The cerebellum has already been shown to participate in the navigation function. We propose here that this structure is involved in maintaining a sense of direction and location during self-motion by monitoring sensory information and interacting with navigation circuits to update the mental representation of space. To better understand the processing performed by the cerebellum in the navigation function, we have reviewed: the anatomical pathways that convey self-motion information to the cerebellum; the computational algorithm(s) thought to be performed by the cerebellum from these multi-source inputs; the cerebellar outputs directed toward navigation circuits and the influence of self-motion information on space-modulated cells receiving cerebellar outputs. This review highlights that the cerebellum is adequately wired to combine the diversity of sensory signals to be monitored during self-motion and fuel the navigation circuits. The direct anatomical projections of the cerebellum toward the head-direction cell system and the parietal cortex make those structures possible relays of the cerebellum influence on the hippocampal spatial map. We describe computational models of the cerebellar function showing that the cerebellum can filter out the components of the sensory signals that are predictable, and provides a novelty output. We finally speculate that this novelty output is taken into account by the navigation structures, which implement an update over time of position and stabilize perception during navigation. The ability to maintain a sense of direction and location while moving in one's environment is a fundamental cognitive function. Humans and more generally animals rely on a spatial cognitive process in complex environments for obtaining food, avoiding dangers and finding their nest/home. The cerebellum has been shown to participate in this spatial cognitive process  or visible from a distance . One can then use this information to get to a place by either moving toward a distantly visible monument or by trying to remember the succession of direction changes performed from the departure point, possibly at the recognizable landmarks. When the city becomes well-known, other elementary processes may take place and allow the navigator to use the knowledge previously acquired. Indeed, Spiers and Maguire  have shoThis detailed description reveals the complexity of navigation and the multiplicity of sub-processes that can vary in time depending on the amount of knowledge one has of one's environment and the given navigational constraints.Interestingly, all these sub-processes of navigation rely on sensory processing to provide the navigator with information about their position and orientation in the environment. Much of the information about where we are is known to come from external or allothetic cues. However, navigation also generates self-motion—also called idiothetic—information when one is moving in this environment. Monitoring such self-motion information is essential to estimate one's movement in space to update one's position and orientation.The continuous monitoring of this self-motion information may subserve the mental handling of spatial knowledge. This review will focus on the engagement of the cerebellum in this continuous process.To this end, we will first review the sensory inputs to the cerebellum and the cerebellar outputs directed toward navigation circuits. We will then discuss the computational algorithm(s) thought to be performed by the cerebellum in this context. Finally, we will review how self-motion signals influence information coded in these navigation circuits. Recent literature now provides anatomo-functional descriptions of the cerebellum at the micro-circuit level, revealing microcomplexes depending on the zebrin-histochemical status of the Purkinje cells, longitudinal zones and microzones of the cerebellar cortex  .The climbing fibers constitute the other main afferent to the cerebellar cortex. They arise exclusively from the inferior olive, a well defined nucleus in the ventral part of the brainstem. The axon of an olivary neuron divides into several branches that terminate in the molecular layer where they wrap around the dendritic tree of a Purkinje cell and make numerous synaptic contacts. Remarkably, in adults rats, each Purkinje cell is contacted by only one climbing fiber but each climbing fiber contacts seven Purkinje cell on average , which receive inputs from cortices involved in eye movements  and the perception of visual motion, sends mossy fiber projections to the dorsal paraflocculus . AOS is known to receive retinal signals related to the speed and direction of movement of large, textured visual patterns (AOS)  and the ventral lamella of the principal olive (PO) while projections from the lobule VII arise from the caudal MAO   receive inputs from TGN  and Crus I Barmack,  as well As the caudal medial accessory olive receives afferents from the superior colliculus  and the dorsal column nuclei (neck proprioception), climbing fiber inputs to lobule VII are modulated by multi-source signals Azizi, . InteresLobule IX and X receive vestibular inputs Barmack,  and propPurkinje cells of the cerebellar cortex receive convergent inputs of the same multi-sensorial information both from mossy and climbing fiber inputs. Brown and Bower described a convergence of mossy fibers and climbing fibers at the level of the Purkinje cells in the lateral hemispheres of the rats (Crus IIa) after peripherical tactile stimulation . However, information coming from each modality is intrinsically ambiguous: first, it is generated by sensors located in different parts of the body , it is therefore measured in relation with the organ and does not give direct access to whole body motion in space; second, each sensory signal can be insufficient to distinguish self-motion from external information by itself . Such ambiguities may only be resolved by combining several signals arising from different sensory modalities. The convergence of multi-source signals in the cerebellum described above is likely to contribute to this disambiguation, and provide the navigation structures with reliable self-motion information. That is what we describe in the following.Locating oneself is only meaningful relative to a spatial reference frame, i.e., a coordinate system into which spatial information is coded. It is defined by the origin on which it is centered, i.e., the point in space relative to which positions are measured, and by a set of axes corresponding to the three directions of space. A reference frame can be centered on the subject (egocentric reference frame) and more precisely on different parts of the subject  or on the external world .Sensory information generated by sensors located in different parts of the body  are initially encoded in the respective reference frames of its sensors. For example, as vestibular organs are located in the head, vestibular signal is detected in head coordinates. To allow the combination and/or comparison of different sensory signals, those must be expressed in a common reference frame. For example, to compute the movement of the whole body in space, vestibular information needs to be integrated relative to the body (taking into account the relative position of the head and the body given by the neck curvature) and also to the world (taking into account gravity).Converting the signal initially in head-fixed coordinates into a signal in body-frame and world-frame coordinates are not necessarily successive computations. Several recent studies showed that these two reference frame transformations may occur  in different cerebellar subregions  and is distributed onto different granule cells (GC), each one extracting a component of this signal. Interestingly, a GC combines the signal from up to four MF in average Albus,  and therThe filter is adaptive because the weight at the PF-PC synapses, corresponding to the synapse efficiency, can be modified through bi-directional plasticity (LTP and LTD). In Dean and Porrill's model, these plasticities are under the control of a teaching or error signal coming from the climbing fibers input. The weight adjustment follows the covariance rule: a PF signal that is positively correlated with an error signal has its weight reduced (through LTD), whereas a signal that is negatively correlated with an error signal has its weight increased (through LTP). The climbing fiber signal is thus considered to implement a supervised learning. Interestingly, LTP at the PF-PC synapses can be induced by PF activity alone . In externally generated self-motion, we can further dissociate sensory inputs which already occurred and are thus predictable from newly occurring features (novelty). The sensory prediction performed by the cerebellum takes into account both the motor efference and the current sensory state of the navigator. With this double input it