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PubMed1990

[Vulvoplethysmographic reaction in homosexually-oriented women].

The author examined, using an electrocapacitance VPG apparatus, 50 women reporting homosexual orientation. The results were compared with a control group of 50 women volunteers who reported a defined heterosexual orientation and had no marked complaints and problems in their sexual life. The general vasomotor reactivity in response to erotic stimuli did not differ in the two groups of women (the number of recorded vasomotor reactions differed only insignificantly). During evaluation of the total number of positive reactions to heterosexual and homosexual categories of stimuli the difference between the two groups was highly significant (similarly as during evaluation of the number of positive reactions which were described as major reactions). Women of the homosexually oriented group responded as expected, significantly more frequently and more markedly to homosexual stimuli. As compared with the control group of heterosexually oriented women, they had a generally poorer capacity to differentiate between different categories of erotic stimuli and a lower reactivity during projection of slides of homosexual partnership activities than during projection of slides of homosexual objects (nudes). In all examined women of the control group an unequivocal heterosexual orientation was recorded, in the group of homosexual women a more or less defined homosexual orientation was confirmed. In both groups was a high correlation between the subjectively reported sexual orientation and the results of the VPG examination. The authors confirmed that it is possible to use electrocapacitance vulvoplethysmography as evidence of the homosexual orientation in women and that this psychophysiological examination method is relatively reliable in the diagnosis of female homosexuality.

Adult↗
PubMed1989

[Effect of performance and state orientation on achievement and attention indicators in a simple stimulus-response task with and without performance feedback].

In formulating his theory of action control, Kuhl (1983) proposed two motivational states: action orientation and state orientation. People who are action oriented are able to ignore all informations in concrete situations which are irrelevant with regard to the preferred goals. Persons who are state oriented tend to focus sooner on the outlast aspects of a special state. Kuhl introduced a questionnaire HAKEMP to record these tendencies. Further on, there occurs the general assumption that in a particular state of state orientation, people have only a limited processing capacity for given tasks. This hypothesis was tested in an experiment (n = 88) with a stimulus-reaction task. The conditions were varied by the type of the task (fixed or variable stimulus interval) and feedback for the subjects' ability to react. It was expected that for the fixed stimulus interval condition, state-oriented people would be less efficient than action-oriented subjects; with feedback there should be increasing results. The experiment however, shows no significant difference between the performance of state- and action-oriented subjects. These results are discussed in relation to modifications of the HAKEMP questionnaire.

Adolescent↗
PubMed1985

Growth-plate-chondrocyte profiles and their orientation.

We studied the proximal tibial physes of mice, seven, fifteen, twenty-two, and twenty-eight days old, to define in mathematical terms the changes in cell profile and profile orientation among growth-plate zones and to determine if cell profile and profile orientation change with changes in the rate of growth. Using electron microscopy, we identified five growth-plate zones: the reserve zone, the upper proliferative zone, the lower proliferative zone, the upper hypertrophic zone, and the lower hypertrophic zone. In transverse sections, cell profiles did not change among growth-plate zones and the degree of cell-profile orientation approached zero in all zones. In longitudinal sections, cell profiles and profile orientations differed significantly among zones. Cell profiles in the upper and lower proliferative zones were eccentric and highly oriented. They became more rounded and the degree of cell orientation decreased between the proliferative and hypertrophic zones. As the rate of longitudinal bone growth decreased, cell profiles and cell-profile orientation changed. The cell profiles in the reserve zone became flatter and in the other zones the cell profiles became more rounded. The degree of cell-profile orientation decreased quadratically in the upper and lower proliferative zones, decreased linearly in the reserve and upper hypertrophic zones, and remained unchanged in the lower hypertrophic zone.

Aging↗
PubMed1979

The orientation of the visuotectal map in Xenopus: developmental aspects.

