Cognitive science and the integration challenge

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Chapter 4:
Cognitive science and the
integration challenge
Overview
• Review multiple choice questions on class test
• Bring out some of the key features and themes of our
historical overview
• Introduce integration challenge
• Sketch out the next stages of the course
Cognitive Science
 José Luis Bermúdez / Cambridge University Press 2010
Question 1
1. According to Marr, which of the following are involved in giving a
computational-level analysis of an information-processing system?
(a) Specifying what the system is doing—its basic task.
(b) Specifying the representational format of the system’s
inputs and outputs.
(c) Specifying the algorithm the system uses to compute.
(d) a and b
(e) b and c
(f) a and c
Cognitive Science
 José Luis Bermúdez / Cambridge University Press 2010
Question 2
2. According to Miller, the advantage of recoding in an
immediate memory task is that it does which of the
following?
(a) Increases the chunks per bit of information.
(b) Increases the bits per chunk of information.
(c) Increases the span of absolute judgment.
(d) Increases the span of perceptual dimensionality.
(e) None of the above.
Cognitive Science
 José Luis Bermúdez / Cambridge University Press 2010
Question 3
To parse a sentence such as “Put the red block on top of the blue
block on the table” SHRDLU would do which of the following?
(a) Examine the micro-world before beginning syntactic processing.
(b) Identify all syntactically possible options, then use information
about the micro-world to identify semantically possible options.
(c) Disambiguate the sentence by asking a question.
(d) Identify a syntactically possible option, then use information
about the micro-world to evaluate whether it is semantically
possible.
Cognitive Science
 José Luis Bermúdez / Cambridge University Press 2010
Question 4
Why is it acceptable to appeal to addition when specifying an
algorithm for multiplication?
(a) Because there is only one algorithm for addition.
(b) Because every Turing machine can compute the addition
function.
(c) Because addition is an algorithmic operation.
(d) Because addition is built into the machine table of every
Turning machine.
(e) None of the above.
Cognitive Science
 José Luis Bermúdez / Cambridge University Press 2010
Question 5
5. Some cognitive scientists interpreted Shepard & Metzler’s results
as evidence for non-digital information coding because. . .
(a) The operations defined over digitally coded information should be
too complex to perform.
(b) The processing time for digitally coded information should be a
function only of the amount of information encoded.
(c) It should not be meaningful to perform the rotation operation on
digitally coded information.
(d) a and b
(e) b and c
(f) a and c
Cognitive Science
 José Luis Bermúdez / Cambridge University Press 2010
What is cognitive science?
• Is there such a thing as cognitive science (as opposed to
the cognitive sciences)?
• Are there any basic assumptions about the mind that
unify all the different models and approaches we have
been considering?
• Does cognitive science have a distinctive methodology?
Cognitive Science
 José Luis Bermúdez / Cambridge University Press 2010
An early model
• Identifies connections between
different cognitive sciences,
but sheds no light on why
there need to be such
connections
• Doesn’t help us to understand
what each discipline
contributes
• Doesn’t give a very accurate
picture of contemporary
cognitive science
Cognitive Science
 José Luis Bermúdez / Cambridge University Press 2010
Two basic assumptions
(1) The mind is too complicated to be understood using the
resources of any discipline on its own

•
Need for interdisciplinarity
(2) The mind has to be understood at many different levels

