Reactivity &

Reductionism

Descartes &Descartes & reductionismreductionism

DescartesDescartes introduced reductionismreductionism, the study of the

world as an assemblage of physical parts that can be broken

apart and analyzed separately.[Edward O. Wilson. Consilience. The unity of knowledge. A.A. Knoff. New York. 1998, p. 29]

REDUCTIONISM REDUCTIONISM Since the 17th century, the mechanistic reductionist world view

associated with Descartes has dominated European and American thought about nature and society.

According to this view, the world is made up of separate objects, things.

These things are essentially passive; they normally remain the way they are but can be set in motion by external causes.

They can be examined in isolation from each other and their properties measured. The resulting quantitative differences are the most important things about them.

Finally, once we have measured and described them, we can combine them into structures that will behave according to the properties analyzed in isolation.

Richard C. Lewontin & Richard Levins, 1988

Stimulus - Reaction

Stimulus Reaction Today

A fundamental issue in neurobiology is how sensory stimuli guide motor behavior

A major component of this problem involves understanding how the brain represents sensory features (p. 487)

Ranulfo Romo & Emilio Salinas. Sensing and deciding in the somatosensory system//

Current Opinion in Neurobilogy1999, 9: 487-493

Reductionism & FunWhile Occam’s razor is a useful tool in the physical

sciences, it can be a very dangerous implement in biology

Francis Crick ( … a vigorous habitual reducer …)

It is, of cause, always more fun reducing than being reduced.

… Crick finds the over-simplicity of the physicists’ view of his own subject much more obvious than his own over simplicity in approaching the social sciences and humanities.

[Mary Midgley. The ethical primate. Humans, Freedom and Morality. London & New York. Routledge. 1994, pg. 38.]

THE FRAGMENT OF THE RATIONALE OF THE SYMPOSIUM “PERILS AND PROSPECTS OF

TNE NEW BRAIN SCIENCES” (Stockholm, September 15 – 19, 2001)

The dominant tendency amongst neurobiologists is severely

reductionist, whilst by contrast amongst psychologists there remain

strong anti-reductionist predilections.

ReductionismThe Scientific Belief

Our minds – the behavior of our brains – can be explained by the interactions of nerve cells (and other cells) and the molecules associated with them.

[F. Crick. The Astonishing Hypothesis. New York: Charles Scribner’s Sons. 1994, p.7]

A Scientific Theory of the Mind

By “scientific” … I mean a description based on the neuronal and phenotypic organization of an individual and formulated solely in terms of physical and chemical mechanisms giving rise to that organization. [G.M. Edelman. The remembered Present.

New York: Basic Books. 1989, pp. 8-9]

THE CARTESIAN THEATERTHE CARTESIAN THEATERDescartes held that for an event to reach

consciousness, it had to pass through a special gateway … which Descartes located in the pineal gland or epiphysis. But everybody knows that Descartes was wrong (?!-Yu.I.A.). Not only is the pineal gland not the fax machine to the soul; it is not the Oval Office of the brain. It is not the “place where it all comes together” for consciousness…

I call this mythic place in the brain where it all comes together … the CARTESIAN THEATERCARTESIAN THEATER.Dennett D.C. Brainchildren. Essays on Designing minds. Penguin Books: London,

1998, p.132

THE NEURAL BASIS OF ROMANTIC LOVE

• Nothing is known about the neural substrates involved in evoking one of the most overwhelming of all affective states, that of romantic love.

• The activity in the brains of 17 subjects who were deeply in love was scanned using fMRI, while they viewed pictures of their partners.

• The activity was restricted to foci in the medial insula and the anterior cingulate coretx and, subcortically, in the caudate nucleus and the putamen.

• A unique network of areas is responsible for evoking this affective state.

Bartels A. & Zeki S. Neuroreport. 2000, 11 (17): 3829-34

Localization of Intelligence

A recent study by Duncan et al. [7] has found evidence that general intelligence is localized to regions of the lateral prefrontal cortex.

M. Atherton et al. Cognitive Brain Research, 16 (2003) 26-31, pg. 27

THE CONNECTIONS EXISTING BETWEEN THE LIMBIC SYSTEM AND THE PREFRONTAL CORTEX OFFER A MATERIAL BASIS FOR RELATIONSHIPS BETWEEN THE EMOTIONAL AND COGNITIVE SPHERES [Changeux J.-P. & Dehaene S. Neuronal models of cognitive functions. Cognition, 1989, 33, 63-109]

C- and U-neurons“I divide the nervous system into two types of

neurons, those concerned with consciousness, “C” neurons, and those which take care of unconscious functions, “U” neurons (the use of the word “neuron” in this context is shorthand for “otherwise unspecified subpart of the brain”). The goal of anesthesia is to interfere temporarily with the function of C neurons without disturbing the U neurons.”

