Summary cognitive psychology
Lecture 1
Psychology
studies human behaviour and attempts to find explanations for it
Experimental Psychology (or cognitive psychology): is a core discipline that studies cognitive functions,
i.e.:
- Perception
- Memory
- Thinking and decision making
- Motor skills
- Attention and consciousness
- Language
- Learning
- Emotion
Functions are the ‘building blocks’ of which all complex behaviour like ‘making a chocolate cake’ is
made.
Cognitive psychology is concerned with questions like :
- Does a photographic memory really exist?
- Is unconscious (subliminal) perception real?
- Why is perception sometimes inaccurate (perceptual illusions)?
- Can animals think, talk, have empathy, or perceive rhythm?
It is closely linked to:
- (Cognitive) neuropsychology: Patients with specific disorders (local brain damage as opposed to
diffuse) allow for more specific and reliable inferences about brain functioning
e.g. patients with
- neglect (hemispatial/unilateral inattention)
- aphasia (trouble producing or understanding speech)
- dyslexia (unable to recognize written words)
- prosopagnosia (unable to recognize faces, but objects are fine)
- visual agnosia (unable to recognize visual objects, but faces are fine)
- Neurosciences: investigate the relationship between mental processes and their biological foundations
in the Central Nervous System (CNS). Certain types of behaviour are accompanied by tractable brain
activity
History
The scientific approach to study the human mind is relatively young compared to other disciplines.
Reasons:
- for a long time, the human mind was viewed as unique
, - theologists and philosophers argued that the “free will” cannot be examined in a scientific way
as can be done with the laws of nature.
Dualism: Descartes (1596-1650) questioned the mind’s ‘supremacy’ and proposed that there is an
interaction between mind and body.
There is behavior in which the free will is not involved, viz. in reflexes. Therefore, reflexes can be
studied scientifically.
One of the first psychologists to conduct experiments was Hermann von Helmholtz (1821-1894). He
studied, amongst others, the conduction velocity of the nerve impulse.
Gustav Fechner (1801-1871) discovered that there is a mathematical relationship between the physical
and the perceptual world.
He introduced the Just Noticable Difference (JND), which is still widely used in psychophysics.
Darwins Evolution Theory (1859) stated that we all share the same ancestor. Via natural selection,
different species evolved.
It justified Comparative psychology as a discipline and allowed scientist to compare
behaviours in different species (including humans).
Franciscus Donders (1818-1889) was a Dutch ophthalmologist (from Tilburg).
In 1868 he introduced Mental Chronometry:
- e.g. how much time does the brain need to decide if it heard ‘ki’ or ‘ku’?
Additive factors logic:
A subject hears ‘ki’, ‘ke’, ‘ka’, or ‘ku’
- condition A: subject only hears ‘ki’ and repeats ‘ki’
Detection RT = 197 ms
- condition B: subject hears ‘ki’, ‘ke’, ‘ka’, ‘ko’ or ‘ku’ and replies ‘ki’, ‘ke’, ‘ka’, ‘ko’ or ‘ku’
Detection + discrimination + decision RT= 285 ms
- condition C: subject hears ‘ki’, ‘ke’, ‘ka’, ‘ko’ or ‘ku’ and only replies if he hears ‘ki’
Detection + discrimination RT = 243 ms
Time for stimulus discrimination: B-C: 285 - 243 = 42 ms
Time for decision making C-A: 243-197 = 46 ms
Additive factor logic is still used, amongst others in modern fMRI research where brain activity in an
Experimental condition is subtracted from a Control condition.
- Structuralism: Wilhelm Wundt (1832-1920) founded the first psychology laboratory in Leipzig in 1879.
Psychology is the science of immediate experience.
The three main components of an experience are:
-sensations
-images (memories)
, -feelings
The combination of these components gives rise a conscious experience.
Wundt used as method the analytical introspection. Around 1920, structuralism disappeared because
the method was very unreliable as the results could not be replicated.
Behaviorism: John Watson (1878-1958).