is possible to predict the future sensory inputs due to internally generated self-motion by “adding” to the current sensory state the evolution of this current state expected from the intended movement  actively generated, (2) passively generated, and (3) external information, novelty can arise from any of those three sources, e.g., (1) internal modification of the muscle strength, (2) obstacle modifying/blocking unexpectedly the trajectory of a limb, (3) new object in the navigator environment inducing tactile stimulation and therefore influence space modulated cells.We saw previously that, once adequately transformed in the cerebellum, the sensory information may provide the neuronal circuits of navigation, in particular the hippocampus, with reliable self-motion information or novelty information. We now describe how this information may influence navigation-related cells.To our knowledge, only one study has reported the consequence of cerebellar impairment on the activity of navigation-related cells  cells system , through the deep cerebellar nuclei and ventro and centro-lateral thalamus  cells fire when a rat's head is facing a specific direction relative to the environment, irrespective of its location or whether it is moving or still (Taube et al., Despite the strong reliance of the HD system on landmark cues (Goodridge and Taube, Interestingly, in the parietal cortex which constitutes the second possible pathway from the cerebellum, at least two types of cells have recently been discovered to be modulated by the displacement of the animal. The first type, which we will call “movement cells” fires whenever the animal moves in a specific direction, irrespective of its location and heading, for example forward or rightward (McNaughton et al., Finally, the entorhinal cortex receives convergent inputs from both the parietal cortex and the retrosplenial cortex, the latter being part of the HD system Taube, . Grid ceSeveral observations indicate that grid cell firing depends primarily on self-motion information (Hafting et al., In conclusion, different types of navigation-related cells display modifications of firing in response to the manipulation or suppression of different modalities of self-motion cues. The direct anatomical projections of the cerebellum toward the HD system and the parietal cortex make HD cells and movement cells likely candidates for potential influence of the cerebellum on the hippocampal spatial representation. Studies manipulating sensory signals from different modalities reveal the diversity of information that is taken into account to build mental maps. They also illustrate the necessity to process multi-source information to extract the signal appropriate to shape the firing characteristics of the spatially modulated cells. We speculate that what will arise in the navigation structures from the cerebellum will convey the novelty signal necessary to implement an update over time of position in the context of navigation and allow stabilization of perception during voluntary navigation.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


The linear optical properties of the antennas are modified due to the large refractive index of the material. This leads to a change in the coupling strength as well as an increase of the effective refractive index of the surrounding. The combination of these two effects causes a red- or blue-shift of the plasmonic modes, respectively. We find that the nonlinear optical properties of the combined system are only modified in the range of one order of magnitude. The observed changes in our experiments in the nonlinear emission can be traced to the changed dielectric environment and thus the modified linear optical properties. The intrinsic nonlinearity of the dielectric used is in fact small when compared to the nonlinearity of the metallic part of the hybrid antennas. Thus, the nonlinear signals generated by the antenna itself are dominant in our experiments. We demonstrate that the well-known nonlinear response of bulk dielectric materials cannot always straightforwardly be used to boost the nonlinear response of nanoscale antenna systems. Our results significantly deepen the understanding of these interesting hybrid systems and offer important guidelines for the design of nanoscale, nonlinear light sources.We study the linear and nonlinear optical properties of hybrid metallic–dielectric plasmonic gap nanoantennas. Using a two-step-aligned electron beam lithography process, we demonstrate the ability to selectively and reproducibly fill the gap region of nanoantennas with dielectric nanoparticles made of lithium niobate (LiNbO The field of plasmonics entails the study of the optical properties of metallic nanoparticles. Collective oscillations of the quasi-free conduction electrons with respect to the fixed ionic background can be excited by an external light field. This displacement of charges leads to strong local electric fields in nanoscale volumes around the nanoparticles. Due to the large resonant dipole moment, which is fundamentally connected to the large number of free conduction electrons, energy can be efficiently channeled from the far-field into the so-called near-field.As previously discussed –2, the sIt was also realized early on that the enhanced local electric field strength could lead to efficient nonlinear optics in these systems  as the rThe first nonlinear optical phenomena in these systems were studied in the beginning of the 1980s. Strong second harmonic generation from metal-island films and microstructured silver films were shown to be related to the enhanced local near-field . Gold anIn recent years a number of papers and experimental studies have shown the predominant role of the linear optical properties on the nonlinear optical ones. It could be shown that even in systems commonly expected to be governed by so-called “hot spot nonlinearities”, such as gap antennas, the linear response still largely determines the nonlinear light generation –39. ThisIn order to benefit from these strongly enhanced fields, a nonlinear optical medium should be placed into the nanoscale gap, or at least within the enhanced near-field in the vicinity of the nanostructure. Even though this combination of field enhancement and nonlinear optics has already been proposed in the first publications on metamaterials and plasmonics , only a 3) or indium tin oxide (ITO) and selectively position them inside the gaps of nanoantennas, as shown in an artist’s impression in One obvious idea drawn from these earlier experiments is thus to use standard nonlinear materials such as lithium niobate crystals .Another benefit afforded by the nanocrystal/nanoantenna array approach is as follows: As the nanoantenna array is inversion symmetric, in first-order approximation it will not exhibit a second harmonic response for a normal incident electric field. The LiNbO3 solution, which consists of the nanocrystals diluted in water. The sample is repeatedly dipped into the solution and afterwards blown dry using nitrogen. The crystals are highly hydrophobic, as is the PMMA layer. However, the particles seem to be strongly attracted to the bare glass surface. Therefore, they agglomerate on the exposed glass surface. Additionally, there is a strong attraction between the LiNbO3 nanocrystals such that clusters of particles form and grow with every additional dipping step. As a final step the PMMA layer is removed in acetone. During this step the sample is rested upside down on additional pieces of glass in order to prevent the nanocrystals on top of the PMMA layer from migrating onto the substrate. The small inset in 3 nanocrystals. The next image shows a reference structure. No antenna structures have been defined, yet with the same periodicity with the same sized openings have been defined. After depositing the particles, one observes a perfect square lattice of LiNbO3 nanocrystals. In particular, no defects or empty lattice sides can be found, indicating the extremely high efficiency of this easy and straightforward process. The last image depicts an array of selectively filled bowtie antennas. Again, every antenna is filled with LiNbO3 nanocrystals. Most importantly, one can see that no particles are deposited in between the antennas.In 3 nanocrystals. The basic size of the triangles has been varied in order to shift the position of the linear resonance over the entire accessible wavelength range of the laser sources, while the gap size has been kept constant. The blue spectra depict the response of the empty bowtie antennas. For excitation along the antenna axis (left column), the strong dipolar resonance undergoes a significant red-shift with increasing size in addition to an increase in the scattering amplitude. This is expected due to the increasing size and volume of the nanostructure. For excitation perpendicular to the antenna axis (right column), one observes a