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PubMed2004

Development of the sport achievement orientation questionnaire for Japanese athletes by exploratory factor analysis.

In this study, a questionnaire to assess achievement orientation in sport for Japanese athletes was developed. We created the questionnaire by picking items from free descriptions of Japanese athletes and using factor analysis of the responses in a Japanese sport setting. The subjects were 2,415 athletes (M=16.7 yr., SD=2.7) in Japan. Factor analyses in this study identified three factors. Top Level Orientation, Demonstrating Ability Orientation, and Win Orientation, respectively. An examination of the intercorrelations among the three scores showed the subscales were related. There were no correlations between the new measure and the Japanese versions of the Sport Orientation Questionnaire and the Task and Ego Orientation in Sport Questionnaire except that the correlation of Win Orientation and the SOQ Athletic Success Orientation was low and negative. These results suggested that the three subscales appeared to be separate but related factors, and that it is an original measurement for only Japanese athletes. The overall factor reliability and validity based on the sample suggested that the Sport Achievement Orientation Questionnaire for Japanese Athletes can be valuable means for the investigation of achievement orientation in Japanese sport and exercise settings.

Achievement↗
PubMed2000

[Causal models of achievement motive, goal orientation, intrinsic interest, and academic achievement in classroom].

This study investigated the effect of achievement motive on goal orientation, and that of goal orientation on intrinsic interest in learning and academic achievement, based on the model proposed by Elliot and Church (1997). A sample of 222 fifth and sixth grade students of an elementary school, and another of 307 seventh, eighth and ninth grade students of a junior high school participated in the study. The approach-avoidance framework of Elliot and Harackiewicz (1996) was used to classify goal orientations. With multiple-sample structural equation modeling, the paths in two causal models, one for each of the elementary and junior high school samples, were compared. A path was found from hope for success to mastery orientation, from both hope for success and fear of failure to performance-approach orientation, and from fear of failure to performance-avoidance orientation. Mastery and performance-approach orientations each had a positive effect on intrinsic interest in learning. For elementary school children, performance-approach orientation enhanced academic achievement, and for junior high school students, mastery orientation mainly facilitated it. Performance-avoidance orientation had a negative effect on both intrinsic interest and academic achievement.

Achievement↗
PubMed2002

Orientation selectivity in macaque V1: diversity and laminar dependence.

We studied the steady-state orientation selectivity of single neurons in macaque primary visual cortex (V1). To analyze the data, two measures of orientation tuning selectivity, circular variance and orientation bandwidth, were computed from the tuning curves. Circular variance is a global measure of the shape of the tuning curve, whereas orientation bandwidth is a local measure of the sharpness of the tuning curve around its peak. Circular variance in V1 was distributed broadly, indicating a great diversity of orientation selectivity. This diversity was also reflected in the individual cortical layers. However, there was a tendency for neurons with high circular variance, meaning low selectivity for orientation, to be concentrated in layers 4C, 3B, and 5. The relative variation of orientation bandwidth across the cortical layers was less than for circular variance, but it showed a similar laminar dependence. Neurons with large orientation bandwidth were found predominantly in layers 4C and 3B. There was a weak correlation between orientation selectivity and the level of spontaneous activity of the neurons. We also assigned a response modulation ratio for each cell, which is a measure of the linearity of spatial summation. Cells with low modulation ratios tended to have higher circular variance and bandwidth than those with high modulation ratios. These findings suggest a revision to the classical view that nonoriented receptive fields are principally found in layer 4C and the cytochrome oxidase-rich blobs in layer 2/3. Instead, a broad distribution of tuning selectivity is found in all cortical layers, and neurons that are weakly tuned for orientation are ubiquitous in V1 cortex.

Action Potentials↗
PubMedDate not supplied

Residency orientation: what we present and its effect on our residents.

BACKGROUND AND OBJECTIVES: This study describes the content of family practice residency orientation programs, presents data about resident satisfaction with orientation, and determines if residents feel prepared for residency duties. METHODS: We surveyed program directors and first-year residents at 100 family practice residency programs. We used questionnaires to collect data about orientation activities; program demographics; and resident characteristics, satisfaction, and preparation. RESULTS: Sixty-nine percent of directors and 68% of their residents responded. The activity most frequently presented was a social event with faculty, while the least frequently presented was an assessment of cognitive knowledge. Even though residents desire orientation to clinical programs, and directors wish to promote group cohesion, the greatest number of orientation activities were presented to introduce hospital services and administration. Eighty-seven percent of residents were at least "somewhat satisfied," and 83% felt at least "somewhat prepared" for clinical duties after completing orientations. Residents from military programs were more likely not to be satisfied with their orientations. Extreme satisfaction was associated with residents in community-based programs. Being totally prepared was associated with having had prior graduate medical education. CONCLUSIONS: While residents had previously reported having clinical needs from an orientation, the most frequently reported activities were nonclinical. Most residents reported having been satisfied with their orientations and having felt prepared for their new duties. Directors should consider increasing the clinical content of their orientations, including an assessment of residents' knowledge and clinical skills.

