scholarly journals Motion sensitivity and fixation variability along individual meridians

2010 ◽  
Vol 5 (8) ◽  
pp. 137-137
Author(s):  
H. E. Bedell ◽  
T. C. Lien ◽  
J. Tong ◽  
P. M. Cisarik ◽  
S. S. Patel
2010 ◽  
Vol 6 (6) ◽  
pp. 575-575
Author(s):  
c. C. Lien ◽  
J. Tong ◽  
H. E. Bedell ◽  
P. M. Cisarik ◽  
S. S. Patel

Background: Binasal Occlusion (BNO) is a clinical technique used by many neurorehabilitative optometrists in patients with mild traumatic brain injury (mTBI) and increased visual motion sensitivity (VMS) or visual vertigo. BNO is a technique in which partial occluders are added to the spectacle lenses to suppress the abnormal peripheral visual motion information. This technique helps in reducing VMS symptoms (i.e., nausea, dizziness, balance difficulty, visual confusion). Case Report: A 44-year-old AA female presented for a routine eye exam with a history of mTBI approximately 33 years ago. She was suffering from severe dizziness for the last two years that was adversely impacting her ADLs. The dizziness occurred in all body positions and all environments throughout the day. She was diagnosed with vestibular hypofunction and had undergone vestibular therapy but reported little improvement. Neurological exam revealed dizziness with both OKN drum and hand movement, especially in the left visual field. BNO technique resulted in immediate relief of her dizziness symptoms. Conclusion: To our knowledge, this is the first case that illustrates how the BNO technique in isolation can be beneficial for patients with mTBI and vestibular hypofunction. It demonstrates the success that BNO has in filtering abnormal peripheral visual motion in these patients.


2019 ◽  
Vol 23 (4) ◽  
pp. 465-470 ◽  
Author(s):  
Ryan N. Moran ◽  
Tracey Covassin ◽  
Jessica Wallace

OBJECTIVEMigraine history has recently been identified as a risk factor for concussion and recovery. The authors performed a cross-sectional study examining baseline outcome measures on newly developed and implemented concussion assessment tools in pediatrics. The purpose of this study was to examine the effects of premorbid, diagnosed migraine headaches as a risk factor on vestibular and oculomotor baseline assessment in pediatric athletes.METHODSPediatric athletes between the ages of 8 and 14 years with a diagnosed history of migraine headache (n = 28) and matched controls without a history of diagnosed migraine headache (n = 28) were administered a baseline concussion assessment battery, consisting of the Vestibular/Ocular Motor Screening (VOMS), near point of convergence (NPC), and the King-Devick (K-D) tests. Between-groups comparisons were performed for vestibular symptoms and provocation scores on the VOMS (smooth pursuit, saccades, convergence, vestibular/ocular reflex, visual motion sensitivity), NPC (average distance), and K-D (time).RESULTSIndividuals diagnosed with migraine headaches reported greater VOMS smooth pursuit scores (p = 0.02), convergence scores (p = 0.04), vestibular ocular reflex scores (p value range 0.002–0.04), and visual motion sensitivity scores (p = 0.009). Differences were also observed on K-D oculomotor performance with worse times in those diagnosed with migraine headache (p = 0.02). No differences were reported on NPC distance (p = 0.06) or headache symptom reporting (p = 0.07) prior to the VOMS assessment.CONCLUSIONSPediatric athletes diagnosed with migraine headaches reported higher baseline symptom provocation scores on the VOMS. Athletes with migraine headaches also performed worse on the K-D test, further illustrating the influence of premorbid migraine headaches as a risk factor for elevated concussion assessment outcomes at baseline. Special consideration may be warranted for post-concussion assessment in athletes with migraine headaches.


2012 ◽  
Vol 18 ◽  
pp. 1102-1117 ◽  
Author(s):  
Joseph M. Furman ◽  
Dawn A. Marcus
Keyword(s):  

Perception ◽  
1974 ◽  
Vol 3 (2) ◽  
pp. 151-152 ◽  
Author(s):  
J I Nelson

1996 ◽  
Vol 11 ◽  
pp. 422s ◽  
Author(s):  
A.J. Richardson ◽  
J.H. Gruzelier ◽  
B.K. Puri

1997 ◽  
Vol 14 (4) ◽  
pp. 741-749 ◽  
Author(s):  
Colin W.G. Clifford ◽  
Michael R. Ibbotson ◽  
Keith Langley

AbstractThere are marked similarities in the adaptation to motion observed in wide-field directional neurons found in the mammalian nucleus of the optic tract and cells in the insect lobula plate. However, while the form and time scale of adaptation is comparable in the two systems, there is a difference in the directional properties of the effect. A model based on the Reichardt detector is proposed to describe adaptation in mammals and insects, with only minor modifications required to account for the differences in directionality. Temporal-frequency response functions of the neurons and the model are shifted laterally and compressed by motion adaptation. The lateral shift enhances dynamic range and differential motion sensitivity. The compression is not caused by fatigue, but is an intrinsic property of the adaptive process resulting from interdependence of temporal-frequency tuning and gain in the temporal filters of the motion detectors.


2021 ◽  
Author(s):  
Nicole X Han ◽  
Puneeth N. Chakravarthula ◽  
Miguel P. Eckstein

Face processing is a fast and efficient process due to its evolutionary and social importance. A majority of people direct their first eye movement to a featureless point just below the eyes that maximizes accuracy in recognizing a person's identity and gender. Yet, the exact properties or features of the face that guide the first eye movements and reduce fixational variability are unknown. Here, we manipulated the presence of the facial features and the spatial configuration of features to investigate their effect on the location and variability of first and second fixations to peripherally presented faces. Results showed that observers can utilize the face outline, individual facial features, and feature spatial configuration to guide the first eye movements to their preferred point of fixation. The eyes have a preferential role in guiding the first eye movements and reducing fixation variability. Eliminating the eyes or altering their position had the greatest influence on the location and variability of fixations and resulted in the largest detriment to face identification performance. The other internal features (nose and mouth) also contribute to reducing fixation variability. A subsequent experiment measuring detection of single features showed that the eyes have the highest detectability (relative to other features) in the visual periphery providing a strong sensory signal to guide the oculomotor system. Together, the results suggest a flexible multiple-cue approach that might be a robust solution to cope with how the varying eccentricities in the real world influence the ability to resolve individual feature properties and the preferential role of the eyes.


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