resonance as well, yet due to the smaller dimensions of the antennas in this direction, the resonance is significantly blue-shifted.In 3-filled antennas. For all geometries, one observes spectral shifts in the position of the resonances, indicating that the antenna gaps have been filled with high efficiency. On closer inspection, one observes a red-shift for excitation along the antenna axis and a blue-shift for excitation perpendicular to the antenna axis. The reason for this behavior is the different character of the plasmonic modes. In both cases, they are hybridized modes between the two dipolar modes of the individual triangles. Yet, for excitation along the antenna axis, it is a head-to-tail configuration, whereas for excitation perpendicular to the axis, one observes a head-to-head configuration (see sketches with green arrows in The red spectra in f = 100 mm). The fundamental light is filtered out with a quartz glass prism sequence for measurement. The spectrally resolved detection is performed by a grating monochromater and an attached LN2-cooled UV-enhanced CCD camera sensitive to the fundamental as well as second harmonic light.3 filled antennas stems from the nanocrystals. However, several points have to be considered: First of all, the bowtie antenna array produces a second harmonic (SH) signal, which is symmetry forbidden in the lowest order, that is, in the electric dipole approximation. Second, we have not taken the modified linear optical properties into account. When examining The laser spectrum is centered at a wavelength of 817 nm, as shown in f pulse shaper for amplitude and phase modulation, emitting 30 fs laser pulses tunable from 900 to 1180 nm. The radiated SH intensity is measured with a Peltier-cooled CCD camera [The results shown in D camera ,73. The These findings indicate that we do not observe second harmonic generation from the nanocrystals. First of all, it is puzzling why the structures without the crystals already show a significant SH emission. In the electric dipole approximation we do not expect second harmonic emission from an inversion symmetric structure illuminated under normal incidence. However, strong SH emission from such structures has been reported . Second,(2) tensor components are actually small when compared to those of gold. As the particles have a size of about 50 nm, they are extremely weak frequency converters. This conclusion is supported by the recent reports by Knabe et al. on the second harmonic emission from single lithium niobate nanocrystals, showing small conversion efficiencies under excitation with tightly focused, nanosecond laser pulses [(2) tensor components are symmetry allowed. Therefore, it makes a huge difference how the particles are deposited inside the gap and in which direction they are aligned with respect to the antenna axis and thus relative to the polarization direction of the enhanced near-field. On the one hand, the absolute values of the components are very different, rendering the conversion efficiency strongly dependent on the orientation of the particles. On the other hand, the SH contributions from different nanocrystals are emitted with different phases, probably causing destructive interference of the SH emission from an ensemble of particles. There are actually several possible explanations for the observed behavior: Firstly, lithium niobate (under these circumstances) is a poor frequency converter. Lithium niobate exhibits an off-resonant nonlinearity which becomes efficient only for phase-matched geometries in bulk crystals of several mm in length. The absolute values of the χr pulses . The nan3 particles, which intrinsically break inversion symmetry, we have to align them with respect to the antenna axis. As the particles are ferroelectric and exhibit a spontaneous macroscopic electric polarization, such an alignment can be accomplished by so-called corona poling [We wanted to suppress the strong nonlinearity of gold itself by rendering the antenna array centrosymmetric. No second harmonic signal should then be observable. Our findings seem to indicate a fundamental problem, as they suggest that symmetry considerations do not completely hold for our structures. This is possibly because the entire concept of tensorial nonlinear optics, based on effective media, does not hold, as our systems in fact consist of a 2D array of optical resonators of wavelength dimensions. Also, the structures exhibit significant surface roughness, which might be responsible for the observed signals. Such a signal would originate from a random effect (roughness) and is therefore only weak, if at all, linked to the geometry of the underlying array. A signal from the antennas themselves might therefore not be suppressible. One possible solution is the use of single crystalline, atomically flat, gold flakes fabricated via wet chemical synthesis and subsequent nanostructuring . In ordea poling . When ap(2) nonlinearity of lithium niobate might be too small in order to observe a strong SH emission from the hybrid system. The particles are only about 50 nm in diameter; hence the small conversion volume needs to be compensated by a significantly enhanced, fundamental field strength. However, the absolute value of the enhanced near-field is still highly debated and it is not yet fully understood what fundamentally limits the field strength and what values can actually be achieved. Ultimately, the electric field strength might be limited by either electron tunneling processes between the extremely close spaced metallic nanoparticles [Nevertheless, our results suggest that the χarticles –76 or byarticles . Yet, itarticles –79, selfarticles , spacer articles , self-asarticles ,80–83 orarticles  are veryThe field of nonlinear plasmon optics is still in the very beginning stages. Even though the first experiments were already conducted in the early 1980s, several questions and problems remain unresolved. Surprisingly, this is often caused by the high complexity of the studied systems. This complexity is motivated by several reasons: Firstly, linear optical properties of these structures can be manipulated almost arbitrarily. Secondly, the structural geometry of the systems can be changed. This is supposed to be especially important because nonlinear optical processes are strongly dependent on symmetry. Thirdly, the dream to disentangle nonlinear and linear optical properties is a strong incentive for researchers, i.e., the hope to obtain strongly different nonlinear optical responses of two systems despite identical linear optical ones .However, most of these properties are intimately connected and it is extremely difficult to disentangle the respective contributions. It is in particular important to realize the huge importance of the properties of the plasmonic resonances on the radiated nonlinear signals. The linewidth, representing the dephasing time and thus the time the energy is stored in the plasmonic cavity, is of particular importance. The nonlinear signal is thus extremely sensitive to seemingly minute changes in the linear optical properties of the plasmonic resonances. In fact, a number of experiments might actually be dominated entirely by the change in the linear optical properties rather than by the intended manipulation of, e.g., the symmetry of the system.The dream, however, would be to go beyond this restriction and gain additional tunability, that is to have similar or even identical linear optical responses, yet the nonlinear optical properties would be strongly different. Only a limited number of experiments have demonstrated that the linear and nonlinear optical properties of a plasmonic or plasmon-hybrid system can indeed be decoupled. In all these cases, the cause for this deviation is actually the contribution of a dielectric medium, e.g., a waveguide. Utikal and co-workers demonstrated that the nonlinear response of different plasmon waveguide hybrid systems can be different in spite of nearly identical linear optical properties . In thisFrom the conclusions above, it thus appears that the most promising route is the combination of plasmonically active components and dielectrics into hybrid structures, in particular for dielectric subsystems exhibiting strong nonlinear optical properties. As in the case of the nonlinear waveguide, the dielectric system does not manifest itself optically and thus does not allow for an accurate prediction of the nonlinear properties solely from the linear ones. The same holds for the nonlinear self-assembled monolayers on top of silver triangles . Here, tThe field of nonlinear plasmon optics remains partially uncharted. With advances in sophisticated fabrication techniques for composite and hybrid structures, as well as advances in the rapidly growing field of theoretical and simulation-based descriptions of nonlinear plasmon optics, one can expect quite a number of fascinating discoveries in the next few years.


