A Systems Factorial Technology Dataset using Visual and Tactile Cues to Guide Balance

This data contains response times for 19 participants from a Systems Factorial Technology paradigm using visual and vibratory cues, as described in The Balance Between Vision and Touch [1] . These cues could indicate one of four directions, and participants responded by shifting their weight in that direction. This was detected using a Wii Balance Board. Each participant has 720 trials: 1/3 with only a haptic cue, 1/3 with only vision, and 1/3 with both. Cues were equally divided into high and low salience versions

The Many Faces of Garner Interference

Thesis (Ph.D.) - Indiana University, Psychological & Brain Sciences, 2014A series of speeded classification tasks proposed by Garner (1974) has become a well-entrenched method for identifying interactions between perceptual dimensions. The theory proposes that integral dimensions should produce a redundancy gain when a second dimension covaries perfectly with the attended dimension, and interference if the second dimension varies irrelevantly. This work questions the interpretation of such results as indicating interactive dimensions, reviewing independent models which naturally exhibit such effects. Furthermore, there are several methodological confounds which make the cause of Garner interference non-identifiable in the standard experimental context, the most serious of which is the conflation of changes in the number of stimuli with changes in the number of irrelevant dimensions. Here is proposed a novel three-dimensional extension of the Garner paradigm capable of disambiguating these experimental factors, which includes several conditions designed to help distinguish between various competing models of the related phenomena. This new paradigm was implemented with two stimulus sets, both composed of known integral dimensions, but from opposite sides of the complexity spectrum: color patches differing in their saturation, brightness, and hue; and faces differing in weight, age, and gender. Results show typical Garner interference effects for both stimulus sets, although the redundancy gains were rather modest. When a three-dimensional analog of the Garner filtering test is created by allowing a second irrelevant dimension to vary, however, the expected interference effects do not appear. Counter-intuitively, this additional variation often leads to an improvement in performance, an effect which cannot be predicted by the extant models. This effect is shown to be driven primarily by the extra dimension of variation rather than the additional stimuli. The implications for these (and other) findings are considered with regards to the utility of the Garner paradigm and the models that have attempted to describe it

The Many Faces of Garner Interference

A series of speeded classification tasks proposed by Garner (1974) has become a well-entrenched method for identifying interactions between perceptual dimensions. The theory proposes that integral dimensions should produce a redundancy gain when a second dimension covaries perfectly with the attended dimension, and interference if the second dimension varies irrelevantly. This work questions the interpretation of such results as indicating interactive dimensions, reviewing independent models which naturally exhibit such effects. Furthermore, there are several methodological confounds which make the cause of Garner interference non-identifiable in the standard experimental context, the most serious of which is the conflation of changes in the number of stimuli with changes in the number of irrelevant dimensions. Here is proposed a novel three-dimensional extension of the Garner paradigm capable of disambiguating these experimental factors, which includes several conditions designed to help distinguish between various competing models of the related phenomena. This new paradigm was implemented with two stimulus sets, both composed of known integral dimensions, but from opposite sides of the complexity spectrum: color patches differing in their saturation, brightness, and hue; and faces differing in weight, age, and gender. Results show typical Garner interference effects for both stimulus sets, although the redundancy gains were rather modest. When a three-dimensional analog of the Garner filtering test is created by allowing a second irrelevant dimension to vary, however, the expected interference effects do not appear. Counter-intuitively, this additional variation often leads to an improvement in performance, an effect which cannot be predicted by the extant models. This effect is shown to be driven primarily by the extra dimension of variation rather than the additional stimuli. The implications for these (and other) findings are considered with regards to the utility of the Garner paradigm and the models that have attempted to describe it

Comparative Analysis of Two Cryogenic Force Balance Calibration Systems

Cryogenic wind-tunnel facilities face unique challenges in the calibration and operation of various measurement systems and instrumentation. Instruments that are subjected to the cryogenic conditions of the test plenum require careful design and calibration procedures to maintain instrument performance. NASAs National Transonic Facility (NTF) and the European Transonic Windtunnel (ETW) are two cryogenic wind-tunnel facilities, each with the ability to calibrate force measurement systems (FMS) at cryogenic conditions. These facilities have different methodologies and processes for calibrating these systems. This paper discusses differences in the methodologies and processes and compares the results of two separate cryogenic calibrations of the NTF-118A force balance that were completed at both wind-tunnel facilities

