RESUMO
We examined 30 infants in whom cortical visual impairment was diagnosed during their first year of life to ascertain prognostic factors for the development of object vision, defined as the ability to recognize faces or hand-held toys. All patients were followed up for a minimum of 12 months. The most common causes of cortical visual impairment in the 30 infants were hydrocephalus in nine infants (30.0%), birth asphyxia or neonatal hypoxia in eight infants (26.7%), intracranial hemorrhage with or without hydrocephalus in seven infants (23.3%), and meningitis in five infants (16.7%). Lack of development of object vision was associated only with hypoxia (P = .013). Findings on ophthalmic examination, an abnormality in the visual pathway on computed tomographic or magnetic resonance scan, and seizures, hydrocephalus, intracranial hemorrhage, meningitis, cerebral palsy, developmental delay, prematurity, microcephaly, and hearing deficit, did not appear to be risk factors for the lack of development of object vision.
Assuntos
Percepção de Forma/fisiologia , Transtornos da Visão/fisiopatologia , Córtex Visual/fisiopatologia , Encefalopatias/complicações , Encefalopatias/fisiopatologia , Feminino , Seguimentos , Humanos , Lactente , Masculino , Prognóstico , Fatores de Risco , Transtornos da Visão/etiologiaRESUMO
Prior work on generalized matched filters (GMF(s)) was limited to eighty points and a 1-D signal. We show here how to calculate arbitrarily large GMF(s). We then compare GMF(s) with other common pattern recognition filters for one particular image using computer simulation. The GMF appears to offer improvements in terms of smaller within-class variability and greater between-class separation relative to matched filters. In addition, the GMF permits far more accurate location of the object in the input scene than the matched filter.