Driven by the challenge of representing and measuring psychological attributes, this article outlines a psychometric method aimed at identifying problem facets. The method, which integrates theoretical and empirical steps, is applied in the context of the construct of trait emotional intelligence (trait EI), using data from six different samples (N = 1284) collected across Europe. Alternative representations of the trait EI variance, derived from the outcome variables used in previous validation studies of the Trait Emotional Intelligence Questionnaire, were regressed on the 15 trait EI facets using the stepwise method. The analyses revealed five facets, which did not occupy unique construct variance in any of the six samples. As expected, a composite of the remaining 10 facets consistently showed greater construct validity than the original 15-facet composite. Implications for construct and scale development are discussed, and directions for further validation of the method and for its application to other constructs are provided. © 2014 The Authors. European Journal of Personality published by John Wiley & Sons Ltd on behalf of European Association of Personality Psychology. Examining the literature of an individual-differences construct, one often finds a diversity of measures, with an overall abundance of facets. Even individual measures composed of a fairly large number of facets are quite common. In some cases, the arrays of facets used to represent the same construct diverge considerably (in quantity and/or types), and correlations between their composites are weak or moderate , it also has implications for the latter. The method is intended to supplement the contemporary theoretical and empirical approaches to scale construction, by targeting ‘problem’ facets detrimental to construct validity. It thereby aims to minimize the plethora of facets through which constructs are often represented. The basic principle of the method is to identify problem facets based on their inability to occupy a unique part of the target construct's variance. It uses an alternative representation of the construct to assess whether a measure's facets fulfil this general criterion.facet to refer to a variable representing a narrow and highly homogenous subset of affective, behavioural, or cognitive tendencies associated with a given construct. Facets are interrelated and define the hypothetical domain of a construct; their common variance is conceptualized as representing the construct of interest. We use the term factor to designate a variable that subsumes the common, construct-related variance of several facets. Factors provide a mid-level between facets and the latent construct, serving to organize the facets into subcategories and providing the basis for subscales.Prior to describing the method in detail, it is necessary to specify its unique focus and explain how it supplements existing test construction methods. We then proceed with a brief review of the construct of trait emotional intelligence (trait EI), on which the method will be applied in the present investigation. Similar to definitions commonly used in the literature , or even an antecedent of the construct (e.g. parenting style). Second, a facet should share a non-negligible amount of variance with the other facets. Modest correlations between facets, or weak loadings of individual facets on the latent composite, may be due to untargeted sources, such as other constructs or response biases. However, although often taken as such, the common variance is insufficient as the sole empirical criterion for the validity of facets. A third criterion is that a facet should occupy a unique portion of the variance attributed to the construct it is theorized to represent (i.e. common variance not covered by other facets). This last criterion is the main focus of the method presented here.extraneous and redundant facets . The best way to describe these facets is with respect to their component variance, as graphically illustrated in FigureAs regards the second and third criteria earlier, two types of problem facets can be operationally defined. We refer to them as Both these two types of problem facet compromise the construct validity of a model or set of facets. RD facets lead to an unbalanced representation of the target construct's variance by over-representing some of its manifestations, while ET facets result in representations that extend beyond the target construct's boundaries, representing expressions of other, non-targeted dimensions. At the empirical level, both are prone to compromising the validity of the global composite derived from the facet scores. Neither is uniquely representative of the target construct and, hence, unlikely to occupy a distinctive portion of its variance vis-à-vis the other facets. When combined into a global composite, the effects of predictive facets are averaged out with those of the non-predictive facets . For many constructs, it is difficult to classify individuals unambiguously, because there is no shared agreement of how people at the extremes are like, which relates back to the conceptual ambiguity of these constructs.Variants of these traditional approaches or altogether different approaches focused on either construct testing or scale development have emerged in more recent years . This composite can then be used to assess whether each of the hypothetical facets occupies unique construct variance. Thus, Step 1 is to obtain a comprehensive sample of construct-relevant outcomes with common-variance representative of the target construct. Naturally, Step 1 also involves administering the chosen set of outcomes along with a comprehensive and multi-faceted measure of the target construct to multiple samples.While using individual or multiple validation criteria is not instrumental for identifying RD and ET facets, a single variable that is representative of the target construct's variance should be defined by the shared variance of construct-relevant outcomes. Using latent composites of these outcome variables therefore appears to be a reasonable and practical solution to capturing the variance of a given construct comprehensively  that share the general theme of the construct and correlate in the expected direction with it. More indirectly related outcomes increase the chances of significant incremental effects of ET facets.While it may be impractical to administer a representative sample of measures to a single sample of participants, it would be legitimate to spread out the measures across samples to ensure that all parts of the construct variance are represented. The number of measures per sample would then depend on the total number of measures needed to represent the construct variance and on how many measures one can reasonably administer to each sample without compromising the validity of the responses. Ideally, one would randomly assign outcomes corresponding to each empirically or theoretically derived higher-order factor across samples to ascertain that their common variance is representative of the target construct.In Step 2, one extracts the first principal component from the chosen set of criteria, because it is, in theory, the one that is representative of the target construct's variance. Divergent outcome variables, specifically those that have low loadings on the first principal component and that mostly vary because of sources other than the target construct, can be readily identified and excluded. The method can thereby account for and, to some extent, resolve inconsistencies in researchers' conceptualizations of the target construct and in the outcomes they deem relevant.Step 3 of the method examines whether each of the facets occupies a significant portion of variance in the derived outcome-based composite. Facets that consistently fail to account for variance in this composite are likely to be redundant or extraneous and should be excluded from the set of facets used to represent the construct. The most straightforward statistical procedure for this purpose is to regress the outcome-based composite on the theoretical set of facets, using statistical