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PubMed1977

Training of spatial orientation with a senile demented patient. An experimental case study.

An 82 year old man, with the diagnosis senile dementia, was trained to find his own way to objects of importance on the ward (bed - toilet, dinner table - bed, dayroom - dinner table). The ward distances were divided into smaller units. A single case experimental design was used. During baseline the patient was given the opportunity to walk the distance. As long as he succeeded in finding the final destination, the distance was gradually extended one unit at a time. After one week each unit of the first distance was marked with a distinctive symbol and instructions were provided on their meaning. The two other distances served as control distances under baseline condition. One week later the second distance was also included in the intervention, while the third remained at baseline. Finally all distances were included in the intervention. There was a significant improvement in two of the three distances. This improvement was, however, only temporary.

Activities of Daily Living↗
PubMed1999

Spatial orientation of the angular vestibulo-ocular reflex.

During vestibular nystagmus, optokinetic nystagmus (OKN), and optokinetic afternystagmus (OKAN), the axis of eye rotation tends to align with the vector sum of linear accelerations acting on the head. This includes gravitational acceleration and the linear accelerations generated by translation and centrifugation. We define the summed vector of gravitational and linear accelerations as gravito-inertial acceleration (GIA) and designate the phenomenon of alignment as spatial orientation of the angular vestibuloocular reflex (aVOR). On the basis of studies in the monkey, we postulated that the spatial orientation of the aVOR is dependent on the slow (velocity storage) component of the aVOR, not on the short latency, compensatory aVOR component, which is in head-fixed coordinates. Experiments in which velocity storage was abolished by midline medullary section support this postulate. The velocity storage component of the aVOR is likely to be generated in the vestibular nuclei, and its spatial orientation was shown to be controlled through the nodulus and uvula of the vestibulocerebellum. Separate regions of the nodulus/uvula appear to affect the horizontal and vertical/torsional components of the response differently. Velocity storage is weaker in humans than in monkeys, but responds in a similar fashion in both species. We postulate that spatial orientation of the aVOR plays an important role in aligning gaze with the GIA and in maintaining balance during angular locomotion.

Humans↗
PubMed1994

Absence of an association between motor coordination and spatial orientation in lurcher mutant mice.

Lurcher mutant mice were impaired in spatial orientation and motor coordination in comparison to normal mice. Both groups improved across days in both invisible and visible water maze platform conditions. Contrary to normal mice, lurcher mutants did not improve over days in terms of the time taken to reach a side-bar in a motor coordination test, an indication of defective motor learning. However, lurchers were able to stay on the bar longer across days. These results indicate that motor learning deficits in this cerebellar-damaged animal are not absolute but dependent on the type of measurement attempted. There was no correlation between motor coordination and spatial orientation for normal mice. A similar absence of correlation was noted for lurcher mutants, except for falling latencies in the coat-hanger test during the middle of training.

Animals↗
PubMed2000

[Processes underlying young children's spatial orientation].

The purpose of this study was to investigate the processes underlying spatial orientation in 3-year-old children. After the subjects had seen the experimenter hide an object in one of the two hiding locations on a turntable, they were asked to indicate the location of the object under three conditions: (a) only the table is rotated up to 180 degrees by 45 degrees steps, (b) only the subject is moved to an opposite side by 45 degrees steps, and (c) both the table and the subject were moved simultaneously up to 180 degrees by 45 degrees steps. The results showed that the discrepancy between the locations subjects indicated and the correct locations increased with the degree of rotation in all conditions although there were no significant differences among the conditions. Some of the individual patterns, however, indicated abrupt increases of the discrepancy. These findings suggest that the spatial orientation consists of perceptual and representational processes.

Child Development↗
PubMedDate not supplied

Spatial orientation during locomotion [correction of locomation] following space flight.

To investigate changes in spatial orientation ability and walking performance following space flight, 7 astronaut subjects were asked pre- and post-flight to perform a goal directed locomotion paradigm which consisted of walking a triangular path with and without vision. This new paradigm, involving inputs from different sensory systems, allows quantification of several critical parameters, like orientation performance, walking velocities and postural stability, in a natural walking task. The paper presented here mainly focuses on spatial orientation performance quantified by the errors in walking the previously seen path without vision. Errors in length and reaching the corners did not change significantly from pre- to post-flight, while absolute angular errors slightly increased post-flight. The significant decrease in walking velocity and a change in head-trunk coordination while walking around the corners of the path observed post-flight may suggest that during re-adaptation to gravity the mechanisms which are necessary to perform the task have to be re-accomplished.

Electronic Data Processing↗
PubMed1988

Heart-rate response to water-immersion isolation as a function of spatial orientation.

The present study investigates the effect of spatial orientation of the body on heart rate during conditions of water-immersion sensory isolation. Two groups of three men and three women each were exposed to one of two isolation conditions. In one condition the subject was suspended in a buoyant but vertical attitude; in a second condition the subject was suspended in a buoyant but horizontal attitude. Heart-rate data were obtained continuously during each session. There was no significant difference in mean heart rate between the two conditions. The data were interpreted as providing support for the position that studies comparing recumbent subjects in air isolation with underwater subjects in a vertical suspension attitude are valid, at least for some measures, and are not an artifact of spatial bodily orientation. The possible importance of neutral buoyancy in accounting for the nonsignificant effect of body attitude on heart rate is discussed.

