Taken together, it seemed that feedforward, contrast energy–based models of deprivation sufficed to explain these effects. In addition, because phase scrambling did not induce deprivation effects, it seemed that a reduction in the amplitude of the high-frequency components was not just sufficient but also necessary to induce shifts in eye balance. They concluded that deprivation in overall monocular contrast was not necessary to induce short-term deprivation effects, because the removal of just high-frequency contrast information was sufficient (i.e., low-pass filtering triggered deprivation effects, while high-pass did not). In an effort to evaluate the determinants of this new form of short-term plasticity, Zhou, Reynaud, and Hess ( 2014) studied the consequence of other types of monocular deprivation such as band-pass filtering, parametric reductions in contrast, and contrast-preserving phase scrambling. As well, they observed comparable effects with both light-tight and diffuser-lens deprivation (a ground glass that eliminates contrast but preserves overall illumination). ( 2013) extended this finding by showing that the deprived eye has greater influence in dichoptic phase combination, global motion coherence (GMC), and contrast matching tasks.
#KALEIDOSCOPE EFFECT PATCH#
( 2011) first observed that short-term (150-min) monocular deprivation with a translucent patch affected the dynamics of binocular rivalry, resulting in the previously deprived eye prevailing twice as often as the nondeprived eye. In addition, since the suppression of the kaleidoscopic image likely requires feedback from higher-level processes capable of determining the behavioral relevance of an eye's information (Foley & Miyanshi, 1969 Jiang, Costello, & He, 2007 Kovács, Papathomas, Yang, & Fehér, 1996 Wolf & Hochstein, 2011), feedforward-only models may need to be elaborated. This rules out contrast imbalance as the sole factor driving these shifts in sensory eye balance. Kaleidoscopic deprivation produced effects indistinguishable from traditional light-tight patching. Here, we used a novel “kaleidoscopic” monocular deprivation that, although it rendered images fractionated and uninformative, preserved gross luminance, color, spatial frequency, motion, and contrast information, effectively sneaking the image degradation past early, feedforward mechanisms, targeting higher levels. This could be accommodated in a feedforward model of binocular combination (Meese, Georgeson, & Baker, 2006 Sperling & Ding, 2010), in which the shift reflects a (persistent) reweighting induced by an interocular gain control mechanism tasked with maintaining binocular balance (Zhou, Clavagnier, et al., 2013). Various types of deprivation-light-tight, diffuser lenses, image degradation-have been tested, and it seemed that a deprivation of contrast was necessary, and sufficient, for these shifts. Short-term monocular deprivation (∼150 min) temporarily shifts sensory eye balance in favor of the deprived eye (Lunghi, Burr, & Morrone, 2011 Zhou, Clavagnier, & Hess, 2013), opposite to classic deprivation studies (Hubel & Wiesel, 1970).
0 kommentar(er)