regression  to remove facets, although starting with all hypothetical facets at the initial step. Stepwise regression is the appropriate algorithm in this instance, as it both removes and adds predictors. Facets will be removed from the analysis successively if they do not explain unique variance in the criterion. In this process, RD and ET facets may initially suppress the (significant) effects of valid facets and lead to their removal at initial steps. Yet, the stepwise method re-enters facets removed from the analysis at preceding steps if they gain their significant explanatory effect at later steps .High intercorrelations among predictors are generally considered problematic, because they can compromise the explanatory effects of individual predictors  against the original composite comprising all facets. These two composites are compared in their degree of convergence with the outcome-based composite derived at Step 2. Using a composite of all facets averages predictive and non-predictive facets, and the correlation of this composite with the outcome-based composite should be weaker than that of a composite encompassing predictive facets only  to distinguish between RD and ET facets. RD facets should show substantial zero-order correlations with this composite, whereas ET facets should not.A construct of contemporary interest that illustrates the challenge of representing constructs is EI. Much has been said about what constitutes EI, as is apparent from the diversity of EI models and operationalizations. The divergence of research into the two increasingly distinct subareas of trait EI and ability EI has brought some structure into the field. Petrides and Furnham  pointed Trait EI has provided a framework for reconceptualizing self-report measures of EI initially supposed to assess cognitive emotional abilities, which they are hardly able to measure . The data from each sample included measurements of various construct-relevant outcomes. This approach was deemed appropriate for this initial investigation, as the criteria assessed across these samples were diverse and representative of the four TEIQue factors. The principal components from the outcomes assessed in each of the samples were extracted in order to provide alternative representations of global trait EI (Step 2 of the method). These outcome-based composites were then regressed onto the 15 trait EI facets to identify any non-predictive facets. A composite comprising facets with predictive effects in any one or more of the six samples was compared with the original 15-facet composite in terms of its associations with the six criterion-based composites. Facets that did not occupy unique variance in any of the outcome-based composites were further examined to classify them as redundant versus extraneous.The data came from five cross-sectional studies (six samples), in which the criterion validity of the TEIQue across different sets of outcomes was investigated. We selected the samples based on their relevance to the present investigation, as they comprised thematically related, proximate outcomes. Samples 1, 4, and 5 were Greek, Spanish, and Georgian, respectively, whereas Samples 2, 3, and 6 were British. The demographic characteristics of the six samples are summarized in TableThe outcome variables are presented in TableAll measures in this study were based on self-report, mostly using multiple-point response scales.The full form of the TEIQue, which yields global, factor (4), and facet (15) scores, was administered to all six samples. Samples 1–4 completed the initial version , whereas Samples 5 and 6 completed the current version . Samples 2, 3, and 6 completed the TEIQue in its original language (English), whereas Greek, Spanish, and Georgian translations were administered to Samples 1, 4, and 5, respectively. The TEIQue was translated by the researchers who conducted the studies  to 7 (agree completely). Internal consistencies at the facet level were predominantly within a range of .70 to .80 across studies. Cronbach's alphas for global trait EI ranged from .81 (Sample 5) to .96 (Sample 6).The four factors and their constituent facets are Well-Being , Self-Control , Emotionality , and Sociability . Two facets (adaptability and self-motivation) have not been included in any of the four factors but contribute directly to the global score. More detailed descriptions of the facets and factors can be found in Petrides . The TEIA summary of the outcome measures and references can be found in TableThe Satisfaction with Life Scale , .84 (detached coping), .83 , and .68 (avoidant coping).The Center for Epidemiologic Studies Depression Scale Radloff,  is a 20-The Dysfunctional Attitudes Scale  in excess of .50 or (b) of .30–.49 that were greater than their loadings on ensuing components. Conversely, variables were excluded from the analyses if they loaded weakly on the first principal component (<.50) and more strongly on ensuing components. These variables were deemed to be too distinct from the target construct, with additional dimensions implicit in them increasing the chances of predictive effects for ET facets (or for the specific variance of RD facets).The derived outcome-based composites were regressed onto the 15 trait EI facets, using the stepwise method in each analysis. All facets were entered at the first step and subsequently removed successively, starting with the least significant one. Because the stepwise method was used, as required by the method, it was possible for facets already removed to be re-entered at later steps of the analyses.Z tests were computed to examine if there are significant differences in the correlations of these two composites with the outcome-based composites across samples.The original composite of all 15 trait EI facets and a composite comprising facets included in the final model in at least one of the six regression analyses were compared in terms of their associations with the outcome-based composites. Facets with significant predictive effects in any of the six samples were included in this composite to account for variations in the outcomes used to derive the outcome-based composites. Steiger's To differentiate between RD and ET facets, zero-order correlations of any non-predictive facets with a revised composite comprising the predictive facets only were also examined. In theory, RD facets should correlate significantly with the global construct, whereas ET facets should show correlations closer to zero.Results of the principal component analyses for the outcomes used in each sample are presented in TableSummaries of the stepwise regression analyses with the outcome-based composites as the dependent variables are presented in TableOf the 15 trait EI facets, five did not explain unique variance in the outcome-based composites in any sample and, thus, do not appear in the final regression models. These facets were trait empathy, emotion perception, emotion expression, emotion management, and social awareness. In addition to being manually excluded from Samples 3, 4, and 6, emotion management did not appear in the final regression models in Samples 1, 2, and 5, based on the stepwise method. Likewise, trait empathy and emotion perception, which were manually removed from the Sample 6 regression, were non-predictive in the other samples. Therefore, neither these three facets nor the two non-predictive facets appear in TableR2, which can account for the unequal degrees of freedom. As is apparent across all six samples, the shortened sets accounted for virtually the same amount of the variance as the 15-facet composite. Even the unadjusted change in R2 from the initial to final model was negligible and non-significant in the six samples. As discussed, however, regression analysis does not reveal the impact of non-predictive facets or facets with atheoretical, inverted effects on the explanatory power of higher-order composites, such as global trait EI. For example, the non-predictive facets of emotion expression and trait empathy can be expected to weaken the convergence of global trait EI with the outcome-based composites, because they are averaged along with