Consumer Behavior↗
PubMed1992

Thermoregulatory responses of rats exposed to 9.3-GHz microwaves: a comparison of E and H orientation.

The purpose of this study was to determine the effects of exposure orientation relative to electric and magnetic fields (E and H fields) on the thermal, cardiovascular, and respiratory changes in ketamine-anesthetized rats exposed to far-field, continuous-wave, 9.3-GHz radiofrequency radiation (RFR). Irradiation (specific absorption rate = 12.5 W/kg in both orientations; power levels of 79 and 59 mW/cm2 in E and H orientations, respectively) was conducted to produce 1 degree C colonic temperature changes (38.5 to 39.5 degrees C). During experimentation, arterial blood pressure and respiratory rate, colonic (Tc) tympanic (Tt) left and right subcutaneous (Tsl & Tsr) (sides toward and away from RFR source), and tail temperatures (Tta) were continuously recorded. The Tsr change during E-orientation exposure was considerably less than the Tc change; the Tt and Tsr (H-orientation) changes approximated the Tc increase; and the Tsl and Tta changes (both orientations) were considerably greater than the Tc increase. The Tt and Tsl increases were virtually equal under the two exposure conditions; however, the Tsr increase was significantly greater during H-orientation irradiation, and the Tta increase was significantly greater during E-orientation exposure. Heart rate and mean arterial pressure increased significantly during irradiation; however the cardiovascular responses were not affected by exposure orientation. The latter findings at 9.3 GHz contrast with the marked cardiovascular response differences between E- and H-orientation exposure noted during previous studies at 0.7 to 2.45 GHz.

Animals↗
PubMed1991

[From the phenomenon of nondisjunction to the problem of chromosome co-orientation (75th anniversary of Bridges' article].

The concepts of the mechanism of chromosome nondisjunction in Drosophila are described in a historical retrospective. Evidences are given for the appropriateness of the term co-orientation in the traditional sense used by geneticists treating nondisjunction. There are 6 variants of co-operation in Drosophila meiosis depending upon the number and particular chromosomes involved in co-orientation. The classical chromosome nondisjunction is a variant of co-orientation in the bivalent composed of two homologous chromosomes. By comparing the different variants of pairing (pairing in bi- and multivalents) resulting in co-orientation, the elementary events preceding co-orientation may be identified. The author reviews his recent data concerning the similarities of the co-orientation of two homologs and the co-orientation of two nonhomologs in Drosophila meiosis. The concept of the role of pairing in the precentromeric heterochromatic region during chromosome co-orientation is considered, and the hypothesis of delayed pairing in this region during meiotic prophase is put forward. Based on the suggested hypothesis clarified are (i) the relationship of pairing, crossing over, and disjunction of homologous chromosomes (ii) the relationship of crossing over and co-orientation of nonhomologous chromosomes, and (iii) the time when the contact resulting in nonhomolog co-orientation takes place.

Animals↗
PubMed1997

Role of nonrandomly oriented cell division in shaping and bending of the neural plate.

Neural plate shaping and bending are crucial to the process of neural tube formation. Shaping requires intrinsic forces generated by alterations in neuroepithelial cell behavior, whereas bending requires similar intrinsic forces and extrinsic forces generated by alterations in cell behaviors outside the neural plate. This study evaluates the role of nonrandomly oriented cell division in neural plate shaping and epidermal ectoderm expansion during bending by examining mitotic spindle orientation in the neuroepithelium and epidermal ectoderm throughout neurulation. Neuroepithelial mitotic spindles are oriented preferentially in the rostrocaudal plane, suggesting a role for nonrandomly oriented (i.e., rostrocaudal) neuroepithelial cell division in longitudinal lengthening of the neural plate during shaping. Epidermal ectoderm mitotic spindles are oriented preferentially in both rostrocaudal and mediolateral planes, suggesting a role for nonrandomly oriented cell division in epidermal ectoderm elongation and expansion. In neural plate and epidermal ectoderm isolates separated prior to shaping and bending, mitotic spindles continued to be oriented preferentially in the rostrocaudal plane; however, a preferential mediolateral mitotic spindle orientation could not be demonstrated in the epidermal ectoderm isolates. We conclude that the nonrandom rostrocaudal orientation of cell division in the neuroepithelium and epidermal ectoderm is an autonomous process, occurring in the absence of forces from adjacent tissues, whereas the nonrandom mediolateral orientation of cell division in the epidermal ectoderm is dependent upon interactions with the neural plate.

