PSYCH 230 EXAM 1 UIUC QUESTIONS
Sensation - Answers- The ability to detect a stimulus and perhaps turn that detection
into a private experience
Perception - Answers- The act of giving meaning to a detected sensation
Psychophysics - Answers- The science of defining quantitative relationships between
physical and psychological events
Two point threshold - Answers- the minimum distance at which two stimuli are just
perceptible as separate
Just Noticeable Difference (JND) - Answers- the minimum difference necessary to tell
two stimulus apart
Method of adjustment - Answers- Similar to method of limits, but participant controls the
stimulus directly
Magnitude Estimation - Answers- the participant assigns values according to perceived
magnitudes of the stimuli
Cross Modality Matching - Answers- matches magnitude between two stimuli (ex:
visual and auditory)
Signal Detection Theory - Answers- A psychophysical theory that quantifies the
response of an observer to the presentation of a signal in the presence of a noise -
distinction between an observers ability to perceive a signal and willingness to report it
Signal Detection Theory Hit - Answers- Stimulus is present and observer responds
"yes"
Signal Detection Theory Miss - Answers- Stimulus is present and observer responds
"no"
Signal Detection Theory False Alarm - Answers- Stimulus is not present and observer
responds "Yes"
Stimulus Detection Theory Correct Rejection - Answers- Stimulus is not present and
observer responds "no"
Stimulus Detection Theory Criterion - Answers- An internal threshold that is set by the
observer. If the internal response is above criterion, the observer gives one response.
Below criterion, another response.
, Signal Detection Theory Sensitivity - Answers- A value that defines the ease with which
an observer can tell the difference between the presence and absence of a stimulus or
the difference between stimulus 1 and stimulus 2
d' - Answers- Representation for sensitivity. Measure of how discriminable 2
distributions are, distance between the distribution means.
Doctorine of specific nerve energies - Answers- Formulated by Müller, states that the
nature of a sensation depends on which sensory fibers are stimulated, not how they are
stimulated
Sensory nerves - Answers- olfactory, optic, auditory
Motor nerves - Answers- oculomotor, trochlear, abducens
Nature of synaptic communication - Answers- Chemical
How do neurons fire? - Answers- In all or none fashion for each spike; # of spikes per
second determines how excited the neuron is
EEG - Answers- Great precision in timing, not in brain location. Used when interested in
when an event happens in the brain.
fMRI - Answers- measure metabolic changes to precisely localize activity of neurons in
the brain, little precision in timing.
What is light? - Answers- a narrow band of electromagnetic radiation that can be
conceptualized as a wave or stream of photons
Cornea - Answers- The transparent tissue that covers the front of the eye.
Absolute threshold - Answers- the minimum stimulation needed to detect a particular
stimulus 50 percent of the time
Weber's Law - Answers- Larger stimulus values have greater JNDs, Smaller stimulus
values have smaller JNDs
Fechner's Law - Answers- The magnitude of subjective sensation increases
proportionally to the logarithm of the stimulus intensity
Stevens power law - Answers- The relation between physical intensity and
psychological intensity is linear
Method of constant stimuli - Answers- many stimuli, ranging from rarely to almost
always perceivable are presented one at a time
Sensation - Answers- The ability to detect a stimulus and perhaps turn that detection
into a private experience
Perception - Answers- The act of giving meaning to a detected sensation
Psychophysics - Answers- The science of defining quantitative relationships between
physical and psychological events
Two point threshold - Answers- the minimum distance at which two stimuli are just
perceptible as separate
Just Noticeable Difference (JND) - Answers- the minimum difference necessary to tell
two stimulus apart
Method of adjustment - Answers- Similar to method of limits, but participant controls the
stimulus directly
Magnitude Estimation - Answers- the participant assigns values according to perceived
magnitudes of the stimuli
Cross Modality Matching - Answers- matches magnitude between two stimuli (ex:
visual and auditory)
Signal Detection Theory - Answers- A psychophysical theory that quantifies the
response of an observer to the presentation of a signal in the presence of a noise -
distinction between an observers ability to perceive a signal and willingness to report it
Signal Detection Theory Hit - Answers- Stimulus is present and observer responds
"yes"
Signal Detection Theory Miss - Answers- Stimulus is present and observer responds
"no"
Signal Detection Theory False Alarm - Answers- Stimulus is not present and observer
responds "Yes"
Stimulus Detection Theory Correct Rejection - Answers- Stimulus is not present and
observer responds "no"
Stimulus Detection Theory Criterion - Answers- An internal threshold that is set by the
observer. If the internal response is above criterion, the observer gives one response.
Below criterion, another response.
, Signal Detection Theory Sensitivity - Answers- A value that defines the ease with which
an observer can tell the difference between the presence and absence of a stimulus or
the difference between stimulus 1 and stimulus 2
d' - Answers- Representation for sensitivity. Measure of how discriminable 2
distributions are, distance between the distribution means.
Doctorine of specific nerve energies - Answers- Formulated by Müller, states that the
nature of a sensation depends on which sensory fibers are stimulated, not how they are
stimulated
Sensory nerves - Answers- olfactory, optic, auditory
Motor nerves - Answers- oculomotor, trochlear, abducens
Nature of synaptic communication - Answers- Chemical
How do neurons fire? - Answers- In all or none fashion for each spike; # of spikes per
second determines how excited the neuron is
EEG - Answers- Great precision in timing, not in brain location. Used when interested in
when an event happens in the brain.
fMRI - Answers- measure metabolic changes to precisely localize activity of neurons in
the brain, little precision in timing.
What is light? - Answers- a narrow band of electromagnetic radiation that can be
conceptualized as a wave or stream of photons
Cornea - Answers- The transparent tissue that covers the front of the eye.
Absolute threshold - Answers- the minimum stimulation needed to detect a particular
stimulus 50 percent of the time
Weber's Law - Answers- Larger stimulus values have greater JNDs, Smaller stimulus
values have smaller JNDs
Fechner's Law - Answers- The magnitude of subjective sensation increases
proportionally to the logarithm of the stimulus intensity
Stevens power law - Answers- The relation between physical intensity and
psychological intensity is linear
Method of constant stimuli - Answers- many stimuli, ranging from rarely to almost
always perceivable are presented one at a time
