1 / 5

Psychophysics

Psychophysics. Introduction Study of relationship between physical stimuli and sensations Gustav Fechner Three psychophysical problems What is the weakest stimulus that can be detected (the stimulus threshold)?

bertha-reid
Télécharger la présentation

Psychophysics

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Psychophysics • Introduction • Study of relationship between physical stimuli and sensations • Gustav Fechner • Three psychophysical problems • What is the weakest stimulus that can be detected (the stimulus threshold)? • What is the smallest difference between stimuli that can be detected (the difference threshold)? • What is the relationship between intensity of stimulus and intensity of sensation?

  2. Detection • Classical psychophysical methods • Method of constant stimuli • Method of limits • Adaptive testing -- staircase method • The theory of signal detection • Signal detection methodology • Outcome matrices • Sensitivity and criterion measurement

  3. Discrimination • Difference thresholds (jnd’s) • Weber’s Law (DI = kI) • Reaction time (RT) measures • Simple RT • Choice RT

  4. Identification • Information theory • Information = reduction of uncertainty • Quantification of information: the bit • Channel capacity • Hick’s Law: Choice RT is a linear function of amount of information in the stimulus

  5. Scaling • Quantification of the strength of a sensation • Prothetic vs metathetic continua • Indirect scaling: Fechner’s Law • S = k log(I/Io) • Direct scaling: Magnitude estimation and Stevens’ Law • (S = aIm) • Cross-modality matching • Multidimensional scaling • Context and bias: Adaptation Level theory

More Related