Adolescent↗
PubMed1989

Current concepts of the vestibular system reviewed: 2. Visual/vestibular interaction and spatial orientation.

The vestibular system contributes to the generation of conjugate eye movements, spatial orientation, and postural control. The functional connections of the vestibular end-organs and of the descending vestibulospinal pathways and their importance to postural control were reviewed in the previous paper by Keshner and Cohen (pp. 320-330). This paper reviews the ascending vestibular pathways, the visual/vestibular interactions, and the role of the vestibular system in oculomotor control and spatial orientation.

Eye Movements↗
PubMed1986

Visual-spatial orientation, gaze direction and dichotic listening asymmetries.

The effects of visual-spatial orientation on dichotic listening performance were investigated in a sample of right-handed male and female adults. The 30 pairs of dichotic stimuli (/ba/ka/da/ga/ta/pa) were presented under three conditions: eye gaze fixed toward center, eye gaze directed 20 degrees to the right, and eye gaze directed 20 degrees to the left of center. Although no effect for gender or order was evident, a significant right ear advantage was found under all conditions. However, over all dichotic listening accuracy was significantly increased when visual-spatial orientation was directed to the right or left side of space.

Adult↗
PubMed2006

Subthalamic nucleus influences spatial orientation in extra-personal space.

While the role of frontal and parietal cortex in spatial orientation has been studied extensively, the contribution of the basal ganglia and especially the subthalamic nucleus to spatial orientation remains less clear. Here we use subthalamic nucleus (STN) deep brain stimulation (DBS) in Parkinson's disease (PD) as a reversible model of functional lesioning to evaluate the influence of the STN in extra-personal space orientation. To this end, 12 PD patients were examined 1 year after implantation of DBS electrodes in the STN after overnight withdrawal of L-dopa. Patients were tested in a pseudo-randomized order while both stimulators, the right only, the left only, or no stimulator, were switched on. Patients performed line bisection and a reaction time task responding to stimuli of the middle, the left, and the right extra-personal space. A separate assessment of the right and left hand responding to visual stimuli in each hemispace made it possible to distinguish hemi-spatial and hemi-motor impairments. No asymmetries in space orientation were found when both stimulators were switched OFF, when both stimulators were switched ON, and when only the right stimulator was switched ON. When only the left subthalamic stimulation was switched ON, the reaction times of both hands to visual stimuli in the left extra-personal hemispace increased significantly and the line bisection test showed a significant orientation to the right. These results lead to the conclusion that the STN and its cortical projections influence the network involved in visuospatial orientation. These patterns of symptoms of neglect demonstrate the influence of the STN on the attentional system of the nondominant hemisphere.

Attention↗
PubMedDate not supplied

Evidence of direction loss in elderly movement preparation is not due to spatial orienting effects.

Twenty elderly and young subjects performed matched movement plan restructuring and spatial orienting tasks. In the restructuring task, a precue stimulus was presented for 200 ms, followed by a preparation (PI; 250, 500, 1000, or 2000 ms), and the target stimulus. On 75% of the trials, the precue specified the aiming movement response enabling movement plan preparation concerning parameters of arm and direction. On 25% of the trials, the precue incorrectly specified the response requiring movement plan restructuring. The orienting task assessed shifts in perceptual localization of the precue and target stimuli for restructuring task conditions. At PIs of 1000 and 2000 ms, elderly, but not young, subjects restructured a movement plan for direction more quickly than for arm or both parameters. Spatial orienting shifts did not account for these effects.

Adolescent↗
PubMed1998

Perception of spatial orientation in microgravity.

Experiments during space and parabolic flights have shown that human spatial orientation in microgravity differs to a significant extent from its performance on earth. Due to the missing reference of gravitational force, unusual perceptual phenomena are observed, from inversion illusions to errors of perceived motion and position with respect to the spacecraft. This article gives an overview of results collected from space missions and parabolic flight campaigns, and proposes new lines of research about the perceptual phenomena of spatial orientation in microgravity. It is shown that most of the disorientation phenomena can be explained by the existence of an internal estimate of the gravitational vertical. In microgravity it is still maintained, but incorrectly updated, and thus alters the processing of sensory information in the central nervous system. This in turn leads to the observed illusions, and probably also facilitates space motion sickness.

Humans↗
PubMed2004

Global-local visual biases correspond with visual-spatial orientation.

