Non-visual Channel Research Articles

Visual and non-visual effects of integrated lighting based on spectral information

Light meets the visual needs of the human body through the visual channel, and guides the physiological system of the human body to synchronize with the cycle of luminous environment through the non-visual channel, affecting emotions, sleep quality, alertness and even health. The indoor luminous environment of buildings where people spend more and more time is divided into two parts: artificial lighting and daylighting, both of which are separated from each other in terms of standards and research. However, integrated lighting scenes where daylight and artificial light exist at the same time are very common in real-life indoor environments, and the relationship between the two in integrated lighting and the impact of integrated lighting on non-visual effects remain unclear. In this study, the amount of daylight was manipulated by controlling sunshades in different artificial lighting environments, and the relationship between daylight and artificial light in integrated lighting was explored based on the subject evaluations. The results show that the direction and shading form have a significant impact on the perception of daylight, and the front facing direction has its particularity because it directly receives daylight. Additionally, artificial lighting settings with varying illuminance and correlated color temperature can also affect the perception of daylight. Furthermore, compared to artificial lighting alone, integrated lighting in sunny conditions can significantly increase circadian stimulus, which could improve daytime work efficiency.

The Topo-Speech sensory substitution system as a method of conveying spatial information to the blind and vision impaired.

Humans, like most animals, integrate sensory input in the brain from different sensory modalities. Yet humans are distinct in their ability to grasp symbolic input, which is interpreted into a cognitive mental representation of the world. This representation merges with external sensory input, providing modality integration of a different sort. This study evaluates the Topo-Speech algorithm in the blind and visually impaired. The system provides spatial information about the external world by applying sensory substitution alongside symbolic representations in a manner that corresponds with the unique way our brains acquire and process information. This is done by conveying spatial information, customarily acquired through vision, through the auditory channel, in a combination of sensory (auditory) features and symbolic language (named/spoken) features. The Topo-Speech sweeps the visual scene or image and represents objects' identity by employing naming in a spoken word and simultaneously conveying the objects' location by mapping the x-axis of the visual scene or image to the time it is announced and the y-axis by mapping the location to the pitch of the voice. This proof of concept study primarily explores the practical applicability of this approach in 22 visually impaired and blind individuals. The findings showed that individuals from both populations could effectively interpret and use the algorithm after a single training session. The blind showed an accuracy of 74.45%, while the visually impaired had an average accuracy of 72.74%. These results are comparable to those of the sighted, as shown in previous research, with all participants above chance level. As such, we demonstrate practically how aspects of spatial information can be transmitted through non-visual channels. To complement the findings, we weigh in on debates concerning models of spatial knowledge (the persistent, cumulative, or convergent models) and the capacity for spatial representation in the blind. We suggest the present study's findings support the convergence model and the scenario that posits the blind are capable of some aspects of spatial representation as depicted by the algorithm comparable to those of the sighted. Finally, we present possible future developments, implementations, and use cases for the system as an aid for the blind and visually impaired.

A Study on Nonvisual Effects of Natural Light Environment in a Maternity Ward of a Hospital in Cold Area.

Thanks to the discovery of human eye photoreceptor cells, ipGRC and human nonvisual channels, the nonvisual effects of light have gradually come to our vision and been rationally utilized. Along with this trend, people have expanded their demand for the light environment to both visual and nonvisual needs from only visual needs. With a good natural daylighting, parturients will find their psychological pressure and physiological pain relieved, their rehabilitation rate increased, and they get rehabilitated more quickly. This study was carried out in a representative maternity ward in Harbin based on the latest research results on nonvisual effects at home and abroad. Specifically, the nonvisual effects on the natural light environment in the ward throughout the year were simulated and analyzed from the aspects of equivalent melanopic lux (EML), stimulus frequency (Stim.freq), and circadian effective area (CEA). During the study, natural light in the ward was measured on site, and the evaluation tool and workflow of nonvisual effects were created with the aid of Grasshopper modeling platform, Ladybug+Honeybee, and VB script editor. The results show that the nonvisual effects of natural light on the body of parturients gradually weaken as they further go inside the ward. What is worse, in the most unfavorable all-overcast condition, daylighting on beds far away from the window does not meet the stimulus of human circadian rhythm from April to August. Therefore, additional light is required. The wards have the best nonvisual natural light environment when they are south facing and have a window to floor ratio of 0.3.

