PSYC 230 TEST 1 UIUC QUESTIONS
Sensation - Answers- The ability to detect a stimulus and, perhaps, to turn that
detection into a private experience.
Perception - Answers- The act of giving meaning to a detected sensation.
qualia - Answers- In philosophy, private conscious experiences of sensation or
perception.
dualism - Answers- the idea that the mind has an existence separate from the material
world of the body.
Materialism - Answers- The idea that the only thing that exists is matter, and that all
things, including the mind and consciousness, are the results of interaction between bits
of matter.
panpsychism - Answers- The idea that the mind exists as a property of al matter- that
is, that all matter has consciousness
psychophysics - Answers- The science of defining quantitative relationships between
physical and psychological (subjective) events
Fechner's Law - Answers- A principle describing the relationship between stimulus and
resulting sensation that says the magnitude of subjective sensation increases
proportionally to the logarithm of the stimulus intensity
- S = k log (R)
S= psychological sensation R= physical stimulus
k= constant
Gustav Fechner - Answers- - invented psychophysics
- thought by some to be the true founder of experimental psychology
absolute threshold - Answers- The minimum amount of stimulation necessary for a
person to detect a stimulus 50% of the time
Method of constant stimuli - Answers- A psychophysical method in which many stimuli,
ranging from rarely to almost always perceivable (or rarely to almost always perceivably
different from a reference stimulus), are presented one at a time. Participants respond
to each presentation: "yes/no," "same/different," and so on.
Methods of limits - Answers- The magnitude of a single stimulus or the difference
between two stimuli is varied incrementally until the participant responds differently
,- The experimenter begins with the same set of stimuli-- in this case, tones that vary in
intensity. Instead of random presentations, tones are presented in order of increasing or
decreasing intensity.
- ascending: asked to report when tone is first detected
- descending : report when tone is no longer audible
Method of adjustment - Answers- Similar to the method of limits, but the participant
controls the stimulus directly
- subject is the one who steadily increases or decreases the intensity of the stimulus
Magnitude estimation - Answers- The participant assigns values according to perceived
magnitudes of the stimuli
- EX: give observers series of sugar solutions and ask them to assign numbers to each
sample.
- i.e. Solution 2 is 2x as sweet as Solution 1
Stevens' power law - Answers- Magnitude estimates are well described by
________________ .
- S = aI^(b)
(S) is related to stimulus intensity
(I) by an exponent (b)
- A principle describing the relationship between the stimulus and resulting sensation
that says the magnitude of subjective sensation is proportional to the stimulus
magnitude raised to an exponent.
- exponent for brightness is 0.3, so change from 1 candle to 11 is quite dramatic,
but adding 10 to 100 results in only a modest change
Adding 10 to 10,000 wouldn't even be noticeable
VS.
Apparent length = 1.0
- exponent for electric shock is quite large (3.5), meaning that the pain grows with
I^(3.5), so a 4-fold increase in the electrical current is experienced as a 128-fold
increase in pain
two-lint touch threshold - Answers- The minimum distance at which two stimuli (e.g. 2
simultaneous touches) are just perceptible as separate
just noticeable difference (JND) - Answers- Also known as the difference threshold
The smallest detectable difference between two stimuli, or the minimum change in a
stimulus that enables it to be correctly judged as different from a reference stimulus.
, Weber fraction - Answers- The constant (K) of proportionality in Weber's Law.
For weight: 1:40
Line length: 1:100
Weber's Law - Answers- The principle describing the relationship between stimulus and
resulting sensation that says the JND is a constant fraction (K) of the comparison
stimulus.
Weber's law vs. Fechner's law vs. Stevens' power law - Answers- Weber's law: involves
a clear objective measurement . We know how much we varied the stimulus, and either
the observers can tell that the stimulus changed or they cannot.
Fechner's law: begins with same objective measurements as Weber's, but the law is
actually a calculation based on some assumptions about how sensation works.
- assumes that all JNDs are perceptually equivalent
(they are not)
Stevens' power law: describes rating data well BUT the rating data are qualitatively
different from the data that supported Weber's law.
- no way to know whether subjects' ratings are objectively right or wrong
Propylthiouracil (PROP) - Answers- molecule that some people experience as very
bitter, while others experience it as tasteless
Cross-modality matching - Answers- The participant matches the intensity of a
sensation in one sensory modality with the intensity of a sensation in another
Ex: Ask participant to adjust the brightness of a light so it matches the perceived
loudness of a particular tone
Signal detection theory - Answers- A psychophysical theory that quantifies the response
of an observer to the presentation of a signal in the presence of noise
- internal noise (when close your eyes still see grey with occasional brighter flashes)
- external noise (when looking at a mammogram there are similar regions that look like
the signal (cancer) but aren't
- makes a distinction between an observers' ability to perceive a signal and their
willingness to report it
Hit - Answers- (Signal detection theory)
Stimulus is present and observer responds "Yes"
Miss - Answers- Stimulus is present and observer responds "No"
False alarm - Answers- Stimulus is not present and observer responds "Yes"
Sensation - Answers- The ability to detect a stimulus and, perhaps, to turn that
detection into a private experience.
