Weber-Fechner law
5.64 Weber-Fechner law. Equal stimulus ratios correspond to equal sensation differences. Now largely replaced by the psychophysical power law, see 5.49.
trial
5.63 trial. Sequence of events during an experimental session in which a subject (or subjects) is presented a stimulus set and the resulting response set is recorded. Annotation 1 In a psychophysical experiment the sequence of events is usually as follows: warning interval, pause, first observation interval, …nth observation interval, response interval (subject’s decision). The presentation of the stimulus may occur during the observation intervals. Annotation 2 An experimental session usually consists of many trials, with appropriately spaced rest periods.
transition region
5.62 transition region. Region of a psychometric function in which the performance measure along the response dimension changes from that obtainable by chance to some near-maximum value.
threshold of tickle
5.61 threshold of feeling; threshold of tickle. For a specified signal, minimum time-average sound pressure level (see A3.15) of that signal at the entrance to the external acoustic meatus which, in a specified fraction of the trials, will stimulate the ear to a point at which there is a feeling that is different from the sensation of hearing. Unit, decibel (dB). Annotation Instead of the method of constant stimuli, which is implied by the phrase “a specified fraction of the trials,” another specified psychophysical method may be employed.
threshold of feeling
5.61 threshold of feeling; threshold of tickle. For a specified signal, minimum time-average sound pressure level (see A3.15) of that signal at the entrance to the external acoustic meatus which, in a specified fraction of the trials, will stimulate the ear to a point at which there is a feeling that is different from the sensation of hearing. Unit, decibel (dB). Annotation Instead of the method of constant stimuli, which is implied by the phrase “a specified fraction of the trials,” another specified psychophysical method may be employed.