Rotations and translocations of the eye anlage were performed in Xenopus embryos of stages ranging from 21/22 to 30. Some of the operations involved grafting wild-type eye anlagen into albino host orbits. Operations were performed under a variety of operating media and conditions. In later larval life, or after metamorphosis, the visuotectal maps from the operated eyes were recorded electrophysiologically. Results fell into two classes. In the majority, the orientation of the visuotopic map corresponded to the orientation of the eye at the time of recording. In the minority the visuotopic maps were 'compound', consisting of two parts each with its own independent orientation. The organization of the compound maps was such that one component was oriented in correspondence with the orientation of the eye, while the other component was normally oriented. Histological analysis and observations on genetically marked grafts indicated that the component parts of the compound eye were of dual cellular origin. The component giving the rotated (or translocated) map belonged to the originally operated eye tissue; whereas the component giving the normally oriented map was derived from newly grown eye tissue coming from the optic stalk. In no case was a normally oriented map obtained from a rotated or translocated eye. The results are discussed in relation to mechanisms proposed to account for the determination of map-related retinal specificity.

Animals↗
PubMed1978

Perception of orientation of short lines: its dependence on line's length and intensity.

The threshold intensity necessary for correct identification of orientation of a briefly presented line was measured as a function of line's lenght and number of possible orientations (2 orientations differing by 90 degrees, 4 differing by 45 degrees, and 8 differing by 22.5 degrees). The thresholds were the same for 2, 4 and 8 orientations when the lines were longer than 20 min of arc. On the contrary, in the case of short lines, the correct report of 8 orientations required much more intensive stimulation than the report of 2 orientations. The discrimination of small differences in orientation of short lines involves additional processes to those for their detection and coarse perception of their orientation.

Discrimination, Psychological↗
PubMed1995

Visual deprivation does not affect the orientation and direction sensitivity of relay cells in the lateral geniculate nucleus of the cat.

Visual deprivation in early life profoundly affects the characteristic sensitivity of visual cortical cells to stimulus orientation and direction. Recently, relay cells in the lateral geniculate nucleus (LGNd) have been shown to exhibit significant degrees of orientation and direction sensitivity. The effects of visual deprivation upon these properties of subcortical cells are unknown. In this study cats were reared from birth to 6-12 months of age in total darkness; the orientation and direction sensitivities of area 17 (striate cortex) and LGNd cells were compared. All cells were studied using identical quantitative techniques and statistical tests designed to analyze distributions of angles. The results confirm previous work and indicate that the orientation and direction sensitivities of cells in area 17 are profoundly reduced by dark rearing. In marked contrast, these properties of LGNd relay cells are unaffected. The result is that, unlike in the normal cat, in dark-reared cats the orientation and direction sensitivities of cells in the LGNd and visual cortex do not differ. It is concluded that (1) the orientation and direction sensitivities of cortical cells contribute little, if at all, to the sensitivities of LGNd cells since LGNd cells exhibit normal sensitivities even though the cortical cells projecting to them exhibit greatly reduced sensitivities and (2) during normal development intracortical mechanisms appear to expand upon and/or modify the weak orientation and direction sensitivities of their inputs. These intracortical mechanisms depend upon normal visual experience since in dark-reared cats, but not normal ones, the orientation and direction sensitivities of cells in the LGNd and visual cortex do not differ quantitatively or qualitatively.

Animals↗
PubMed1994

Receptive field analysis and orientation selectivity of postsynaptic potentials of simple cells in cat visual cortex.

Postsynaptic potentials (PSPs) were recorded from cat striate cortical cells by the whole-cell in vivo recording technique using patch-clamp electrodes. EPSPs and IPSPs evoked by flashing bars on the receptive field at different positions and orientations revealed the spatial structure of the excitatory and inhibitory inputs. The elongation of the excitatory input field (length:width ratio) was found to be minimal (mean ratio of 1.7) and much lower than those reported for spike discharges. Two-dimensional receptive field response profiles of early PSPs were recorded by flashing a small spot of light over a square matrix covering the receptive field. These recordings also showed only mild degrees of elongations of the receptive field. Such elongations could be the result of either an excitatory input from the geniculate that is already biased for orientation or an excitatory convergence from a limited number of LGN fields arranged in a row. In most first-order cells, we found that inhibition was contributing significantly to orientation selectivity. Often prominent IPSPs could be evoked by stimuli of nonoptimum orientations. Presence of inhibition could also be inferred by the way that EPSPs were sharply cut off by inhibition. When the amplitude of an EPSP was measured at different latencies after its onset, the EPSP was found to be very broadly tuned to orientation at the beginning, but showing increasing orientation selectivity with time. It is proposed that this progressive development of orientation selectivity is due to (1) inhibitory inputs arriving after the first wave of excitation, (2) intracortical excitatory inputs from other cells tuned to similar orientations, and (3) voltage-sensitive mechanisms such as NMDA channels.

