Nonvisual Condition Research Articles

Point Estimation with Markers for Effective Mobile Auditory Graphs

While researchers have performed numerous studies to understand the human interpretation of visual graphs in reading, comprehending and interpreting displayed data; visually impaired (VI) students still face many challenges that prevent them from fully benefiting from these graphs in class. In this study, we conducted a test with 20 students to track the work described in studies in an expanded scenario. As we have tried to answer the question as to whether adding multi-reference mapping of sonification to auditory graphs could improve the of point estimation accuracy in non-visual condition. We also emphasize the efficiency of the performance of multi-reference graphs to make them as efficient as mapping using single pitch. Our proposed study improved performance of multi-reference task completion time by having fewer reference note. The results help provide empirical evidence that the multi-reference mode provides more accurate results than the single-pitch mode and confirms that adding contexts to auditory graphs could be used for better comprehension.

Chronic medical conditions in adult survivors of retinoblastoma.

10019 Background: Increased risk of second malignant neoplasms (SMN) in retinoblastoma survivors (RBS) is well documented, but little is known about their long-term burden of chronic non-visual morbidity. Methods: RBS treated in NYC were asked to complete a comprehensive questionnaire, adapted from the Childhood Cancer Survivor Study (CCSS) surveys; frequencies of chronic conditions, excluding SMN, in 470 RBS and 2,377 CCSS siblings were calculated. A severity score, based on the NCI CTCAE v4 (ranging from grade 1 [mild] to grade 4 [disabling/life-threatening]) was assigned to each condition. Logistic regression was used to estimateodds ratios of chronic condition risk in RBS vs CCSS siblings, adjusted for age, sex, and race/ethnicity, reported as relative risks (RR) and 95% confidence intervals (CIs). Results: RBS and CCSS siblings were mean ages of 43 years (SD 11) and 38 years (SD 9), respectively, at the time of questionnaire completion. 53.6% of RBS had bilateral disease. After excluding SMN, 70.2% of RBS had at least one non-visual chronic condition while 14% had a grade 3-4 condition. The adjusted RR of a non-visual chronic condition in a survivor compared to siblings was 1.5 (95% CI, 1.2-1.8); for a grade 3-4 condition, the risk was 1.5 (95% CI, 1.1-2.1). The most common grade 3-4 non-visual conditions in RBS were hearing loss (3.6%; bilateral 5.6%, unilateral 1.3%, p=0.023) and thyroid nodules requiring partial or full thyroidectomy (3.4%; bilateral 5.6%, unilateral 0.9%, p=0.008). Rates of grade 3-4 thyroid nodules and hearing loss did not differ significantly when stratified by treatment received. Rates of all conditions in RBS are reported in the Table. Conclusions: RBS have a modestly increased risk of non-visual chronic conditions when compared to individuals of comparable age, sex and race/ethnicity. [Table: see text]

Study on a Method of Single – Phase Grounding Fault Locating for Hybrid Transmission Line

It is difficult to achieve precise fault location for hybrid transmission line of distribution network, because it has wave impedance discontinuity point. Section location is the premises of precise location. On the basis of others’ research results, the matrix algorithm of distribution network single-phase ground fault section location is improved in the paper. It makes the sparse degree of matrix is higher, computation is less. An algorithm of recovery the network topology only based on the fault description matrix is suggested when the visualization data of a line network topology is loss or the operating is in the non-visual condition. The method is applied to revise fault description matrix, so that the matrix algorithm has some fault-tolerance. The applicability and validity of the improved algorithm was verified by an illustration. The method realizes the fault section location, and the subsequent accurate fault location is presented in this paper.

Peripheral vestibular damage causes impaired navigation tasks on memorized routes in humans

Objectives To investigate if a well-compensated unilateral peripheral vestibular hypofunction could interfere with navigation tasks on memorized routes in humans. Methods After a complete otoneurological investigation, fifty labyrinthine-defective patients and fifty controls were invited to visually memorize three different routes (a triangle, a circle and a square) on a grey carpet and then to walk along them with eye closed clockwise and counter-clockwise (mental map navigation). The same test was then repeated with eye open (actual navigation) and again with eye closed (mental navigation). Execution time was recorded in each test. Corsi block test and a psychiatric questionnaire completed the neuropsychological examination. Results Labyrinthine-defective patients showed higher levels of anxiety and depression and performed Corsi block test with more difficulties than controls. Patients spent more time than controls in the first and third session (eye closed). No difference was recorded between clockwise and counter-clockwise navigation tasks both in patients and in controls. Patients showed a greater improvement in the third navigation task than controls. Conclusion Walking on memorized routes in non-visual condition is impaired by a peripheral vestibular damage, even if patients are well compensated. This impairment could be due to a defect of the visuospatial short-term memory, as supported by Corsi block tests, but a residual sensorimotor impairment and/or an interference of psychological distress could not be definitively excluded.

