Editing Psychophysics (section)

{{Short description|Branch of knowledge relating physical stimuli and psychological perception}}
{{Psychology sidebar}}

'''Psychophysics''' is the field of [[psychology]] which quantitatively investigates the relationship between physical [[stimulus (physiology)|stimuli]] and the [[sensation (psychology)|sensations]] and [[perception]]s they produce. Psychophysics has been described as "the scientific study of the relation between stimulus and [[Sensation (psychology)|sensation]]"<ref name=GescheiderpIX>{{Cite book |author=Gescheider G |year=1997 |title=Psychophysics: the fundamentals | edition=3rd |isbn=978-0-8058-2281-6 |doi=10.4324/9780203774458|s2cid=241358787 }}</ref> or, more completely, as "the analysis of perceptual processes by studying the effect on a subject's experience or behaviour of systematically varying the properties of a stimulus along one or more physical dimensions".<ref name=Bruce1996>{{cite book |vauthors=Bruce V, Green PR, Georgeson MA |year=1996 |title=Visual perception | edition=3rd |publisher=Psychology Press}}</ref>

''Psychophysics'' also refers to a general class of methods that can be applied to study a [[perceptual system]]. Modern applications rely heavily on threshold measurement,<ref name=Boff_Kaufman_Thomas>{{cite book|editor1=Boff KR|editor2=Kaufman L|editor3=Thomas JP|title=Handbook of perception and human performance: Vol. I. Sensory processes and perception|year=1986|place=New York|publisher=John Wiley}}</ref> [[ideal observer analysis]], and [[Detection theory|signal detection theory]].<ref name=GescheiderChap5>{{cite book |author=Gescheider G |year=1997 |title=Psychophysics: the fundamentals | edition=3rd |publisher=Lawrence Erlbaum Associates | chapter=Chapter 5: The Theory of Signal Detection |isbn=978-0-8058-2281-6 }}</ref>

Psychophysics has widespread and important practical applications. For instance, in the realm of [[digital signal processing]], insights from psychophysics have guided the development of models and methods for [[lossy compression]]. These models help explain why humans typically perceive minimal loss of signal quality when audio and video signals are compressed using lossy techniques.