Sofia Mechanistic explanation - НБУold.nbu.bg/cogs/events/1_Sofia Mechanistic  · Mechanistic Explanation

  • View
    212

  • Download
    0

Embed Size (px)

Text of Sofia Mechanistic explanation - НБУold.nbu.bg/cogs/events/1_Sofia Mechanistic  · Mechanistic...

  • Mechanistic Explanation in Cognitive Science and Neuroscience

    Edouard Machery

    University of Pittsburgh

  • Three Issues

    (1) What is a mechanistic explanation?

    (2) Are explanations in neuroscience mechanistic?

    (3) How are explanations in neuroscience and in psychology related?

  • Plan

    1. Mechanistic explanation

    2. Explanation in neuroscience

    3. The relation of psychology and neuroscience

  • Plan

    1. Mechanistic explanation

    2. Explanation in neuroscience

    3. The relation of psychology and neuroscience

  • A Refresher on Explanation

    http://plato.stanford.edu/entries/scientific-explanation/

  • Hempels Deductive-Nomological (DN) Model of Explanation

    Explanantia:

    Sentence (in a language L) of a Law(s)

    of Nature

    Sentence describing the initial

    conditions .

    Explanandum:

    Sentence describing the event or

    generalization to be explained

  • But Explanation is Asymmetric

    h

    l

  • Relevance and Explanation

    All males who take birth control pills regularly fail to get pregnant

    !

    John Jones is a male who has been taking birth control pills regularly

    !

    John Jones fails to get pregnant

    !

    (Salmon, 1981)

  • Underlying Issue

    What seems amiss is that we want to explain an event by citing its causes:

    - causes are asymmetric

    - causes are relevant

  • Lack of Laws

    It is unclear what laws are in biology, psychology, sociology, etc.

  • Upshot

    Another model of explanation is needed, which acknowledges the explanatory role of causes and

    does not require laws.

  • Mechanistic Explanation: The MDC Model

    Phil Sci 2000

  • Mechanism

  • Mechanism

  • Mechanism

    A mechanism is a physical object that does something (for artifacts, its function) by virtue of the organization of its parts and of their activities

    (what they do).

  • Mechanisms in Science

  • Mechanistic Explanation

    To explain a phenomenon is to describe the mechanism producing it

  • Mechanistic Explanation

    That is, (1) to identify the parts of a mechanism and (2) their activities, which produce the

    phenomenon to be explained.

  • Protein Synthesis

  • Mechanistic Explanations and then Failure of the DN Model

    The mechanistic model of explanation acknowledges the explanatory role of causes and does not require laws, from which a phenomenon

    can be deduced.

  • No Laws At All?

    Generalizations describing the behavior of parts are however needed: Laws in situ (Cummins) or mechanistically fragile generalizations (Craver).

  • Constitutive Explanation

    Mechanistic explanations are constitutive (in contrast to merely etiological): An explanation of

    a phenomenon P involves determining what a mechanism is.

  • Decomposition and Recomposition

    Discovering explanations depends on two complementary discovery heuristics: decomposition and recomposition.

  • Multi-Level Explanation

    Mechanistic explanations are hierarchical and multi-level in that the activities of the parts of

    mechanisms need to be explained as well.

  • Plan

    1. Mechanistic explanation

    2. Explanation in neuroscience

    3. The relation of psychology and neuroscience

  • The Issue

    Are explanations in neuroscience mechanistic?

  • Explanation in Neuroscience

    Explanations in neuroscience are mechanistic.

  • Craver, chap. 4

  • Case Study:

    The Action Potential

  • Case Study:

    The Action Potential

  • Case Study:

    The Action Potential

  • Case Study:

    The Action Potential

  • Case Study:

    The Action Potential

    The discovery of the explanation of the action potential consists in understanding the

    mechanism responsible for it: replacing filler terms with mechanism parts and their

    interactions, etc.

  • Contrast with Cumminss Functional Explanation

    To explain a capacity of a system (characterized extensionally as a I-O function) is to identify a set of subcapacities that together

    constitute .

  • A Narrow Perspective on Explanation in Cognitive Science and

    Neuroscience

    It is dubious that all explanations in neuroscience are mechanistic. In particular, computational

    explanations are not mechanistic.