[John C. Kulli. Is Searle conscious? BBS, 1990, 13:4, 614]

Left: microtubule, a cylindrical lattice of tubulin proteins. Right: coupled to position of a pair of quantum coupled electrons in an internal hydrophobic pocket, each tubulin may occupy two classical conformations (top) or exist in quantum superposition of both conformational states (bottom). A tubulin may thus act as a classical bit (top) or as a

quantum bit, or ‘qubit’

Microtubule simulation in which classical computing (step 1) leads to emergence of quantum coherent superposition and quantum computing (steps 2, 3) in certain (gray) tubulins. Step 3 (in coherence with other microtubule tublins) meets critical threshold related to quantum gravity for selfcollapse (Orch OR). A conscious event (Orch OR) occurs in the step 3 to 4 transition. Tubulin states in step 4 are noncomputably chosen in the collapse, and evolve by classical computing to regulate neural function. (b) Schematic graph of proposed quantum coherence (number of tubulins) emerging versus time in microtubules (MTs). Area under curve connects superposed mass energy E with collapse time T in accordance with E=h−bar/T. E may be expressed as Nt, the number of tubulins whose mass separation (and separation of underlying space time) for time T will selfcollapse. For T=25 ms (e.g. 40 Hz oscillations), Nt=2×1010 tubulins.Conduction pathways in microtubules, biological quantum

computation, and consciousness S. Hameroff , A. Nip, M. Porter, J. Tuszynski

Byosystems,2002,64,149-168

FROM PREPARATION TO THE BEHAVIOR

Predictions are

fallacious

Many results regarding ...

physiology and pharmacology during anesthesia cannot be anesthesia cannot be

extrapolatedextrapolated to behavioral conditions

[West M.R. Anesthetics eliminate somatosensory-evoked discharges of neurons in the somatotopically organized

sensorimotor striatum of the rat. The Journal of Neuroscience, 1998,18, 9055-9068]

Reductionism and fundamental understanding

Continued reductionism and atomization will probably not,

on its own, lead to fundamental understanding.

[Koch Ch. & Laurent G. Complexity And The Nervous System. Science, 1999, 284, 96-98]

REDUCTIONISM & $$• The most productive scientists, installed in

million-dollar laboratories, have no time to think about the big picture and see little profit in it.

• The eyes of most leading scientists, alas, are fixed on the GOLGGOLG.

• It is therefore not surprising to find physicists who do not know what a gene is, and biologists who guess that string theory has something to do with violins.

[Edward O. Wilson. Consilience. The unity of knowledge. A.A. Knoff. New York. 1998, pp. 31, 39]

Behaviorism represented an important, progressive force. BUT

ALL THINGS MUST END, WHETHER GOOD OR BAD,ALL THINGS MUST END, WHETHER GOOD OR BAD,

Explanatory reductionism still reignsExplanatory reductionism still reigns in biology, neurobiology, and in much of cognitive science. BUT

†and behaviorism began to give way in the final decades of the 20th century †

Now, however, this strategy is starting to show signs of strain around the edgesthis strategy is starting to show signs of strain around the edges It is weak when it comes to supplying explanations for many biological problems that involve numerous components interacting as a system.

New ways of thinking are needed to grapple with these problemsNew ways of thinking are needed to grapple with these problemsSystems level of explanations are both possible and achievable.Systems level of explanations are both possible and achievable.

BUT

Aristotel (384-322 years BC)

The essence of Aristotle’s The essence of Aristotle’s teleology is thus his rejection teleology is thus his rejection of a reductive understanding of a reductive understanding of living things.of living things.The central thesis of Aristotle’s Aristotle’s anti-reductive viewanti-reductive view is that the change by which the form of a mature animal or plant comes to be in appropriate matter cannot be understood solely in terms of …. the elements, of which both parent and offspring aremade.Mirus C. V. ARISTOTLE’S TELEOLOGY AND MODERN MECHANICS. A Dissertation, Notre Dame, Indiana, 2004.

Causes are the concern of the applied sciences

“The prime aim of the physical sciences is not the discovery of causes or causes chains... The study of the causes of this or that event is … always an application of physics. It is, then, still in case where our interest is in how one might … produce or counteract some spot-lighted development, that we talk about causes. … From this we can see why the term “cause” is at home in the … applied sciences, such as medicine and engineering, rather than in the physical sciences. For the theories of the physical sciences differ from those of the diagnostic and applied sciences much us maps differ from itineraries. In the physical sciences … the regularities we find … are represented in a way which is application-neutral. …Simple chain-like prescriptions can be given only in restricted sets of circumstances: we can confidently match causes and effects only in a given context. So once we shift from the diagnostic to the physical sciences the idea of a causal chain is of as little use as the term “cause” itself. ”

Stephen Toulmin The philosophy of science. Hutchinson’s university library, Hutchinson House, London. 1958

PRO:

Development of Western science is based on two great achievements:the invention of the formal logical system (in Euclidean geometry) bythe Greek philosophers, and the discovery of the possibility to find outcausal relationships by systematic experiment (during the Renaissance).

Albert Einstein

CONTRA:

“The prime aim of the physical sciences is not the discovery of causesor causes chains... Causes are the concern of the applied sciences[medicine, engineering, etc].”

Stephen Toulmin