An introduction to Cognitive

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An introduction to Cognitive Sciences

Pierre De Loor [email protected]

www.enib.fr/~deloor

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What are cognitives sciences ?

• Human knowledge, How does it work ?

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What are cognitive sciences ?

Philosophy

Psychology

Linguistic Computer Sciences

Neurosciences

Anthropology

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Some classical (unresolvable?) questions

• What difference beetwen human and animals ?

• Is it necessary to speak a langage for thinking ?

• Can we understand the functionning of the brain ? If yes, how ? And so what ?

• Can we understand our own functionning (circularity of cognitive science)

?

• How is organised the memory ?

• How can we learn ?

• How can we recognize a shape or a music ?

• What is the role of the body in cognition ?

• Is the environment more important than the brain ?

• What is consciousness, is it in the brain ?

• Does colors exist objectively ?

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This course

• Is an introduction,

• One part about SC and Cognitive Psychology

• The next part discutes more general advances in cognitive sciences (in philosophy,

psychology, neurosciences, biology and computer sciences)

• Evaluation : Practical work &

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Before cognitive sciences

Biology

Sense Mind

Representations

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Before cognitive sciences

• Behaviorism in opposition to Philosophy

• Introspection can’t be objective and can’t explain « the human »

• Representations are … representations, the mind is a black box and we cannot affirm representations in it

• We can just observe the link beetween stimulus and behavior

: behaviorism

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Before cognitive sciences

• Behaviorists : Watson 1908, Thorndike 1911,

Pavlov 1927, Skinner 1938

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Return of representations

• Tolman ~1930 : Representation of the maze is inevitable …

Reward is not

necessary : latent

learning

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Cognitive psychology

• Observing the behavior of human to explain

– Experimentations / Analysis

– Models (simulation/prediction)

– Epistemological postulate : Environment ->

Information -> Processing -> Behavior

– This epistemological postulate is discuted by

philosophy and critiquized by recent fields of

cognitives sciences

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Main fields in cognitive psychology

• Precursor : Nativism (Chomsky ~1968)

– All human own a generic langage. It is the only way to explain that we can speak different

langages.

– By the studies of different langage, and their link with the environment, Psychologists can explain this generic langage

– By the studies of the evolution from baby to adult we can find how this generic langage is

progressively transformed

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Main fields in cognitive psychology

• Piagitian field : constructivism

• Action for understanding

• Assimilation - Equilibration - Accomodation

• Abstraction

Piaget 1896-1980

Studies of the « stages » of cognitive capabilities

of childrens

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Main fields in cognitive psychology

• Examples of Piaget’s phases studies

– 0-2 years – sensorimotor phase -> scheme.

• 6 mounth : If i can’t touch the object it doesn’t exist

– 2-7 years – preoperatory phase

– Concrete operation (7-11 years) – Formal operation (11 years and +)

Quantity preservation

Numbers

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Main fields in cognitive psychologie

• Ecological field

– Role of environnment

• Social (Vygotski ~ 1934)

– thoughts evolve along with know-how

– Social interactions allow the internalisation of thoughts

• Physic

– Gestalttheorie: there are links beetween us and the shape of things. We are able to detect « interesting » shapes

– Affordances : Environnement help us to resolve problems. No

thoughts

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Main fields in cognitive psychologie

• Example of gestalttheorie items

We can detect the

shape from the ground but here there are 2 possible

shapes/grounds.

Square is a « good

mental shape » and we

can detect him even if it

is not present.

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Main fields in cognitive psychologie

• Example : affordance (Gibson)

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The work of a researcher in cognitive science

• The natural sciences do not imagine or create, they discover

Theory Hypotheses Observable

Experimentation validation

Model

Debate in the community

Epistemic Debate

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3 kinds of observables

• Neuronal activity

• Immediat behavior

• Activity

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Neuronal activity

• EEG / MEG : electrical activity (+ dynamic)

Example :

After 400 ms there is a different activity if

The subject recognizes something

• fMRI : oxygen (+ localisation)

Example :

Brain area’s activations

According to congruence image / sound

• The brain do something but what exactly ?

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Some examples in neurosciences

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Problems of neurosciences

• Granularity, dynamic, observables ???

• 150 000 000 000 neurons

• Local exchanges but also global phenomena (oscillation)

• Role of the endocrine system

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A question for the next part of this course

Is it serious to think that neuroscience could explain :

- « What it is like to see, to

undersdand, to love, to suffer ... » - First person experience,

- Phenomenal consciousness

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Immediat observable

• Answer

– Fast : possibility to test a lot of people

– But it is not always easy to « classify » an answer

• Time response

– Easy

– But some perturbations are possible : order of

exercices, tiredness, concentration

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Example of problem of obervation of Immediat behavior [Zibetti 2000]

• Hypothesis : Actions are perceived relative to a goal

• Observables : the answer of people who don’t see the goal of an action on a video : A man who go toward a bakery and push the door.

• 4 examples of answers,

– I saw a man who buy bred

– I saw a man who enter a bakery

– I saw a man who goes toward a bakery

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Example of problem of obervation of Immediat behavior [Zibetti 2000]

• Is a « unvisible » goal attributed by the observer ?

– I saw a man who buy bred

– I saw a man who enter a bakery

– I saw a man who goes toward a bakery

– A man entered in a shop, he wanted something

• How many are true or false relative to the hypothesis ?

• Classically, more than one « judges » are

sollicited and compared [Cohen, 1960]

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Activity observation

• for problem solving, psychologists

generally equate activity with state graphs,

• It is also possible to refine observations, for example with eye tracking,

• Verbalization

– Very informative

– But subjective bias

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Cognitive psychologist is a statistician

• It is important to evaluate the possibility of bias (order of exercices, natural variability, links beetwen variables …)

• It is important to evalutate the « robustness » of the results.

• Example of factors to evaluate

– S : Subject (each subject is different)

– O : order (if some exercices, the order of these exercices) – D : duration (in limited time)