Flexibility in Spatial Attention Before and After Practice

1997 ◽  
Vol 8 (5) ◽  
pp. 399-403 ◽  
Author(s):  
Kyle R Cave ◽  
James M Zimmerman
Keyword(s):  
Visual Field ◽  
Spatial Attention ◽  
Target Letter ◽  
Target Identification ◽  
Search Rate ◽  
Letter Array ◽  
Before And After

These experiments used spatial probes to measure how spatial attention is allocated across the visual field during search for a target letter in an eight-letter array There were three main findings Attentional strength is flexibly adjusted according to the confusability between target and distractors Distractor locations near the target receive more inhibition than those farther from the target, indicating that the nearby distractors interfere more with target identification Despite the fact that consistent practice improves search rate it does not diminish the strength of spatial attention in this task

On Why Objects Appear Smaller in the Visual Periphery

2019 ◽  
Vol 31 (1) ◽  
pp. 88-96 ◽  
Author(s):  
Wladimir Kirsch ◽  
Roland Pfister ◽  
Wilfried Kunde
Keyword(s):  
Visual Field ◽  
Visual System ◽  
Structural Properties ◽  
Spatial Attention ◽  
Visuospatial Attention ◽  
Peripheral Target ◽  
Perceptual Distortion ◽  
Visual Periphery ◽  
Peripheral Location ◽  
Exogenous Cue

An object appears smaller in the periphery than in the center of the visual field. In two experiments ( N = 24), we demonstrated that visuospatial attention contributes substantially to this perceptual distortion. Participants judged the size of central and peripheral target objects after a transient, exogenous cue directed their attention to either the central or the peripheral location. Peripheral target objects were judged to be smaller following a central cue, whereas this effect disappeared completely when the peripheral target was cued. This outcome suggests that objects appear smaller in the visual periphery not only because of the structural properties of the visual system but also because of a lack of spatial attention.

Occipitoparietal alpha-band responses to the graded allocation of top-down spatial attention

2014 ◽  
Vol 112 (6) ◽  
pp. 1307-1316 ◽  
Author(s):  
Isabel Dombrowe ◽  
Claus C. Hilgetag
Keyword(s):  
Visual Field ◽  
Spatial Attention ◽  
Brain Regions ◽  
Alpha Band ◽  
Top Down ◽  
Attentional Resources ◽  
Parietal Lobes ◽  
Visual Spatial ◽  
Entire Visual Field ◽  
Band Activity

The voluntary, top-down allocation of visual spatial attention has been linked to changes in the alpha-band of the electroencephalogram (EEG) signal measured over occipital and parietal lobes. In the present study, we investigated how occipitoparietal alpha-band activity changes when people allocate their attentional resources in a graded fashion across the visual field. We asked participants to either completely shift their attention into one hemifield, to balance their attention equally across the entire visual field, or to attribute more attention to one-half of the visual field than to the other. As expected, we found that alpha-band amplitudes decreased stronger contralaterally than ipsilaterally to the attended side when attention was shifted completely. Alpha-band amplitudes decreased bilaterally when attention was balanced equally across the visual field. However, when participants allocated more attentional resources to one-half of the visual field, this was not reflected in the alpha-band amplitudes, which just decreased bilaterally. We found that the performance of the participants was more strongly reflected in the coherence between frontal and occipitoparietal brain regions. We conclude that low alpha-band amplitudes seem to be necessary for stimulus detection. Furthermore, complete shifts of attention are directly reflected in the lateralization of alpha-band amplitudes. In the present study, a gradual allocation of visual attention across the visual field was only indirectly reflected in the alpha-band activity over occipital and parietal cortexes.

scholarly journals Comparison of Latanoprost/Timolol with Carbonic Anhydrase Inhibitor and Dorzolamide/Timolol with Prostaglandin Analog in the Treatment of Glaucoma

