Improvement of contrast sensitivity with practice is not compatible with a sensory threshold account.
J Opt Soc Am A Opt Image Sci Vis
; 34(6): 870-880, 2017 Jun 01.
Article
em En
| MEDLINE
| ID: mdl-29036070
ABSTRACT
In forced-choice detection, incorrect responses are routinely ascribed to internal noise, because experienced psychophysical observers do not act as if they have a sensory threshold, below which all perceived intensities would be identical. To determine whether inexperienced observers have sensory thresholds, we examined psychometric functions (percent correct versus log contrast) for detection and detection in full-screen, dynamic visual noise. Over five days, neither type of psychometric function changed shape, but both shifted leftwards, indicating increased sensitivity. These results are not consistent with a lowered sensory threshold, which would decrease psychometric slope. Our results can be understood within the context of Dosher and Lu's "stochastic" perceptual template model [Vis. Res.40, 1269 (2000)], augmented to allow intrinsic uncertainty. Specifically, our results are consistent with a combination of reduced internal additive noise and improved filtering of external noise.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Limiar Sensorial
/
Sensibilidades de Contraste
Tipo de estudo:
Diagnostic_studies
Limite:
Humans
Idioma:
En
Revista:
J Opt Soc Am A Opt Image Sci Vis
Assunto da revista:
OFTALMOLOGIA
Ano de publicação:
2017
Tipo de documento:
Article