EXPERIMENTAL PSY
Psychology: the scientific study of mind and behaviour.
- mind: private inner experience of perception, thoughts, memories and feelings.
- behaviour: observable actions of human beings and non-human animals.
Experiment: a technique of establishing a causal relationship between variables.
Experimental/Cognitive psychology: the scientific study of mind and behavior by means of
experiments.
How to study mind and behavior?
→ Focus on cognitive functions
Cognition: all mental processes that lead to thoughts, knowledge, and awareness.
Cognitive processes: mechanisms that underly cognition.
Cognitive processes govern Cognitive functions like attention, memory, learning, decision-
making, language, perception, motor-skills, imagination, etc.
Cognitive functions are the ‘building blocks’ of all complex behavior (like ‘eating peas’).
This task requires: - Perception - Decision making - Motor skills - Attention - …….etc.
Experimental psychology is closely linked to Cognitive neuropsychology:
- Patients with (local) brain damage allow for more specific and reliable inferences about brain
functioning.
e.g. patients with ;- neglect (hemi spatial/unilateral inattention) - time
- aphasia (trouble producing or understanding speech)
- dyslexia (trouble with reading [and auditory speech perception])
- prosopagnosia (inability to recognize faces [object recognition is fine])
- visual agnosia (inability to recognize visual objects [but not faces])
Cognitive neuroscience attempts to understand the biological foundations of cognition (the
main idea is that cognitive processes produce brain activity that can be tracked and traced).
,In the 19th century, Psychology started to evolve into a science
One of the first psychologists to conduct experiments was Hermann von Helmholtz (1821-
1894). He studied, for example, the conduction velocity of the nerve impulse.
Inspired by Ernst Weber (1795–1878), Gustav Fechner
(1801-1871) introduced the Just Noticeable Difference (JND), which is still widely used in
psychophysics. JND: the minimum difference in stimulation that a person can detect 50% of the
time.
Franciscus Donders (1818-1889, from Tilburg)
introduced Mental Chronometry
- How much time do you need to decide whether you heard the syllable ‘ka’, ‘ta’, or ‘pa’?
(1) Simple reaction time: press a button whenever you hear a syllable (RT = 198 ms). →
DETECTION RT
(2) Differential/choice reaction time: press ‘k’ when you hear ‘ka’, press ‘t’ when you hear ‘ta’,
press ‘p’ when you hear ‘pa’ (RT = 278 ms). → DETECTION RT + DISCRIMINATION RT + DECISION
RT
(3) Go/No go reaction time: press ‘k’ when you hear ‘ka’, but do nothing when you hear ‘ta’ or
‘pa’ (RT =269 ms). → DETECTION RT + DISCRIMINATION RT
The time you need for stimulus discrimination = (3) – (1) = 71 ms, and the time you need only for
decision making = (2) – (3) = 9 ms. Time you need to make a decision that includes
discrimination = (2) – (1) = 80 ms.
This additive factor logic is still used in modern day research where brain activity (measured with
EEG or fMRI, for example) in an experimental condition is subtracted from a control condition or
when two experimental conditions are subtracted
,In the 19th & 20th centuries, several competing schools emerged
Structuralism: consciousness should be the focus of study via analyses of the basic elements
that constitute the mind (Wilhelm Wundt; 1832-1920).
- Achieved by breaking down consciousness into sensations and feelings via analytical
introspection:
Some melody is played to a participant:
“I hear tones of different duration, pitch and loudness (sensations), that are structured in an
unfamiliar rhythm which makes me feel confused (subjective interpretation/feelings).”
- Further developed by Edward Titchener (1867-1927) who proposed 3 elementary states of
consciousness (Sensations [sights, sounds, tastes], Images [components of thoughts], and
Affections [components of emotions]) and identified thousands of ‘elemental qualities of
conscious experience’.
Behaviorism (John Watson, 1878-1958): The introspective processes cannot be studied (too
vague and subjective) and overt behavior (what people do) should be studied instead because:
- The only way to understand animal and human learning and adaptation is to focus solely on
their behavior;
- Behavior can be observed by anyone and measured objectively;
- The goal of scientific psychology is to predict and control behavior in a way that benefits
society.
Behaviorism was a part of the logical positivism movement that introduced the operational
definition: A description of a/an (abstract) property in terms of a concrete condition that can be
measured.
Operational definitions have big advantages as they allow for precise measurements and direct
comparisons between studies (replications).
But, operational definitions are not always good definitions (clear measurable conditions can
still be quite useless):
- happiness is the number of smiles during a specific episode.
- age is the response that participants provide on a questionnaire.