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Kenji Inoue ◽  
Shoichi Soeda ◽  
Goji Tomita
Keyword(s):  
Visual Field ◽  
Fixed Combination ◽  
Open Angle Glaucoma ◽  
Field Testing ◽  
Mean Deviation ◽  
Single Action ◽  
Before And After ◽  
Group 2 ◽  
Concomitant Medications ◽  
Medication Changes

Purpose.We retrospectively reviewed medical records of glaucoma patients to investigate how switching medications may affect intraocular pressure (IOP) management. Three concomitant medications were changed to two medications: one combination drop and one single-action drop. Associated adverse effects were also examined.Subjects and Methods.A total of 112 patients with primary open-angle glaucoma or ocular hypertension were examined. All patients were concomitantly using a prostaglandin (PG) analog, aβ-blocker, and a carbonic anhydrate inhibitor (CAI). Fifty-five patients began using latanoprost (PG analog)/timolol (β-blocker) fixed-combination (LTFC) drops and a CAI (group 1), and 57 patients began using dorzolamide (CAI)/timolol fixed-combination (DTFC) drops and a PG analog (group 2). The IOP was measured every 6 months for 2 years following medication changes. Changes in visual field mean deviation (MD) and medication discontinuations were also examined.Results.There were no significant differences in IOP or MD values before and after medication changes in either group. The proportion of medication discontinuations, uncontrolled IOP, and adverse reactions was similar in both groups.Conclusion.Switching patients from multiple single-action medications to combination medications was not associated with changes in IOP, visual field testing results, or adverse event frequency.

Spatially Consistent, Localized Visual Field Loss before and after Disc Hemorrhage

2009 ◽  
Vol 50 (10) ◽  
pp. 4727 ◽  
Author(s):  
Carlos Gustavo V. De Moraes ◽  
Tiago S. Prata ◽  
Craig A. Liebmann ◽  
Celso Tello ◽  
Robert Ritch ◽  
...  
Keyword(s):  
Visual Field ◽  
Visual Field Loss ◽  
Disc Hemorrhage ◽  
Before And After

A COMPARISON OF ASSESSMENT, DIAGNOSIS AND TREATMENT OF PATIENTS WITH CEREBRAL VENOUS THROMBOSIS BEFORE AND AFTER INTRODUCTION OF A NEW POLICY AND GUIDELINE ACROSS GREATER MANCHESTER

2015 ◽  
Vol 86 (11) ◽  
pp. e4.103-e4
Author(s):  
James Keitley ◽  
Timothy Lavin ◽  
Martin Punter ◽  
Jason McMinn ◽  
Mark Kellett
Keyword(s):  
Visual Acuity ◽  
Visual Field ◽  
Venous Thrombosis ◽  
Cerebral Venous Thrombosis ◽  
Diagnosis And Treatment ◽  
Clinical Assessments ◽  
Before And After ◽  
Valid Comparison ◽  
High Level ◽  
The Impact

BackgroundFrom June 2014, regional guidelines to transfer within 24 hours all radiologically confirmed cases of cerebral venous thrombosis (CVT) were implemented across Greater Manchester. This service review assesses the impact on assessment, diagnosis and treatment.MethodsWe prospectively recorded all CVT cases transferred into our unit between June 1st and November 30th 2014 (14 patients), and retrospectively reviewed the casenotes of patients admitted in 2012, 2013 and early 2014 (13 patients).ResultsMean number of days from diagnosis to transfer after guideline introduction was 0.4. More patients underwent fundoscopy (86% vs 77%), visual acuity (50% vs 27%), visual field (79% vs 69%) and otoscopy (29% vs 8%). Patients admitted to SRFT previously had shorter symptom to diagnosis, imaging, transfer, and treatment times.ConclusionsAfter guideline introduction we found a high level of compliance with time to transfer, with improvements in several aspects of clinical assessments. We expect that patients previously admitted to our centre were more unwell or already admitted for other reasons (e.g. neurosurgical) and therefore time from symptoms to diagnosis appears longer. We aim to extend the current evaluation to all patients in the region who weren't transferred to our centre to allow a more valid comparison.

