Psy 368 exam 1 with questions amd well elaborated and defined answers
Psychophysics - correct answer-The study of how physical stimuli are translated into
psychological experience.
recognition/identification - correct answer-What is this? a car
Visual Search - correct answer-search for a target in a display containing distracting
elements
Detection - correct answer-is there a 'T'? no
Discrimination - correct answer-which line is longer? A
magnitude estimation - correct answer-a psychophysical method in which the participant
assigns values according to perceived magnitudes of the stimuli
Fechner's law - correct answer-S= k log l
Empiricists - correct answer-believed that the mind of a person can be understood by
observing that person's experiences
Cartesian Dualists - correct answer-believed that the mind and the body were basically
separate and that it is not possible to understand the mind by studying the body
Fechner's Law - correct answer-the observation that the strength of a sensation is
proportional to the logarithm of physical stimulus intensity
Fechner's methods - correct answer-Method of Limits
Method of Adjustment
Method of Constant Stimuli
crossover point - correct answer-The intensity at which they start saying 'no' (or 'yes')
detection threshold - correct answer-Averaging the crossover points gives the detection
threshold.
absolute threshold - correct answer-the minimum stimulation needed to detect a
particular stimulus
Classical Threshold Theory - correct answer-Predicts a "step" psychometric function
psychometric function - correct answer-relates stimulus intensity (x- axis) to the subject's
detection rate (y-axis).
candle flame - correct answer-48 km on a clear night
, Problems w/ classical threshold theory - correct answer-Relatively minor changes in how
the task is worded greatly affect the psychometric function.
Absolute detection thresholds are influenced by a person's bias.
conservative bias - correct answer-Saying no
liberal bias - correct answer-yes
signal detection theory - correct answer-theory regarding how stimuli are detected under
different conditions
SDT differs from CTT - correct answer-It uses a mathematical analysis of errors to separate
decision factors from perceptual sensitivity
SDT mixes signal-present with signal-absent 'catch' trials
Signal present - correct answer-Yes= hit
No = miss
Signal absent - correct answer-yes = false alarm
no = correct rejection
assumptions of SDT - correct answer-The signal is always embedded in noise, with the
signal+noise distribution shifted relative to the noise-only
distribution
bias - correct answer-liberal bias: more FA less Misses
A conservative bias (bias to respond 'no') minimizes FAs but generates lots of misses.
Sensitivity - correct answer-Ability to differentiate the noise from the signal+noise
distributions
low sensitivity - correct answer--When the separation is small the distributions overlap and
detection is difficult.
-high degree of false-negative results
high sensitivity - correct answer-When the separation is large there is less overlap and
detection is easier.
sensitivity formula - correct answer-d' = hit rate- false alarm rate
Bias formula - correct answer-beta=hit rate/ false alarm rate
Psychophysics - correct answer-The study of how physical stimuli are translated into
psychological experience.
recognition/identification - correct answer-What is this? a car
Visual Search - correct answer-search for a target in a display containing distracting
elements
Detection - correct answer-is there a 'T'? no
Discrimination - correct answer-which line is longer? A
magnitude estimation - correct answer-a psychophysical method in which the participant
assigns values according to perceived magnitudes of the stimuli
Fechner's law - correct answer-S= k log l
Empiricists - correct answer-believed that the mind of a person can be understood by
observing that person's experiences
Cartesian Dualists - correct answer-believed that the mind and the body were basically
separate and that it is not possible to understand the mind by studying the body
Fechner's Law - correct answer-the observation that the strength of a sensation is
proportional to the logarithm of physical stimulus intensity
Fechner's methods - correct answer-Method of Limits
Method of Adjustment
Method of Constant Stimuli
crossover point - correct answer-The intensity at which they start saying 'no' (or 'yes')
detection threshold - correct answer-Averaging the crossover points gives the detection
threshold.
absolute threshold - correct answer-the minimum stimulation needed to detect a
particular stimulus
Classical Threshold Theory - correct answer-Predicts a "step" psychometric function
psychometric function - correct answer-relates stimulus intensity (x- axis) to the subject's
detection rate (y-axis).
candle flame - correct answer-48 km on a clear night
, Problems w/ classical threshold theory - correct answer-Relatively minor changes in how
the task is worded greatly affect the psychometric function.
Absolute detection thresholds are influenced by a person's bias.
conservative bias - correct answer-Saying no
liberal bias - correct answer-yes
signal detection theory - correct answer-theory regarding how stimuli are detected under
different conditions
SDT differs from CTT - correct answer-It uses a mathematical analysis of errors to separate
decision factors from perceptual sensitivity
SDT mixes signal-present with signal-absent 'catch' trials
Signal present - correct answer-Yes= hit
No = miss
Signal absent - correct answer-yes = false alarm
no = correct rejection
assumptions of SDT - correct answer-The signal is always embedded in noise, with the
signal+noise distribution shifted relative to the noise-only
distribution
bias - correct answer-liberal bias: more FA less Misses
A conservative bias (bias to respond 'no') minimizes FAs but generates lots of misses.
Sensitivity - correct answer-Ability to differentiate the noise from the signal+noise
distributions
low sensitivity - correct answer--When the separation is small the distributions overlap and
detection is difficult.
-high degree of false-negative results
high sensitivity - correct answer-When the separation is large there is less overlap and
detection is easier.
sensitivity formula - correct answer-d' = hit rate- false alarm rate
Bias formula - correct answer-beta=hit rate/ false alarm rate