Within the past decade, numerous investigations have demonstrated reliable associations of global-local visual processing biases with right and left hemisphere function, respectively (cf. Van Kleeck, 1989). Yet the relevance of these biases to other cognitive functions is not well understood. Towards this end, the present research examined the relationship between global-local visual biases and perception of visual-spatial orientation. Twenty-six women and 23 men completed a global-local judgment task (Kimchi and Palmer, 1982) and the Judgment of Line Orientation Test (JLO; Benton, Sivan, Hamsher, Varney, and Spreen, 1994), a measure of visual-spatial orientation. As expected, men had better performance on JLO. Extending previous findings, global biases were related to better visual-spatial acuity on JLO. The findings suggest that global-local biases and visual-spatial orientation may share underlying cerebral mechanisms. Implications of these findings for other visually mediated cognitive outcomes are discussed.

Adult↗
PubMed1986

Training the elderly on the ability factors of spatial orientation and inductive reasoning.

We examined the effects of cognitive training with elderly participants from the Seattle Longitudinal Study. Subjects were classified as having remained stable or having declined over the previous 14-year interval on each of two primary abilities, spatial orientation and inductive reasoning. Subjects who had declined on one of these abilities received training on that ability; subjects who had declined on both abilities or who had remained stable on both were randomly assigned to the spatial orientation or inductive reasoning training programs. Training outcomes were examined within an ability-measurement framework with empirically determined factorial structure. Significant training effects, at the level of the latent ability constructs, occurred for both spatial orientation and inductive reasoning. These effects were general, in that no significant interactions with decline status or gender were found. Thus, training interventions were effective both in remediating cognitive decline on the target abilities and in improving the performance of stable subjects.

Aged↗
PubMed2001

A dissociation between object manipulation spatial ability and spatial orientation ability.

We developed psychometric tests of spatial orientation ability, in which people are shown a two-dimensional array of objects, imagine taking a perspective within the array, and indicate the direction to a target object from this perspective. Patterns of errors on these tests were consistent with experimental studies of perspective taking. Characteristic errors and verbal protocols supported the validity of the perspective-taking tests, suggesting that people encoded the objects in the display with respect to a body-centered coordinate system when the imagined perspective was more than 90 degrees different from the orientation of the display. By comparing alternative models in a confirmatory factor analysis, we found that the ability to mentally rotate and manipulate an imagined object (as measured by tests of spatial visualization and spatial relations) and the ability to reorient the imagined self (as measured by the perspective-taking tests) are separable spatial abilities.

Adult↗
PubMed1995

Parallel independent encoding of orientation, spatial frequency, and contrast.

Subjects were presented with a set of 216 test gratings in random order. Each had a different combination of orientation, spatial frequency, and contrast. For each test grating, subjects were instructed to judge whether or not orientation was clockwise of the mean of the stimulus set, whether or not spatial frequency was higher than the mean of the stimulus set, and whether or not contrast was higher than the mean of the stimulus set. Each of the three sets of button presses was analyzed with respect to each of the three parameters, giving nine psychometric functions from one response set. It is concluded that, for gratings of high visibility, changes of orientation, spatial frequency, and contrast are encoded independently and in parallel, at least for small changes in these three visual parameters. In another experiment only one of the three parameters was varied at a time. Neither orientation-discrimination threshold, nor spatial-frequency-discrimination threshold, nor contrast-discrimination threshold was appreciably, if at all, lower than when all three parameters were varied simultaneously. It is concluded that interactions between the processing of small changes in orientation, spatial frequency, and contrast are negligible when all three are processed simultaneously. It is proposed that trial-to-trial variations of orientation, spatial frequency, and contrast are unconfounded by opponent processing within a population of neurons, each of which confounds the three variables.

Adult↗
PubMed2005

Significance of spatial orientation of percutaneously placed bioprosthetic venous valves in an ovine model.

PURPOSE: To investigate two spatial orientations of a percutaneously placed bicuspid second-generation bioprosthetic venous valve (SG-BVV) in the jugular vein (JV). MATERIALS AND METHODS: Twelve SG-BVVs, consisting of small intestinal submucosa attached to a nitinol frame were placed across a natural valve (NV) in the distal JV in six sheep. Six SG-BVVs were oriented as NV leaflets (group A) and the other six SG-BVVs were rotated 90 degrees to NV leaflets (group B). SG-BVV function was studied by venography performed immediately after placement and at 5 weeks after placement. Animals were killed at 5 weeks, and gross examinations were performed. RESULTS: Desired valve orientation after deployment was seen in all SG-BVVs. In group A, all valves exhibited good valve function on immediate and 5-week venography. At gross examination, leaflets were attached mostly at the valve base and free cusp areas were similar in both cusps with a mean of 154.8 mm2 +/- 45.6 for one cusp and 142 mm2 +/- 53.4 for the other cusp (P = .188). In group B, all valves showed good function on immediate venography and in five valves prior to killing. Valve attachment to the vein wall in this group involved a longer segment of leaflets and their free areas were smaller with a wide variety of cusp sizes. Mean free leaflet areas of opposing cusps measured 106.3 mm2 +/- 36.5 and 66.1 mm2 +/- 34.6, respectively (P = .025). Difference in leaflet areas between group A and group B was significant (P = .019). CONCLUSION: Proper spatial orientation of the SG-BVV at deployment is important for valve function and should have the same orientation as the NV.

Animals↗