Search results for "Visual Processing"

Project DyAdd : Nonlinguistic theories of dyslexia predict intelligence

2020

Two themes have puzzled the research on developmental and learning disorders for decades. First, some of the risk and protective factors behind developmental challenges are suggested to be shared and some to be specific for a given condition. Second, language-based learning difficulties like dyslexia are suggested to result from or correlate with also nonlinguistic aspects of information processing. In the current study, we investigated how adults with developmental dyslexia and ADHD as well as healthy controls cluster across various dimensions designed to tap the prominent nonlinguistic theories of dyslexia. Participants were 18–55-year-old adults with dyslexia (n = 36), ADHD (n = 22), and…

Project DyAdd: Non-linguistic Theories of Dyslexia Predict Intelligence

2020

Two themes have puzzled the research on developmental and learning disorders for decades. First, some of the risk and protective factors behind developmental challenges are suggested to be shared and some are suggested to be specific for a given condition. Second, language-based learning difficulties like dyslexia are suggested to result from or correlate with non-linguistic aspects of information processing as well. In the current study, we investigated how adults with developmental dyslexia or ADHD as well as healthy controls cluster across various dimensions designed to tap the prominent non-linguistic theories of dyslexia. Participants were 18–55-year-old adults with dyslexia (n = 36), …

Synergy of features enables detection of texture defined figures

2006

Traditional theories of early visual processing suggest that elementary visual features are handled in parallel by independent neural pathways. We studied the interaction of orientation and spatial frequency in the discrimination of Gabor random fields. Target textures differed from reference textures either in mean feature value, showing an edge-like transition between both textures (edge defined), or in the degree of feature homogeneity with smooth transitions (region defined). Irrespective of the kind of texture definition, we found strong cue summation for targets defined by both cues simultaneously, provided two conditions were fulfilled. First, they were barely discriminable when defi…

Luminance Information Is Required for the Accurate Estimation of Contrast in Rapidly Changing Visual Contexts.

2020

Summary Visual perception scales with changes in the visual stimulus, or contrast, irrespective of background illumination. However, visual perception is challenged when adaptation is not fast enough to deal with sudden declines in overall illumination, for example, when gaze follows a moving object from bright sunlight into a shaded area. Here, we show that the visual system of the fly employs a solution by propagating a corrective luminance-sensitive signal. We use in vivo 2-photon imaging and behavioral analyses to demonstrate that distinct OFF-pathway inputs encode contrast and luminance. Predictions of contrast-sensitive neuronal responses show that contrast information alone cannot ex…

Effects of Intranasal Oxytocin on Emotion Regulation in Insecure Adolescents: Study Protocol for a Double-Blind, Randomized Controlled Trial

2016

Background: Emotional dysregulation and impaired attachment are potential contributors to the development of psychopathology in adolescence. This raises the question of whether oxytocin (OT), the paradigmatic “attachment hormone,” may be beneficial in such contexts. Recent evidence suggests that intranasal administration of OT increases affiliative behavior, including trust and empathy. OT may also facilitate social reciprocity by attenuating the stress response to interpersonal conflict. To date, few studies have investigated the effects of intranasal oxytocin (IN-OT) on neurophysiological emotion regulation strategies in healthy adolescents, particularly during parent-adolescent interacti…

Visual processing in patients with age-related macular degeneration performing a face detection test

2017

Purpose: People with age-related macular degeneration (AMD) have difficulties in familiar face recognition and facial expression discrimination. Our aim was to evaluate the visual processing of faces in AMD patients and whether this would be improved by anti-vascular endothelial growth factor therapy. This was a prospective interventional cohort study. Patients: Twelve patients with monocular wet AMD and 6 control subjects were recruited. Face detection processes were studied using cortical event-related potentials (ERPs). Patients received 3 bevacizumab intravitreal injections to the single affected eye. At baseline and 4–6 weeks after the last injection, clinical presentation and ERPs of …

Preattentive detection of rare audiovisual feature conjunctions by the human brain as reflected by the mismatch negativity

2007

Instruction-based clinical eye-tracking study on the visual interpretation of divergence : how do students look at vector field plots?

2018

Relating mathematical concepts to graphical representations is a challenging task for students. In this paper, we introduce two visual strategies to qualitatively interpret the divergence of graphical vector field representations. One strategy is based on the graphical interpretation of partial derivatives, while the other is based on the flux concept. We test the effectiveness of both strategies in an instruction-based eye-tracking study with N = 41 physics majors. We found that students’ performance improved when both strategies were introduced (74% correct) instead of only one strategy (64% correct), and students performed best when they were free to choose between the two strategies (88…

Do categorical representations modulate early automatic visual processing? A visual mismatch-negativity study.

2021

Perceptual categorization is an important cognitive function. In the auditory domain, categorization already occurs within the first 200 ms of information processing, as indexed by the mismatch negativity. Here, we assessed the characteristics of the visual mismatch negativity (vMMN) elicited during the categorization of previously unknown visual stimuli. To examine this, we used five-dot patterns with characteristics that allow for the formation of categories through rotation and reflection but not through other physical properties. To assess whether or not between-category and within-category vMMN differ in amplitude, the data was analyzed with the Bayesian approach. We observed that both…

Changes in neurophysiologic markers of visual processing following beneficial anti-VEGF treatment in macular degeneration

2013

Pasi Vottonen,1 Kai Kaarniranta,1,2 Ari Pääkkönen,3 Ina M Tarkka41Department of Ophthalmology, Kuopio University Hospital, Kuopio, Finland; 2Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland; 3Department of Clinical Neurophysiology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland; 4Department of Health Sciences, University of Jyväskylä, Jyväskylä, FinlandPurpose: Antivascular endothelial growth factor (VEGF) agents have been shown to improve visual acuity and prevent vision loss in exudative age-related macular degeneration. As the vision im…