Fixational saccades alter the gap effect

2014 ◽  
Vol 39 (12) ◽  
pp. 2098-2106 ◽  
Author(s):  
Masayuki Watanabe ◽  
Yuka Matsuo ◽  
Ling Zha ◽  
Michael R. MacAskill ◽  
Yasushi Kobayashi
2008 ◽  
Author(s):  
Kaitlin Laidlaw ◽  
Sara Stevens ◽  
Jim McAuliffe ◽  
Jay Pratt

1994 ◽  
Author(s):  
Jay Pratt ◽  
Heather Oonk ◽  
Harold Bekkering ◽  
Richard A. Abrams ◽  
Mark B. Law
Keyword(s):  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Talora L. Martin ◽  
Jordan Murray ◽  
Kiran Garg ◽  
Charles Gallagher ◽  
Aasef G. Shaikh ◽  
...  

AbstractWe evaluated the effects of strabismus repair on fixational eye movements (FEMs) and stereopsis recovery in patients with fusion maldevelopment nystagmus (FMN) and patients without nystagmus. Twenty-one patients with strabismus, twelve with FMN and nine without nystagmus, were tested before and after strabismus repair. Eye-movements were recorded during a gaze-holding task under monocular viewing conditions. Fast (fixational saccades and quick phases of nystagmus) and slow (inter-saccadic drifts and slow phases of nystagmus) FEMs and bivariate contour ellipse area (BCEA) were analyzed in the viewing and non-viewing eye. Strabismus repair improved the angle of strabismus in subjects with and without FMN, however patients without nystagmus were more likely to have improvement in stereoacuity. The fixational saccade amplitudes and intersaccadic drift velocities in both eyes decreased after strabismus repair in subjects without nystagmus. The slow phase velocities were higher in patients with FMN compared to inter-saccadic drifts in patients without nystagmus. There was no change in the BCEA after surgery in either group. In patients without nystagmus, the improvement of the binocular function (stereopsis), as well as decreased fixational saccade amplitude and intersaccadic drift velocity, could be due, at least partially, to central adaptive mechanisms rendered possible by surgical realignment of the eyes. The absence of improvement in patients with FMN post strabismus repair likely suggests the lack of such adaptive mechanisms in patients with early onset infantile strabismus. Assessment of fixation eye movement characteristics can be a useful tool to predict functional improvement post strabismus repair.


PLoS ONE ◽  
2017 ◽  
Vol 12 (4) ◽  
pp. e0175295 ◽  
Author(s):  
Aasef G. Shaikh ◽  
Fatema F. Ghasia
Keyword(s):  

1998 ◽  
Vol 31 (10) ◽  
pp. 1313-1318 ◽  
Author(s):  
W. Machado-Pinheiro ◽  
L.G. Gawryszewski ◽  
L.E. Ribeiro-do-Valle

10.29007/275r ◽  
2018 ◽  
Author(s):  
Niraj Shinde ◽  
Devesh Soni

The seismic behavior of multi-storied building supported on Friction pendulum system (FPS) during impact with adjacent structure is examined. One lateral degree of freedom is considered at each floor, base mass and slider. Adjacent structure (i.e. retaining walls or entry bridges) is modeled as an impact element in form of spring and dashpot. The impact response of FPS bearing is studied under 60 records consisting of service level, design basis and maximum credible earthquakes. Newmark’s step by step iteration method is used to solve the differential equations of motion for the isolated system. The impact response of isolated building is studied under the variation of important system parameters such as size of gap and stiffness of impact element. To reduce the influence of impact a viscous damper is employed between the isolated building and adjacent structure. It is concluded that during impact with adjacent structure the superstructure acceleration and base shear increases while bearing displacement decreases. The employment of viscous damper shows considerable reduction in bearing displacements, base shear and impact force during DBE and MCE events. Further, the effects of impact are found critical if the superstructure is flexible and greater stiffness of impact element. The top floor acceleration increases with the isolation gap up to certain limit and again reduces with the increase in isolation gap.Keywords - Adjacent Structure; isolation; Sliding bearing; Viscous Damper; Gap effect; Floor acceleration; Impact


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