RESUMO
In this study, amnesic patients showed significant repetition priming effects in arithmetic fact retrieval tasks. The results indicate that repetition priming effects in arithmetic depend not on explicit recognition, but on the activation of specific long-term representations of arithmetic facts. Processing dissociations between easy and difficult items suggest that the priming effects results from the stage of fact retrieval and not from peripheral activation. This claim is also supported by encoding and naming tasks, which showed only slight priming effects as compared to the priming found in calculation tasks. Significant priming was found for identical (5 x 6 and 5 x 6) and complement problems (5 x 6 and 6 x 5), the latter showing a smaller magnitude of priming.
Assuntos
Amnésia/psicologia , Atenção , Dano Encefálico Crônico/psicologia , Matemática , Rememoração Mental , Resolução de Problemas , Adulto , Amnésia/diagnóstico , Dano Encefálico Crônico/diagnóstico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Tempo de Reação , Retenção Psicológica , Aprendizagem VerbalRESUMO
The extension of holographic techniques from the visible to the infrared is important. Potentially, holographic diffractive elements have a large range of uses in this wave band. Examples include mirrors, lenses, filters, and beam combiners. All these elements would have similar advantages to those enjoyed by their visible band diffractive analogs. The metal photodissolution effect in chalcogenides shows promise as one of the few techniques for producing low-loss holographic materials for use at any given wavelength from 0.6 to beyond 16 microm. To date, the work has concentrated on the photodissolution of silver into arsenic sulfide glasses. Both bulk and surface relief gratings can be fabricated simply by holographic or mask exposure. In principle, kinoforms (e.g., blazed zone plates) and Fresnel lenses can also be made. The results of material studies show that phase gratings with high modulation and low absorption can be produced. A coupled-wave analysis is used to calculate the likely grating performance, and some initial grating characterization results are presented. The limitations of the medium are discussed and possible solutions are considered.