Exploring the effects of large-area dorsal skin irradiation on locomotor activity and plasm melatonin level in C3H/He mice

ABSTRACT As the largest organ exposed to the outside of mammals, skin has direct photosensitivity. Recent studies have even shown that cutaneous irradiation played a role in local circadian systems. However, whether it can further affect the central clock system is controversial. Here, plasm melatonin rhythm of melatonin-proficient C3H/He mice was assessed, and on this basis, a well-designed segmented lighting method was used to investigate the effects of dorsal skin irradiation on locomotor activity and plasm melatonin content in male C3H/He mice. In brief, mice were separately exposed to cutaneous irradiation, intraocular irradiation or darkness for 60 min at specific moments. The results showed that neither blue nor red cutaneous exposure had obvious effect on central rhythm oscillation while intraocular irradiation could significantly change the central clock of mice, and the effect of blue light was more forceful than red light. It suggests that intraocular nonvisual channels still play a dominant role in rhythmic regulation, which has not been challenged by the discovery of local light entrainment in exposed peripheral tissues.

Multi-Sensory Color Code Based on Sound and Scent for Visual Art Appreciation

The development of assistive technologies is improving the independent access of blind and visually impaired people to visual artworks through non-visual channels. Current single modality tactile and auditory approaches to communicate color contents must compromise between conveying a broad color palette, ease of learning, and suffer from limited expressiveness. In this work, we propose a multi-sensory color code system that uses sound and scent to represent colors. Melodies express each color’s hue and scents the saturated, light, and dark color dimensions for each hue. In collaboration with eighteen participants, we evaluated the color identification rate achieved when using the multi-sensory approach. Seven (39%) of the participants improved their identification rate, five (28%) remained the same, and six (33%) performed worse when compared to an audio-only color code alternative. The participants then evaluated and compared a color content exploration prototype that uses the proposed color code with a tactile graphic equivalent using the System Usability Scale. For a visual artwork color exploration task, the multi-sensory color code integrated prototype received a score of 78.61, while the tactile graphics equivalent received 61.53. User feedback indicates that the multi-sensory color code system improved the convenience and confidence of the participants.

Multimodal Information Fusion for Automatic Aesthetics Evaluation of Robotic Dance Poses

Aesthetic ability is an advanced cognitive function of human beings. Human dancers in front of mirrors estimate the aesthetics of their own dance poses by fusing multimodal information (visual and non-visual) to improve their dancing performances. Similarly, if a robot could perceive the aesthetics of its own dance poses, the robot could demonstrate more autonomous and humanoid behavior during robotic dance creation. Therefore, we propose a novel automatic approach to estimate the aesthetics of robotic dance poses by fusing multimodal information. From the visual channel, the shape features (including eccentricity, density, rectangularity, aspect ratio, Hu-moment Invariants, and complex coordinate based Fourier descriptors) are extracted from an image; from the non-visual channel, joint motion features are obtained from the internal kinestate of a robot. The above two categories of features are fused to portray completely a robotic dance pose. To automatically estimate the aesthetics of robotic dance poses, the following ten machine learning methods are deployed: Naive Bayes, Bayesian logistic regression, SVM, RBF network, ADTree, random forest, voted perceptron, KStar, DTNB, and bagging. Experimental results show the feasibility and good performance of the proposed mechanism, which was implemented in a simulated robot environment. The highest correct ratio of aesthetic evaluation is 81.6%, which comes from the ADTree, based on the above mixed features (joint + shape).