Animals↗
PubMed1996

Differences in factors of health orientation of older women.

The purpose of this exploratory study was to examine the factor structure of health orientation. A secondary purpose was to determine differences in the stability and lability of health orientation. The sample consisted of four women in their sixties and four women in their eighties. A replicated, single-subject design was used to assess short-term intraindividual change in health orientation. Participants completed the Health Orientation Scale questionnaire for 100 days, and P-technique factor analysis was used to determine the factor structure of health orientation. These health orientation factors were graphed over time to assess stability and change. Results indicate that health orientation is more complex for participants in their eighties than for those in their sixties; this may represent age-appropriate development. Health orientation factors were found to be more labile or statelike for women in their eighties. These findings may help health care providers understand differences in interest or adherence to health-seeking behavior in the elderly and improve age-appropriate health care for this population.

Age Factors↗
PubMed1997

Collagen fibril orientation in the human corneal stroma and its implication in keratoconus.

PURPOSE: The kind and the degree of preferred collagen fibril orientation in normal human corneal stroma were investigated as important qualities of the cornea with respect to its mechanical properties and, hence, to refractive surgery. To determine whether this information is relevant to corneal disease, the authors investigated collagen fibril orientation in several corneas with keratoconus. METHODS: By means of low-angle x-ray scattering, 17 normal human corneas and four corneas of eyes with keratoconus were investigated. RESULTS: Collagen fibrils in the normal human corneal stroma showed two preferred orientations orthogonal to each other. These were the horizontal and the vertical directions. The authors defined a degree of orientation gamma, determined to be gamma = 0.49 +/- 0.10 (mean +/- SD). This means that the excess of the preferentially oriented fibrils in relation to the total number of fibrils was approximately 49%. It follows from this value that approximately two thirds of the fibrils (66%) were within in a 45 degrees sector (+/-22.5 degrees) around the horizontal and vertical meridians, whereas approximately one third (34%) is oriented in the oblique sectors in between. No statistically significant variation of gamma within a central 7 mm zone could be detected in normal corneas. The orthogonal arrangement of the collagen fibrils was, however, profoundly altered in keratoconus, in which nonorthogonal orientations were found inside the apical scar. CONCLUSIONS: The normal human corneal stroma shows a considerable degree of structural anisotropy. It is characterized by two preferred collagen fibril orientations orthogonal to each other. Alteration of the regular orthogonal arrangement of the fibrils in keratoconus may be related to the biomechanical instability of the tissue.

Adult↗
PubMedDate not supplied

Evaluation of an orientation system for newly employed registered nurses.