the predictive facets into the global trait EI score. Hence, two trait EI composites comprising 15 and 10 facets, respectively, were compared in terms of their associations with the outcome-based composites.In comparing the additive predictive effects of all 15 facets included in the initial prediction model (shown as Model 1) against the final set of facets remaining in the last step of each regression analysis , the appropriate statistic to examine is the adjusted Z tests of significant differences in the convergent validity of the two composites. Except for the latent composite derived from the Sample 3 outcomes, associations of both trait EI composites with the outcome-based composites were consistently strong. Unlike the other samples, in which a latent composite of more diverse emotion-related outcomes was used, the outcome-based composite derived from the aggression variables in Sample 3 was fairly homogenous and narrow and, thus, least representative of trait EI. Correlations of the 10-facet composite with the outcome-based composites were consistently larger than those of the 15-facet composite. In fact, the Steiger Z results indicate that the 10-facet composite had significantly greater convergent validity in all six samples.Pearson correlations of the 15-facet and 10-facet trait EI composites with the outcome-based composites are presented in TableCorrelations between the five non-predictive facets and the 10-facet composite are shown in TableDecades ago, Cronbach and Meehl  noted thApplication of the method to trait EI data from six European samples yielded consistent results. Five facets did not explain unique variance in alternative representations of the construct variance, derived from varying sets of validation outcomes administered across the six samples. Removal of these five facets from the global trait EI composite significantly improved its associations with the outcome-based composites in all samples. Collectively, the results indicate that the five non-predictive facets overlap entirely with the predictive facets in their reliable common variance (i.e. variance attributed to the construct of trait EI), apparently compromising the construct validity of the global trait EI composite. It seems that the revised 10-facet composite gives a better representation of trait EI than the original composite.The trait EI facets identified as non-predictive came exclusively from the TEIQue factors of Emotionality and Sociability. Notably, these two factors have shown little success in explaining incremental criterion variance vis-à-vis the other factors in previous research . This pattern is consistent with some evidence speaking to the distinctiveness of these types of facets . Neither of these types of facet is, therefore, able to take up unique variance in the global construct, thus weakening the construct validity of the model that incorporates them and of its operational vehicles. Overall, the results provide preliminary evidence for the efficacy of the proposed method in identifying RD facets, because all of the non-predictive facets seemed to fall into this category. At least in theory, it should also screen out facets that are completely extraneous and somehow found their way into the researcher's model.Subject to further validation, the method has utility in the optimization of multi-faceted assessment instruments. As discussed, a unique strength of the proposed strategy lies in its potential to identify RD or ET facets, which conventional approaches do not accomplish. Identification and eventual removal of RD and ET facets would help improve the construct validity of measures to which the method is applied. Similarly, the method has promise in enhancing the unidimensionality or homogeneity of scales intended to assess a single construct, the importance of which has been discussed in detail elsewhere  pertaining to the measure or model being scrutinized. By applying the method first in order to gain construct validity, it would be possible to assess and understand the construct's relationships with other constructs and outcomes more accurately.If thoroughly applied, the method would entail realistic benefits for psychology's applications, particularly where quantitative assessment is involved. On a general level, it would enhance the professional and social utility of a range of standardized measures, enabling more accurate assessments of individuals and prediction of their future behaviour. Failing to represent and measure a construct adequately can have consequences, given that psychometric assessment often forms the basis of high-stakes decisions, such as clinical diagnoses, career selection, and people matching. Another benefit of identifying, and eventually removing, RD and ET facets is the reduced length of psychometric measures and shorter assessment times without trade-offs , another worthwhile step would be to cross-validate the results, by comparing the revised and original composites in samples of criteria not used during application of the method.Particularly when used to construct a new measure, the method should be applied in combination with the established methods, of which one  is even a pre-requisite. Furthermore, as indicated throughout the article, it may be wisest to consider the method as an ongoing process, whereby repeated application across samples of participants and outcomes will increase certainty in the identification of RD and ET facets. Beyond the method p-value cut-offs or effect size estimates).Future developments of the method are foreseeable with regard to two of its five steps. The first concerns the process of selecting and testing outcomes for deriving alternative representations of the construct variance at Steps 1 and 2. We anticipate that with theoretical development and repeated application of the method, more specific examples and guidelines for outcome selection will emerge. Second, while the statistical procedures employed in this article (particularly at Step 3) can identify RD and ET facets, they are of limited utility in examining the relative proportions that the remaining facets occupy within the construct variance, because of intercorrelations among predictors. However, new approaches, such as relative weight analysis Johnson, , may be Further validation of the proposed method with respect to other personality constructs is needed to provide definitive evidence for its efficacy. Once a satisfactory level of support has been established, it would be worthwhile to demonstrate that the method also has efficacy within the realm of cognitive abilities, as can be expected. Whereas this article presents the initial application of the method, based on existing data, future studies designed specifically for its evaluation can yield more conclusive results. However, this is not to undermine the utility and relevance of using existing datasets, as the method requires evidence from numerous and relatively large samples. We encourage others who have suitable data  to replicate the analyses we performed here and publish the results.In designing future studies specifically for applying the proposed method, it will be important to sample systematically from the entire theoretical range of relevant outcomes to represent the variance of the target construct as comprehensively as possible. A second question to be addressed in further validation studies of the method is whether using the same measurement format for all variables introduces confounding effects in favour of the method. Measuring the outcomes in the same way as the hypothetical facets creates common-method variance , which may contribute to the pattern of results. Alternative methods (i.e. other than self-report) for assessing outcomes relevant to trait EI and other personality constructs include informant ratings, behavioural observations, electronic diaries, and possibly biodata. Converging evidence from applications of the method across various outcome-based composites will eventually help us arrive at a consensus regarding the best set of facets for representing established, yet still partially elusive, individual-differences constructs.


