Effects of Head-Tilt and Practice on Perception of Visual Direction without Visible Spatial Framework

1974 ◽  
Vol 38 (3) ◽  
pp. 719-725 ◽  
Author(s):  
J. Roger Ware
Keyword(s):  
Head Tilt ◽  
Practice Effect ◽  
Visual Direction ◽  
Perceptual Accuracy ◽  
Knowledge Of Results ◽  
Spatial Framework ◽  
Darkened Room ◽  
Verbal Knowledge ◽  
The Right

A series of 3 experiments concerned with the perception of visual direction was conducted using a single adjustable luminous rod in a completely darkened room. In Exp. I, perceptual accuracies of primary (vertical and horizontal) and intermediate (all other directions) visual directions were compared. Accuracy for primary directions was significantly better ( t = 10.73, p < .001). Head-tilts of 5°, 10°, 20°, and 30° to the right and left of 0° in Exp. II did not significantly affect the perceptual accuracy, but perceptual accuracy differed significantly between primary and intermediate directions ( F = 182.11, p < .001). The introduction of non-verbal knowledge of results in Exp. III yielded little improvement in the perceptual accuracy of intermediate visual direction, but a significant practice effect was found. The results were discussed in terms of previous research and suggestions for further research were outlined.

scholarly journals LGG-05. MOLECULAR GUIDED THERAPY FOR A PEDIATRIC LOW GRADE GLIOMA: A CASE REPORT

2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii367-iii367
Author(s):  
Jayne VonBergen ◽  
Beth Armstrong ◽  
Morgan Schmitt
Keyword(s):  
Targeted Therapy ◽  
Standard Treatment ◽  
Head Tilt ◽  
Study Patient ◽  
Low Grade ◽  
Temporal Region ◽  
Low Grade Gliomas ◽  
Leptomeningeal Involvement ◽  
The Right ◽  
Guided Therapy

Abstract Low grade gliomas are the most common type of central nervous system tumors among children. Despite the fact that they are not typically life threatening, low grade gliomas remain a significant clinical challenge. Case Study: Patient is a 4-year-old male who presented at 20 months of age with several weeks of ataxia, emesis, and head tilt. Imaging revealed a right temporal lobe lesion; he was subsequently taken to surgery, where a gross total resection was achieved. Imaging 9 months post resection revealed recurrent disease within the right temporal region with leptomeningeal involvement. Four months later imaging revealed progression of multifocal disease and new growth within the sella. At this time the patient started standard treatment, Carboplatin and Vincristine, per CCG 9952A. Persistent slow progression was observed despite receiving standard therapy. The patient developed a grade 3 reaction to carboplatin, worsening with each subsequent dose. At this time, he was referred to our Precision Genomics Neuro Oncology program for tumor molecular characterization. Somatic tumor testing revealed an ETV6-NTRK3 fusion, at which time standard treatment was stopped, and patient began targeted therapy, Larotrectinib. Imaging was preformed 2 months post start of targeted therapy and revealed interval decrease in size of previously enhancing nodular lesions; findings consistent with treatment response. Disease burden continues to decrease with therapy. This case illustrates a clear benefit of using molecular guided therapy in low grade gliomas.

A Perplexing Puzzle Involving Perception of Straight Ahead

Perception ◽  
1996 ◽  
Vol 25 (1_suppl) ◽  
pp. 41-41
Author(s):  
J T Enright
Keyword(s):  
Internal Standard ◽  
Test Session ◽  
Image Motion ◽  
Visual Direction ◽  
Visual Environment ◽  
Visual Capture ◽  
Darkened Room ◽  
Standard Of Comparison ◽  
Retinal Information ◽  
Straight Ahead

Perception of visual direction was investigated by requiring subjects repeatedly to adjust a single small light, in an otherwise darkened room, to perceived ‘straight ahead’. This task presumably requires comparing concurrent extra-retinal information (either proprioception or an efference copy) with an internally stored ‘standard’ of comparison. Moment-to-moment precision in that performance is remarkably good, with median threshold (standard deviation) of 47 arc min. Nevertheless, the responses often involved a monotonic shift of direction over a few minutes during a test session in this reduced visual environment. These trends led to final settings that were immediately recognised as grossly erroneous when the room was relit, implying that the presumptive internal standard of comparison, while unstable, can be rapidly updated in a full visual environment. There are clear similarities between this phenomenon and the sudden ‘visual capture’ that occurs in a re-illuminated room, following distortions of visual direction that arose in a similarly reduced setting for subjects whose extraocular muscles were partially paralysed (Matin et al, 1982 Science216 198 – 201). In both cases, the visual stimuli that underlie rapid recalibration are unknown. Among the several possibilities that can be imagined, the strongest candidate hypothesis for this calibration of the straight-ahead direction is that, during fixation in a lit room, one utilises the directional distribution of image motion that arises because of microscale drift of the eye, as it moves toward its equilibrium orientation, much as a moving observer can use optic flow to evaluate ‘heading’ (the dynamic analogue of ‘straight ahead’).