Psychology is the study of the observable (overt) behaviour. The mental (covert) behaviour can not be
studied scientifically.
This was a part of the logical positivism movement. They introduced the operational definition: e.g.
hunger = duration of food deprivation measured in hours. The big advantage is that precise
measurements could made, thus stimulating comparisons between studies (replications).
Ivan Pavlov (1849-1936) Classic conditioning
Skinner (1904-1990). Operant conditioning.
Learning occurs through reward and punishment. In order to understand behaviour, you have to study
the external environment as well as its effects on the behaviour.
Gestalt psychology: Max Wertheimer (1880-1943), Wolfgang Köhler (1887-1967) and Kurt Koffka
(1886-1941).
Key principle: the whole is more than the sum of its parts.
They rejected Wundt’s structuralism (because experience is more than a function of sensation) and
behaviorism, because complex behaviours (“the whole”) is more than the sum of its components
used the phenomenon of apparent motion as a proof of their argument:
• Two lights that light up and then extinguish at the right speed/distance appear as 1 object that
moves through space (think of TV) instead of 2 flashes. This is an example of experience without
sensation
Perception is a construction, not a reflection of the sensation
Construction also exists in the auditory domain: you can either hear gallop-rhythm while 2 tones (high-
low-high) are played, or 2 separate streams, one high the other low.
Methods in Cognitive Neuroscience
• Experimental research with behavioural measures (e.g. RT) or percentage correct traditional
• Non-invasive brain imaging techniques EEG, MEG, fMRI, etc
• Blocking normal brain functioning through pharmacological substances or Transcranial
Magnetic Stimulation (TMS)
• Patients with (preferably) focal laesions
• Computer simulations
Research methods in psychology
Behaviour can be explained on various levels. Roughly:
- Biological factors: chemical, neural, hormonal, genetic
- Individual factors: learning, psychodynamic and cognitive processes
, - Cultural and social factors
Each level has its own research methods. An important distinction is that between descriptive versus
experimental research.
Descriptive research does not provide information about causality (whether A
causes B), whereas Experimental research does.
Descriptive research:
- Naturalistic observation: behaviour is observed within its natural context. Predominantly used
in ethology and useful as a first step.
- Case studies: a detailed study on one subject or event. Used in cognitive neuropsychology
(alongside experimental approach). Important when dealing with unique cases, e.g. extremely
rare (clinical presentations of) diseases.
- Interview: Subjects answer a number of questions about behaviour, attitudes, beliefs etc. Can
be open or (semi-)structured.
-Questionnaires are generally more structured than interviews
- Poll: a sample of subjects that make up a small part of the population on which conclusions for
the whole populations are drawn. The sample needs to be ‘representative’.
- Correlational research:
Measures association between two variables.
For example : ‘large people are heavy’ Or ‘the more cigarettes you smoke, the shorter you live’
It expresses a relation between the variables length and weight, and number of cigarettes and
lifespan, respectively.
A correlation is a statistical measure and varies between -1 and +1.
Positive correlation (0<x<1): both variables change in the
same direction, thus when length increases, weight increases.
Negative correlation (-1<x<0): variables change in opposite
directions, thus when the number of cigarettes increases, the lifespan (e.g. in years) decreases
A correlation of 0 implies that there is no relationship between the two variables.
You can predict an outcome with more certainty when the correlation between the variables
approaches +1 or -1.
However, descriptive research does not lend itself for causal interpretation (causality meaning a change
in A causes change in B) a correlation can not be interpreted causally!
Experimental Research
The researcher manipulates just one aspect of the situation (A) while the rest stays the same. The effect
of this manipulation on behaviour (B) is then measured. This approach does allow inferences about
causality.
Example: Does watching violent tv programs cause aggressive behaviour?
Study:
1) Create two equal groups (size, M/F proportion, aggression levels before experiment)
2) Have one group watch an aggressive film (the experimental group), and the other group a non-
aggressive film (the control group)
3) Examine whether the experimental group displays more aggressive behavior than the control group.