, 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
Psychology: the scientific study of mind and behaviour.
- mind: private inner experience of perception, thoughts, memories and feelings.
- behaviour: observable actions of human beings and non-human animals.
Experiment: a technique of establishing a causal relationship between variables.
Experimental/Cognitive psychology: the scientific study of mind and behavior by means of
experiments.
How to study mind and behavior?
→ Focus on cognitive functions
Cognition: all mental processes that lead to thoughts, knowledge, and awareness.
Cognitive processes: mechanisms that underly cognition.
Cognitive processes govern Cognitive functions like attention, memory, learning, decision-
making, language, perception, motor-skills, imagination, etc.
Cognitive functions are the ‘building blocks’ of all complex behavior (like ‘eating peas’).
This task requires: - Perception - Decision making - Motor skills - Attention - …….etc.
Experimental psychology is closely linked to Cognitive neuropsychology:
- Patients with (local) brain damage allow for more specific and reliable inferences about brain
functioning.
e.g. patients with ;- neglect (hemi spatial/unilateral inattention) - time
- aphasia (trouble producing or understanding speech)
- dyslexia (trouble with reading [and auditory speech perception])
- prosopagnosia (inability to recognize faces [object recognition is fine])
- visual agnosia (inability to recognize visual objects [but not faces])
Cognitive neuroscience attempts to understand the biological foundations of cognition (the
main idea is that cognitive processes produce brain activity that can be tracked and traced).
,In the 19th century, Psychology started to evolve into a science
One of the first psychologists to conduct experiments was Hermann von Helmholtz (1821-
1894). He studied, for example, the conduction velocity of the nerve impulse.
Inspired by Ernst Weber (1795–1878), Gustav Fechner
(1801-1871) introduced the Just Noticeable Difference (JND), which is still widely used in
psychophysics. JND: the minimum difference in stimulation that a person can detect 50% of the
time.
Franciscus Donders (1818-1889, from Tilburg)
introduced Mental Chronometry
- How much time do you need to decide whether you heard the syllable ‘ka’, ‘ta’, or ‘pa’?
(1) Simple reaction time: press a button whenever you hear a syllable (RT = 198 ms). →
DETECTION RT
(2) Differential/choice reaction time: press ‘k’ when you hear ‘ka’, press ‘t’ when you hear ‘ta’,
press ‘p’ when you hear ‘pa’ (RT = 278 ms). → DETECTION RT + DISCRIMINATION RT + DECISION
RT
(3) Go/No go reaction time: press ‘k’ when you hear ‘ka’, but do nothing when you hear ‘ta’ or
‘pa’ (RT =269 ms). → DETECTION RT + DISCRIMINATION RT
The time you need for stimulus discrimination = (3) – (1) = 71 ms, and the time you need only for
decision making = (2) – (3) = 9 ms. Time you need to make a decision that includes
discrimination = (2) – (1) = 80 ms.
This additive factor logic is still used in modern day research where brain activity (measured with
EEG or fMRI, for example) in an experimental condition is subtracted from a control condition or
when two experimental conditions are subtracted
,In the 19th & 20th centuries, several competing schools emerged
Structuralism: consciousness should be the focus of study via analyses of the basic elements
that constitute the mind (Wilhelm Wundt; 1832-1920).
- Achieved by breaking down consciousness into sensations and feelings via analytical
introspection:
Some melody is played to a participant:
“I hear tones of different duration, pitch and loudness (sensations), that are structured in an
unfamiliar rhythm which makes me feel confused (subjective interpretation/feelings).”
- Further developed by Edward Titchener (1867-1927) who proposed 3 elementary states of
consciousness (Sensations [sights, sounds, tastes], Images [components of thoughts], and
Affections [components of emotions]) and identified thousands of ‘elemental qualities of
conscious experience’.
Behaviorism (John Watson, 1878-1958): The introspective processes cannot be studied (too
vague and subjective) and overt behavior (what people do) should be studied instead because:
- The only way to understand animal and human learning and adaptation is to focus solely on
their behavior;
- Behavior can be observed by anyone and measured objectively;
- The goal of scientific psychology is to predict and control behavior in a way that benefits
society.
Behaviorism was a part of the logical positivism movement that introduced the operational
definition: A description of a/an (abstract) property in terms of a concrete condition that can be
measured.
Operational definitions have big advantages as they allow for precise measurements and direct
comparisons between studies (replications).
But, operational definitions are not always good definitions (clear measurable conditions can
still be quite useless):
- happiness is the number of smiles during a specific episode.
- age is the response that participants provide on a questionnaire.
, 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