Jaw and finger movement accuracy under visual and nonvisual feedback conditions.

The present study revisited the issue whether the presence of added visual feedback differentially affects the accuracy of finger and jaw movements. 15 men were instructed to move either the index finger on the dominant (right) hand, or the jaw, to a predefined target position with the highest precision possible. During execution of the task, on-line visual feedback of the moving articulator was either present or removed. In contrast to previous findings, significant improvement was observed for both finger and jaw movements in the visual feedback condition. Movement error in the nonvisual condition was proportionally greater for finger than for jaw movements which may have reflected a speed-accuracy trade-off because finger movements in the nonvisual condition were executed significantly faster than those of the jaw. The present findings support the beneficial effects of adding visual feedback during dynamic oral and finger movements that require a high spatial precision. Such findings support current methods of clinical intervention in speech-language pathology anl other disciplines. Furthermore, the results contribute to our understanding of the role of various modalities of feedback during motor execution.

The relationship between stuttering severity and kinesthetic acuity for jaw movements in adults who stutter

Previous research using a minimal movement paradigm has suggested a deficiency in the processing of oral kinesthetic sensations in adults who stutter. In the present study, the relationship between oral kinesthesia and stuttering severity was investigated. Eight stuttering adults (four very mild and four moderate/severe), and four normally fluent speakers were instructed to make the smallest possible movements with the jaw, both with and without continuous visual feedback. The adults with very mild stuttering showed a significantly larger increase in jaw displacement from the visual to the nonvisual condition compared to the normally fluent control group. Significant group differences also were found for movement duration. When only proprioceptive information was available to judge articulatory movements, the adults with moderate/severe stuttering took significantly longer than either of the other two subject groups to complete movements of the jaw. While providing partial support for the hypothesis that adults who stutter have a reduced oral kinesthetic acuity, the present data confirm previous findings that the most robust differences between stuttering and nonstuttering adults are observed for the movements of the jaw. The significance of this observation for our understanding of the role of temporal discoordinations in stuttering is discussed.

QUANTITATIVE MEASUREMENT OF IMPROVEMENT IN SITTING BALANCE IN CHILDREN WITH SPASTIC CEREBRAL PALSY AFTER SELECTIVE POSTERIOR RHIZOTOMY1

Severe muscular spasticity encountered frequently in patients with spastic cerebral palsy not only affects patient locomotor function but also causes musculoskeletal complications. Significant reduction of spasticity over pelvis and lower limbs after selective posterior rhizotomy (SPR) results in improvement of trunk stability, locomotor function, and function of upper limbs also. The purpose of this study was to investigate the difference of sitting balance before and after SPR using a quantitative measurement in sitting stability represented as dispersion index provided by the Chattecx Balance System. Seventeen children with spastic cerebral palsy, ten boys and seven girls, with a mean age of 5.06 yr, underwent SPR. Their sitting stability under static and dynamic, visual and nonvisual testing conditions was assessed before SPR and three mo after SPR. Their sitting balance showed significant improvement at postoperative evaluation except for the static-nonvisual testing condition. Dispersion index under the dynamic testing condition was significantly higher than under the static testing condition, which implies that dynamic sitting balance was worse than static sitting balance in these patients. There was no statistical difference of sitting performance between visual and nonvisual condition both preoperatively and postoperatively. Quantitative measurement of dispersion index provided by the Chattecx Balance System offers an objective evidence of improvement in sitting balance for children after SPR.

Human muscle spindle afferent activity in relation to visual control in precision finger movements.

1. Impulse activities of muscle spindle afferents from the finger extensor muscles were recorded in the radial nerve of human subjects. In addition to single unit activity, surface EMG was recorded as well as finger joint position and angular velocity. 2. All units were studied under two conditions of voluntary finger movements. In the visual condition, the subject tracked ramp and hold sequences at a single metacarpophalangeal joint. In the non-visual condition the subject was asked to produce the same movement while visual control was denied altogether. 3. With sixteen units, detailed statistical analyses failed to reveal significant differences in muscle spindle afferent activity between the visual and the non-visual task. However, with two group Ia units, impulse rate was marginally but significantly higher in the visual task even when differences in average movement velocity, velocity variability and EMG level had been factored out. 4. The findings suggested that access to visual information for movement control did not produce any large-scale differences in spindle afference, although a small effect of an increased and independent gamma-activation emerged in the statistical analysis in 11% of the units.

