MBB Part II.

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MBB Part II. Cognitive Psychology Lecture
1. History of Cognitive Psychology.
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How has Cognitive Psychology Evolved?
Different from other areas in psychology, though
not completely distinct. An umbrella term for
all higher mental processes (Ashcraft,
2002). Cognitive currently the dominant
paradigm in Psychology. Struggled to achieve
this historically - early quarrels with
Empiricism. Growth of technology over past 5
decades helps provide scientific evidence.
Lecture - Early origins of studies of
mind. Descartes I think, therefore I am.
(cogito ergo sum) Late 19th/ early 20th C
Growth of Psychology as a science . Challenge of
Behaviourism. Response to Behaviourism. What
is Cognitive Psychology today?
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Early Greeks (circa 350 B.C.)
One of the first to consider the nature of the
mind. Philosophers - sought
knowledge. Rationalists use reasoning to
establish truths, but often wrong. (e.g. the
mind is located in the heart, people can
survive injury to the brain, but never the heart).
But provide beginnings.. 1. Learning and
remembering occur by associations in the
mind. 2. Observation should be basis for any
study/determining truths. 3. The mind is a
blank slate learning occurs by experience.
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Descartes (1596 - 1650)
Mathematician, scientist philosopher -
Rationalist. Interested in the quest to
establish truths and knowledge. Religion.
Conflict - Observation is the key (Materialism)
- but cant observe God! (Galileo Earth is NOT
centre of the Universe). This viewed as heresy.
Need to resolve conflict, so distinguish between
mind and body. (Cogito ergo sum - the act of
thinking could not be doubted). Mind exists
otherwise God cannot!
Legacy - credibility for the existence of mind.
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Rationalism.
Science today demands empirical methods, however
Descartes used reasoning. School of thought also
employ mathematics as a basis for truth (e.g. 1
1 always equals 2.).
Current - Connectionism. e.g. - mathematical
models constructed to model thought processes
Used to explain construction of Semantic
categories, and also word and sentence
building/production (Psycholinguistics).
Challenges from Positivism e.g. Auguste Comte
(1758 1857). Science needs facts
observation, experimentation description of
experienced phenomena.
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1800 1878. Psychophysics.
Gustav Fechner (1801 1887). Consciousness. Inte
rested in the relationship between what happens
in the external environment and what is actually
perceived. How bright is a light? We make
sense of this ourselves therefore brightness
is a psychological construct.
Helmholtz (1821 1894) Visual Perception. We
make inferences about the world around us based
on prior knowledge. We do not back off in
terror when a canary is close to us not a giant
yellow monster. External stimuli our
experience of them are not the same (noumena
phenomena).
Mind makes sense of things.
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Structuralists (1879) Wilhelm Wundt. Science
should concern itself with how people consciously
experience the world.
Studies based on Chemistry (deconstructionist
approach) an existing and credible
science. Different elements combine to produce
more complex structures.
3 components of consciousness Sensation F
eelings Images.
Can understand all mental experiences by breaking
them down in this way. Do this by method of
Introspection. Think through and describe
thoughts.
But journalistic accounts highly subjective.
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Functionalists (e.g. William James, 1842
1910). Disagree with this approach. Study
mind, yes. But dont break it down. Consciousnes
s/awareness is a continuous process, snapshot
view is unrealistic. If we start thinking about
conscious experience, we immediately change the
experience itself.
Study functions of mind, not experience
process, not structure E.g. Ask - what is the
function/purpose of anger? (not describe it).
William James (1890). The Principles of
Psychology Provides outlines of the functions
of basic cognitive processes e.g. Attention,
Remembering, Emotions Thinking.
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Behaviourism. (e.g. John B. Watson 1878 1958).
American origins, spread throughout
Europe. Reject Structuralism
Functionalism. Psychology needs observable
measurable (scientific) subject matter. Study
behaviour its relationship to the environment
(stimulus response). Mind cannot explain why
we behave as we do. Black Box unimportant
bridge between S R.
But dont completely reject mind! Individuals do
have conscious experiences (although irrelevant
for study) Hunger. Results from tangible
stimuli (e.g. drop in insulin levels / smell of
chips). Provokes response behaviour eating.
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1900s 1950s. What happened to Mind?
Behaviourist paradigm flourished but not the
whole story. Others still exploring mental
processes, though largely hidden.
Early pioneers.. Hermann Ebbinghaus (1913).
Influenced by empiricists. Memory
studies. Carried out many trials on himself to
test his own capacity for learning. Controlled
conditions use nonsense syllables to eliminate
effects of previous learning. Found -
Savings. More times a list was learned, the
less time it took to recall items in consequent
trials.
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Ebbinghaus Principles.

• Retention increases with the frequency of
  repetitions.
• 2. Learning curve (or forgetting curve)
  forgetting occurs rapidly in the early stages of
  learning or retention, then slows down
  considerably.