In this article, the authors discussed the successful evaluation of an orientation system for newly employed registered nurses in a large teaching hospital using the IOP model. This methodology can be successfully applied to any educational program that is consolidated into an organization's goals. Although not well examined, orientation has been reported to be costly (Bethel, 1992; del Bueno, Weeks, Brown-Stewart, 1987). The system presently used at this hospital uses at least 1 week of a nurse educator's time, 3-10 weeks for a newly employed registered nurse, and 3-10 weeks for a preceptor RN. Such an investment of personnel resources mandates examination of the processes and outcomes of the program to ensure newly employed RNs become competent practitioners as efficiently as possible. The use of the IOP model particularly was useful in examining a complex orientation system in a multicentered hospital. Use of this systematic program evaluation separated the overall orientation process into workable components. Tools, such as the algorithm, allowed for easy visualization and comprehension of the process steps. This was indispensable because of the number and scope of people involved in the orientation program. The evaluation process was impartial and focused on the program steps, not on the individuals. Because of this impartiality, people were able to gather and work cohesively to improve the overall program. Use of the IOP model assisted the nurse educators in determining that PBDS was not achieving the goal of identifying individual learning needs. Rather, PBDS was a useful tool in establishing baseline competency of newly employed RNs. The system clearly identified those individuals who had above average knowledge bases and those individuals who had more learning needs. For those with more learning needs, PBDS provides a starting point for planning a structured orientation. Thus, a Phase II PBDS assessment could be used as a more unit-specific assessment to validate whether the RN has achieved the orientation objectives. Although the IOP model is not a strict research methodology, it is appropriate for examination of a program as fluid and ongoing as this. Finally, ongoing run charts or statistical trends will assist the nurse educators in monitoring the quality and effectiveness of the orientation program.

Adult↗
PubMed1997

The development and evaluation of the hypertension temporal orientation (HTO) scale.

Temporal orientation is a multidimensional concept that describes the perception of time among individuals. Time perception is structured by life experiences and can vary depending upon the particular context involved. Whether a person is past-, present- or future-oriented has been shown to influence his/her approach and reaction to health situations. Because the management of hypertension is based on achieving some future health state, hypertension provides a context in which an individual's time perspective may be particularly influential. One purpose of this study was to develop and evaluate a scale to measure temporal orientation that was specific to hypertension, namely the hypertension temporal orientation (HTO) scale. Data were collected via telephone interviews with 300 people who had been diagnosed by a physician as having hypertension. Principal components factor analysis revealed three dimensions of hypertension temporal orientation: (1) a nonexperiential domain; (2) an experiential disease domain; and (3) an experiential treatment domain with coefficient alpha estimates of 0.76, 0.66, and 0.63, respectively. The HTO scale was significantly discriminant of African Americans and whites on the experiential treatment domain whereby African Americans were more present-oriented regarding the daily management (or treatment) of hypertension as compared to whites. Additional evidence for the validity of the HTO scale was found with temporal orientation group comparisons on health perceptions. The findings provide early support for the reliability and validity of the HTO scale for measuring temporal orientation among people with hypertension.

Adult↗
PubMed1982

Exposure to lines of only one orientation modifies dendritic morphology of cells in the visual cortex of the cat.

To determine whether selective exposure to lines of one orientation modifies the shape of the dendritic fields of cells in visual cortex, we examined the dendritic morphology of neurons in area 17 of five normally reared cats, five cats reared viewing only vertical lines, and three cats reared viewing only horizontal lines. Kittens were placed with their mothers into a totally dark room before their eyes had opened. Beginning at 4 weeks of age, the kittens were brought out for daily periods of exposure wearing masks that limited the vision of each eye to a field of three vertical lines or three horizontal lines. After a minimum of 170 hours of exposure, the animals were killed and blocks of visual cortex were impregnated by the Golgi-Kopsch procedure and cut tangential to the pial surface. Complete neurons from layers III and IV were drawn with the aid of a camera lucida, and the orientations of the dendritic fields wer analyzed using Sholl diagrams. In normal cats, the distributions of the orientations of dendritic fields were uniform, whereas in strip-reared cats, the distributions for the layer III pyramidal cells were shifted. The direction of this shift varied with the experience of the cat: In cats reared viewing only vertical lines, the dendritic fields were oriented orthogonal to the representation of the vertical meridian, and in cats reared viewing only horizontal lines, the fields were oriented parallel to the representation of the vertical meridian. In contrast, the distribution of dentritic orientations for the stellate cells was not affected by stripe-rearing. These results demonstrate a morphological effect of early visual experience that is specific to the particular stimulus presented during rearing and suggest that (1) cortical cells differ in the degree to which they can be modified by such experience, and (2) the dendritic morphology of cortical neurons is related to their preferred orientations.

