Perceptual learning reflects external noise filtering and internal noise reduction through channel reweighting
AUTOR(ES)
Dosher, Barbara Anne
FONTE
The National Academy of Sciences
RESUMO
To investigate the nature of plasticity in the adult visual system, perceptual learning was measured in a peripheral orientation discrimination task with systematically varying amounts of external (environmental) noise. The signal contrasts required to achieve threshold were reduced by a factor or two or more after training at all levels of external noise. The strong quantitative regularities revealed by this novel paradigm ruled out changes in multiplicative internal noise, changes in transducer nonlinearites, and simple attentional tradeoffs. Instead, the regularities specify the mechanisms of perceptual learning at the behavioral level as a combination of external noise exclusion and stimulus enhancement via additive internal noise reduction. The findings also constrain the neural architecture of perceptual learning. Plasticity in the weights between basic visual channels and decision is sufficient to account for perceptual learning without requiring the retuning of visual mechanisms.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=25004Documentos Relacionados
- Filtering out the noise: evaluating the impact of noise and sound reduction strategies on sleep quality for ICU patients
- Early perceptual learning.
- Perceptual learning in clear displays optimizes perceptual expertise: Learning the limiting process
- Perceptual learning and adult cortical plasticity
- The Steady-State Internal Redox State (NADH/NAD) Reflects the External Redox State and Is Correlated with Catabolic Adaptation in Escherichia coli