Animals↗
PubMed1998

Peripheral neural mechanisms determining the orientation of cylinders grasped by the digits.

When a human grasps a cylindrical object, feedback on the orientation of the cylinder with respect to the axes of the digits is crucial for successful manipulation of the object. We measured the ability of humans to discriminate the orientations of cylinders passively contacting the fingerpad. For a cylinder of curvature of 521 m-1 (radius, 1.92 mm) subjects were able to discriminate, at the 75% level, orientation differences of 5.4 degrees; for a less curved cylinder (curvature, 172 m-1; radius, 5.81 mm) the difference limen decreased to 4.2 degrees. The neural mechanisms underlying the determination of tactile orientation were investigated by recording the responses of single slowly adapting type I afferents (SAIs) innervating the fingerpads of anesthetized monkeys. When cylinders were stepped across the receptive field of an SAI, the resulting response profiles were Gaussian in shape; the shape corresponded to the shape of the cylinder, increasing in height and decreasing in width for more curved cylinders. All SAIs had the same underlying profile shape except for a multiplicative constant determined by the sensitivity of the individual afferent. Thus it was possible to reconstruct the response of the population of active SAIs in the fingerpad. Changing the orientation of the cylinder resulted in a rotation of the population response, but the change in angle of the population response was greater than the change in orientation of the cylinder. This discrepancy increased as the orientation of the cylinder moved closer to the orientation of the axis of the finger and was more pronounced for the less curved cylinder. Measured contact areas between the cylinders and the skin were elliptical, with orientations exceeding those of the cylinder; again the differences were greater for the less curved cylinder and for orientations closer to that of the finger axis. The human discrimination performance could be explained in terms of the SAI population responses.

Adult↗
PubMed1996

Function of identified nerves in orientation to water flow in Tritonia diomedea.

We determined which sensory and motor nerves mediate orientation to flow in the marine slug Tritonia diomedea, and tested the hypothesis that the slug orients to water flow by comparing the intensities of water flow stimulation on each side of its body. Lesion experiments revealed which nerves carried information necessary for flow orientation. The lateral branches of Cerebral Nerve #2 were the only cerebral nerves necessary for flow orientation. Cutting all cerebral nerves except the lateral branches of Cerebral Nerve #2 did not eliminate flow orientation. Thus, the lateral branches of Cerebral Nerve #2 were both necessary and sufficient (among the cerebral nerves) for flow orientation. Denervation of one side of the head by cutting Cerebral Nerves #1-4 on one side did not eliminate normal flow orientation. We have revised our model of how Tritonia diomedea orients to flow to allow for this unilateral determination of flow direction. Unilaterally cutting Pedal Nerve #3, which contains many pedal motor axons, reduced turning toward that side, but did not affect final orientation to flow. The ability to detect flow direction was not compromised by the inability to initially turn towards flow.

Animals↗
PubMed1989

Orientation discrimination sensitivity of single units in cat primary visual cortex.

Responses of visual cortex (area 17) neurons to moving oriented stimuli were recorded from anesthetized cats. The variance of response (SD2) to repeated identical stimuli was directly proportional to response magnitude (R), (SD2 = C2R). The values of C were not found to differ significantly between different types of cortical cells. The relationship predicts that the coefficient of variation (SD/R) will be smallest near the peak of the tuning curve, indicating that the peak response is most reliable for detecting an orientation but not necessarily the most sensitive to a change in orientation. Tuning curves and response variability were then examined to determine the orientation at which the neuron was most sensitive to changes in stimulus orientation using signal detection theory. The discrimination index (d' = [R1-R2]/SD) for a 1 degree change in stimulus orientation was greatest along the flanks of the tuning curve. In order to generalize the experimental data, response distributions derived from a model of cells with parameters based on experimental data were examined to determine the minimal discriminable change in stimulus orientation. Changes of stimulus orientation between 0.6 and 5 deg of arc could be detected from single responses of a single cell by an optimal observer with 75% accuracy if the orientation change was centered at the most sensitive part of the tuning curve.

Action Potentials↗
PubMed1984

Retinotopy and orientation columns in the monkey: a new model.