Visual field dependence???independence before and after unilateral vestibular loss

Neuroreport ◽  
2006 ◽  
Vol 17 (8) ◽  
pp. 797-803 ◽  
Author(s):  
Christophe Lopez ◽  
Michel Lacour ◽  
Jacques Magnan ◽  
Liliane Borel
Keyword(s):  
Visual Field ◽  
Field Dependence ◽  
Vestibular Loss ◽  
Before And After ◽  
Visual Field Dependence

scholarly journals Relative motion in the periphery of the visual field is a powerful cue for visuo-spatial attention

2010 ◽  
Vol 5 (8) ◽  
pp. 162-162
Author(s):  
D. A. Poggel ◽  
H. Strasburger ◽  
M. MacKeben
Keyword(s):  
Visual Field ◽  
Spatial Attention ◽  
Relative Motion

scholarly journals Pre-saccadic remapping relies on dynamics of spatial attention

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Martin Szinte ◽  
Donatas Jonikaitis ◽  
Dragan Rangelov ◽  
Heiner Deubel
Keyword(s):  
Visual Field ◽  
Spatial Attention ◽  
Temporal Dynamics ◽  
Receptive Fields ◽  
Spatial Location ◽  
Visual Scene ◽  
Attentional Allocation ◽  
Attentional Resources ◽  
Spatial And Temporal Dynamics ◽  
Saccadic Remapping

Each saccade shifts the projections of the visual scene on the retina. It has been proposed that the receptive fields of neurons in oculomotor areas are predictively remapped to account for these shifts. While remapping of the whole visual scene seems prohibitively complex, selection by attention may limit these processes to a subset of attended locations. Because attentional selection consumes time, remapping of attended locations should evolve in time, too. In our study, we cued a spatial location by presenting an attention-capturing cue at different times before a saccade and constructed maps of attentional allocation across the visual field. We observed no remapping of attention when the cue appeared shortly before saccade. In contrast, when the cue appeared sufficiently early before saccade, attentional resources were reallocated precisely to the remapped location. Our results show that pre-saccadic remapping takes time to develop suggesting that it relies on the spatial and temporal dynamics of spatial attention.

scholarly journals Strategies of the honeybee Apis mellifera during visual search for vertical targets presented at various heights: a role for spatial attention?

F1000Research ◽  
2014 ◽  
Vol 3 ◽  
pp. 174 ◽  
Author(s):  
Linde Morawetz ◽  
Lars Chittka ◽  
Johannes Spaethe
Keyword(s):  
Visual Field ◽  
Spatial Attention ◽  
Search Strategy ◽  
Poor Performance ◽  
Search Performance ◽  
Behavioural Adaptation ◽  
Straight Line ◽  
Search Patterns ◽  
Direct Flight ◽  
Learning Trials

When honeybees are presented with a colour discrimination task, they tend to choose swiftly and accurately when objects are presented in the ventral part of their frontal visual field. In contrast, poor performance is observed when objects appear in the dorsal part. Here we investigate if this asymmetry is caused by fixed search patterns or if bees can use alternative search mechanisms such as spatial attention, which allows flexible focusing on different areas of the visual field. We asked individual honeybees to choose an orange rewarded target among blue distractors. Target and distractors were presented in the ventral visual field, the dorsal field or both. Bees presented with targets in the ventral visual field consistently had the highest search efficiency, with rapid decisions, high accuracy and direct flight paths. In contrast, search performance for dorsally located targets was inaccurate and slow at the beginning of the test phase, but bees increased their search performance significantly after a few learning trials: they found the target faster, made fewer errors and flew in a straight line towards the target. However, bees needed thrice as long to improve the search for a dorsally located target when the target’s position changed randomly between the ventral and the dorsal visual field. We propose that honeybees form expectations of the location of the target’s appearance and adapt their search strategy accordingly. Different possible mechanisms of this behavioural adaptation are discussed.

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