Lecture 1
Psychology
studies human behaviour and attempts to find explanations for it
Experimental Psychology (or cognitive psychology): is a core discipline that studies cognitive functions,
i.e.:
- Perception
- Memory
- Thinking and decision making
- Motor skills
- Attention and consciousness
- Language
- Learning
- Emotion
Functions are the ‘building blocks’ of which all complex behaviour like ‘making a chocolate cake’ is
made.
Cognitive psychology is concerned with questions like :
- Does a photographic memory really exist?
- Is unconscious (subliminal) perception real?
- Why is perception sometimes inaccurate (perceptual illusions)?
- Can animals think, talk, have empathy, or perceive rhythm?
It is closely linked to:
- (Cognitive) neuropsychology: Patients with specific disorders (local brain damage as opposed to
diffuse) allow for more specific and reliable inferences about brain functioning
e.g. patients with
- neglect (hemispatial/unilateral inattention)
- aphasia (trouble producing or understanding speech)
- dyslexia (unable to recognize written words)
- prosopagnosia (unable to recognize faces, but objects are fine)
- visual agnosia (unable to recognize visual objects, but faces are fine)
- Neurosciences: investigate the relationship between mental processes and their biological foundations
in the Central Nervous System (CNS). Certain types of behaviour are accompanied by tractable brain
activity
History
The scientific approach to study the human mind is relatively young compared to other disciplines.
Reasons:
- for a long time, the human mind was viewed as unique
, - theologists and philosophers argued that the “free will” cannot be examined in a scientific way
as can be done with the laws of nature.
Dualism: Descartes (1596-1650) questioned the mind’s ‘supremacy’ and proposed that there is an
interaction between mind and body.
There is behavior in which the free will is not involved, viz. in reflexes. Therefore, reflexes can be
studied scientifically.
One of the first psychologists to conduct experiments was Hermann von Helmholtz (1821-1894). He
studied, amongst others, the conduction velocity of the nerve impulse.
Gustav Fechner (1801-1871) discovered that there is a mathematical relationship between the physical
and the perceptual world.
He introduced the Just Noticable Difference (JND), which is still widely used in psychophysics.
Darwins Evolution Theory (1859) stated that we all share the same ancestor. Via natural selection,
different species evolved.
It justified Comparative psychology as a discipline and allowed scientist to compare
behaviours in different species (including humans).
Franciscus Donders (1818-1889) was a Dutch ophthalmologist (from Tilburg).
In 1868 he introduced Mental Chronometry:
- e.g. how much time does the brain need to decide if it heard ‘ki’ or ‘ku’?
Additive factors logic:
A subject hears ‘ki’, ‘ke’, ‘ka’, or ‘ku’
- condition A: subject only hears ‘ki’ and repeats ‘ki’
Detection RT = 197 ms
- condition B: subject hears ‘ki’, ‘ke’, ‘ka’, ‘ko’ or ‘ku’ and replies ‘ki’, ‘ke’, ‘ka’, ‘ko’ or ‘ku’
Detection + discrimination + decision RT= 285 ms
- condition C: subject hears ‘ki’, ‘ke’, ‘ka’, ‘ko’ or ‘ku’ and only replies if he hears ‘ki’
Detection + discrimination RT = 243 ms
Time for stimulus discrimination: B-C: 285 - 243 = 42 ms
Time for decision making C-A: 243-197 = 46 ms
Additive factor logic is still used, amongst others in modern fMRI research where brain activity in an
Experimental condition is subtracted from a Control condition.
- Structuralism: Wilhelm Wundt (1832-1920) founded the first psychology laboratory in Leipzig in 1879.
Psychology is the science of immediate experience.
The three main components of an experience are:
-sensations
-images (memories)
, -feelings
The combination of these components gives rise a conscious experience.
Wundt used as method the analytical introspection. Around 1920, structuralism disappeared because
the method was very unreliable as the results could not be replicated.
Behaviorism: John Watson (1878-1958).