scholarly journals Acute Parotitis after Lower Limb Amputation: A Case Report of a Rare Complication

2018 ◽  
Vol 2018 ◽  
pp. 1-3
Author(s):  
Konstantinos Ioannis Avgerinos ◽  
Nikolaos Degermetzoglou ◽  
Sofia Theofanidou ◽  
Georgia Kritikou ◽  
Ioannis Bountouris
Keyword(s):  
Risk Factors ◽  
Case Report ◽  
General Anesthesia ◽  
Lower Limb ◽  
Rare Complication ◽  
Head Tilt ◽  
Lower Limb Amputation ◽  
Limb Amputation ◽  
The Right ◽  
Type Of Surgery

Background. Postoperative parotitis is a rare complication that occurs usually after abdominal surgery. Parotitis has never been described as a complication of vascular operations, in literature. In the present article, we describe a case of a postamputation parotitis along with its management and its possible pathogenesis. Case Report. An 83-year-old diabetic man was emergently admitted to hospital because of gangrene below the right ankle and sepsis. The patient underwent a lower limb amputation above the knee. On the 5th postoperative day, he was diagnosed with right parotitis probably because of dehydration, general anesthesia, and immunocompromisation. A CT scan confirmed the diagnosis. He received treatment with antibiotics and fluids. His condition gradually improved, and he was finally discharged on 15th postoperative day. Conclusions. Postoperative parotitis can possibly occur after any type of surgery including vascular. Clinicians should be aware of this complication although it is rare. Several risk factors such as dehydration, general anesthesia, drugs, immunocompromisation, head tilt during surgery, and stones in Stensen’s duct may predispose to postoperative parotitis. Treatment consists of antibiotics and hydration.

Cerebellar cystic meningioma in a dog

2000 ◽  
Vol 36 (5) ◽  
pp. 413-415 ◽  
Author(s):  
RS Bagley ◽  
GM Silver ◽  
PR Gavin
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Head Tilt ◽  
Labrador Retriever ◽  
Histopathological Diagnosis ◽  
Resonance Imaging ◽  
Cystic Meningioma ◽  
Mixed Breed ◽  
Cerebellar Peduncle ◽  
The Right

A 21-kg, seven-year-old, male, mixed-breed Labrador retriever was admitted for incoordination and a head tilt of approximately three months' duration. Ataxia was noted of the trunk and limbs, and there was a head tilt to the right side. Conscious proprioceptive deficits were present in the left thoracic and pelvic limbs (i.e., hemiparesis). These abnormalities were consistent with paradoxical vestibular syndrome and a lesion involving the caudal cerebellar peduncle. A mass lesion consisting primarily of fluid was present on magnetic resonance imaging and at craniectomy. Histopathological diagnosis was a cystic meningioma. Based upon previous reports and experience, the location of this tumor was unusual.

The Relative Efficacy of Different forms of Knowledge of Results for the Learning of a New Relative Timing Pattern

2003 ◽  
Vol 56 (4) ◽  
pp. 1-20 ◽  
Author(s):  
Dominique De Jaeger ◽  
Luc Proteau
Keyword(s):  
Temporal Pattern ◽  
Relative Efficacy ◽  
Relative Timing ◽  
Movement Velocity ◽  
Knowledge Of Results ◽  
Timing Pattern ◽  
Verbal Knowledge ◽  
Source Of Information ◽  
Forms Of Knowledge ◽  
Effective Source

The goal of the present study was to determine the relative efficacy of verbal and auditory knowledge of results for promoting learning of a new constrained relative timing pattern. In a series of four experiments we compared the efficiency of verbal knowledge of results to that of auditory knowledge of results. The results of all four experiments revealed that verbal knowledge of result is a very effective source of information to promote learning of a new imposed relative timing pattern. Auditory knowledge of results favoured learning of a new relative timing pattern in a very limited set of circumstances. In the present study, this was only the case when movement velocity remained constant from one segment of the task to the next and if it resulted in an unfamiliar temporal pattern. The results of all four experiments also provided evidence that movement parameterization and relative timing are independent processes that can be developed in parallel.

Serial MRI and CSF Analysis in a Dog Treated with Intrathecal Amphotericin B for Protothecosis

2012 ◽  
Vol 48 (2) ◽  
pp. 125-131 ◽  
Author(s):  
Martin Young ◽  
William Bush ◽  
Melissa Sanchez ◽  
Pat Gavin ◽  
Mathew Williams
Keyword(s):  
Cerebrospinal Fluid ◽  
Amphotericin B ◽  
Head Tilt ◽  
Mri Findings ◽  
Lipid Complex ◽  
Fluid Analysis ◽  
Csf Analysis ◽  
Transient Improvement ◽  
The Right ◽  
The Brain