Animals↗
PubMed1997

Magnetic orientation and the magnetic sense in arthropods.

The physical properties of the earth's magnetic field are summarized with the aim of emphasizing their significance as cues that can be exploited in orientational tasks. Past work has revealed magnetic orientation in vertebrates as well as invertebrates, including arthropods. The key finding to date has been that, as opposed to many vertebrates, the magnetic compass of arthropods responds to the polarity, rather than to the inclination of the earth's magnetic field. As in the case of vertebrates, the debate over how arthropods detect magnetic fields has yet to be resolved. Currently, evidence has been reported in support of a detection system based on magnetite crystals together with a variety of detection systems based on events occurring at the molecular level. Interactions between the magnetic and other compasses in orientation experiments suggest the existence of an area in the brain where spatial orientation information from magnetic and other stimuli converges. The slow advance of our knowledge on magnetic orientation in arthropods, as opposed to the much better understanding of magnetic orientation in vertebrates, arises from difficulties in identifying the appropriate behavioural contexts in which arthropods respond to magnetic fields in both laboratory and field situations. Arthropods thus present challenges not only in demonstrating magnetic orientation, but also in elucidating the sensory mechanisms involved in the perception of magnetic fields.

Animals↗
PubMed1996

Hippocampal participation in the sun compass orientation of phase-shifted homing pigeons.

The orientation of phase-shifted control and hippocampal lesioned homing pigeons with previous homing experience was examined to investigate the possible participation of the hippocampal formation in sun compass orientation. Hippocampal lesioned pigeons displayed appropriate shifts in orientation indicating that such birds possess a functional sun compass that is used for orientation. However, their shift in orientation was consistently larger than in control pigeons revealing a difference in orientation never observed in pigeons that have not undergone a phase shift. Although alternative interpretations exist, the data suggest the intriguing possibility that following a change in the light-dark cycle, the hippocampal formation participates in the re-entrainment of a circadian rhythm that regulates sun compass orientation.

Animals↗
PubMed1996

The perception and prehension of objects oriented in the depth plane. I. Effects of visual form agnosia.

Previous studies have reported that the visual form agnosic D.F. is able to use information about visual targets for the control of motor acts, but has great difficulty in using the same visual information for perceptual report. This intact visuomotor performance may be mediated by relatively intact parieto-frontal cortical mechanisms. The present study investigated the ability of D.F. to use binocular and monocular information about the orientation of an object in the depth plane for perceptual and visuomotor purposes. A square plaque was presented at seven different orientations in depth to D.F. and to three age- and sex-matched control subjects. Subjects were required to reach out and grasp the plaque using a precision grip (index finger and thumb) under binocular and monocular viewing conditions, and in separate trials to match the orientation of a hand-held plaque to the perceived orientation of the target object, also under both binocular and monocular conditions. D.F.'s performance in grasping trials was found to be normal under binocular conditions, but was substantially worsened by removal of binocular vision. She was severely impaired at matching the orientation of the test square, although under binocular conditions her performance rose clearly above chance. The data suggest that the separation of cortical processing for visuomotor and visual perceptual purposes also applies, at least in part, to information about the orientation in depth of an object. The impaired performance under monocular viewing conditions on the visuomotor task is in agreement with recent physiological data and suggests that posterior parietal systems depend critically on binocular input for the processing of orientation in depth when ventral-stream information is unavailable.

Adult↗
PubMed1995

Dynamic differentiation of GABAA-sensitive influences on orientation selectivity of complex cells in the cat striate cortex.

The influence of GABAA receptors on orientation selectivity of cat complex cells was tested by iontophoresis of the GABAA receptor blockers bicuculline and N-methyl-bicuculline while stimulating with drifting sinusoidal gratings. Reduction of orientation tuning was markedly less than reported in previous studies that used drifting bars as visual stimuli. Only 3/31 cells lost orientation selectivity, with an average increase in bandwidth of 33%, as opposed to half the cells losing selectivity and a bandwidth increase for the remainder of 47% as reported previously. Infusion of GABAA blockers revealed a prominent stimulus onset transient response, lasting about 120 ms, that showed a broadening of orientation selectivity comparable to that found using drifting bars under similar circumstances. We believe that drifting gratings emphasize a steady-state response component that retains, in the presence of GABAA blockers, significant orientation selectivity. Because the onset transient is initially unselective for orientation, we suggest that the steady-state, orientation-selective response component develops from an alternate inhibitory mechanism, possibly mediated by GABAB receptors.

