Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “vision transformers”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 253 records · Page 14Linked to original sources
PubMed2001

Enhancing self-belief with EMDR: developing a sense of mastery in the early phase of treatment.

Deep inside each of us is a seed that holds our vision of truth, peace, and happiness. Our early childhood attachments, societal influences, and innate capacity determine how well that seed is nurtured and the deepest inner vision is set free. This article is about the ways that vision becomes clouded by attachment deficits, trauma, and subsequent symptoms. The deep inner wish to heal allows for transformation, and approaches like Eye Movement Desensitization and Reprocessing, and hypnotherapy can assist in creating a more rapid acceleration of trauma resolution and transformation of self.

Adult↗
PubMed2001

Visual illusions and the control of children arm movements.

The aim of the present study was to determine whether children like adults (Gentilucci M, Chieffi S, Daprati E, Saetti MC, Toni I. Visual illusion and action. Neuropsychologia 1996;34:369-76; Gentilucci M, Daprati E, Gangitano M, Toni I. Eye position tunes the contribution of allocentric and egocentric information to target localisation in human goal directed arm movements. Neurosci Lett 1997;222:123-6) are influenced by visual illusions when they transform visual information in motor command. Children and adults pointed to a shaft extremity of the Müller-Lyer configurations, as well as to an extremity of a control configuration. Movements were executed in two experimental conditions. In the vision condition subjects saw both the stimulus and their hand before and during movement. In the no vision (memory) condition subjects saw the stimulus and their hand before, but not during movement. Movement started 5 s after vision was precluded. The Müller-Lyer illusion affected pointing kinematics of both children and adults. As found previously (Gentilucci M, Chieffi S, Daprati E, Saetti MC, Toni I. Visual illusion and action. Neuropsychologia 1996;34:369-76; Gentilucci M, Daprati E, Gangitano M, Toni I. Eye position tunes the contribution of allocentric and egocentric information to target localisation in human goal directed arm movements. Neurosci Lett 1997;222:123-6), subjects undershot and overshot the shaft extremity of the closed and of the open configuration, respectively. The illusion effect was greater in the no vision than in the vision condition. These results show that in children like in adults the system underlying visual perception in an object-centered frame of reference and that involved in motor control functionally interact with each other. Although the processes of target localisation were the same, the transformation of target position information in a sequence of motor patterns was different in children from that in adults. Even if both children and adults lengthened duration of the deceleration phase in the vision condition, only adults shortened duration of the acceleration phase in order to maintain constant movement time (Viviani P, Schneider R. A developmental study of the relationship between geometry and kinematics in drawing movements. J Exp Psychol 1991;17:198-218). This result suggests that children are yet unable to co-ordinate temporally acceleration with deceleration phase.

Acceleration↗
PubMed1996

The partnership model: working with individuals, families, and communities toward a new vision of health.

Increasingly, health professionals must learn to work in new partnership relationships with clients and community to promote health effectively. A partnership requires a transformation of the professional role from chief actor to partner, and the client role from passive recipient to partner. A partnership approach has particular merit in a reformed health care system that increasingly emphasizes active involvement and self-care actions of individuals and families to maintain health and prevent disease. A partnership approach is also important to professionals working with underserved, vulnerable, and/or minority populations. For too long professionals and policymakers have relegated these groups to passive roles in health decision making and action. This article will provide a description of the partnership process as it has been developed and implemented by nurse practitioners in an urban Hispanic community with emphasis on a community partnership. A partnership model is described and compared to the more traditional professional model. A definition and essential criteria for partnership are presented. Finally, a specific example of how the partnership process was implemented at the community level is discussed.

Community Health Nursing↗
PubMed1994

Non-Fourier motion analysis.

It has been realized for some time that the visual system performs at least two general sorts of motion processing. First-order motion processing applies some variant of standard motion analysis (i.e. spatiotemporal Fourier energy analysis) directly to stimulus luminance, whereas second-order motion processing applies standard motion analysis to one or another grossly non-linear transformation of stimulus luminance. We have developed a method for disentangling the different sorts of mechanisms that may operate in human vision to detect second-order motion. This method hinges on an empirical condition called transition invariance that may or may not be satisfied by a family psi of textures. Any failure of this condition indicates that more than one mechanism is involved in detecting the motion of stimuli composed of the textures in psi. We have shown that the family of sinusoidal gratings oriented orthogonally to the direction of motion and varying in contrast and spatial frequency is transition invariant. We modelled the results in terms of a single-channel motion computation. We have new results indicating that a specific class of textures differing in texture element density and texture element contrast decisively fails the test of transition invariance. These findings suggest that in addition to the single second-order motion channel required by our earlier results there exists at least one other second-order motion channel. We argue that the preprocessing transformation used by this channel is a pointwise non-linearity that maps stimulus contrasts of absolute value less than some relatively high threshold tau onto 0, but increases with magnitude of c-tau for contrasts. c of absolute value greater than tau.