Lighting simply made better: Providing a full range of benefits without much fuss

The effective application of lighting depends upon a definition of light that captures the full range of wavelengths to which the human retina is sensitive. The current definition of light, based upon the photopic luminous efficiency function, V(λ), does not. Rather, V(λ) is biased against short wavelengths that are important for some of the benefits that lighting can provide to people such as brightness perception and circadian regulation, thereby compromising the effective application of lighting. Neuroscience has revealed several visual and non-visual channels that emanate from the retina to different centers in the brain influencing our physiology and behavior. This research has also elucidated the spectral and the absolute sensitivities of these different neural channels. Since the definition of light and the many lighting standards do not reflect the neuroscience, they compromise the beneficial application of lighting. A new definition of light based upon the universal luminous efficiency function, U(λ), would be unbiased with respect to the full range of wavelengths to which the retina is sensitive. Coupled with scientific insight into the spectral and absolute sensitivities of the various neural channels, lighting can easily become more effective for delivering the benefits people expect.

Investigating Redundant Encoding Methods for Tactile Messaging in Multitask Scenarios

In domains characterized by high demand for visual resources of human operators, multitasking performance may be supported when some task-relevant data are communicated via nonvisual channels, such as the sense of touch. Previous research has shown that humans can interpret moderately complex tactile messages and gain performance benefits when when tactile displays are introduced in multitasking domains. The benefits are assumed to stem from a reduced competition for visual resources; however, multitasking performance can also be affected by competition for cognitive processing resources, such as spatial or symbolic working memory. Thus when selecting tactile signal dimensions for encoding messages (e.g., in spatial or temporal patterns), multitasking can be best supported when the cognitive processing demands of concurrent tasks are considered. This study sought to investigate tactile messages that were encoded redundantly and thus could be fully interpreted by engaging either spatial or symbolic processing resources. These messages should better support performance overall as the cognitive resources required for a concurrent visual task varied. Results showed that as expected, dual-task performance was worse when tactile and visual tasks required the same processing code. Redundantly encoded tactile signals showed some promise for offering a means to reduce processing interference but may also negatively affect performance due to a higher overall processing load due to signal complexity.

Initial Experiences Using Vibratory Touchscreens to Display Graphical Math Concepts to Students with Visual Impairments

This article presents initial experiences using vibratory touchscreens and audible sounds to communicate graphical concepts in mathematics education to students with visual impairments. These studies are motivated by the prospect of displaying graphical and mathematical concepts typically taught in a highly visual manner through nonvisual channels. First, a touchscreen-based teaching paradigm for math education of individuals with visual impairments is introduced and hardware and software employing commercially available and open source components are presented. Then, pilot studies on user comprehension of grids and points—graphical entities students encounter early in K–12 mathematics education and that can serve as building blocks for more complex lessons—are presented. These studies, conducted with students with visual impairments, explore perception of objects through haptic feedback alone, auditory feedback alone, and combinations of the two. The results show that each student could successfully find and locate 100% of displayed points on a grid. These results, complemented with the positive qualitative feedback received from students and their teachers, suggest that vibratory touchscreens have the potential to be beneficial in the classroom for conveying graphical math concepts.

Perception of Springs With Visual and Proprioceptive Motion Cues: Implications for Prosthetics

Manipulating objects with an upper limb prosthesis requires significantly more visual attention than doing the same task with an intact limb. Prior work and comments from individuals lacking proprioception indicate that conveying prosthesis motion through a nonvisual sensory channel would reduce and possibly remove the need to watch the prosthesis. To motivate the design of suitable sensory substitution devices, this study investigates the difference between seeing a virtual prosthetic limb move and feeling one's real limb move. Fifteen intact subjects controlled a virtual prosthetic finger in a one-degree-of-freedom rotational spring discrimination task. A custom haptic device was used to measure both real finger position and applied finger force, and the resulting prosthetic finger movement was displayed visually (on a computer screen) and/or proprioceptively (by allowing the subject's real finger to move). Spring discrimination performance was tested for three experimental sensory conditions-visual motion, proprioceptive motion, and visual and proprioceptive motion-using the method of constant stimuli, with a reference stiffness of 290 N/m. During each trial, subjects sequentially pressed the right index finger on a pair of hard-surfaced virtual springs and decided which was stiffer. No significant performance differences were found between the three experimental sensory conditions, but subjects perceived proprioceptive motion to be significantly more useful than visual motion. These results imply that relaying proprioceptive information through a nonvisual channel could reduce visual attention during prosthesis control while maintaining task performance, thus improving the upper limb prosthesis experience.