  • Example: Nosofskys (1986) Generalized Context Model

    Nosofsky 1986

  • Example: Nosofskys (1986) Generalized Context Model

    Nosofsky 1986

  • Example: Nosofskys (1986) Generalized Context Model

    Nosofsky 1986

  • Plan

    1. Mechanistic explanation

    2. Explanation in neuroscience

    3. The relation of psychology and neuroscience

  • The Issue

    Are psychological explanations (particularly, the kind of explanation provided in cognitive science) autonomous from neuroscientific explanations?

  • The Claim

    Psychological explanations are not autonomous because they are mechanisms sketches

    (incomplete, to-be-filled-in) of neuroscientific mechanistic explanations.

  • The Target

  • The Argument1. Psychological explanations are functional explanations.

    2. Functional explanations are sketches of mechanistic explanations.

    3. Mechanistic explanations of cognitive competences are neuroscientific explanations.

    4. If type-A explanations are sketches of type-B explanations, type-A explanations improve (get more explanatory) as their explanantia are connected to type-B explanantia

    5. type-A explanations are autonomous from type-B explanations iff type-A explanations do not improve (get more explanatory) as their explanantia are connected to type-B explanantia.

    6. Psychological explanations are not autonomous.

  • The Argument1. Psychological explanations are functional explanations.

    2. Functional explanations are sketches of mechanistic explanations.

    3. Mechanistic explanations of cognitive competences are neuroscientific explanations.

    4. If type-A explanations are sketches of type-B explanations, type-A explanations improve (get more explanatory) as their explanantia are connected to type-B explanantia

    5. Type-A explanations are autonomous from type-B explanations iff type-A explanations do not improve (get more explanatory) as their explanantia are connected to type-B explanantia.

    6. Psychological explanations are not autonomous.

  • Functional Explanation

    Explaining a capacity by functional analysis consists in identifying subcapacities and their organization, which are constitutive of the possession of the capacity to be explained.

  • Example

  • Functional Explanation in Psychology

    Explaining a psychological capacity by functional analysis consists in identifying psychological

    subcapacities and their organization, which are constitutive of the possession of the capacity to

    be explained.

  • Example

    Coltheart et al. 2001

  • Optimality Explanation

    Sanborn et al. 2001

  • Optimality Explanation

    Sanborn et al. 2001

  • The Argument1. Psychological explanations are functional explanations.

    2. Functional explanations are sketches of mechanistic explanations.

    3. Mechanistic explanations of cognitive competences are neuroscientific explanations.

    4. If type-A explanations are sketches of type-B explanations, type-A explanations improve (get more explanatory) as their explanantia are connected to type-B explanantia

    5. Type-A explanations are autonomous from type-B explanations iff type-A explanations do not improve (get more explanatory) as their explanantia are connected to type-B explanantia.

    6. Psychological explanations are not autonomous.

  • The Argument1. Psychological explanations are functional explanations.

    2. Functional explanations are sketches of mechanistic explanations.

    3. Mechanistic explanations of cognitive competences are neuroscientific explanations.

    4. If type-A explanations are sketches of type-B explanations, type-A explanations improve (get more explanatory) as their explanantia are connected to type-B explanantia

    5. Type-A explanations are autonomous from type-B explanations iff type-A explanations do not improve (get more explanatory) as their explanantia are connected to type-B explanantia.

    6. Psychological explanations are not autonomous.

  • The Argument1. Psychological explanations are functional explanations.

    2. Functional explanations are sketches of mechanistic explanations.

    3. Mechanistic explanations of cognitive competences are neuroscientific explanations.

    4. If type-A explanations are sketches of type-B explanations, type-A explanations improve (get more explanatory) as their explanantia are connected to type-B explanantia

    5. Type-A explanations are autonomous from type-B explanations iff type-A explanations do not improve (get more explanatory) as their explanantia are connected to type-B explanantia.

    6. Psychological explanations are not autonomous.

  • Autonomy

    Different types of autonomy:

    (1) ontological autonomy

    (2) evidential autonomy

    (3) explanatory autonomy

  • Evidential Heteronomy

    (1) Findings at a lower level can confirm or undermine high-level theories.

    (2) Findings at a low