Psychology is the study of the observable (overt) behaviour. The mental (covert) behaviour can not be
studied scientifically.
This was a part of the logical positivism movement. They introduced the operational definition: e.g.
hunger = duration of food deprivation measured in hours. The big advantage is that precise
measurements could made, thus stimulating comparisons between studies (replications).
Ivan Pavlov (1849-1936) Classic conditioning
Skinner (1904-1990). Operant conditioning.
Learning occurs through reward and punishment. In order to understand behaviour, you have to study
the external environment as well as its effects on the behaviour.
Gestalt psychology: Max Wertheimer (1880-1943), Wolfgang Köhler (1887-1967) and Kurt Koffka
(1886-1941).
Key principle: the whole is more than the sum of its parts.
They rejected Wundt’s structuralism (because experience is more than a function of sensation) and
behaviorism, because complex behaviours (“the whole”) is more than the sum of its components
used the phenomenon of apparent motion as a proof of their argument:
• Two lights that light up and then extinguish at the right speed/distance appear as 1 object that
moves through space (think of TV) instead of 2 flashes. This is an example of experience without
sensation
Perception is a construction, not a reflection of the sensation
Construction also exists in the auditory domain: you can either hear gallop-rhythm while 2 tones (high-
low-high) are played, or 2 separate streams, one high the other low.
Methods in Cognitive Neuroscience
• Experimental research with behavioural measures (e.g. RT) or percentage correct traditional
• Non-invasive brain imaging techniques EEG, MEG, fMRI, etc
• Blocking normal brain functioning through pharmacological substances or Transcranial
Magnetic Stimulation (TMS)
• Patients with (preferably) focal laesions
• Computer simulations
Research methods in psychology
Behaviour can be explained on various levels. Roughly:
- Biological factors: chemical, neural, hormonal, genetic
- Individual factors: learning, psychodynamic and cognitive processes
, - Cultural and social factors
Each level has its own research methods. An important distinction is that between descriptive versus
experimental research.
Descriptive research does not provide information about causality (whether A
causes B), whereas Experimental research does.
Descriptive research:
- Naturalistic observation: behaviour is observed within its natural context. Predominantly used
in ethology and useful as a first step.
- Case studies: a detailed study on one subject or event. Used in cognitive neuropsychology
(alongside experimental approach). Important when dealing with unique cases, e.g. extremely
rare (clinical presentations of) diseases.
- Interview: Subjects answer a number of questions about behaviour, attitudes, beliefs etc. Can
be open or (semi-)structured.
-Questionnaires are generally more structured than interviews
- Poll: a sample of subjects that make up a small part of the population on which conclusions for
the whole populations are drawn. The sample needs to be ‘representative’.
- Correlational research:
Measures association between two variables.
For example : ‘large people are heavy’ Or ‘the more cigarettes you smoke, the shorter you live’
It expresses a relation between the variables length and weight, and number of cigarettes and
lifespan, respectively.
A correlation is a statistical measure and varies between -1 and +1.
Positive correlation (0<x<1): both variables change in the
same direction, thus when length increases, weight increases.
Negative correlation (-1<x<0): variables change in opposite
directions, thus when the number of cigarettes increases, the lifespan (e.g. in years) decreases
A correlation of 0 implies that there is no relationship between the two variables.
You can predict an outcome with more certainty when the correlation between the variables
approaches +1 or -1.
However, descriptive research does not lend itself for causal interpretation (causality meaning a change
in A causes change in B) a correlation can not be interpreted causally!
Experimental Research
The researcher manipulates just one aspect of the situation (A) while the rest stays the same. The effect
of this manipulation on behaviour (B) is then measured. This approach does allow inferences about
causality.
Example: Does watching violent tv programs cause aggressive behaviour?
Study:
1) Create two equal groups (size, M/F proportion, aggression levels before experiment)
2) Have one group watch an aggressive film (the experimental group), and the other group a non-
aggressive film (the control group)
3) Examine whether the experimental group displays more aggressive behavior than the control group.
