A Binocular Approach to Treating Amblyopia: Antisuppression Therapy
ABSTRACT We developed a binocular treatment for amblyopia based on antisuppression therapy.
A novel procedure is outlined for measuring the extent to which the fixing eye suppresses the fellow amblyopic eye. We hypothesize that suppression renders a structurally binocular system, functionally monocular.
We demonstrate using three strabismic amblyopes that information can be combined normally between their eyes under viewing conditions where suppression is reduced. Also, we show that prolonged periods of viewing (under the artificial conditions of stimuli of different contrast in each eye) during which information from the two eyes is combined leads to a strengthening of binocular vision in such cases and eventual combination of binocular information under natural viewing conditions (stimuli of the same contrast in each eye). Concomitant improvement in monocular acuity of the amblyopic eye occurs with this reduction in suppression and strengthening of binocular fusion. Furthermore, in each of the three cases, stereoscopic function is established.
This provides the basis for a new treatment of amblyopia, one that is purely binocular and aimed at reducing suppression as a first step.
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- "First, the remarkable acquisition of stereopsis by Sue Barry (''Stereo Sue'') in middle-age, documented first by Oliver Sacks (2006) and by Barry (2009) herself, points to the ability of binocular training to either establish, or more likely fine-tune, existing binocular connections that may have been retained despite longstanding alternating strabismus. In addition, remarkable success has been reported in a recent clinical study conducted on three adult strabismic amblyopes from a purely binocular approach to treatment (''antisuppression therapy'') unaccompanied by any patching of the fellow eye (Hess et al., 2010). "
ABSTRACT: Short daily periods of binocular vision, if concordant and continuous, have been shown to outweigh or protect against much longer daily periods of monocular deprivation to allow the development of normal visual acuity in both eyes of kittens. The greater weight placed on binocular visual input could arise because of an inherent bias for binocular input within the visual pathway at all times during development (Binocular model), or else from a more passive process that follows from its match to a highly binocular template at the time mixed daily visual input began (Template model). To distinguish between the predictions of these two models, kittens were monocularly deprived from normal eye-opening until either 4, 5, or 6 weeks of age at which time they received mixed daily visual input for 4 weeks. According to the Template model, the preferred input for these animals would be monocular exposure (ME) because of its match to the monocular template produced by a period of preceding monocular deprivation. However, instead of short daily period of ME offsetting much longer periods of binocular exposure (BE) to perpetuate the dire effects of the prior deprivation, short daily periods of BE promoted significant recovery of vision in the deprived eye. The fit to the Binocular model implies the existence of a robust substrate for binocular vision that is highly resistant to disruption and which could form the substrate for binocular approaches to treatment of amblyopia.Vision research 06/2011; 51(12):1351-9. DOI:10.1016/j.visres.2011.04.011 · 2.38 Impact Factor
Conference Paper: Automatic language identification with recurrent neural networks[Show abstract] [Hide abstract]
ABSTRACT: Automatic language identification (LID), an important domain in speech processing, means the capability of a machine to determine a natural language from a spoken utterance. We present a novel approach to LID, which involves recurrent neural networks (RNN) as the main mechanism. We propose that, because of acoustical context issues, RNNs are particularly suitable for the LID task. Our approach also introduces perceptually guided training (PGT), a novel training method, that exploits the concept of perceptually significant regions (PSR) postulated by our approach. We present our overall approach and describe LIREN/PGT, the have we have developed, implementing our approach. We also discuss our LID experiments with English, German, and Mandarin. In the paper, we concentrate on the architecture and training of RNNs for automatic language identificationNeural Networks Proceedings, 1998. IEEE World Congress on Computational Intelligence. The 1998 IEEE International Joint Conference on; 06/1998
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ABSTRACT: The antioxidative enzyme copper-zinc superoxide dismutase (Sod1) is an important cellular defence system against reactive oxygen species (ROS). While the majority of this enzyme is localized to the cytosol, about 1% of the cellular Sod1 is present in the intermembrane space (IMS) of mitochondria. These amounts of mitochondrial Sod1 are increased for certain Sod1 mutants that are linked to the neurodegenerative disease amyotrophic lateral sclerosis (ALS). To date, only little is known about the physiological function of mitochondrial Sod1. Here, we use the model system Saccharomyces cerevisiae to generate cells in which Sod1 is exclusively localized to the IMS. We find that IMS-localized Sod1 can functionally substitute wild type Sod1 and that it even exceeds the protective capacity of wild type Sod1 under conditions of mitochondrial ROS stress. Moreover, we demonstrate that upon expression in yeast cells the common ALS-linked mutant Sod1(G93A) becomes enriched in the mitochondrial fraction and provides an increased protection of cells from mitochondrial oxidative stress. Such an effect cannot be observed for the catalytically inactive mutant Sod1(G85R). Our observations suggest that the targeting of Sod1 to the mitochondrial IMS provides an increased protection against respiration-derived ROS.Biochemical and Biophysical Research Communications 11/2010; 403(1):114-9. DOI:10.1016/j.bbrc.2010.10.129 · 2.28 Impact Factor