PSYC 213 Lecture Notes - Lecture 2: Cognitive Revolution, Information Theory, Scientific Method
16 May 2018
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Lecture 002 - 01/11/2018
Recap from last class:
• Philosophy: Idea of Aristotle & Plato have contributed to different aspects of cognitive
psychology
o Plato → Rationalism (influenced theory development)
o Aristotle → Empiricism (influenced experimental method development)
• Other examples of philosophers:
o Augustine (around 300CE): thought that the mind is the interface between the
world and the divine and that memory is the root of psychological function
o Aquinas (around 1250): distinguished between the soul & reason → he thought
that senses help us acquire knowledge that governs reason
• Structuralism (late 1800): sought to understand the configuration of the basic elements
of the mind by studying the components of percepts/ sensations
o Looking for the Lego pieces of the mind
o Introspection is an experimental method of self-observation
• Functionalism: psychologists should focus on why the mind words rather than studying
the structure of the mind, methodological approach was eclectic
o The “usefulness of knowledge” was a driving force
• Behaviorism (1900’s): focused on the stimulus & the response (aka only what can be
observed) → mental processed were treated as mysterious black box that should be
avoided,
o Shift from human to animal research (because offers more control)
• Cognitive revolution: because there were problems with behaviorism (aka it could not
deal w/ complexity of human activity) this lead to the cognitive revolution→
accepted internal mental states and the use of rigorous scientific method to study these
states
o Using classic models focused on information processing
• 3 main stages of CP: (fluid field)
o 50/60s: human experimental psych
o 70s: computer analogies info processing approach
o 80s: cognitive neuroscience
• Ecological validity: studying cognition in real world
Today’s class
• Classic view: we are processors of information → overall view of cogsci, related to
many other scientific fields,
o main idea: the world contains information for us to store and process
o Focuses on the process that transform/ store/ recover sense of perception
• Basic assumptions:
o 1. The mind if a general purpose processing system that performs a series of
specific computations
o 2. The mind carries out tasks as programmed sequential steps, each step in a
sequence changes its immediate predecessor
▪ Info flows from one step to the next & the aim is to specify the processes
that underlie performance at each step
find more resources at oneclass.com
find more resources at oneclass.com
o 3. Processing these steps takes time and resources: there is a limit in how much
mental activity can occurs in one time
▪ How long it takes to do something can provide insight into how much
cognitive resources are used
• Most basic unit of info is Bit (stands for binary digit), typically used in comp program, for
cogsci, idea of a ‘bit’ allows us to make predictions about the function of info in our envi
• Information theory: the function of information is to reduce uncertainty in our minds -
the amount of info provided in a message is inversely related to its probability of
occurrence
o AKA The less likely an event is, the more info it contains to us
• Example: which missing word contains more info?
o The zebra has black and white __ VS. the zebra ran through the __?
o Stripes Vs field → field gives more info because there are a lot of possible
choices
• William Hick (1952): determined the relationship between choice reaction time and
information content of stimuli with this experiment
o Participants saw a display of 10 lamps in a circle, one lamp lit up every few
seconds and participants pressed the button underneath the display as soon as
the light was lit → he could manipulate the number of lamps that could light up
▪ Sometimes only one of the 10 lamps could light or sometimes any of
them could light up
• The more lights they saw lead to increased response time → when have more options/
lights, will be less certain so will have a slower response
• Led to Hick’s law: a math equation to show that the more info contained in a signal (aka
the more bits), the longer it takes to make a correct response to this signal (the more
energy consumed)
o aka: the more info contained in a signal, the more processing it takes, so it will
take longer to make a correct response
• Ray Hyman: (1953) participants responded to a set of 8 light where the lights were
assigned learned names
o Exp 1: increasing the variety of the number of light participants had to name that
could light up increased naming time
o Exp 2: reaction time to name a light decreased for lights that were presented
often (more frequently) over a series of trials
o Exp 3: over trials Hyman manipulated the sequential probabilities of the lights
▪ High sequential probability: one light is very likely to follow another light
(ie: Bix always after Bee)
▪ Low sequential probability: many lights are equally likely to come before a
particular light (bore could come either after Blap or Beg)
o Lights in low sequential probability were named slower than those in high
sequential probability → more uncertainty led to longer response time
• When somebody is faced with a decision, the greater the number of potential choices
means that taking a decision will take longer because more resources are required
o Ie: Netflix!!!
• Decision fatigue: too many options = poor decision making
• The more choices to pick from, the more energy needed for choosing → depletion in
energy taxes cognitive processed and has consequences on making decisions in the
future (ie: making healthy meal choice after picking Netflix shows to watch is more
difficult that if didn’t have to pick a show)
find more resources at oneclass.com
find more resources at oneclass.com
