Use of Simulated Thermal Cues for Material Discrimination and Identification with a Multi-Fingered Display

Abstract

Thermal cues provide information about the thermal properties of an object held in the hand. These cues can be simulated in a thermal display and used to assist in identifying the object. Two experiments were conducted using a thermal display that simulated the cues associated with contact with different materials. The thermal contact model was based on a semi-infinite body model that included thermal contact resistance and blood perfusion. Its performance was evaluated in two experiments, the first of which involved discriminating between simulated materials, and in the second, subjects were required to identify simulated materials based on the thermal cues presented to one, three, or five fingers. The results from the first experiment indicated that when the temperature profile associated with contact with a real material is presented to the finger, subjects can use this cue to discriminate between simulated materials. Their performance on this task is comparable to that achieved with real materials with similar thermal properties. In the second experiment, the accuracy with which subjects identified a simulated material based on thermal cues improved as the number of fingers stimulated increased, suggesting that spatial summation of cold occurs when the area stimulated is noncontiguous. However, most of the improvement in identifying materials occurred when the display presented thermal cues to three as compared to one finger, with little further enhancement in performance when five fingers were stimulated. These results indicate that thermal displays can be used effectively to present information about the material composition of objects in virtual environments.

Enhanced heat discrimination in congenital blindness

“…Indeed, changing the size of a thermal stimulus drastically affects the perceived intensity. This property is especially important in warmth perception in which intensity and spatial extent of the stimulus have equal influence on the perceived intensity [12,22]. Unpublished preliminary data from our lab suggested that the spatial extent of thermal stimulation more strongly affects perceptual decision making in blind compared to sighted participants.…”

“…It has been shown that people can discriminate between a broad range of materials by relying solely on thermal diffusivity properties [11][12][13]. Because of their lack of vision, blind individuals might http://dx.doi.org/10.1016/j.bbr.2015.01.037 0166-4328/© 2015 Elsevier B.V. All rights reserved.…”

“…Thermal perception is not only dependent on stimulus intensity but also on spatial summation [12,20,21]. Indeed, changing the size of a thermal stimulus drastically affects the perceived intensity.…”

Influence of contact conditions on thermal responses of the hand

“…Current models have considered the effects of blood perfusion and the thermal and mechanical properties of the skin and contact material (Bergamasco et al, 1997;Citerin et al, 2006;Deml et al, 2006;Ho & Jones 2006a;Yamamoto et al, 2004;Yang et al 2008). Ho and Jones (2006a) where the ratio of contact pressure to microhardness is 1E-6 to 2E-2.…”

Perspectives on the Evolution of Tactile, Haptic, and Thermal Displays

“…Thermal models are developed that capture the responses of the skin on contact with different materials (e.g., ceramic, plastic, aluminum) and the models are then implemented in a thermal display typically consisting of thermoelectric coolers, thermal sensors, and a temperature control system (Bergamasco, Alessi, & Calcara, 1997;Ho & Jones, 2007). The results from studies on virtual object recognition using thermal cues indicate that model-based displays are able to present cues that can be used effectively to identify and discriminate between materials and that performance on these tasks is comparable to that achieved with real materials (Ho & Jones, 2007;Yang, Jones, & Kwon, 2008).…”