depth perception
Latest
Augmented-reality guided lumpectomy
Abstract Far too many women with a newly diagnosed breast cancer must undergo repeat surgery because positive margins were found at the time of their initial lumpectomy. Supine volumetric MRI has potential to improve surgical accuracy, and reduce re-excision rates by nearly 50%. Spurred by our preliminary results improving depth perception via projected apertures and integrating intra-operative marker tracking into commercial Augmented Reality systems, we have developed a highly accurate initial prototype Augmented Reality system to project volumetric MRI data inside the breast to guide surgery. In Aim 1, we will compare methods of projecting apertures in a phantom model of lumpectomy. In Aim 2, we will test the final prototype system in a pilot study of 30 women with new breast cancer. Standardized use of cavity- and shave-margins will enable paired comparisons between standard and AR-guided techniques in the same patients, including ability to reduce positive margin rates and minimize overexcision. Ultimately the system will be ready for future randomized controlled trials to measure efficacy as the next step toward broad clinical adoption.
Seeing the world through moving photoreceptors - binocular photomechanical microsaccades give fruit fly hyperacute 3D-vision
To move efficiently, animals must continuously work out their x,y,z positions with respect to real-world objects, and many animals have a pair of eyes to achieve this. How photoreceptors actively sample the eyes’ optical image disparity is not understood because this fundamental information-limiting step has not been investigated in vivo over the eyes’ whole sampling matrix. This integrative multiscale study will advance our current understanding of stereopsis from static image disparity comparison to a morphodynamic active sampling theory. It shows how photomechanical photoreceptor microsaccades enable Drosophila superresolution three-dimensional vision and proposes neural computations for accurately predicting these flies’ depth-perception dynamics, limits, and visual behaviors.
Neural network models of binocular depth perception
Our visual experience of living in a three-dimensional world is created from the information contained in the two-dimensional images projected into our eyes. The overlapping visual fields of the two eyes mean that their images are highly correlated, and that the small differences that are present represent an important cue to depth. Binocular neurons encode this information in a way that both maximises efficiency and optimises disparity tuning for the depth structures that are found in our natural environment. Neural network models provide a clear account of how these binocular neurons encode the local binocular disparity in images. These models can be expanded to multi-layer models that are sensitive to salient features of scenes, such as the orientations and discontinuities between surfaces. These deep neural network models have also shown the importance of binocular disparity for the segmentation of images into separate objects, in addition to the estimation of distance. These results demonstrate the usefulness of machine learning approaches as a tool for understanding biological vision.
Learning to perceive with new sensory signals
I will begin by describing recent research taking a new, model-based approach to perceptual development. This approach uncovers fundamental changes in information processing underlying the protracted development of perception, action, and decision-making in childhood. For example, integration of multiple sensory estimates via reliability-weighted averaging – widely used by adults to improve perception – is often not seen until surprisingly late into childhood, as assessed by both behaviour and neural representations. This approach forms the basis for a newer question: the scope for the nervous system to deploy useful computations (e.g. reliability-weighted averaging) to optimise perception and action using newly-learned sensory signals provided by technology. Our initial model system is augmenting visual depth perception with devices translating distance into auditory or vibro-tactile signals. This problem has immediate applications to people with partial vision loss, but the broader question concerns our scope to use technology to tune in to any signal not available to our native biological receptors. I will describe initial progress on this problem, and our approach to operationalising what it might mean to adopt a new signal comparably to a native sense. This will include testing for its integration (weighted averaging) alongside the native senses, assessing the level at which this integration happens in the brain, and measuring the degree of ‘automaticity’ with which new signals are used, compared with native perception.
depth perception coverage
4 items
Add content
Have a seminar, talk, or paper on depth perception? Post it so others working in this area can find it.
Post content