Primacy Recency Effects. Importance of word
items position in a list.
Theoretical basis for ensuing studies of
memory.(e.g. current - Working Memory). Experimen
tal methods. Still used in wide range of other
areas in cognition
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Sir Frederick Bartlett (1932)
Everyday memory. Disagreed with excessive
controls. (e.g. nonsense syllables). Gave
passages of prose to read.
Found - not only certain details omitted, but
others inserted.
Suggest Memory is not passive, but creative
and constructive. A thing or a
process? Top-down or bottom-up processing ?
(Problem-Solving) Schemas (Semantic Memory).
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Challenges to Behaviourism. Does it really
capture the whole richness and complexity of
human behaviour? Can we really afford to neglect
the mind? - evidence suggests not.
McNamara, Long Wike (1956). Learning without
responding. Trial 1. 2 conditions (a) rats run
T maze to food (b) rats pushed to food in
cart. (argument) Rats in carts are not
stimulated by the maze).
Trial 2. Both groups of rats run T maze.
Predict Stimulated responding rats should
reach food more quickly.
Result - Both showed same preference for side of
the maze where food placed. Explanation? - Rats
in carts still see maze, and expect food to be
in same place.
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Tolman (1948) Cognitive maps.
Rats allowed to explore a maze 3 different
paths to food. Route 1 (shortest) Route 2
(medium) Route 3 (longest).
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3
1
Experiment - Block Route 1, rats opt for Route
2. Block Route 2, predict rats will opt for
Route 1 (strongest association with food).
Result? Rats opt for Route 3 (no association).
Behaviourists cannot explain.
Cognitive explanation rats have mental
representations of maze expect Routes 1 2 to
be blocked
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More challenges. Kohler (1920s) Problem-Solving
Behaviour in Chimps.
Used tools to get out-of-reach bananas. No
banana, no reward, so predict chimp should stop
tryingwhich didnt happen.
Found Chimps managed to solve their problems
suddenly, rather than by trial and error.
Once solved, they could solve the same problem
again, with few irrelevant moves. They were
able to transfer what they had learnt previously
to novel situations. Problems for the idea of
stimulus-response learning.
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More direct challenges. Lashley (1948) Complex
behaviours.
How can simple S-R explain complex behaviours
such as playing a piano? Each note 1
response? To what stimulus? Whats the reward?
How many do you need for one tune? Audience
applause is reward?
Not enough! Need to plan and organise long
sequences of notes before ever playing
(responding!)
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Language. (Chomsky, 1959).
Skinner Language is verbal behaviour. Spoken
word (e.g. tea), is simply a response to being
presented with a cup of brown liquid.
Chomsky But we dont always verbally
respond!
Cup of brown liquid can produce other responses
such as drink, or coke. Any given stimuli can
produce wide range of responses.
Children learn a language spontaneously no real
stimuli
People often speak in the absence of any stimuli
(or even sing
We generate creative and complex sentences that
we have never been rewarded for before.
Devastating criticisms behaviourists cannot
answer.
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Re-establishment of Cognitive Psychology (1950s)
Growth of technology. Development of
communications systems (Radio telephone)
Shannon (1946) How do they work?
Key components- Information source Transmitter
Receiver Good analogy of how humans process
information
rehearsal
Sensory store
Short- term store
Long Term store
External world
retrieval
Early progress but whats in the boxes? What
goes down the lines?
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The Massachusetts Institute of Technology
Symposium on Information Theory. (September
1956). (Miller, 1985) The birthday of
Cognitive Psychology
George Miller. Memory capacity 7 /- 2 Humans
are information processors with limited powers
and capacities.
Newell Simon.Logic Theory Machine Computers
present new paradigm for exploring the mind /
thought processes
Both can perform a wide variety of tasks based
on the manipulation of symbols. Both
translate incoming information into different
forms. Both capable of executing logical
step-by-step sequences based on decision making
processes. (If A then B). Both capable of
storing information, as well as storing the
knowledge needed to do something with that
information.
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Computers Cognition
1950s 60s. New paradigm highly productive for
Cognitive Scientists Experimentalists.
But how appropriate IS this analogy? Are we
really just computers? 1. Computers are much
better at solving complex mathematical problems
very quickly, whereas humans are not. 2.
Computer programs tend to fall apart if even a
small piece of their program is wrong or
missing. Humans do not they improvise. 3.
Computers are all or none humans can give
partial responses. 4. Brain changes as it
learns (Churchland, 1989)
What can this tell us about bottom-up and
top-down processing? Also parallel, not
serial processing?
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Cognitive Psychology in 21st C. Broadly divided
into 3 camps
Experimentalists. Empiricists? Controlled
trials, manipulation of IVs e.g. (Words - 1
syallable v 3 syllables) DVs Reaction
times, number of items recalled, mistakes made,
etc. Used in virtually all areas of Cognition
Stroop Task ( 1935)
Blue Blue Green Green Red Red Orange Orange Bl
ack Black
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Cognitive Scientists.
Rationalists?? Construct mathematical (logical)
models to explain thought patterns/processes. Th
eoretical but based on past findings/observation
s. Use principle of Spreading Activation
Connectionism - Semantic Memory how we form
concepts. Speech Production (Psycholinguistics)

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Basic example of a Connectionist model of Word
Retrieval
Excitatory Inhibitory

• Spreading activation.
• Links are excitatory and inhibitory
• Activation spreads both ways.

cog
gun
big
bag
words
ag
un
og
ig
rimes
a
b
c
g
phonemes
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Cognitive Neuroscience
Study brain impairments (birth or
trauma). Compare performance of impaired
unimpaired. What can these tell us about
organisation and processing of information?
Eg. Syz, (1937). 45 year old male, head trauma.
Result in memory loss for new, though not old
information. Memory returned later, though still
couldnt retain new information for names. Early
case study, demonstrates that memory is not a
unitary store (STM LTM). Also tells us that
there are stores for different kinds of
information, and that any of these can become
damaged, whilst leaving others intact.