Perception - Answers- The act of giving meaning to a detected sensation.
qualia - Answers- In philosophy, private conscious experiences of sensation or
perception.
dualism - Answers- the idea that the mind has an existence separate from the material
world of the body.
Materialism - Answers- The idea that the only thing that exists is matter, and that all
things, including the mind and consciousness, are the results of interaction between bits
of matter.
panpsychism - Answers- The idea that the mind exists as a property of al matter- that
is, that all matter has consciousness
psychophysics - Answers- The science of defining quantitative relationships between
physical and psychological (subjective) events
Fechner's Law - Answers- A principle describing the relationship between stimulus and
resulting sensation that says the magnitude of subjective sensation increases
proportionally to the logarithm of the stimulus intensity
- S = k log (R)
S= psychological sensation R= physical stimulus
k= constant
Gustav Fechner - Answers- - invented psychophysics
- thought by some to be the true founder of experimental psychology
absolute threshold - Answers- The minimum amount of stimulation necessary for a
person to detect a stimulus 50% of the time
Method of constant stimuli - Answers- A psychophysical method in which many stimuli,
ranging from rarely to almost always perceivable (or rarely to almost always perceivably
different from a reference stimulus), are presented one at a time. Participants respond
to each presentation: "yes/no," "same/different," and so on.
Methods of limits - Answers- The magnitude of a single stimulus or the difference
between two stimuli is varied incrementally until the participant responds differently
,- The experimenter begins with the same set of stimuli-- in this case, tones that vary in
intensity. Instead of random presentations, tones are presented in order of increasing or
decreasing intensity.
- ascending: asked to report when tone is first detected
- descending : report when tone is no longer audible
Method of adjustment - Answers- Similar to the method of limits, but the participant
controls the stimulus directly
- subject is the one who steadily increases or decreases the intensity of the stimulus
Magnitude estimation - Answers- The participant assigns values according to perceived
magnitudes of the stimuli
- EX: give observers series of sugar solutions and ask them to assign numbers to each
sample.
- i.e. Solution 2 is 2x as sweet as Solution 1
Stevens' power law - Answers- Magnitude estimates are well described by
________________ .
- S = aI^(b)
(S) is related to stimulus intensity
(I) by an exponent (b)
- A principle describing the relationship between the stimulus and resulting sensation
that says the magnitude of subjective sensation is proportional to the stimulus
magnitude raised to an exponent.
- exponent for brightness is 0.3, so change from 1 candle to 11 is quite dramatic,
but adding 10 to 100 results in only a modest change
Adding 10 to 10,000 wouldn't even be noticeable
VS.
Apparent length = 1.0
- exponent for electric shock is quite large (3.5), meaning that the pain grows with
I^(3.5), so a 4-fold increase in the electrical current is experienced as a 128-fold
increase in pain
two-lint touch threshold - Answers- The minimum distance at which two stimuli (e.g. 2
simultaneous touches) are just perceptible as separate
just noticeable difference (JND) - Answers- Also known as the difference threshold
The smallest detectable difference between two stimuli, or the minimum change in a
stimulus that enables it to be correctly judged as different from a reference stimulus.
, Weber fraction - Answers- The constant (K) of proportionality in Weber's Law.
For weight: 1:40
Line length: 1:100
Weber's Law - Answers- The principle describing the relationship between stimulus and
resulting sensation that says the JND is a constant fraction (K) of the comparison
stimulus.
Weber's law vs. Fechner's law vs. Stevens' power law - Answers- Weber's law: involves
a clear objective measurement . We know how much we varied the stimulus, and either
the observers can tell that the stimulus changed or they cannot.
Fechner's law: begins with same objective measurements as Weber's, but the law is
actually a calculation based on some assumptions about how sensation works.
- assumes that all JNDs are perceptually equivalent
(they are not)
Stevens' power law: describes rating data well BUT the rating data are qualitatively
different from the data that supported Weber's law.
- no way to know whether subjects' ratings are objectively right or wrong
Propylthiouracil (PROP) - Answers- molecule that some people experience as very
bitter, while others experience it as tasteless
Cross-modality matching - Answers- The participant matches the intensity of a
sensation in one sensory modality with the intensity of a sensation in another
Ex: Ask participant to adjust the brightness of a light so it matches the perceived
loudness of a particular tone
Signal detection theory - Answers- A psychophysical theory that quantifies the response
of an observer to the presentation of a signal in the presence of noise
- internal noise (when close your eyes still see grey with occasional brighter flashes)
- external noise (when looking at a mammogram there are similar regions that look like
the signal (cancer) but aren't
- makes a distinction between an observers' ability to perceive a signal and their
willingness to report it
Hit - Answers- (Signal detection theory)
Stimulus is present and observer responds "Yes"
Miss - Answers- Stimulus is present and observer responds "No"
False alarm - Answers- Stimulus is not present and observer responds "Yes"