Coordination between the transport and the grasp components during prehension movements.

In this study, the possible influence of the transport on the grasp component of prehension movements was investigated. The first phase of the transport (acceleration phase) and of the grasp (finger aperture phase) kinematics were studied under conditions of visual and non-visual object presentation (prehension experiment). In the non-visual condition, object size was estimated by haptics and object position was estimated by proprioception. Eight subjects were required to reach and grasp three objects of different size located at two distances. An additional experiment (matching experiment) was carried out to control the scaling of object size in two conditions. The results showed that in the matching experiment size estimation for large objects was similar in the two conditions, whereas small stimuli were underestimated in the haptic condition. In the prehension experiment, maximal finger aperture and velocity of finger aperture were greater in the non-visual than in the visual condition, and the difference was greater for small than for large stimuli. Moreover, in both conditions, finger opening was larger for prehension movements directed to the far than to the near objects, but only for smaller stimuli. Hand trajectory variability increased in the non-visual condition and with the distance, whereas finger opening variability was only affected by the non-visual condition. For smaller stimuli, increased finger opening with distance was positively correlated with the increase in wrist variability in the visual condition, but not in the non-visual condition. Furthermore, increased finger opening between visual and non-visual conditions was correlated with the increase in wrist variability, for smaller objects at the near object location.(ABSTRACT TRUNCATED AT 250 WORDS)

Visual and Nonvisual Neglect After Unilateral Brain Lesions: Modulation by Visual Input

A spatial exploratory task was given to 110 patients with unilateral brain lesions [66 right brain-damaged (RBD) patients and 44 left brain-damaged (LBD) patients] in two conditions, with and without the aid of vision. Exploratory deficits mainly involved the contralesional half-space and were most frequently associated with right brain damage. A double dissociation was found between the visual and the nonvisual conditions of the task; selective impairments in the visual and in the nonvisual condition were associated with the presence and the absence of visual field deficits, respectively. The suggestion is made that discrete "visual" and "tactile-kinesthetic" spatial representational systems are involved in exploration of extrapersonal space. A further distinction is made between input and output spatial system. The association between visual field deficits and visual neglect is explained in terms of the impairment of an input visuospatial component, which feeds an output component involved in spatial exploration. Finally, the ambiguous nature of the visual field deficits in neglect patients is discussed and the suggestion is made that an attentional modality-specific nonsensory component may be present.

Postural Control in Blinds and in Usher's Syndrome

The postural control mechanisms were evaluated in 10 blinds and in 10 subjects with Usher's syndrome. The results were compared with 27 age matched healthy volunteers. In visual conditions the subjects with Usher's syndrome performed worse, but in nonvisual condition they performed equally well as the controls. The results were the same irrespective of whether the tests were performed on a rigid surface or foam rubber covered surface. The blinds and controls performed equally well on the bare surface, but the blinds performed significantly better on the foam rubber covered surface. The results indicate that in subjects with Usher's syndrome the vestibulo-cochlear degeneration is well compensated but the postural stability aggravated due to retinal degeneration. Blind subjects have a better postural control than their seeing referents, but the difference is only evident in situations in which the postural control is hampered by surface perturbation.

KINAESTHETIC ACUITY OF STUTTERERS AND NON-STUTTERERS FOR ORAL AND NON-ORAL MOVEMENTS

Six adult stutterers and six normal speakers were instructed to make the smallest possible movements of the jaw, lower lip, tongue and right index finger, both with and without continuous visual feedback. In the non-visual (kinaesthetic) condition, the stutterers showed significantly larger minimal displacements (MDs) than did the non-stutterers for oral but not for finger movements. However, movements made in the presence of visual feedback were consistently smaller for all subjects than those made without, and no differences in MD were found between the stutterers and the non-stutterers when visual feedback was provided. The results suggested the presence of a sensorimotor deficit among at least some adult stutterers that is confined to oral movements. Given the importance of somatic sensory feedback during speech production, these observed orosensory deficiencies among stutterers may provide important insights into causal factors which contribute to the breakdowns in stutterers' speech.

