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At least 217 records · Page 12Linked to original sources
PubMed1997

Aviation spatial orientation in relationship to head position, altitude interpretation, and control.

INTRODUCTION: Recently, a visually driven neck reflex was identified as causing head tilt toward the horizon during VMC flight. If this is the case, then pilots orient about a fixed rather than moving horizon, implying current attitude instruments inaccurately present spatial information. The purpose of this study was to determine if the opto-kinetic cervical neck reflex has an effect dependent on passive (autopilot) or active control of the aircraft. Further, findings could help determine if the opto-kinetic cervical reflex is characteristic of other flight crewmembers. METHODS: There were 16 military pilots who flew two 13-min VMC low-level routes in a large dome flight simulator. Head position in relation to aircraft bank angle was recorded by a head tracker device. During one low-level route, the pilot had a supervisory role as the autopilot flew the aircraft (passive). The other route was flow manually by the pilot (active). RESULTS: Pilots consistently tilted the head to maintain alignment with the horizon. Similar head tilt angles were found in both the active and passive flight phases. However, head tilt had a faster onset rate in the passive condition. CONCLUSION: Results indicate the opto-kinetic cervical reflex affects pilots while actively flying or in a supervisory role as the autopilot flies. The consistent head tilt angles in both conditions should be considered in attitude indicator, HUD, and HMD designs. Further, results seem to indicate that non-pilot flight crewmembers are affected by the opto-kinetic cervical reflex which should be considered in spatial disorientation and airsickness discussions.

Aerospace Medicine↗
PubMed1983

[Spatial orientation capability in the elderly].

A labyrinth-learning experiment was conducted with 83 elderly subjects (median 53 years), which was validated against the architectural "reality" of the clinic in which the test was conducted. The orientation capability of psychologically normal subjects was compared with the performance of patients with a depressive syndrome and/or with an organic mental syndrome. Factor Analysis revealed the independent influence of component functions, the most important being spatial imaging, memory, goal-seeking orientation, labyrinth learning and right-left coordination. Orientation in reality is not accurately predicted by performance on the labyrinth test model. Contrary to our expectation, the presence of OMS alone did not decrease performance; however the presence of a depressive syndrome, both alone as well as in conjunction with OMS did. Diagnostic and therapeutic implications are discussed.

Aged↗
PubMed2002

Supramodal effects of covert spatial orienting triggered by visual or tactile events.

Event-related functional magnetic resonance imaging was used to identify brain areas involved in spatial attention and determine whether these operate unimodally or supramodally for vision and touch. On a trial-by-trial basis, a symbolic auditory cue indicated the most likely side for the subsequent target, thus directing covert attention to one side. A subsequent target appeared in vision or touch on the cued or uncued side. Invalidly cued trials (as compared with valid trials) activated the temporo-parietal junction and regions of inferior frontal cortex, regardless of target modality. These brain areas have been associated with multimodal spatial coding in physiological studies of the monkey brain and were linked to a change in the location that must be attended to in the present study. The intraparietal sulcus and superior frontal cortex were also activated in our task, again, regardless of target modality, but did not show any specificity for invalidly cued trials. These results identify a supramodal network for spatial attention and reveal differential activity for inferior circuits involving the temporo-parietal junction and inferior frontal cortex (specific to invalid trials) versus more superior intraparietal-frontal circuits (common to valid and invalid trials).

Adult↗
PubMed1988

Does the mutant mouse lurcher have deficits in spatially oriented behaviours?

Lurcher mutant mice, in comparison to normal mice, had directional deficits in the Morris milk tank test and in a water-maze spatial alternation task. The lurcher mutants also showed an initial lack of spontaneous alternation and did not alternate in one behavioral condition when the inter-trial interval was lengthened. Lurcher mice were slower to learn a simple left/right position response to escape a T-maze by swimming although their motor coordination was good. Paradoxically, no deficit was observed in learning to select a left or right position for food in the same T-maze although the goal-directed locomotion was very ataxic. Overall, the lurcher mutants have difficulty in guiding themselves in the water toward a visible goal.

Animals↗
PubMed1989

[Comparison of the effects of thyroliberin and ACTH4-7 PGP on the learning of rats during the solving of spatial orientation tasks].

The influence of TRH (100 micrograms/kg) and ACTH4-7 Pro-Gly-Pro (15 micrograms/kg and 25 micrograms/kg) involved an acceleration of the spatial learning on the 12-arm radial maze and on T-maze in rats; an increase in the number of correct choice after short (5-10 min) retention interval; and affected the working and reference spatial memory in the test of reinforced place performance. The effects of the TRH and ACTH4-7 Pro-Gly-Pro did not interfere with one another.

Adrenocorticotropic Hormone↗
PubMed2003

Effects of ventrolateral-ventromedial thalamic lesions on motor coordination and spatial orientation in rats.

The ventrolateral-ventromedial (VL-VM) nuclei are classified as a motor area of the thalamus on the basis of predominant input from the cerebellum and the basal ganglia and output to the motor cortex. The sensitivity to electrolytic lesions of the VL-VM thalamic nuclei in rats was evaluated for tests requiring balance and equilibrium. VL-VM lesions impaired acquisition of the rotorod test but had no effect on stationary beam and hole-board tests. A selective impairment was also observed in the Morris water maze, as VL-VM thalamic lesions slowed down acquisition of the hidden platform but not the visible platform condition. These results support the hypothesis that thalamic motor nuclei participate in the acquisition of sensorimotor and spatial learning.

