Generic Properties of Curvature Sensing through Vision and Touch Generic properties of curvature representations formed on the basis of vision and touch were examined as a function of mathematical properties of curved objects. Virtual representations of the curves were shown on a computer screen for visual scaling by sighted observers (experiment 1). Their physical counterparts were placed in the two hands of blindfolded and congenitally blind observers for tactile scaling. The psychophysical data show that curvature representations in congenitally blind individuals, who never had any visual experience, and in sighted observers, who rely on vision most of the time, are statistically linked to the same mathematical properties of the curves. The perceived magnitude of object curvature, sensed through either vision or touch, is related by a mathematical power law, with similar exponents for the two sensory modalities, to the aspect ratio of the curves, a scale invariant geometric property. This finding supports biologically motivated models of sensory integration suggesting a universal power law for the brain control and balance of motor responses to environmental stimuli from any sensory modality to inspire adaptive systems design.

An assistive lowvision platform that augments spatial cognition through proprioceptive guidance: PointtoTellandTouch Spatial cognition, as gained through the sense of vision, is one of the most important capabilities of human beings. However, for the visually impaired (VI), lack of this perceptual capability poses great challenges in their life. Therefore, we have designed PointtoTellandTouch, a wearable system with an ergonomic humanmachine interface, for assisting the VI with active environmental exploration, with a particular focus on spatial intelligence and navigation to objects of interest in an alien environment. Our key idea is to link visual signals, as decoded synthetically, to the VIxe2x80x99s proprioception for more intelligible guidance, in addition to visiontoaudio assistance, i.e., finger pose, as indicated by pointing, is used as xe2x80x9cproprioceptive laser pointerxe2x80x9d to target an object in that line of sight. The whole system consists of two features, PointtoTell and PointtoTouch, both of which can work independently or cooperatively. The PointtoTell feature contains a camera with a novel onestage neural network tailored for blindcentered object detection and recognition, and a headphone telling the VI the semantic label and distance from the pointed object. the PointtoTouch, the second feature, leverages a vibrating wrist band to create a haptic feedback tool that supplements the initial vectorial guidance provided by the first stage (hand pose being direction and the distance being the extent, offered through audio cues). Both platform features utilize proprioception or joint position sense. Through hand pose, the VI end user knows where he or she is pointing relative to their egocentric coordinate system and we are able to use this foundation to build spatial intelligence. Our successful indoor experiments demonstrate the proposed system to be effective and reliable in helping the VI gain spatial cognition and explore the world in a more intuitive way.