Psychophysics
Ans: * Allows us to make quantitative statements about perception
Quiz Threshold
Ans: * The minimum amount of a variable that an individual can detect 50% of the time
Quiz Threshold is an inverse of..
Ans: * Sensitivity
Quiz Method of ascending limits
Ans: * The experimenter increases the intensity of the stimuli incrementally from presentation to
presentation
,Quiz Dark adaptation is determined by..
Ans: * Method of ascending limits
Quiz Method of descending limits
Ans: * The experimenter decreases the intensity of stimuli incrementally from presentation to
presentation
Quiz Method of constant stimuli
Ans: * The experimenter varies the intensity of the stimuli randomly from presentation to presentation
_ This ensures that the patient will not anticipate the next stimulus, resulting in a more accurate
determination of threshold
_ Not used clinically
Quiz Stairstep method
Ans: * The experimenter gradually increases the intensity of the stimuli one step at a time (staircase
manner) until the patient detects the stimuli and then gradually decreases the intensity one step at a
time until the patient can no longer see the light
_ This minimizes anticipation and allows for a more time efficient method of refining threshold
Quiz Automated visual field testing is determined by..
Ans: * The staircase method
,Quiz Adjustment method
Ans: * The experimenter allows the subject to adjust the stimuli intensity until it is just perceivable
Quiz Forced choice method
Ans: * The experimenter forces the patient to choose between two alternatives that are presented at
the same time
_ This minimizes the effects of variable individual threshold criteria
Quiz Teller acuity cards are an example of..
Ans: * A forced choice method
Quiz Details of SDT
Ans: * Noise is considered to be random and Gaussian distributed, like a bell curve
_ Noise corrupts the signal
* The visual system does not receive the pure signal, instead it receives a combination of the signal and
noise
_ Also shaped like a bell curve
Quiz Detectability
Ans: * Characterizes the distance between the means of the signal and noise distribution and the noise
distribution
, _ The greater the separation between the noise bell curve and the signal and noise bell curve, the
greater the detectability of the signal
Quiz Type I Error
Ans: * The disease is absent, but the test is positive
* False positive
Quiz Type II Error
Ans: * The disease is present but the test is negative
* False negative
Quiz Sensitivity
Ans: * The probability the test will accurately detect those patients with the disease
Quiz False negative rate
Ans: * 1-sensitivity
Quiz Specificity
Ans: * The probability that the test will accurately detect those patients without the disease
Quiz False positive rate
Ans: * Allows us to make quantitative statements about perception
Quiz Threshold
Ans: * The minimum amount of a variable that an individual can detect 50% of the time
Quiz Threshold is an inverse of..
Ans: * Sensitivity
Quiz Method of ascending limits
Ans: * The experimenter increases the intensity of the stimuli incrementally from presentation to
presentation
,Quiz Dark adaptation is determined by..
Ans: * Method of ascending limits
Quiz Method of descending limits
Ans: * The experimenter decreases the intensity of stimuli incrementally from presentation to
presentation
Quiz Method of constant stimuli
Ans: * The experimenter varies the intensity of the stimuli randomly from presentation to presentation
_ This ensures that the patient will not anticipate the next stimulus, resulting in a more accurate
determination of threshold
_ Not used clinically
Quiz Stairstep method
Ans: * The experimenter gradually increases the intensity of the stimuli one step at a time (staircase
manner) until the patient detects the stimuli and then gradually decreases the intensity one step at a
time until the patient can no longer see the light
_ This minimizes anticipation and allows for a more time efficient method of refining threshold
Quiz Automated visual field testing is determined by..
Ans: * The staircase method
,Quiz Adjustment method
Ans: * The experimenter allows the subject to adjust the stimuli intensity until it is just perceivable
Quiz Forced choice method
Ans: * The experimenter forces the patient to choose between two alternatives that are presented at
the same time
_ This minimizes the effects of variable individual threshold criteria
Quiz Teller acuity cards are an example of..
Ans: * A forced choice method
Quiz Details of SDT
Ans: * Noise is considered to be random and Gaussian distributed, like a bell curve
_ Noise corrupts the signal
* The visual system does not receive the pure signal, instead it receives a combination of the signal and
noise
_ Also shaped like a bell curve
Quiz Detectability
Ans: * Characterizes the distance between the means of the signal and noise distribution and the noise
distribution
, _ The greater the separation between the noise bell curve and the signal and noise bell curve, the
greater the detectability of the signal
Quiz Type I Error
Ans: * The disease is absent, but the test is positive
* False positive
Quiz Type II Error
Ans: * The disease is present but the test is negative
* False negative
Quiz Sensitivity
Ans: * The probability the test will accurately detect those patients with the disease
Quiz False negative rate
Ans: * 1-sensitivity
Quiz Specificity
Ans: * The probability that the test will accurately detect those patients without the disease
Quiz False positive rate