Animals↗
PubMed2004

Spatial transformations for eye-hand coordination.

Eye-hand coordination is complex because it involves the visual guidance of both the eyes and hands, while simultaneously using eye movements to optimize vision. Since only hand motion directly affects the external world, eye movements are the slave in this system. This eye-hand visuomotor system incorporates closed-loop visual feedback but here we focus on early feedforward mechanisms that allow primates to make spatially accurate reaches. First, we consider how the parietal cortex might store and update gaze-centered representations of reach targets during a sequence of gaze shifts and fixations. Recent evidence suggests that such representations might be compared with hand position signals within this early gaze-centered frame. However, the resulting motor error commands cannot be treated independently of their frame of origin or the frame of their destined motor command. Behavioral experiments show that the brain deals with the nonlinear aspects of such reference frame transformations, and incorporates internal models of the complex linkage geometry of the eye-head-shoulder system. These transformations are modeled as a series of vector displacement commands, rotated by eye and head orientation, and implemented between parietal and frontal cortex through efficient parallel neuronal architectures. Finally, we consider how this reach system might interact with the visually guided grasp system through both parallel and coordinated neural algorithms.

Animals↗
PubMed2004

Image enhancement in the JPEG domain for people with vision impairment.

An image enhancement algorithm for low-vision patients was developed for images compressed using the JPEG standard. The proposed algorithm enhances the images in the discrete cosine transform domain by weighting the quantization table in the decoder. Our specific implementation increases the contrast at all bands of frequencies by an equal factor. The enhancement algorithm has four advantages: 1) low computational cost; 2) suitability for real-time application; 3) ease of adjustment by end-users (for example, adjusting a single parameter); and 4) less severe block artifacts as compared with conventional (post compression) enhancements. Experiments with visually impaired patients show improved perceived image quality at moderate levels of enhancement but rejection of artifacts caused by higher levels of enhancement.

Algorithms↗
PubMed1997

Viewer-centered frame of reference for pointing to memorized targets in three-dimensional space.

Pointing to a remembered visual target involves the transformation of binocular visual information into an appropriate motor output. Errors generated during pointing tasks may indicate the reference frames used by the CNS for the transformation and storage of the target position. Previous studies have proposed eye-, shoulder-, or hand-centered reference frames for various pointing tasks, depending on visual conditions. We asked subjects to perform pointing movements to remembered three-dimensional targets after a fixed memory delay. Pointing movements were executed under dim lighting conditions, allowing vision of the fingertip against a uniform black background. Subjects performed repeated movements to targets distributed uniformly within a small (radius 25 mm) workspace volume. In separate blocks of trials, subjects pointed to different workspace regions that varied in terms of distance and direction from the head and shoulder. Additional blocks were performed that differed in terms of starting position, effector hand, head rotation, and memory delay duration. Final pointing positions were quantified in terms of the constant and variable errors in three dimensions. The orientation of these errors was examined as a function of workspace location to identify the underlying reference frames. Subjects produced anisotropic patterns of variable error, with greater variability for endpoint distances from the body. The major axes of the variable-error tolerance ellipsoids pointed toward the eyes of the subject, independent of workspace region, effector hand (left or right), initial hand position, and head rotations. Constant errors were less consistent across subjects, but also tended to point toward the head and body. Both overshoots and undershoots of the target position were observed. Increasing the duration of the memory delay period increased the size but did not alter the orientation of the variable-error ellipsoids. Variability of the endpoint positions increased equally in all three Cartesian directions as the memory delay increased from 0.5 to 8.0 s. The anisotropy of variable errors indicates a viewer-centered reference frame for pointing to remembered visual targets with vision of the finger. The anisotropy of pointing variability stems from variability in egocentric binocular cues as opposed to reliance on allocentric visual references or to specific approximations in the sensorimotor transformation. Nevertheless, observed increases in variability with longer memory delays indicate that the short-term storage of the target position does not simply mirror the retinal and ocular sensory signals of the visually acquired target location. Thus spatial memory is carried out in an internal representation that is viewer-centered but that may be isotropic with respect to Cartesian space.