A model is presented in which orientation columns arise directly out of retinotopy. According to the model, iso-orientation lines are arrayed radially around nodal centers which correspond to cytochrome oxidase patches. The nodal centers form a square matrix superimposed upon the map of ocular dominance stripes. In the supragranular layers horizontal iso-orientation lines run down the centers of ocular dominance stripes, with vertical iso-orientation lines crossing perpendicularly. Diagonal orientations (45 degrees and 135 degrees) are represented as alternating iso-orientation zones at the centers of the interstices in the matrix (internodal centers). Preferred orientations in the infragranular layers are reversed with respect to the supragranular layers. The model is consistent with new data concerning ocularity and preferred orientation in systematic penetrations through striate cortex, and helps to explain some previously puzzling features of the relationship between ocular dominance columns, orientation columns and retinotopy.

Animals↗
PubMed2000

Pattern vision of the honeybee (Apis mellifera). What is an oriented edge?

Pairs of black patterns on a white background, one rewarded the other not, were presented vertically each in one arm of a Y-maze. During training the locations of the black areas were changed every 5 min to prevent the bees using them as cues, but cues from edges were kept consistent. Bees detect orientation even in a gradient that subtends 36 degrees from black to white (normal to the edge). Orientation cues in short lengths of edge are detected and summed on each side of the fixation point, irrespective of the lay-out of the pattern. Edges at right angles reduce the total orientation cue. The polarity of edges in a sawtooth grating is weakly discriminated, but not the orientation of a fault line where two gratings meet. Edge quality can be discriminated, but is not recognised in unfamiliar orientations. When spot location is excluded as a cue, the orientation of a row of spots or squares which individually provide no net orientation cue is not discriminated. In conclusion, when locations of black areas are shuffled, the bees remember the sum of local orientation cues but not the global pattern, and there is no re-assembly of a pattern based on differently oriented edges. A neuronal model consistent with these results is presented.

Animals↗
PubMed1998

Orientation tuning curves: empirical description and estimation of parameters.

This paper compares the ability of some simple model functions to describe orientation tuning curves obtained in extracellular single-unit recordings from area 17 of the cat visual cortex. It also investigates the relationships between three methods currently used to estimate preferred orientation from tuning curve data: (a) least-squares curve fitting, (b) the vector sum method and (c) the Fourier transform method (Wörgötter and Eysel 1987). The results show that the best fitting model function for single-unit orientation tuning curves is a von Mises circular function with a variable degree of skewness. However, other functions, such as a wrapped Gaussian, fit the data nearly as well. A cosine function provides a poor description of tuning curves in almost all instances. It is demonstrated that the vector sum and Fourier methods of determining preferred orientation are equivalent, and identical to calculating a least-square fit of a cosine function to the data. Least-squares fitting of a better model function, such as a von Mises function or a wrapped Gaussian, is therefore likely to be a better method for estimating preferred orientation. Monte-Carlo simulations confirmed this, although for broad orientation tuning curves sampled at 45 degree intervals, as is typical in optical recording experiments, all the methods gave similarly accurate estimates of preferred orientation. The sampling interval, the estimated error in the response measurements and the probable shape of the underlying response function all need to be taken into account in deciding on the best method of estimating referred orientation from physiological measurements of orientation tuning data.

Animals↗
PubMed2005

Orientation-invariant object recognition: evidence from repetition blindness.

The question of whether object recognition is orientation-invariant or orientation-dependent was investigated using a repetition blindness (RB) paradigm. In RB, the second occurrence of a repeated stimulus is less likely to be reported, compared to the occurrence of a different stimulus, if it occurs within a short time of the first presentation. This failure is usually interpreted as a difficulty in assigning two separate episodic tokens to the same visual type. Thus, RB can provide useful information about which representations are treated as the same by the visual system. Two experiments tested whether RB occurs for repeated objects that were either in identical orientations, or differed by 30, 60, 90, or 180 degrees . Significant RB was found for all orientation differences, consistent with the existence of orientation-invariant object representations. However, under some circumstances, RB was reduced or even eliminated when the repeated object was rotated by 180 degrees , suggesting easier individuation of the repeated objects in this case. A third experiment confirmed that the upside-down orientation is processed more easily than other rotated orientations. The results indicate that, although object identity can be determined independently of orientation, orientation plays an important role in establishing distinct episodic representations of a repeated object, thus enabling one to report them as separate events.

Adult↗
PubMed2004

Neural networks underlying endogenous and exogenous visual-spatial orienting.