Several studies showed the effect of osteopathic manipulative treatment on neonatal care in reducing length of stay in hospital, gastrointestinal problems, clubfoot complications and improving cranial asymmetry of infants affected by plagiocephaly. Despite several results obtained, there is still a lack of standardized osteopathic evaluation and treatment procedures for newborns recovered in neonatal intensive care unit (NICU). The aim of this paper is to suggest a protocol on osteopathic approach (NE-O model) in treating hospitalized newborns.The NE-O model is composed by specific evaluation tests and treatments to tailor osteopathic method according to preterm and term infants’ needs, NICU environment, medical and paramedical assistance. This model was developed to maximize the effectiveness and the clinical use of osteopathy into NICU.The NE-O model was adopted in 2006 to evaluate the efficacy of OMT in neonatology. Results from research showed the effectiveness of this osteopathic model in reducing preterms’ length of stay and hospital costs. Additionally the present model was demonstrated to be safe.The present paper defines the key steps for a rigorous and effective osteopathic approach into NICU setting, providing a scientific and methodological example of integrated medicine and complex intervention. Osteopathy is a manual medicine classified as complementary and alternative medicine (CAM). It is based on manual contact for diagnosis and treatment. It stresses the importance on the structural and functional integrity of the body as well as the intrinsic ability of the body for self-healing. Osteopaths can use numerous manual techniques to treat somatic dysfunction (SD) (ICD-10-CM Diagnosis Code M99.0-9) in order to enhance physiological functions  and WescThe osteopathic scenario, however, lacks standardized guidelines for the evaluation and treatment of newborns. Even more uncertainty is present if osteopathic care within a NICU environment is considered.The aim of this paper is to describe a specific osteopathic approach to evaluate and treat hospitalized neonates. Since the attention to the care of neonates osteopathically treated is increased, we considered the need to address the lack of a standardized approach, based upon our experience of osteopathy in neonatology field. In recent years, we have focused on the development of an osteopathic care pathway. In this paper, we provide a detailed description of this procedure, the development of the method and its clinical application and validity. The ultimate goal is to improve effectiveness in the use of osteopathy in neonatology practice and make the use of a standardized approach more efficient.An Osteopathic model in Neonatology ward (NE-O model) was designed from the NE-O group of the Accademia Italiana Osteopatia Tradizionale (AIOT). The aim of the NE-O model was to codify an osteopathic procedure to increase reliability, internal and external validity, efficiency and accuracy of osteopathic diagnosis and treatment on newborns. The NE-O model was tested on newborns, both preterm and term infants, of either sex with parents’ or legal guardians’ written informed consent. No exclusion criteria were applied. It is composed of a set of evaluation and treatment procedures. The duration of an osteopathic session lasts 30 minutes, 10 min for evaluation and 20 min for treatment. The model has been developed following two phases: a run-in pre-test period and a research period. The 8-month run-in period was carried out between April 2006 and December 2006. It consisted of pre-test evaluation and treatment of 100 newborns by 3 licensed osteopaths , with a mean of 9.6 ± 4.0 years of clinical experience and same osteopathic curricula. Osteopaths were following the same evaluation procedure and treatments. The techniques of choice were balanced ligamentous and membranous tension techniques. After the run-in period, the model was applied to research context and results from different clinical trials were published elsewhere [A specific osteopathic evaluation has been designed and described as follows. The first step in newborns’ evaluation is to look at the general condition of the child in terms of asymmetries and defects of posture.Then, the operator takes place beside or aside the crib of the newborn. The assessment starts from the skull, continuing with the spine and the pelvis passing through upper and lower limbs and ends with the rib cage and viscera. The evaluation is performed according to TART  criteria  aiming tThe skull is assessed in order to detect any cranial strain pattern (CSP), condylar compression and suture/fontanelles abnormalities. The position of the operators is aside to the child.Firstly a general CSP assessment is performed with a modified fronto-occipital hold and a modified five fingers hold. The former is performed putting the first and the second finger of one hand (anterior hand) upon the greater wings of the sphenoid bone and the other hand (posterior hand) on the occiput (occiput hold) Figure . The modSecondly occipital condylar evaluation is carried out using the second and the fourth fingers of only one hand unlike the traditional hold performed with both hands Figure .Thirdly, a sutures and fontanelles evaluation is conducted to state if there are overlapping margins or premature fusing of cranial sutures. Due to fragile newborns conditions the suture evaluation is restricted to external sutures only.The test of choice for the assessment of the spine is a modified spring test. The traditional spring test is performed with patient in prone position in order to investigate the presence of an anterior torsion or a unilateral flexion of the sacrum . In neonThe operator always stands next to the child and with a sacroiliac hold performs the pelvis assessment in order to evaluate the presence of any sacrum intraosseous lesion, any sacrolumbar or sacroiliac compression and pubic dysfunction Figure .The assessment of the upper limbs has the aim to investigate the articular range of motion in each joint. Examinations are passive and specific for each joint, illustrated as follows:Shoulder: small and delicate movements is required to evaluate flexion-extention, ab-adduction, internal and external rotation;Elbows: internal and external rotation and flexion-extention test is performed;Wrists: flexion-extention test is carried out.As for the upper arms, the assessment of the lower limbs consists of a passive test performed to evaluate the range of motion. They can be described according to areas as follows:Hips: the range of motion in the three axes planes is tested: flexion-extention, ab-adduction, internal and external rotation;Knee: flexion-extention test of knee joint and internal-external rotation of the tibia are performed;Ankle: flexion-estention test of tibio-tarsal joint is conducted.The operator places the hands over the chest of the newborns. A gentle pressure on the rib cage is performed in order to evaluate resistance, elasticity and mobility of the ribs Figure .The operator stands aside the newborn and places the anterior hand on the diaphragmatic cupola and the posterior one on the diaphragmatic pillars testing the area for restrictive barrier and tissue alteration.The assessment ends with the evaluation of the visceral fascia. It was decided to approach the visceral fascia by dividing it into three different regions: the anterior region of the neck, the mediastinal region and the abdominal-pelvic region. The assessment considers the relation between the range of motion of tissues of the anterior area and the referred dermatomeric area of the column. One hand (anterior) is placed on the visceral region whilst the other hand (posterior) is located on the column Figure . The antAnterior region of the neck:The operator places one hand (anterior hand) over the throat and the other hand (posterior hand) under the cervical spine looking