Timing and accuracy of visually directed movements in children: Control of direction and amplitude components

The reaction times (RTs), movement times (MTs), and final accuracy of hand movements directed towards visual goals were measured in 6-, 8-, and 10-year-old childen, using tasks in which direction and amplitude components of movement were distinctly required. The tasks were performed with and without visual feedback of the limb. RTs decreased with age, and were shorter in directional than in amplitude task, in all ages. MTs were the longest at age 8 in both tasks, equally short at ages 6 and 10 in the directional task, the shortest at age 10, and intermediate at age 6, when amplitude had to be regulated. In the amplitude task, the target distance generally affected MTs under both visual conditions, but to a lower degree at age 10 than in the two younger groups. Movement accuracy, which was in all cases higher with visual feedback, showed different developmental trends among the two spatial components: directional accuracy was not different among the three groups of age, whereas amplitude accuracy showed a nonmonotonic development in the nonvisual condition, with an increase between age 6 and age 10, and the lowest level at age 8. In the visual condition, amplitude acuracy did not change with age. The specification of direction seems therefore to predominantly load the preparatory stage of the response. Amplitude specification seems to be more dependent on on-going regulations and to undergo a longer and more complex development, with a critical period around age 8 when a greater propensity for a feedback-based control appears on the two components. With increasing age, amplitude tends to be specific to a greater extent by a feedforward process.

Internuclear ophthalmoplegia in 14 patients: Clinical and topographic correlation using magnetic resonance imaging

In a clinicotopographic study of 14 patients with internuclear ophthalmoplegia (INO) confirmed by electrooculography (EOG), the pattern of visual dysfunction was compared to the location and severity of lesions of the medial longitudinal fasciculus (MLF) visualized by magnetic resonance imaging (MRI). Of the 12 patients with classically-defined 'anterior' INO, nine were classed as having definite multiple sclerosis (MS), and three as probable or possible. Five of the 12 had MR-imaged MLF lesions, and five including one with MLF lesions, had cerebellum-associated lesions. Of the two patients with so-called 'posterior' INO, one presented a heredodegenerative disease and cerebellum-related lesions, and in the other, a non-visual neurological condition was not diagnosed. The finding that MR-imaged MLF lesions do not always occur simultaneously with INO may indicate that INO could be the expression of a functional disorder in the posterior fossa, preceding MLF lesion development.

The relative weightings of visual and nonvisual coding in a simple motor learning task.

A linear positioning task was used to examine the effects of visual and nonvisual inputs on motor learning. The experiment had three factors with two levels of each namely: sensory modality (visual-nonvisual), transfer at recall (changed-unchanged), size of movement (25.4 cm, 50.8 com). Three dependent variable were used: absolute error (AE), constant error (CE), and variable error (VE). The results suggest that visual dominance causes disruption of recall in the visual, changed conditions. No disruption of recall was found for the nonvisual condition other than in terms of CE with respect to movement sizes. The results are taken to follow Posner et al.'s (1976) theory of visual dominance, but some account of the spatial qualities of visual and kinesthetic information is needed.

Effects of response delay and token relocation on token test performance of aphasic subjects

Abstract Performance of 12 aphasic subjects was analyzed on a delayed response task using commands similar to those found in the Token Test, under Standard, Relocation, and Nonvisual conditions. In Standard Condition, subjects could see the tokens as commands were presented and during delay intervals that were interposed between the end of the command and the subject's response. In Relocation Condition, subjects could see the tokens during command presentation and delay intervals, but the tokens were repositioned before the subject was allowed to respond. In Nonvisual Condition, no visual information was available to the subject until the delay interval was over. Results suggested that performance was not significantly affected by the presence of delay except in Part III of the test. The effects of delay appeared only in Part III, where most aphasic subjects began making errors. No appreciable differences in performance were found across conditions. These results suggest that aphasic subjects did not rely to any great extent on visual or visual-spatial strategies to perform successfully on the delayed response task. It appears that subjects may have been using some type of verbal strategy to mediate the delay interval, in spite of their impaired language systems.

Verbal cues in the mediation of experimenter bias.

In a replication of Rosenthal's experimenter bias study, 6 male Es obtained significantly higher ratings when expecting high ratings from their 5 female Ss than when expecting low ratings ( n = 5 each) in a person-perception task. The instructions read by these Es were tape recorded and played back in the absence of any E (non-visual condition) to a second set of Ss. It was concluded from the significant bias effect in the non-visual condition that verbal cues are sufficient mediators of E bias. Suggestions were made as to the nature of the bias transmission process in this study.