A 3 yr old female spayed English setter mixed-breed dog presented with diarrhea, weight loss, side stepping to the right, and a right head tilt. Rectal and cerebrospinal fluid cytology and culture confirmed a diagnosis of Prototheca zopfii. MRI of the brain showed inflammation of the brain and meninges, ventriculomegaly, and syringomyelia. Treatment with prednisone, itraconazole, and amphotericin B lipid complex administered intrathecally yielded transient improvement. Progressive brainstem signs were noted, and a repeat MRI and cerebrospinal fluid analysis documented persistent disease. This is the first description of the MRI findings and treatment with intrathecal amphoteracin B lipid complex for protothecosis of the central nervous system. Protothecosis should be considered in dogs with chronic diarrhea and compatible MRI findings.

scholarly journals Use of iris pattern recognition to evaluate ocular torsional changes associated with head tilt

2018 ◽  
Vol 10 ◽  
pp. 251584141880649 ◽  
Author(s):  
Mohamed Hussein ◽  
David Coats
Keyword(s):  
Pattern Recognition ◽  
Digital Images ◽  
Computer Software ◽  
Head Tilt ◽  
Computer Assisted ◽  
Strongly Correlated ◽  
Ocular Torsion ◽  
Software Program ◽  
The Right ◽  
Iris Pattern Recognition

Purpose: To describe the use of enhanced iris images and a computer software program to quantify ocular torsional changes associated with head tilt. Methods: Pixel coordinates of the pupil and different iris landmarks were obtained manually using paint program from digital images of the right and left iris of 3 subjects with normal extraocular motility. Photographs of the right eye and of the left eye were taken in the straight-ahead position and at various degrees of right and left head tilt. A computer software program converted the x- and y-pixel coordinates into angles of rotation after averaging multiple points and determining the degree and the direction of torsion for each eye. The degree of head tilt was mathematically calculated from the digital images. The degree and the direction of ocular torsion were correlated with the degree and the direction of head tilt. Results: The average degree of head tilt was 27.5 degrees (from 8 to 43 degrees). The average intorsion of the lower eye per degree of head tilt was 0.61 degrees (from 0.54 to 0.65 degrees). The average extorsion of the higher eye per degree of head tilt was 0.56 degrees (from 0.43 to 0.60 degrees). The average ocular torsional changes strongly correlated with the degree of head tilt (correlation coefficient = 0.92). Conclusions: Computer-assisted iris pattern recognition and analysis of the ocular torsional changes associated with head tilt may provide a useful and objective means of assessing ocular torsion.

Serial Processing Shown by Mutual Masking of Icons

1975 ◽  
Vol 40 (2) ◽  
pp. 399-408 ◽  
Author(s):  
E. Rae Harcum ◽  
D. Stephen Nice
Keyword(s):  
Compound Words ◽  
Perceptual Accuracy ◽  
Serial Processing ◽  
Sequential Processing ◽  
The Right

In a procedure called mutual masking, two compound words were tachistoscopically exposed successively at the same location. Perceptual accuracy for both words was examined. With fixation at the center of the arrays, Ss often identified the component at the left within the temporally first word and at the right within the second. These results imply a left-to-right serial processing. With fixation on beginning or end component, Ss tended to identify the component away from fixation of the first word and the fixated part of the second. This implies scanning from periphery toward fixation. Therefore, sequential processing of iconic information was obtained, with direction of processing determined by specific conditions.

Effects of Aircraft Noise on Vigilance Performance and Perceived Workload

1992 ◽  
Vol 36 (18) ◽  
pp. 1513-1517 ◽  
Author(s):  
Ami B. Becker ◽  
Joel S. Warm ◽  
William N. Dember ◽  
JoAnn Sparnall ◽  
Laura DeRonde
Keyword(s):  
Vigilance Task ◽  
Aircraft Noise ◽  
Maximum Intensity ◽  
Perceptual Sensitivity ◽  
Negative Effects ◽  
Vigilance Performance ◽  
Knowledge Of Results ◽  
Perceived Workload ◽  
Signal Detectability ◽  
The Right

This study examined the effects of exposure to intermittent jet aircraft noise played through stereophonic speakers (70dBA or 95dBA maximum intensity) on performance efficiency and perceived workload in a 40-min visual vigilance task. The noise featured a Doppler-like quality in which planes seemed to approach from the monitor's left and recede to the right. Performance in noise, measured in terms of perceptual sensitivity (d***'), was significantly poorer than in a quiet condition. Moreover, in comparison to subjects performing in quiet, those who operated in noise were less able to profit from knowledge of results (KR) regarding performance efficiency. In addition to its negative effects upon signal detectability, noise significantly elevated perceived workload, as indexed by the NASA-TLX. This effect was robust; it was not mitigated by KR, even though KR served generally to reduce the overall level of perceived workload in the study. The consistency of the effects of noise in regard to both performance efficiency and perceived workload challenges a recent conclusion offered by Koelega and Brinkman (1986) that lawful relations are not observable in studies of the effects of noise on vigilant behavior.

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