for movement restriction and tissue alteration.Mediastinum:The operator puts one hand (anterior hand) over the sternum and the other hand (posterior hand) on the dorsal spine covering the area between T1 - T6 Figure .Abdominal-pelvic region:The operator puts the anterior hand over the subject’s belly and the posterior hand on the thoracolumbar tract Figure .The second phase of the NE-O model is based on treatment. The term osteopathic manipulative treatment (OMT) currently includes nearly twenty-five types of manual treatments. These techniques are used to treat SD within the body’s framework, including skeletal, arthrodial, and myofascial structures and associated vascular, lymphatic and neural components . The OMTIn Sutherland’s original thinking, the ability of healing is handled by intrinsic forces of the body, rather then to the action of the operator . The indSpecifically the treatment method used follows Sutherland’s point of maximum freedom  model. According to Sutherland’s model, all the joints in the body are balanced ligamentous articular mechanisms. The attention is focused on the balance point defined as the point in the range of motion of a joint where the anatomical structures  laid in maximum freedom and minimal tension. This is usually between the normal tension present in a rest position and the increased tension preceding the strain or fixation which occurs when a joint is carried beyond its normal physiology. Therefore it is the most “neutral” position possible under the influence of all factors responsible for strains. SD tends to alter the balance of ligamentous framework. Consequently the first step of an indirect treatment procedures is to determine the point of balance. To do this it is necessary to gently test the area with SD, in every direction within the existing range of motion, seeking for tissue barriers and eventually reaching the point of balance .Balanced Ligamentous Tension (BLT) and Balanced Membranous Tension (BMT) techniques follow these principles and thus are the techniques of choice in the present osteopathic model Table . These tAccording to Sutherland’s theory, ligaments provide both proprioceptive information that guides muscle response for joint positioning and the anatomical framework to control motion of the articular components . BLT appBLT techniques applied to CSP are referred as BMT. The anatomical component of BMT are the cranial bones and indirectly the dura mater; more precisely the relationship between flax cerebri, tentorium and flax cerebelli described by Sutherland as reciprocal tension membranes . AlthougContextually to the development of the NE-O model, an ad-hoc software (EBOM-GCCN) has been built to improve efficiency and accuracy of data as well as to support osteopaths and NICU stuff in patients’ management. Specifically, two of the three sections were designed to collect osteopathic evaluation and treatment data, respectively.http://www.clinicaltrials.gov (identifier number: NCT01902563).Written informed consent was obtained for each subjects and the use of the model was approved by the institutional review board of Pescara’s hospital. The model has been registered at The NE-O model was developed in April 2006 to evaluate the efficacy of OMT in neonatology. Infants enrolled included preterm and term newborns admitted to the NICU of the civil hospital of Pescara, Italy.During the entire study period (2006 - present), the model has been tested on over 2000 hospitalized preterm and term newborns both healthy and clinically complicated as well as on neonates with congenital and genetic conditions. No adverse events have been recorded, suggesting that the model is safe.The effectiveness of this model was demonstrated elsewhere -9 and itThe present paper has the aim to introduce an osteopathic evaluation and treatment model within the NICU. Results from recent studies documented the effectiveness and safety of the model.Nevertheless, here we can describe our first experiences with the NE-O model and make recommendations for future practice. Since 2006 we have undertaken comprehensive research with the aim of creating an osteopathic standardized procedure that could systematically improve the use of osteopathy as adjutant therapy in neonatology. The NE-O procedures appears to be an efficient method to achieve this goal. In the context of using osteopathic approach in clinical practice, it is noteworthy to consider some issues. Infants anatomy is different from that on adults. This difference should be taken into account especially for the cranial approach. In newborns, sutures are not fully developed as well as bones, as justified by the presence of fontanelles. For this reason, traditional cranial treatment on sutures should be adapted to infants’ skull. A global approach to the cranium  could be considered the preferred way to assure safety and increase effectiveness of the treatment. Direct sutural techniques may be biased from incomplete skull development.In addition, the visceral model proposed has been built upon clinical and anatomical consideration. Looking at the osteopathic literature, the only visceral approaches described are those providing a direct contact with the organ (direct approach) , howeverAnother peculiarity about the NE-O model is the osteopathic evaluation. It is tailored to hospitalized infants and differs from that on adults mainly for patient’s position  and type of tests used (only passive tests are applicable). Furthermore, the model fits the needs of all NICU levels.Therefore the NE-O model has the strengths to be clinically validated, effective, safe, methodologically reproducible and applicable into all NICU levels. However, due to lack of standardized osteopathic procedures in neonatology, the NE-O model could not be compared to pre-existing methods.Interestingly, the application of this model into a neonatology unit could be considered one of the first real osteopathic example of complex intervention. The latter is widely used in health services, public health practices and health-related policies and it is mainly based on synergic and integrated collaborations. To optimize the osteopathic intervention within an integrated care system, osteopathic session should be included into a precise medical care timetable, without interfering with routine medical and paramedical procedures. Examples came from the NE-O study where osteopathic care is administered early afternoon before the visiting hours and after the medical and paramedical daily assistance ,8. The cThis paper provides a method for the osteopathic care of infants admitted to neonatal intensive care unit. Specifically, it aims to provide an osteopathic action plan for evaluation and treatment in the specific field of neonatology. Moreover it proposes an osteopathic model in terms of newborns’ evaluation and treatment.The success of the methodology proposed is supported by some positive experiences with the use of the NE-O model in different NICUs across Italy. Results from these research showed the effectiveness of this osteopathic model in reducing preterms’ length of stay and hospital costs. Additionally the present model has been demonstrated to be safe.Therefore the standardization of the procedure could be a keynote step to optimize the osteopathic approach and its potential benefit in neonatal field as well as to make the method reproducible in NICU setting.BLT: Balanced ligamentous tension; BMT: Balanced membranous tension; CAM: Complementary and alternative medicine; CSP: Cranial strain pattern; NICU: Neonatology intensive care unit; OMT: Osteopathic manipulative treatment; SD: Somatic dysfunction; TART: Tissue alteration, asymmetry, range of motion and tenderness.The authors declare that they have no competing interests.FC and MM wrote the paper. GB, VC, CR and GP reviewed the paper for important intellectual content. All authors read and approved the final manuscript.