
