Animals↗
PubMed1992

Binocular processing in the cat's dorsal lateral geniculate nucleus. III. Spatial frequency, orientation, and direction sensitivity of nondominant-eye influences.

The present experiments examined the extent to which binocular processing in the cat's dorsal lateral geniculate nucleus (LGN) depends upon the spatial frequency, orientation, and direction of movement of stimuli presented to the nondominant eye. In Experiment 1, we tested the effects of varying these stimulus parameters on the responses of LGN cells to nondominant-eye stimulation. Sixteen of 34 cells tested had statistically significant responses to the nondominant eye and, in agreement with a previous study (Guido et al. 1989), the responsive cells were spatial-frequency sensitive. However, there was little evidence for orientation or direction sensitivity in responses to the nondominant eye: changes in discharge with changes in stimulus orientation and direction were small and were statistically significant in only nine of the cells. In Experiment 2, we tested the effects of varying spatial frequency, orientation, and direction of movement of stimuli presented to the nondominant eye on its ability to influence responses to the dominant eye (i.e., on binocular interactions). The dominant eye was stimulated with the optimal spatial frequency for the cell being tested. For 22 of 45 cells tested, nondominant-eye stimulation had a statistically significant effect on the response to the dominant eye. Fourteen of these cells showed band-pass spatial-frequency sensitivity in the nondominant-eye influence, and eight showed low-pass spatial-frequency sensitivity. However, only 11 of the cells had statistically significant variations in their binocular interactions that depended on the orientation or direction of stimuli presented to the nondominant eye. Furthermore, even for those cells, the effect of varying orientation and direction was only about half as strong as the effect of varying spatial frequency. We conclude that binocular processing in the LGN, including responses to the nondominant eye and nondominant-eye influences on responses to the dominant eye, are affected significantly by the spatial frequency of the nondominant-eye stimulus and relatively little by stimulus orientation or direction of movement. The significance of these findings for understanding the functions of LGN binocular processing is discussed.

Analysis of Variance↗
PubMed1975

Response of the elasmobranch utricle to maintained spatial orientation, transitions and jitter.

1. The spike discharges of single first order afferents from the utricle were recorded in the isolated head of the guitarfish and tested for responses to maintained spatial orientation, to transitions and to a small positional jitter representing natural perturbations. Sensitivity to maintained orientation is referred to as "tonic", and to transitions and jitter as "phasic". 2. Most responsive cells were either phasically, or phasically and tonically sensitive. A few were exclusively tonic. Tonic responsiveness implied that maintained orientation was associated with a stationary discharge which differed from one position to another; it sometimes differed also from one station to another at the same position. Transitions from one position to another evoked a rate change that later adapted to the level of the tonic response. Opposite transitions evoked rate changes in the opposite sense. The phasic rate change was usually larger for transitions that increased the rate. Many units were non-responsive. The prevalence of phasic over tonic sensitivity is stressed, and the remarkable heterogeneity of utricular afferents confirms that the macula is not uniform, probably coding a wide variety of head accelerations. 3. The jitter increased the ongoing scatter of intervals and binrates, changing, complicating, or abolishing their periodicity. The jitter could influence the effects of maintained orientation, increasing, decreasing, inverting or even revealing directional sensitivity. It could also force previously independent units into an orientation-dependent correlation; hence, between-cell correlation is potentially useful in coding of spatiel orientation. Naturally occurring perturbations may sonstitute a significant issue of normal operation. 4. Certain afferents from the horizontal semicircular canal showed a slow tonic response to maintained spatial orientation.

Action Potentials↗