Animals↗
PubMed1992

Selective corticosteroid antagonists modulate specific aspects of spatial orientation learning.

Receptors for mineralocorticoids (MRs) and glucocorticoids (GRs) display a high concentration and distinct distribution in the hippocampus. The effects of corticosteroids on behavior mediated by central MRs and GRs were assessed in rats. Spatial navigation is considered to be a sensitive measure for hippocampal functioning. Removal of circulating corticosteroids (via adrenalectomy) impaired spatial learning. In intact rats, blockade of central MRs and GRs by intracerebroventricular injection of selective MR and GR antagonists influenced different aspects of spatial learning. The analysis of the behavioral pattern revealed that treatment with the MR antagonist altered search-escape strategies in the water maze. The injection of the GR antagonist after training resulted in increased latencies to find the platform, which reflects the disturbed consolidation of spatial information. Corticosteroids affect in a differential and coordinated manner behavioral strategies and storage of spatial information.

Adrenal Medulla↗
PubMed2004

Neural correlates of the automatic and goal-driven biases in orienting spatial attention.

How do stimuli in the environment interact with the goals of observers? We addressed this question by showing that the relevance of an abruptly appearing visual object (cue) changes how observers orient attention toward a subsequent object (target) and how this target is represented in the activity of neurons in the superior colliculus. Initially after the appearance of the cue, attention is driven to its locus. This capture of attention is followed by a second bias in orienting attention, where observers preferentially orient to new locations in the visual scene-an effect called inhibition of return. In the superior colliculus, these two automatic biases in orienting attention were associated with changes in neural activity linked to the appearance of the target-relatively stronger activity linked to the capture of attention and weaker activity linked to inhibition of return. This behavioral pattern changes when the cue predicts the upcoming location of the target-the benefit associated with the capture of attention is enhanced and inhibition of return is reduced. These goal-driven changes in behavior were associated with an increase in pretarget- and target-related activity. Taken together, the goals of observers modify stimulus-driven changes in neural activity with both signals represented in the salience maps of the superior colliculi.

Action Potentials↗
PubMed2005

The frontal pelvic plane provides a valid reference system for implantation of the acetabular cup: spatial orientation of the pelvis in different positions.

BACKGROUND: The frontal pelvic plane has traditionally served as the reference plane for implantation of the acetabular cup during total hip arthroplasty, with referencing performed with the patient supine on the operating table. During daily activities in an upright position, the frontal pelvic plane changes from a horizontal to a vertical orientation. If this change in orientation is accompanied by a substantial change in pelvic inclination angle, it would mean that the use of the frontal pelvic plane as a reference plane for implantation of the acetabular cup would not be valid for proper alignment of the cup. To evaluate this possibility, we measured the change of inclination of the pelvis from the supine to the standing position. SUBJECTS AND METHODS: We evaluated 120 patients, first positioned in a standing position and then supine on a table. Three pelvic landmarks were digitized percutaneously, and the spatial coordinates were calculated with regard to pelvic orientation in the horizontal and the vertical plane. RESULTS: We found a mean inclination of 6.7 degrees in the standing position and 5.6 degrees in the supine position. Patients who were more than 60 years of age who did not have coxarthrosis had a greater inclination angle (8.7 degrees ) while standing. Pelvic orientation was stable with regard to the supine and standing positions. These results were independent of sex, level of arthrosis, or status after implantation of a total hip replacement. INTERPRETATION: The frontal pelvic plane is a valid reference plane for implantation of the acetabular cup.

Acetabulum↗
PubMed2005

Host finding by Uscana lariophaga (Hymenoptera: Trichogrammatidae) in stored cowpea: the effect of distance, time interval, host patch size and spatial orientation.

Host finding and parasitization by Uscana lariophaga Steffan, a potential biocontrol agent of the storage pest Callosobruchus maculatus (Fabricius), were investigated in stored cowpea. Host finding was shown to be a function of distance, time, host patch size and the spatial position of U. lariophaga relative to the host patch. Uscana lariophaga females were able to find hosts up to 75 cm horizontal distance from the host patch, which was the largest distance tested. The probability that a host patch was found when an individual U. lariophaga female was released at 2.5 cm horizontal distance from the host patch ranged from 0.6 after 2 h foraging time to 0.9 after 8 h foraging time. At 10 cm from the host patch, host finding probability ranged from 0.2 to 0.45 at these respective foraging times. Finding probabilities doubled compared to horizontal distances when U. lariophaga was released below the host patch, and halved when it was released above the host patch. The negative geotaxic response was shown not to be an artefact of the release method. The median net displacement rate in the direction of the host patch was two beans per hour (1.4 cm h(-1)). The results suggest that U. lariophaga females start searching for hosts regardless of the quality of the olfactory information they receive. Additional observations indicated that U. lariophaga is adapted to a host with a patchy distribution, which implies that host finding over larger distances is relevant for U. lariophaga.

Animals↗