Adult↗
PubMed1990

Structural features and adaptive properties of photoreceptors in the skate retina.

In the duplex (rod/cone) retinae of most vertebrates, electrical responses associated with nocturnal vision can be recorded in relative isolation only over a limited intensity range before there is encroachment by signals from the cone system; e.g., at mesopic levels of illumination, the rods begin to saturate, and the cone mechanism is brought into play. On the other hand, the retinae of some sub-species of skate appear to contain only one class of photoreceptors, namely rods. Nevertheless, skate photoreceptors, as well as other retinal neurons, are able to respond to incremental stimuli presented on background fields so intense that 90% or more of the available rhodopsin is bleached during the exposure. These and other findings raise some doubts as to whether the skate has, in fact, an all-rod retina. In this paper, we present a body of evidence--based on the results of photochemical, anatomical, and electrophysiological studies--to support the view that only a single class of photoreceptor subserves vision in the skate retina. In addition, recent findings will be described that: a) demonstrate how the visual cells transform from sluggishly responding rods to brisk, cone-like elements, and b) may provide some insight into the functional significance of this unusual adaptive property.

Adaptation, Ocular↗
PubMed2026

Epigenetic Reprogramming and Zygotic Genome Activation in Human Preimplantation Development: Mechanisms, Models, and Translational Prospects.

PURPOSE: Early human embryogenesis unfolds through a tightly coupled sequence of events-clearance of maternal transcripts, remodeling of parental chromatin, zygotic genome activation (ZGA), lineage segregation, implantation, and post-implantation patterning-accompanied by epigenetic reprogramming, including X-chromosome dosage compensation around the time of implantation. This review aims to synthesize recent advances in understanding this developmental program and to consider their implications for reproductive medicine. METHODS: I review recent literature on human early embryogenesis, with particular emphasis on findings enabled by single-cell genomics and stem-cell-based embryo modeling, and integrate these insights to identify human-specific features of early development. RESULTS: These approaches have made previously inaccessible aspects of human early embryogenesis experimentally tractable, revealing molecular and epigenetic features that distinguish human development from that of model organisms, including species-specific dynamics of ZGA, maternal transcript clearance, chromatin reprogramming, and X-chromosome dosage compensation. CONCLUSIONS: Advances in single-cell genomics and embryo modeling are transforming our understanding of human early embryogenesis. Building on these insights, while recognizing their current limitations, I propose a vision for improving reproductive medicine, including the potential for next-generation embryo selection strategies.

Journal Article↗
PubMed1995

The state psychiatric center as an academically affiliated tertiary care hospital.

Conventional wisdom views state psychiatric hospitals as a problem as much as a solution in the fight against mental illness. The legacy of the historic shortcomings of these hospitals--overcrowding, dreary environment, ineffective treatments, understaffing--frames the discussions of their future. The authors argue that a positive, constructive mission and vision for state hospitals is emerging in New York. This vision calls for fewer, smaller, specialized centers redefined as academically affiliated, community based, consumer oriented, tertiary care centers. To transform these centers, a major reengineering is proposed, including centralized treatment, patient and family participation, continuing education for all staff, outcome research, specialization, multi-service campuses, and technology transfer programs. With this transformation, State Psychiatric Centers become partners in efforts to improve the quality of life for people with mental illness throughout society.

Combined Modality Therapy↗
PubMed1994

Lie transformation groups, integral transforms, and invariant pattern recognition.

This paper considers image representations based on integral transforms which are invariant under certain transformations, while preserving the uniqueness of the encoding. Necessary and sufficient conditions are determined for the existence of such representations and a method to determine the kernels of the related integral transforms is presented. Finally, the possible relevance of such considerations for the understanding of invariant recognition systems in biological vision is also explored.

Humans↗
PubMed2000

Pain and suffering in childbirth. A look at attitudes, research and history.

