Evaluating a model of global psychophysical judgments for brightness: I. Behavioral properties of summations and productions

Transfer of competency in a perceptual task often depends on shared information between anatomically different perceptual subsystems. The problem of studying transfer involves isolating conditions of similarity and then trying to account for any resulting differences in transfer. To respect this twofold aspect, this article takes a twopronged approach to transfer in dynamic touch. The present research first tests the hypothesis that functional equivalence supports the transfer of dynamic touch. Participants were trained to wield unseen objects with the hand or foot and were then tested on anatomically disparate limbs (i.e., the foot or hand, respectively). Next, we examined motion capture of these wielding behaviors for predictors of any asymmetry in transfer. Temporally fractal fluctuations of exploratory behavior can modulate information detection, and we tested whether the fractality of wielding might predict asymmetries in transfer across disparate limbs. Results suggest that transfer of training to anatomically disparate limbs respects functional conditions of similarity and also that the degree of temporally fractal fluctuations predicted limb differences in transfer.

Section: Methodsmentioning

confidence: 99%

Transfer of calibration between hand and foot: Functional equivalence and fractal fluctuations

Stephen

Hajnal

2011

“…Luce (2004) and Steingrimsson (2009) are contemporary examples. The present application, however, entails nonnumerical representation.…”

Section: Psychophysics and Representationmentioning

confidence: 99%

Fechner, information, and shape perception

Lappin

Norman

Phillips

2011

How do retinal images lead to perceived environmental objects? Vision involves a series of spatial and material transformations-from environmental objects to retinal images, to neurophysiological patterns, and finally to perceptual experience and action. A rationale for understanding functional relations among these physically different systems occurred to Gustav Fechner: Differences in sensation correspond to differences in physical stimulation. The concept of information is similar: Relationships in one system may correspond to, and thus represent, those in another. Criteria for identifying and evaluating information include (a)resolution, or the precision of correspondence; (b)uncertainty about which input (output) produced a given output (input); and (c)invariance, or the preservation of correspondence under transformations of input and output. We apply this framework to psychophysical evidence to identify visual information for perceiving surfaces. The elementary spatial structure shared by objects and images is the second-order differential structure of local surface shape. Experiments have shown that human vision is directly sensitive to this higher-order spatial information from interimage disparities (stereopsis and motion parallax), boundary contours, texture, shading, and combined variables. Psychophysical evidence contradicts other common ideas about retinal information for spatial vision and object perception. The fundamental problem of vision is to understand how retinal images lead to perceived environmental objects Spatial vision is so marvelously effective that usually it is taken for granted. We perceive environmental objects but not the visual instrument by which they are revealed. Spatial vision pervades our conscious experience, but our understanding of the underlying visual mechanisms has substantial gaps.Gaps in understanding occur especially at the interfaces between visual subsystems, where information is transferred from one physical and spatial format to another. How does vision transcend vast changes in format-involving 3-D objects and spaces, 2-D optical images, neural spike trains and synaptic interactions in multiple neural areas, conscious perceptions, and behavioral actions? How do immaterial knowledge and experience arise from material objects and events? The present article offers a theoretical framework for addressing these issues-based on the concept of information, involving corresponding relational structures in physically separate domains. We describe criteria for identifying and evaluating structural correspondence and then apply these criteria to research on shape perception. Fechner' s insightIn the 19th century, Gustav Fechner struggled for years to find a scientific rationale for linking the material and mental worlds. Material objects have mass and spatial extent, but mental experience has neither. Some have concluded that mental events belong to a spiritual world. Fechner, however, believed that mind and body are inseparable and that mental events are emerg...

“…Triangles and circles refer to the smallest and largest standard differences suggests that participants could also have the ability to directly evaluate ratios of brightness differences. Indeed, the ability to evaluate ratios of sensory differences is assumed in several current models of the rating response with end anchors (Masin & Busetto, 2010) and in recent studies of brightness judgment (Steingrimsson, 2009(Steingrimsson, , 2011. The following experiment was designed to test the existence of this ability for brightness.…”

Section: Methodsmentioning

confidence: 99%

On the ability to directly evaluate sensory ratios

Masin

2012

The study explored whether participants could directly evaluate sensory ratios. The results indicate that they did not exhibit this ability for the extensive continuum of length and the intensive continua of brightness and brightness difference. Functional measurement analysis, combined with a chronometric analysis of responses, indicated that participants used mental counting for length and used difference evaluation for brightness and brightness difference. The finding that participants evaluated brightness differences under instructions to evaluate brightness ratios suggests that difference judgments may be a general human capability. It resolves questions raised by prior tests of Torgerson's conjecture and by prior consistency tests of ratio evaluation.