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Cognitive psychology is a branch of psychology concerned with the scienti c study of the mind.
The mind creates and controls mental capacities such as perception, attention and memory, and
creates representations of the world that enable us to function.
The work of Donders (simple vs choice reaction time) and Ebbinghaus (the forgetting curve for
nonsense syllables) are examples of early experimental research on the mind.
Because the operation of the mind cannot be observed directly, its operation must be inferred
from what we can measure, such as behaviour or physiological responding. This is one of the
basic principles of cognitive psychology.
The rst laboratory of scienti c psychology, founded by Wundt in 1879, was concerned largely
with studying the mind. Structuralism was the dominant theoretical approach of this laboratory,
and analytic introspection(known as experimental self-observation) was one of the major methods
used to collect data.
Structuralism focused on breaking down mental processes into the most basic components.
Researchers tried to understand the basic elements of consciousness using a method known
as introspection.
William James, in the United States, used observations of his own mind as the basis of his
textbook, Principles of Psychology.
In the rst decades of the 20th century, John Watson founded behaviourism, partly in reaction to
structuralism and the method of analytic introspection. His procedures were based on classical
conditioning. Behaviourism’s central tenet was that psychology was properly studied by
measuring observable behaviour, and that invisible mental processes were not valid topics for the
study of psychology.
Beginning in the 1930s and 1940s, B.F.Skinner’s work on operant conditioning assured that
behaviourism would be the dominant force in psychology through the 1950s.
Classical conditioning involves associating an involuntary response and a stimulus, while operant
conditioning is about associating a voluntary behaviour and a consequence.
In the 1950s, a number of events occurred that led to what has been called the cognitive
revolution—a decline in the in uence of behaviourism and a re-emergence of the study of the
mind. These events included the following: Chomsky’s critique on Skinner’s book Verbal
Behaviour, the introduction of the digital computer and the idea that the mind processes
information in stages like a computer, Cherry’s dichotic listening experiments and Broadbent’s
introduction of ow diagrams to depict the processes involved in attention, and interdisciplinary
approaches to arti cial intelligence and information theory.
Models play an essential role in cognitive psychology by representing structures or processes.
Structural models represent structures in the brain and how they are connected. Process models
illustrate how a process or function operates. Models make complicated systems easier to
understand and often provide a starting point for research.
Our increased understanding of the functioning of our mind can be used to design proper control
panels and tra c situations. In uence decision making and consumer behaviour, improve
protocols relating to eyewitness interrogation, develop working memory and executive control
training programmes and stimulate good practice in education.
A cognitive map is a type of mental representation which serves an individual to acquire, code,
store, recall, and decode information about the relative locations and attributes of phenomena in
their everyday or metaphorical spatial environment
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We can easily describe the relation between parts of a scene, but it is often challenging to indicate
the reasoning that led to the description. This illustrated the need to go beyond the pattern of light
and dark in a scene to describe the process of perception.
Perception is the process of selecting, organizing, and interpreting information.
Attempts to program computers to recognise objects have shown how di cult it is to program
computers to perceive at a level comparable to humans. A few of the di culties facing computers
are:
The stimulus on the receptors is ambiguous, as demonstrated by the inverse projection
problem.
Objects in a scene can be hidden of blurred.
Objects look di erent from di erent viewpoints
The inverse projection problem: Light from an object is inverted as it falls on the retina. The same
pattern of light could be caused by an in nite number of di erent objects, yet our brains usually
manage to make the correct interpretation. This is known as the inverse projection problem.
Perception starts with bottom-up processing, which involves stimulation of the receptors, creating
electrical signals that reach the visual receiving area of the brain. Perception, however, also
involves top-down processing, which originates in the brain and involves expectation, experience,
culture and knowledge.
Bottom-up refers to the way it is built up from the smallest pieces of sensory information.
Data driven, Focuses on incoming sensory data, Takes place in real time
Top-down processing, on the other hand, refers to perception that is driven by cognition. Your
brain applies what it knows and what it expects to perceive and lls in the blanks, so to speak.
Info is interpreted using contextual clues, Uses previous experience and expectations.
There are four approaches to object perception:
1. The idea that perception depends on knowledge was proposed by Helmholtz’s theory of
unconscious inference.
2. The Gestalt approach to perception proposed a number of laws of perpetual
organisation, which were based on how stimuli usually occur in the environment.
3. Regularities of the environment are characteristics of the environment that occur
frequently; we take both physical regularities and semantic regularities into account when
perceiving.
4. Bayesian inference is a mathematical procedure for determine what is likely to be “out
there”; it takes into account a persons’s prior beliefs about a perceptual outcome and the
likelihood of that outcome based on additional evidence.
Physical regularities are regularly occurring physical properties of the environment.
Semantic regularities are de ned as characteristics associated with the functions carried out in
di erent types of scenes.
One of the basic operating principles of the brain is that it contains some neurons that respond
best to things that occur regularly in the environment.
Experience-dependent plasticity is one of the mechanisms responsible for creating neurons that
are tuned to respond to speci c things in the environment. The experiments in which kittens were
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