Approaches to the Study of Haptic Sensing

Abstract

Henriques, Denise Y. P. and John F. Soechting. Approaches to the study of haptic sensing. J Neurophysiol 93: 3036 -3043, 2005; doi:10.1152/jn.00010.2005. This review surveys results from a new approach to the problem of haptic sensing, in which subjects use primarily proximal arm movements to explore the shapes of virtual objects. These shapes are generated using a robotically controlled manipulandum. We begin by summarizing distortions of simple geometric properties (such as the length and orientation of lines) in the haptic perception of space. We then consider the extent to which the sense of more complex shapes (such as quadrilaterals) can be explained by these geometric distortions, i.e., the extent to which the shape of a complex object is synthesized from simpler constituent elements, and some of the sensory cues that may be important in this process. Haptic and visual processing of shapes appear to lead to some similar illusions. However, we argue that the processing of haptic information differs fundamentally from visual processing in that the former requires the integration of information that evolves in time as well as in space.

Differences in curvature between constrained and unconstrained goal-directed movements to haptic targets

“…In a study of Bongers and Zaal (2010), a higher friction reduced curvature. The force opposite to the movement direction has been shown to contribute to haptic curvature judgments (Robles-De-La-Torre and Hayward 2001), while the force orthogonal to the finger has been shown not to contribute much to haptic perception of curvature (Henriques and Soechting 2005), which is in agreement with our interpretations of our results. So the friction force might be one of the information sources that reduce movement curvature.…”

Two hands, one perception: how bimanual haptic information is combined by the brain

“…We know that haptic sensing requires the integration of spatially disparate sensory signals from cutaneous afferents in the digits with proprioceptive signals of the arm (a process of intersensory integration). However, we know very little about how the brain combines the haptic information of our two hands to achieve a single percept of an object and about the underlying mechanism of how the nervous system integrates or fuses information from two haptic systems.To investigate issues of haptic sensing in a controlled experimental setting, virtual force environments have been used to present haptic stimuli (Chib et al 2006;Fasse et al 2000;Henriques and Soechting 2005;Hogan et al 1990). In these studies, subjects usually grasped the handle or stylus of a robotically controlled manipulandum, which generated appropriate boundary forces resembling the surfaces of virtual objects.…”

“…To investigate issues of haptic sensing in a controlled experimental setting, virtual force environments have been used to present haptic stimuli (Chib et al 2006;Fasse et al 2000;Henriques and Soechting 2005;Hogan et al 1990). In these studies, subjects usually grasped the handle or stylus of a robotically controlled manipulandum, which generated appropriate boundary forces resembling the surfaces of virtual objects.…”

“…In these studies, subjects usually grasped the handle or stylus of a robotically controlled manipulandum, which generated appropriate boundary forces resembling the surfaces of virtual objects. The advantage of this technique is that object shape and boundary stiffness can be modified from trial to trial (Chib et al 2006;Henriques and Soechting 2003), shapes that are not realizable physically can be simulated (Fasse et al 2000), and subjects' sensitivities can be computed with great precision (Henriques and Soechting 2005). Whereas a number of these psychophysical studies have investigated unimanual curvature discrimination (Louw et al 2000;Pont et al 1997Pont et al , 1998Pont et al , 1999van der Horst and Kappers 2008;Wheat and Goodwin 2001), scant attention has been paid to bimanual curvature discrimination, because the technology for bimanual haptic environments has just recently become available.…”

Probabilistic Classification of Grasping Behaviours Using Visuo-Haptic Perception

“…Most often, haptic perception refers to the extraction of information about an object's properties through exploratory actions usually of the hands and arms [2]. While the importance of vision for object recognition and action planning has long been recognized [3], the role of the haptic sense for object recognition and manipulation has received considerably less attention.…”