scholarly journals Residual abilities in age-related macular degeneration to process spatial frequencies during natural scene categorization

2011 ◽  
Vol 28 (6) ◽  
pp. 529-541 ◽  
Author(s):  
BENOIT MUSEL ◽  
RUXANDRA HERA ◽  
SYLVIE CHOKRON ◽  
DAVID ALLEYSSON ◽  
CHRISTOPHE CHIQUET ◽  
...  
Keyword(s):  
Spatial Frequency ◽  
Macular Degeneration ◽  
Reaction Times ◽  
Age Related Macular Degeneration ◽  
Natural Scenes ◽  
Natural Scene ◽  
Scene Categorization ◽  
Age Related ◽  
Spatial Frequencies ◽  
Healthy Participants

AbstractAge-related macular degeneration (AMD) is characterized by a central vision loss. We explored the relationship between the retinal lesions in AMD patients and the processing of spatial frequencies in natural scene categorization. Since the lesion on the retina is central, we expected preservation of low spatial frequency (LSF) processing and the impairment of high spatial frequency (HSF) processing. We conducted two experiments that differed in the set of scene stimuli used and their exposure duration. Twelve AMD patients and 12 healthy age-matched participants in Experiment 1 and 10 different AMD patients and 10 healthy age-matched participants in Experiment 2 performed categorization tasks of natural scenes (Indoors vs. Outdoors) filtered in LSF and HSF. Experiment 1 revealed that AMD patients made more no-responses to categorize HSF than LSF scenes, irrespective of the scene category. In addition, AMD patients had longer reaction times to categorize HSF than LSF scenes only for indoors. Healthy participants’ performance was not differentially affected by spatial frequency content of the scenes. In Experiment 2, AMD patients demonstrated the same pattern of errors as in Experiment 1. Furthermore, AMD patients had longer reaction times to categorize HSF than LSF scenes, irrespective of the scene category. Again, spatial frequency processing was equivalent for healthy participants. The present findings point to a specific deficit in the processing of HSF information contained in photographs of natural scenes in AMD patients. The processing of LSF information is relatively preserved. Moreover, the fact that the deficit is more important when categorizing HSF indoors, may lead to new perspectives for rehabilitation procedures in AMD.

Age-related macular degeneration changes the processing of visual scenes in the brain

2018 ◽  
Vol 35 ◽  
Author(s):  
STEPHEN RAMANOËL ◽  
SYLVIE CHOKRON ◽  
RUXANDRA HERA ◽  
LOUISE KAUFFMANN ◽  
CHRISTOPHE CHIQUET ◽  
...  
Keyword(s):  
Spatial Frequency ◽  
Macular Degeneration ◽  
Scene Perception ◽  
High Spatial Frequency ◽  
Age Related Macular Degeneration ◽  
Age Related ◽  
Spatial Frequencies ◽  
Visual Scenes ◽  
High Pass ◽  
Frequency Processing

AbstractIn age-related macular degeneration (AMD), the processing of fine details in a visual scene, based on a high spatial frequency processing, is impaired, while the processing of global shapes, based on a low spatial frequency processing, is relatively well preserved. The present fMRI study aimed to investigate the residual abilities and functional brain changes of spatial frequency processing in visual scenes in AMD patients. AMD patients and normally sighted elderly participants performed a categorization task using large black and white photographs of scenes (indoors vs. outdoors) filtered in low and high spatial frequencies, and nonfiltered. The study also explored the effect of luminance contrast on the processing of high spatial frequencies. The contrast across scenes was either unmodified or equalized using a root-mean-square contrast normalization in order to increase contrast in high-pass filtered scenes. Performance was lower for high-pass filtered scenes than for low-pass and nonfiltered scenes, for both AMD patients and controls. The deficit for processing high spatial frequencies was more pronounced in AMD patients than in controls and was associated with lower activity for patients than controls not only in the occipital areas dedicated to central and peripheral visual fields but also in a distant cerebral region specialized for scene perception, the parahippocampal place area. Increasing the contrast improved the processing of high spatial frequency content and spurred activation of the occipital cortex for AMD patients. These findings may lead to new perspectives for rehabilitation procedures for AMD patients.

scholarly journals Scene perception in age-related macular degeneration: Effect of spatial frequencies and contrast in residual vision

