Search results for " blindness"
showing 10 items of 27 documents
Next-generation sequencing confirms the implication ofSLC24A1in autosomal-recessive congenital stationary night blindness
2016
Congenital stationary night blindness (CSNB) is a clinically and genetically heterogeneous retinal disorder which represents rod photoreceptor dysfunction or signal transmission defect from photoreceptors to adjacent bipolar cells. Patients displaying photoreceptor dysfunction show a Riggs-electroretinogram (ERG) while patients with a signal transmission defect show a Schubert–Bornschein ERG. The latter group is subdivided into complete or incomplete (ic) CSNB. Only few CSNB cases with Riggs-ERG and only one family with a disease-causing variant in SLC24A1 have been reported. Whole-exome sequencing (WES) in a previously diagnosed icCSNB patient identified a homozygous nonsense variant in SL…
Das Usher-Syndrom, eine Ziliopathie des Menschen
2018
ZusammenfassungDas humane Usher-Syndrom (USH) ist eine seltene, komplexe genetische Erkrankung, die sich in kombinierter Taubblindheit manifestiert. Aufgrund der Ausprägung des Krankheitsbilds werden 3 klinische Typen (USH1 – 3) unterschieden. Für eine korrekte Diagnose sind zusätzlich zu den auditorischen Tests im Zuge des Neugeborenenscreens auch frühe ophthalmologische Untersuchungen und eine molekulargenetische Abklärung notwendig. Die bislang 10 bekannten USH-Gene codieren für heterogene Proteine, die in Proteinnetzwerken miteinander in Funktionseinheiten kooperieren. Im Auge und im Ohr werden USH-Proteine vor allem in den mechanosensitiven Haarsinneszellen und den Stäbchen- und Zapfen…
Anger superiority effect for change detection and change blindness
2013
Abstract In visual search, an angry face in a crowd “pops out” unlike a happy or a neutral face. This “anger superiority effect” conflicts with views of visual perception holding that complex stimulus contents cannot be detected without focused top-down attention. Implicit visual processing of threatening changes was studied by recording event-related potentials (ERPs) using facial stimuli using the change blindness paradigm, in which conscious change detection is eliminated by presenting a blank screen before the changes. Already before their conscious detection, angry faces modulated relatively early emotion sensitive ERPs when appearing among happy and neutral faces, but happy faces only…
Event-related potentials reveal rapid registration of features of infrequent changes during change blindness.
2009
Abstract Background Change blindness refers to a failure to detect changes between consecutively presented images separated by, for example, a brief blank screen. As an explanation of change blindness, it has been suggested that our representations of the environment are sparse outside focal attention and even that changed features may not be represented at all. In order to find electrophysiological evidence of neural representations of changed features during change blindness, we recorded event-related potentials (ERPs) in adults in an oddball variant of the change blindness flicker paradigm. Methods ERPs were recorded when subjects performed a change detection task in which the modified i…
Look at them and they will notice you : Distractor-independent attentional capture by direct gaze in change blindness
2018
Humans have shown a detection advantage of direct vs. averted gaze stimuli in visual search tasks. However, instead of attentional capture by direct gaze, the detection advantage in visual search may depend on attention-grabbing potential of the distractor stimuli to which the target needs to be compared. We investigated attentional capture by direct gaze using the change blindness paradigm, in which successful detection does not require comparison between the target and the distractor items. Participants detected a masked gaze direction change in one of four simultaneously presented schematic faces. The distractor gaze directions were systematically varied across three experiments. Changes…
Whatever next? Predictive brains, situated agents, and the future of cognitive science
2012
In the target article, Andy Clark addresses the question of how a probabilistic predictive coding model of the mind relates to our personal level mental lives. This question, he suggests, is “potentially the most important” (MS46). The question is important indeed, but Clark’s answer fails to capitalize on another possible advantage of this approach. Clark suggests that there is a disconnect between the way the world appears to us, on one hand, and the way that it is represented in the brain, on the other. He deals with this disconnect by limiting the scope of the theory, by pointing out that he is discussing a theory of how brains encode and process information, not a theory about how thin…
Wavelet analysis of human photoreceptoral response
2010
Feature detection of biomedical signals is crucial for deepening our knowledge of the physiological phenomena giving rise to them. To achieve this aim, even if many analytic approaches have been suggested only few are able to deal with signals whose features are time dependent, and to provide useful clinical information. In this work we use the wavelet analysis to extract peculiarities of the early response of the photoreceptoral human system, known as a-wave ERG-component. The analysis of the a-wave features is important since this component reflects the functional integrity of the two populations of photoreceptors, rods and cones whose activation dynamics are not well known. Moreover, in …
Functional analysis of Normal and CSNB a-wave ERG component
2009
The features of a-wave of the human electroretinogram are one of the more debated problems in electrophysiology since the a-wave reflects the functional integrity of the two photoreceptoral populations (rods and cones). Although different models concerning the contributions of the early photoreceptoral response are available in current literature, a fully comprehensive theory is difficult to formulate because of the large amount of individual photoreceptors. We study the kinetics of the photoreceptoral response through the analysis of the a-wave shape both in healthy and in patients affected by the Congenital Stationary Night Blindness, that interests the rod population only. The physiologi…
Empirical mode decomposition and neural network for the classification of electroretinographic data
2013
The processing of biosignals is increasingly being utilized in ambulatory situations in order to extract significant signals' features that can help in clinical diagnosis. However, this task is hampered by the fact that biomedical signals exhibit a complex behaviour characterized by strong non-linear and non-stationary properties that cannot always be perceived by simple visual examination. New processing methods need be considered. In this context, we propose to apply a signal processing method, based on empirical mode decomposition and artificial neural networks, to analyse electroretinograms, i.e. the retinal response to a light flash, with the aim to detect and classify retinal diseases…
Touchless gestural interfaces for networked public displays
2015
In the near future, we can easily imagine a significant increment in diffusion of networked public displays, as well as novel interaction modalities used in their applications. In the following, we present two of the main challenges related to networked displays we are dealing with, with a particular focus on touchless gestural interfaces: overcoming interaction blindness (i.e. enable users to immediately guess the interactivity of the display, and the gestural nature of it) and performing evaluations in-the-wild (i.e. outside any controlled environment).