Textural properties corresponding to visual perception based on the correlation mechanism in the visual system

We present a set of texture parameters that correspond to perceptual properties of visual texture. For machine vision or a computer interface, it is important that the computational measurements of texture correspond well to the perceptual properties. To understand the mechanism of our visual system, it is important to know how we extract or characterize information for texture perception. In this study, we show that the autocorrelation function (ACF) analysis provides useful measures for representing three salient perceptual properties of texture: contrast, coarseness, and regularity. The validity of the ACF analysis was examined by comparing the calculated factors to the subjective scores collected for various kinds of natural textures. The effectiveness of the analysis depends on the structure of the estimated ACF. When a texture has a harmonic structure, the estimated ACF has periodical peaks corresponding to the periods of the texture. Both perceived coarseness and regularity are strongly related to these peaks in the ACF. However, the estimated ACF does not have a periodical structure when the texture is random. In this case, the texture coarseness and regularity are represented by the decay rate of the ACF.     

Bidirectional influences between maternal parenting and children's peer problems: a longitudinal monozygotic twin difference study

This twin study examined the bidirectional relationship between maternal parenting behaviors and children's peer problems that were not confounded by genetic and family environmental factors. Mothers of 259 monozygotic twin pairs reported parenting behaviors and peer problems when twins were 42 and 48 months. Path analyses on monozygotic twin difference scores revealed that authoritative parenting (the presence of consistent discipline and lack of harsh parenting) and peer problems simultaneously influenced each other. Authoritative parenting reduced peer problems, and peer problems increased authoritative parenting. Neither consistent discipline nor harsh parenting alone was associated with peer problems. These results suggest that maternal authoritative parenting works protectively in regard to children's peer problems, and peer problems can evoke such effective parenting.