Need for an integrated multilevel explanation
Cognitive Science
 José Luis Bermúdez / Cambridge University Press 2010
The example of neuroscience
Neuroscience has evolved enormously since the early days of
cognitive science
It is itself highly interdisciplinary and multilevel
Illustrates the close connection between
• levels of organization
• levels of explanation
• available scientific tools and techniques
Cognitive Science
 José Luis Bermúdez / Cambridge University Press 2010
Levels of explanation
A
B
C
D
E-H
Cognitive Science
 José Luis Bermúdez / Cambridge University Press 2010
Experimental psychology
Cognitive neuroscience
Behavioral neuroscience
Systems neuroscience
Cellular neuroscience
Molecular neuroscience
Tools and levels in neuroscience
Cognitive Science
 José Luis Bermúdez / Cambridge University Press 2010
Organization in psychology
• Scientific psychology is not organized vertically
in terms of levels
• Instead organized horizontally in terms of
domains
MIND AND BEHAVIOR AT THE LEVEL OF THE ORGANISM
General cognitive capacities
COGNITIVE PSYCHOLOGY
Cognition in a social context
SOCIAL PSYCHOLOGY
Individual personality and character
PERSONALITY PSYCHOLOGY
Cognitive Science
 José Luis Bermúdez / Cambridge University Press 2010
Non-human cognition
COMPARATIVE PSYCHOLOGY
How cognitive abilities develop
DEVELOPMENTAL PSYCHOLOGY
Cognitive Science
 José Luis Bermúdez / Cambridge University Press 2010
The integration challenge
•The challenge of providing an unified account of
cognition that draws upon and integrates the
whole space
• Many regions within the “space” of
cognitive science remain little studied
• The “space” is not organized by discipline
Cognitive Science
 José Luis Bermúdez / Cambridge University Press 2010
3 approaches to IC
Local integrations
• Examples of specific cases where cognitive
scientists have built bridges across levels of
explanation and between disciplines
Global models of integration
• Blueprints for solving the integration challenge
The mental architectures approach
Cognitive Science
 José Luis Bermúdez / Cambridge University Press 2010
Local integration 1
• Inspired by experiments in the psychology of reasoning
showing that people are systematically prone to very
specific types of fallacies in deductive reasoning
• Evolutionary psychologists suggest that these patterns of
error are by-products of highly specialized cognitive
mechanisms that emerged to solve adaptive problems
• massive modularity thesis
• cheater detection module
Cognitive Science
 José Luis Bermúdez / Cambridge University Press 2010
Local integration 1
•Solution of adaptive problems
Explains
•Emergence of dedicated cheater detection system
Explains
•Patterns of error in logical reasoning tasks
Cognitive Science
 José Luis Bermúdez / Cambridge University Press 2010
Local integration 2
•Cognitive scientists often treat functional neuroimaging as
if it provides direct “map” of the mind in action
•But neuroimaging directly measures blood flow (PET) or
levels of blood oxygen (fMRI) – whereas the “motor” of
cognitive activity is neuronal activity
•How do we integrate BOLD signal information with
information about neuronal activity?
Cognitive Science
 José Luis Bermúdez / Cambridge University Press 2010
Local integration 2
•Research question: What are the neural correlates of the
BOLD signal?
•Experiments by Logothetis explored this question by
calibrating fMRI data with microelectrode recording
• bridging levels of organization and levels of
spatial resolution
• allowed fMRI data to connect up with neural
models (and computational neuroscience)
Cognitive Science
 José Luis Bermúdez / Cambridge University Press 2010
Models of global integration
Two main candidates:
• Marr’s tri-level hypothesis - explicitly proposed
as a way of bridging different levels of
explanation
• Models of inter-theoretic reduction derived from
philosophy of science
– analogy with unity of science hypothesis
in the physical sciences
Cognitive Science
 José Luis Bermúdez / Cambridge University Press 2010
Mental architectures approach
Starts off from the basic assumption that cognition is a form of
information-processing
Assumption governs all levels of organization
(from neurons upwards) and almost all
explanatory models/hypothesis within the
individual cognitive sciences
But there is relatively little discussion w/in those disciplines of
how information and information-processing are to be
understood
Cognitive Science
 José Luis Bermúdez / Cambridge University Press 2010
Mental architecture
A mental architecture is a model of how the mind is
organized and how it works to process information
1) In what format does a cognitive system carry
information?
2) How does that system transform and process
information?
3) How is the mind as a whole organized into informationprocessing sub-systems?
Cognitive Science
 José Luis Bermúdez / Cambridge University Press 2010
Timetable
•Evolutionary psychology
Wednesday 9-30
•BOLD signal
Friday 10-2
•Global models & mental architectures
Monday 2-5
Cognitive Science
 José Luis Bermúdez / Cambridge University Press 2010
Two models of informationprocessing
The physical symbol system hypothesis
• e.g. Turing machine model of informationprocessing
• associated with classical, symbolic AI
Connectionism/artificial neural networks
• neurally-inspired models of informationprocessing
• used to model cognitive/perceptual abilities that
posed problems for classical AI
Cognitive Science
 José Luis Bermúdez / Cambridge University Press 2010
have
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