The orienting of visual-spatial attention is fundamental to most organisms and is controlled through external (exogenous) or internal (endogenous) processes. Exogenous orienting is considered to be reflexive and automatic, whereas endogenous orienting refers to the purposeful allocation of attentional resources to a predetermined location in space. Although behavioral, electrophysiological and lesion research in both primates and humans suggests that separate neural systems control these different modes of orienting, previous human neuroimaging studies have largely reported common neuronal substrates. Therefore, event-related FMRI (ER-FMRI) was used to independently examine different components of the orienting response including endogenous facilitation, exogenous facilitation and inhibition of return (IOR). In contrast to previous studies, endogenous versus exogenous facilitation resulted in widespread cortical activation including bilateral temporoparietal junction, bilateral superior temporal gyrus, right middle temporal gyrus, right frontal eye field and left intraparietal sulcus. Conversely, IOR compared to endogenous facilitation resulted in only a single focus of activation in the left superior temporal gyrus. These findings suggest that endogenous orienting activates a large cortical network to achieve internally generated shifts of attentional resources versus the automatic orienting that occurs with exogenous cues. However, similar networks may mediate endogenous orienting and IOR. The activation of the temporoparietal junction suggests that it is involved in more effortful processes, such as endogenous orienting, as well as in attentional reorienting and locating targets. Current results are discussed in terms of the functional development of the visual-spatial attentional system.

Adult↗
PubMed2006

Haptic orientation perception: sex differences and lateralization of functions.

The present study examined sex differences in haptic orientation representation using three tasks: a bimanual parallel-setting task comprising haptic orientation perception and motor matching action, and two unimanual tasks focusing on the perception and action elements separately. A verbal judgment task focused on haptic orientation perception: participants were to assign a number of minutes to a felt orientation. An orientation production task required the rotation of a bar to match a verbally presented number of minutes. Although both male and female performance was systematically biased we found that males are more accurate in parallel-setting and verbal judgment of orientation, suggesting differences in haptic orientation perception, in particular. Increasing allocentric reference frame involvement by delaying the action in the parallel-setting task did not affect the sex difference found. In addition to a male advantage over tasks, performance on both unimanual tasks suggests sex differences in lateralization of haptic orientation processing; a dependence on hand orientation was found only for right hand performance in males.

Adolescent↗
PubMed2004

Sensitivity to curvatures in orientation-based texture segmentation.

Texture segregation has long been attributed to changes in the distribution of elementary features across the visual field [Nature 290 (12) (1981) 91; Biol. Cybernet. 54 (1986) 245]. The study of orientation, a conspicuous feature, has led to models of orientation-based texture segmentation (OBTS) that depend on the magnitude of one or two orientation gradients [Vis. Res. 31 (4) (1991) 679; Vis. Res. 31 (6) (1991) 1073] and influenced further by the relative configuration between the orientation textons and the global orientation edge [Percept. Psychophys. 52 (4) (1992) 255; Vis. Res. 35 (20) (1995) 2863]. Here we show that these models are at best partial and that the notion of orientation gradient has been incompletely used in the study of OBTS. To do so, we first study the behavior of orientation in orientation-defined texture patches. Geometrical analysis identifies two texture curvatures and reveals the incompleteness of previous stimuli. Psychophysical experimentation then demonstrates that segmentation is strongly affected by discontinuities in these curvatures. Importantly, we show that this sensitivity to curvature is independent of the orientation gradients and inconsistent with the simple configural considerations proposed in the past.

Discrimination, Psychological↗
PubMed2005

Grouping local orientation and direction signals to extract spatial contours: empirical tests of "association field" models of contour integration.

Over the last decade or so a great deal of psychophysical research has attempted to delineate the principles by which local orientations and motions are combined across space to facilitate the detection of simple spatial contours. This has led to the development of "association field" models of contour detection which suggest that the strength of linking between neighbouring elements in an image, is determined by the degree to which they aligned along smooth (first-order) curves. To test this assumption we used a path detection paradigm to compare the ability of observers to identify the presence of contours defined by either spatial orientation, motion direction or by specific combinations of both types of visual attribute. The relative alignment of the local orientations and/or directions with respect to the axis of the depicted contour was systematically varied. For orientation-defined contours detection was best when the elements were aligned along (parallel with) the contour axis, approached chance levels for obliquely oriented elements and then improved for elements that were orthogonal to the contour axis (i.e., performance was a U-shaped function of degree of orientation misalignment). This pattern of results was found for both straight and curved contours and is not readily explicable in terms of current association field theories. For motion-defined contours, however, performance simply deteriorated as the relative directions of the constituent path elements were progressively misaligned with respect to the contour. Thus the rules by which local orientations are linked to define spatial contours are qualitatively different from those used for linking local directions and each may be mediated by distinct visual mechanisms. When both orientation and motion cues were simultaneously available, contour detection performance was generally enhanced, in a manner that is consistent with probability summation. We suggest that association field models of orientation linking may need to be extended in light of the present findings.

Cues↗