2017 ◽  
Vol 130 ◽  
pp. 36-47 ◽  
Author(s):  
Carole Peyrin ◽  
Stephen Ramanoël ◽  
Alexia Roux-Sibilon ◽  
Sylvie Chokron ◽  
Ruxandra Hera
Keyword(s):  
Macular Degeneration ◽  
Scene Perception ◽  
Age Related Macular Degeneration ◽  
Residual Vision ◽  
Age Related ◽  
Spatial Frequencies

scholarly journals Cortical Thickness and Natural Scene Recognition in the Child’s Brain

2020 ◽  
Vol 10 (6) ◽  
pp. 329
Author(s):  
François Orliac ◽  
Grégoire Borst ◽  
Grégory Simon ◽  
Katell Mevel ◽  
Julie Vidal ◽  
...  
Keyword(s):  
Cortical Thickness ◽  
Reaction Times ◽  
Imaging Study ◽  
Scene Recognition ◽  
Natural Scenes ◽  
Natural Scene ◽  
Processing Efficiency ◽  
Parahippocampal Cortex ◽  
Spatial Frequencies ◽  
Coarse Information

Visual scenes are processed in terms of spatial frequencies. Low spatial frequencies (LSF) carry coarse information, whereas high spatial frequencies (HSF) subsequently carry information about fine details. The present magnetic resonance imaging study investigated how cortical thickness covaried with LSF/HSF processing abilities in ten-year-old children and adults. Participants indicated whether natural scenes that were filtered in either LSF or HSF represented outdoor or indoor scenes, while reaction times (RTs) and accuracy measures were recorded. In adults, faster RTs for LSF and HSF images were consistently associated with a thicker cortex (parahippocampal cortex, middle frontal gyrus, and precentral and insula regions for LSF; parahippocampal cortex and fronto-marginal and supramarginal gyri for HSF). On the other hand, in children, faster RTs for HSF were associated with a thicker cortex (posterior cingulate, supramarginal and calcarine cortical regions), whereas faster RTs for LSF were associated with a thinner cortex (subcallosal and insula regions). Increased cortical thickness in adults and children could correspond to an expansion mechanism linked to visual scene processing efficiency. In contrast, lower cortical thickness associated with LSF efficiency in children could correspond to a pruning mechanism reflecting an ongoing maturational process, in agreement with the view that LSF efficiency continues to be refined during childhood. This differing pattern between children and adults appeared to be particularly significant in anterior regions of the brain, in line with the proposed existence of a postero-anterior gradient of brain development. Taken together, our results highlight the dynamic brain processes that allow children and adults to perceive a visual natural scene in a coherent way.

scholarly journals Initial Exploration of Oral Pazopanib in Healthy Participants and Patients With Age-Related Macular Degeneration

2013 ◽  
Vol 131 (12) ◽  
pp. 1595 ◽  
Author(s):  
Megan M. McLaughlin ◽  
Marcella G. Paglione ◽  
Jason Slakter ◽  
Michael Tolentino ◽  
Li Ye ◽  
...  
Keyword(s):  
Macular Degeneration ◽  
Age Related Macular Degeneration ◽  
Age Related ◽  
Healthy Participants ◽  
Initial Exploration

Contrast sensitivity function in patients with macular disease and good visual acuity

2021 ◽  
pp. bjophthalmol-2020-318494
Author(s):  
Karen M Wai ◽  
Filippos Vingopoulos ◽  
Itika Garg ◽  
Megan Kasetty ◽  
Rebecca F Silverman ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Macular Degeneration ◽  
Contrast Sensitivity ◽  
Visual Function ◽  
Sensitivity Function ◽  
Age Related Macular Degeneration ◽  
Macular Disease ◽  
Age Related ◽  
Spatial Frequencies ◽  
Healthy Control

IntroductionContrast sensitivity function (CSF) may better estimate a patient’s visual function compared with visual acuity (VA). Our study evaluates the quick CSF (qCSF) method to measure visual function in eyes with macular disease and good letter acuity.MethodsPatients with maculopathies (retinal vein occlusion, macula-off retinal detachment, dry age-related macular degeneration and wet age-related macular degeneration) and good letter acuity (VA ≥20/30) were included. The qCSF method uses an intelligent algorithm to measure CSF across multiple spatial frequencies. All maculopathy eyes combined and individual macular disease groups were compared with healthy control eyes. Main outcomes included area under the log CSF (AULCSF) and six CS thresholds ranging from 1 cycle per degree (cpd) to 18 cpd.Results151 eyes with maculopathy and 93 control eyes with VA ≥20/30 were included. The presence of a maculopathy was associated with significant reduction in AULCSF (β: −0.174; p<0.001) and CS thresholds at all spatial frequencies except for 18 cpd (β: −0.094 to −0.200 log CS, all p<0.01) compared with controls. Reductions in CS thresholds were most notable at low and intermediate spatial frequencies (1.5 cpd, 3 cpd and 6 cpd).ConclusionCSF measured with the qCSF active learning method was found to be significantly reduced in eyes affected by macular disease despite good VA compared with healthy control eyes. The qCSF method is a promising clinical tool to quantify subtle visual deficits that may otherwise go unrecognised by current testing methods.