Measurement Effects in Decision-Making

When participants are shown a series of stimuli, their responses differ depending on whether they respond after each stimulus or only at the end of the series, in what we call a measurement effect. These effects have received paltry attention compared with more well-known order effects and pose a unique challenge to theories of decision-making. In a series of two preregistered experiments, we consistently find measurement effects such that responding to a stimulus reduces its impact on later stimuli. While previous research has found such effects in noncumulative tasks, where participants are instructed only to respond to the most recent stimulus, this may be the first demonstration of these effects when participants are asked to combine information across either two or four stimuli. We present modeling results showing that although several extant classical and quantum models fail to predict the direction of these effects, new versions can be created that can do so. Ways in which these effects can be described using either quantum or classical models are discussed, as well as potential connections with other well-known phenomena like the dilution effect

Mechanical Behavior of Microelectromechanical Microshutters

A custom micro-mechanical test system was constructed using off-the-shelf components to characterize the mechanical properties of microshutters. Microshutters are rectangular microelectromechanical apertures which open and close about a narrow torsion bar hinge. Displacement measurements were verified using both capacitive and digital image correlation techniques. Repeatable experiments on Si3N4 cantilever beams verified that the test system operates consistently. Using beam theory, the modulus of elasticity of the low stress Si3N4 was approximately 150 GPa, though significant uncertainty exists for this measurement due primarily to imprecise knowledge of the cantilever thickness. Tests conducted on microshutter arrays concluded that reducing the Si3N4 thickness from 250 nm to 500 nm reduces the torsional stiffness by a factor of approximately four. This is in good agreement with analytical and finite element models of the microshutters

Trunk Velocity-Dependent Light Touch Reduces Postural Sway during Standing

Light Touch (LT) has been shown to reduce postural sway in a wide range of populations. While LT is believed to provide additional sensory information for balance modulation, the nature of this information and its specific effect on balance are yet unclear. In order to better understand LT and to potentially harness its advantages for a practical balance aid, we investigated the effect of LT as provided by a haptic robot. Postural sway during standing balance was reduced when the LT force (~ 1 N) applied to the high back area was dependent on the trunk velocity. Additional information on trunk position, provided through orthogonal vibrations, further reduced the sway position-metric of balance but did not further improve the velocity-metric of balance. Our results suggest that limited and noisy information on trunk velocity encoded in LT is sufficient to influence standing balance. © 2019 Saini et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Optimizing Exterior Lighting Illuminance and Spectrum for Human, Environmental, and Economic Factors.

With the recent widespread adoption of LED lighting in outdoor areas, numerous concerns have been raised about the potential for harmful effects on humans, animals, plants, and the night sky. These stem from the high blue light content of some LED bulbs and an incentive to increase lighting levels caused by higher efficiency and lower costs. While new lighting installations are often described as environmentally friendly due to their energy efficiency, factors such as light pollution are often neglected or not given enough weight. This research focuses on optimizing the design of exterior lighting for human, environmental, and economic factors using a multi-criteria decision analysis. Based on data in the literature and survey research, illuminance and spectrum alternatives were scored relative to each other using the analytic hierarchy process and multi-attribute utility theory. The findings of this study support the use of artificial illumination at levels similar to a full moon (0.01 fc) and a warm white spectrum (2700K or 2200K), with amber LED becoming a better choice if its energy efficiency and cost effectiveness improve in the future. This methodology can be used in the future as a framework for lighting design optimization in different settings

Guiding a Human Follower with Interaction Forces: Implications on Physical Human-Robot Interaction

This work challenges the common assumption in physical human-robot interaction (pHRI) that the movement intention of a human user can be simply modeled with dynamic equations relating forces to movements, regardless of the user. Studies in physical human-human interaction (pHHI) suggest that interaction forces carry sophisticated information that reveals motor skills and roles in the partnership and even promotes adaptation and motor learning. In this view, simple force-displacement equations often used in pHRI studies may not be sufficient. To test this, this work measured and analyzed the interaction forces (F) between two humans as the leader guided the blindfolded follower on a randomly chosen path. The actual trajectory of the follower was transformed to the velocity commands (V) that would allow a hypothetical robot follower to track the same trajectory. Then, possible analytical relationships between F and V were obtained using neural network training. Results suggest that while F helps predict V, the relationship is not straightforward, that seemingly irrelevant components of F may be important, that force-velocity relationships are unique to each human follower, and that human neural control of movement may affect the prediction of the movement intent. It is suggested that user-specific, stereotype-free controllers may more accurately decode human intent in pHRI