"I think it is a manufactured culture that women get brainwashed into and then it drags us along." Human beings are different from other animals in that we have highly developed cultures that shape the way we view ourselves, other people, and the world we live in. Every aspect of our lives is affected by our culture, and it is much easier to observe cultural differences in others than it is to identify our own cultural expectations and norms. We believe that our own culture is normal and natural, when indeed very few human activities are purely instinctual and/or natural. In that sense, all culture is manufactured, we are all brainwashed, and we are all subject to blind spots in our vision of reality. As midwives we view ourselves as the guardians of normal birth. We believe that our mission is to be with women as they accomplish the magnificent feat of giving birth. Thus we have the responsibility to try to remove the blind spots from our vision as much as possible. We must attempt to tell the whole truth about birth, the truth that includes transformation, mastery, satisfaction, personal power, and the difference between pain and suffering. At the same time, however, we must respect the choices women make even when we may not personally agree with those choices. Women who choose pain medication deserve the supportive presence of a midwife just as much as those who opt for a less interventive style of birth experience.

Analgesia, Obstetrical↗
PubMed2003

Color vision.

Color vision starts with the absorption of light in the retinal cone photoreceptors, which transduce electromagnetic energy into electrical voltages. These voltages are transformed into action potentials by a complicated network of cells in the retina. The information is sent to the visual cortex via the lateral geniculate nucleus (LGN) in three separate color-opponent channels that have been characterized psychophysically, physiologically, and computationally. The properties of cells in the retina and LGN account for a surprisingly large body of psychophysical literature. This suggests that several fundamental computations involved in color perception occur at early levels of processing. In the cortex, information from the three retino-geniculate channels is combined to enable perception of a large variety of different hues. Furthermore, recent evidence suggests that color analysis and coding cannot be separated from the analysis and coding of other visual attributes such as form and motion. Though there are some brain areas that are more sensitive to color than others, color vision emerges through the combined activity of neurons in many different areas.

Animals↗
PubMedDate not supplied

Designing nursing learning centers of the future.

As Drucker notes in The Atlantic Monthly (1994:53), the 21st century will be one of transformations and challenges. Nurse educators will need to think through the purposes, values, and content of educational programs and lifelong learning opportunities. Nurse educators as knowledge workers must prepare to meet challenges by developing nursing learning centers for future needs. Whereas a bold vision of the future, concrete plans that a customer driven, and monitoring for improvement are important, the nurse educator as manager/dean/director for the learning center and faculty teaching here will be key to facilitating nursings' transformation into the information age.

Computer-Assisted Instruction↗
PubMed2000

Perception of three-dimensional shape from texture is based on patterns of oriented energy.

This paper presents empirical support for a new observer model of inferring three-dimensional shape from monocular texture cues. By measuring observers' abilities to estimate the relative three-dimensional curvature along a textured surface from two-dimensional projected images, and concurrently examining the local spectral changes occurring in the projected image for various texture patterns, we have found that correlated changes in oriented energy along lines corresponding to the lines of maximum and minimum curvature of the surface are crucial for conveying the three-dimensional shape of the surface. Energy along these lines of maximum and minimum curvature can be used to compute the orientation of local surface patches. Texture patterns consisting of simple and complex sinusoidal gratings and plaids, and filtered noise were drawn onto a surface that was corrugated sinusoidally in depth about the horizontal axis and projected in perspective onto an image plane. The perceived relative surface curvature was reconstructed from measurements of local ordinal depth around a central fixation point at 12 different phases of the corrugation. Our results show that: (1) it is neither necessary nor sufficient to identify individual texture elements or texture gradients in order to extract the shape of the surface; (2) one-dimensional frequency modulation is insufficient for conveying complex three-dimensional shape. (3) Veridical ordinal depth is seen only when the projected pattern contains changes in oriented energy along lines corresponding to projected lines of maximum curvature of the surface. (4) For a surface corrugated in depth about the horizontal axis, this pattern of oriented energy arises from energy along the vertical direction in the global Fourier transform of the pre-corrugated pattern. (5) Local orientation changes across lines of minimum curvature can be also critical for conveying shape. (6) These correlated orientation changes along lines of maximum and minimum curvature are entirely lost in parallel projection. Hence texture is a useful cue for shape if the image is a perspective projection. (7) Only some natural textures will provide sufficient monocular cues to support veridical shape inferences, and this can be predicted from their global Fourier transforms.

Computer Simulation↗
PubMed1983

Accurate visual measurement of three-dimensional moving patterns.

Human observers discriminated relative three-dimensional distances in simple patterns of motion parallax with an acuity similar to vernier acuity under comparable conditions. Accurate visual measures of three-dimensional distance can be derived from the structural invariance of patterns undergoing perspective transformations.

Depth Perception↗