scholarly journals Retinotopic and Lateralized Processing of Spatial Frequencies in Human Visual Cortex during Scene Categorization

2013 ◽  
Vol 25 (8) ◽  
pp. 1315-1331 ◽  
Author(s):  
Benoit Musel ◽  
Cécile Bordier ◽  
Michel Dojat ◽  
Cédric Pichat ◽  
Sylvie Chokron ◽  
...  
Keyword(s):  
Spatial Frequency ◽  
Anterior Part ◽  
Hemispheric Specialization ◽  
Temporal Cortex ◽  
Posterior Part ◽  
Occipital Cortex ◽  
Natural Scenes ◽  
Group Level ◽  
Scene Categorization ◽  
Spatial Frequencies

Using large natural scenes filtered in spatial frequencies, we aimed to demonstrate that spatial frequency processing could not only be retinotopically mapped but could also be lateralized in both hemispheres. For this purpose, participants performed a categorization task using large black and white photographs of natural scenes (indoors vs. outdoors, with a visual angle of 24° × 18°) filtered in low spatial frequencies (LSF), high spatial frequencies (HSF), and nonfiltered scenes, in block-designed fMRI recording sessions. At the group level, the comparison between the spatial frequency content of scenes revealed first that, compared with HSF, LSF scene categorization elicited activation in the anterior half of the calcarine fissures linked to the peripheral visual field, whereas, compared with LSF, HSF scene categorization elicited activation in the posterior part of the occipital lobes, which are linked to the fovea, according to the retinotopic property of visual areas. At the individual level, functional activations projected on retinotopic maps revealed that LSF processing was mapped in the anterior part of V1, whereas HSF processing was mapped in the posterior and ventral part of V2, V3, and V4. Moreover, at the group level, direct interhemispheric comparisons performed on the same fMRI data highlighted a right-sided occipito-temporal predominance for LSF processing and a left-sided temporal cortex predominance for HSF processing, in accordance with hemispheric specialization theories. By using suitable method of analysis on the same data, our results enabled us to demonstrate for the first time that spatial frequencies processing is mapped retinotopically and lateralized in human occipital cortex.

Age related macular degeneration (ARMD) – pathophysiological and clinical features and therapeutic concepts

2001 ◽  
Vol 58 (1) ◽  
pp. 28-35 ◽  
Author(s):  
Ursula Körner-Stiefbold
Keyword(s):  
Macular Degeneration ◽  
Clinical Features ◽  
Altersbedingte Makuladegeneration ◽  
Age Related Macular Degeneration ◽  
Genetische Faktoren ◽  
Age Related ◽  
Therapeutic Concepts

Die altersbedingte Makuladegeneration (AMD) ist eine der häufigsten Ursachen für einen irreversiblen Visusverlust bei Patienten über 65 Jahre. Nahezu 30% der über 75-Jährigen sind von einer AMD betroffen. Trotz neuer Erkenntnisse in der Grundlagenforschung ist die Ätiologie, zu der auch genetische Faktoren gehören, noch nicht völlig geklärt. Aus diesem Grund sind die Behandlungsmöglichkeiten zum jetzigen Zeitpunkt noch limitiert, so dass man lediglich von Therapieansätzen sprechen kann. Die derzeit zur Verfügung stehenden Möglichkeiten wie medikamentöse, chirurgische und laser- und strahlentherapeutische Maßnahmen werden beschrieben.

Nutrition in Age-Related Macular Degeneration Survey

2018 ◽  
Author(s):  
Rebekah Stevens ◽  
Richard Cooke ◽  
Hannah Bartlett
Keyword(s):  
Macular Degeneration ◽  
Age Related Macular Degeneration ◽  
Age Related
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